DETAILED PROJECT REPORT
FOR
PHASE-II - 2 x 660 MW SUPERCRITICAL COAL BASED POWER PLANT AT SALAYA,
GUJARAT
TATA CONSULTING ENGINEERS LTD.
73/1, St. MARK’S ROAD
BANGLORE – 560 001
JUNE 2010
0
CONTENTS
CHAPTER
TITLE
PAGE NO.
NO.
I
INTRODUCTION
9
II
SUMMARY
10
- Purpose
10
- Scope
10
- Recommendations
19
NEED AND JUSTIFICATION OF THE PROJECT
20
- Installed Generation Capacity
24
- Availability of power
24
- Ministry of Power’s Blueprint for Power Development
24
- Justification for the Project
24
SITE FEATURES
25
- Location of Site
25
- Accessibility to Site
25
- Availability of Land
25
- Availability of Water
26
- Coal Supply
26
- Power Evacuation
26
- Environmental Aspects
26
- Transportation of Equipment
27
-
27
III
IV
V
Suitability of site
FUEL LINKAGE and TRANSPORTATION TO SITE
1
28
CHAPTER
TITLE
PAGE NO.
NO.
VI
VII
- Type of Fuel
28
- Source of Fuel and Quality
28
- Annual Coal Requirement
28
- Transportation of Coal to the Site and Storage
28
- Fuel Oil System
28
PLANT LAYOUT AND CIVIL ASPECTS
30
- Plant Layout
30
- Site Topography and Grade Level
31
- Station Building
31
- Steam Generator Area and Bunker Bay
31
- Chimney
32
- Soil Profile
33
- Machine foundations
33
- Plant Roads
34
- Fencing / Compound Wall
34
- Sewage Disposal
34
- Landscaping
35
MAIN PLANT EQUIPMENT AND SYSTEMS
36
- Plant Capacity
36
- Unit Size
36
- Turbine Cycle Heat Rate
36
- Steam Generator and Accessories
37
- Steam Turbine Generator, Accessories and Cycle
39
Equipment
- Plant Cycle
40
2
VIII
- Bypass system
40
- Condensate Pumps
40
- Boiler Feed Pumps
41
- Low Pressure Heaters
41
- Deaerator
41
- High Pressure Heaters
41
- Gland Steam Condenser
41
- Condensate Polishing Unit
42
- Chemical Dosing System
42
- Oxygenated Treatment
42
- Fuel Oil System & Monitoring Systems
42
INSTRUMENTATION AND CONTROL SYSTEM
44
- Distributed Microprocessor Based Instrumentation and
44
Control System (IC)
- Salient Features of DCS
44
- Controls Included in DCS
45
- Control Loop Grouping Philosophy
46
- Local Operation
47
- Utility Packages
47
- Operation Package
48
- Unit Control Panel/Unit Control Desk
48
- Control Room
49
- Features of IC System
50
- Annunciation System
50
- Analytical Instruments
51
- Steam & Water Supplying System
51
- Control Valves
51
- Final Control Element Actuators
51
- Field Instruments
52
3
IX
X
- Air Supply for Pneumatic Equipment
52
- Power Supply
52
- Testing & Calibration Instruments
53
- Cables
53
- Instrumentation Pipes /Tubes & Fittings
53
- Vibration Monitoring System
54
- Pollution System
54
- Instrumentation Earthing
54
- Master Clock
54
ELECTRICAL SYSTEMS
55
- Generator
55
- Generator Circuit Breaker
55
- Generator Bus Duct
56
- Generator Transformers
57
- Evacuation of Power
58
- 400 kV Switchyard
59
- Auxiliary Power Supply System
61
- D.C. System
68
- Emergency Power Supply
69
- Uninterruptible Power Supply System
69
- Cabling System
76
- Lighting System
77
- Safety Earthing and Lightning Protection
78
- Communication System
79
- Fire Detection/Alarm and Fire Proof Sealing System
80
- Elevators
80
- Cathodic Protection
80
PLANT WATER SYSTEMS
81
4
XI
XII
- General
81
- Sea Water System
81
- Plant Water Requirement
82
- Condenser Cooling Water (CW) System
83
- Auxiliary Cooling Water (ACW) System
85
- Water Treatment (WT) Plant
86
- Service and Potable Water Systems
87
- Fire Protection System
88
- Effluent Disposal System
89
COAL HANDLING SYSTEM
91
- General
91
- Design Criteria and Assumptions
91
- System Capacity
92
- System Description
92
- Salient Features of System
92
ASH HANDLING SYSTEM
95
- General
95
- Capacity and Time Cycle
95
- System Description
96
 Bottom Ash Handling
96
 Fly Ash Handling System
97
- Automatic Sequential Controls for ash removal system
97
- Ash disposal and ash pond area

Ash disposal
98

Ash pond area
99
5
- Possible areas of ash utilisation
XIII
XIV
100
MISCELLANEOUS SYSTEMS
- Compressed Air System
101
- Air Conditioning System
101
- Ventilation System
102
- Hydrogen Gas System
102
- Cranes and Hoists
102
- Workshop Equipment
103
- Chemical Laboratory Equipment
104
ENVIRONMENTAL PROTECTION AND WASTE
107
MANAGEMENT
- Types of Pollution
108
- Air Pollution
108
- Water Pollution
114
- Noise Pollution
119
- Pollution Monitoring and Surveillance Systems
120
- Green Belt
121
- Impact of Pollution/Environmental Disturbance
121
- Environmental Clearance
121
PROJECT SCHEDULING AND IMPLEMENTATION
122
- Project Schedule
122
- Transportation/Handling of Equipment
122
- Operation and Maintenance
123
- Preliminary and Other Works
124
XVI
PERMITS AND CLEARANCES
127
XVII
PROJECT COST ESTIMATES
130
XV
6
LIST OF EXHIBITS
EXHIBIT NO.
TITLE
1
PLOT PLAN
2
HEAT BALANCE DIAGRAM AT 567/593 RH, 247 bar,
100% TG MCR, 0.1 bar (a) CONDENSER BACK
PRESSURE AND 0% MAKE-UP
3
WATER BALANCE SCHEME
4
COAL HANDLING SYSTEM – FLOW DIAGRAM
5
BOTTOM ASH HANDLING SYSTEM - FLOW
DIAGRAM
6
FLY ASH HANDLING SYSTEM – FLOW DIAGRAM
7
PRESSURE TYPE ASH DISPOSAL SYSTEM –
FLOW DIAGRAM
8
ELECTRICAL KEY ONE LINE DIAGRAM
9
PROJECT MILESTONE SCHEDULE
10
O AND M ORGANISATION CHART
7
LIST OF APPENDICES
APPENDIX NO.
TITLE
PAGE
NO.
1
PROJECT SITE DATA
133
2
SEA WATER ANALYSIS
134
3
COAL ANALYSIS
135
4
FUEL ANALYSIS
135
5
BASIC INFORMATION FOR ENVIRONMENTAL
136
APPRAISAL
8
CHAPTER I
INTRODUCTION
1
ESSAR POWER GUJARAT LTD. (EPGL) proposes to install a 2x660 MW Super
critical imported coal based thermal power station as phase II nearby Nana
Manda, Khajurda Dist. Devbhumi Dwarka, Gujarat. The phase II of 2x660 MW is a
capacity addition along with phase I of 2X600MW. Net output from phase II of
Salaya shall be 1240MW (1320-80MW (approx Aux consumption)). EPGL has
already executed a PPA with GUVNL for supply of 800MW on long term 25 years
basis at a tariff of Rs. 2.80 per Unit. Balance will be supplied to prospective
consumers connected to STU/CTU through short/medium term or through
power exchange on day ahead basis.
Power Purchase agreements (PPA), which is yet to be executed.
2
The demand for electricity has been steadily increasing in the state of Gujarat due
to rapid industrialization and large scale use of electricity for irrigation, domestic
and commercial purposes. Based on this forecast, GUVNL has signed a longterm
power purchase agreement with EPGL for 800 MW.
3
Further the prevailing power generation scenario in the state reveals that the
projected demand for peak power and energy would quickly outstrip the planned
generation capacity. In order to mitigate some of the problem and as a capacity
building measure EPGL has decided to set up a 1320 MW (2 x 660 MW ) power
generating unit as phase II nearby Nana Manda, Khajurda Village Dist.
Devbhumi Dwarka, Gujarat.
4
EPGL has retained the services of TCE, Bangalore for preparing a Detailed Project
Report (DPR) for the proposed 2X660 MW phase-II super critical thermal power
station..
9
CHAPTER II
EXECUTIVE SUMMARY
PURPOSE
1.
The purpose of this report is to present the techno-economic details of the installation of
2 x 660 MW Phase II super critical imported coal based thermal power plant nearby
Nana Manda & Khajurda, Dist. Devbhumi Dwarka,, Gujarat.
2.
This detailed project report highlights the details of the selected site, coal supply,
availability and use of water, technical features of the main plant equipment, coal and
ash handling systems, water systems, electrical systems, plant instrumentation and
control system, evacuation of power, environmental aspects and schedule for project
implementation of the proposed thermal power project.
SCOPE OF SERVICES
3
The scope of this report covers the following:
a)
Justifying the need for installing the power plant.
b)
Company’s background with details of promoter(s).
c)
Suitability of the site identified by EPGL for the installation of the proposed power plant
based on the following considerations:i)
Availability of adequate space for locating the power plant
ii)
Geology and topography of the site
iii)
Accessibility to site
iv)
Availability of water
v)
Environmental aspects
vi)
Convenience of power evacuation
vii)
Fuel linkage aspects including fuel receipt and handling arrangement
10
d)
Brief description of major plant features and salient technical parameters of the following
equipment and systems:
i)
Main power generating equipment and auxiliaries
ii)
Control and instrumentation system
iii)
Water systems including sea water and cooling water system (within plant battery
limits)
e)
iv)
Fuel storage and handling system (within plant battery limits)
v)
Fire protection system
vi)
Effluent disposal system
vii)
Electrical auxiliary systems
vii)
Power evacuation system
ix)
Ash handling and ash disposal system
x)
Civil & structural works – Design considerations.
Environmental Aspects:
The report will cover data to be included in the standard format given by central pollution
control authorities. (Technical data relevant to this study generated by TCE as part of this
assignment will be taken care of by TCE; other required data for this purpose shall be
furnished by EPGL).
f)
Preparation of preliminary plant layout, heat and mass balance diagrams, water balance
diagram, electrical one line diagram and fuel handling system scheme.
g)
Preparation of project implementation schedule in the form of a bar chart.
h)
Status of various clearances / approvals / contracts / agreements / facilities required for
implementation of the power plant
i)
Brief note on risks indicated below perceived during the pre-construction phase, during
construction and post-construction operation phase of the project along with mitigation
measures.
11
i)
ii)
Pre-construction phase such as –


Finalization of contracts
Approval & permits

Availability of taxes & concessions as applicable for a project of this size

Availability of land

Availability of water
Risks during construction such as –

Ability of the Company to manage the project during the construction and
operation phase given the enormity of the project size.

Ability of the Company to infuse the required equity (both upfront and balance
along with the debt) in the project at the required time periods.
iii)
iv)
v)

Increase in project cost

Delay in completion

Force majeure / damage / destruction

Delay in construction of evacuation facilities
Post-construction operation risks such as –

Fuel availability risk

Fuel transportation risk

Equipment performance risk

Force majeure

Plant generation level (less than planned)

Escalation in O&M costs.
Off -take risks

Price risk

Payment risk
Other risks

Political / economic risk

Exchange rate fluctuation
12

j)
Change in law
Conclusions.
NEED FOR POWER PLANT
4
Demand for electrical power in Gujarat State has been increasing due to rapid industrial
growth. In spite of the steps taken by Gujarat Urja Vikas Nigam Ltd (GUVNL) to set-up
new power plants, the demand for power exceeds the availability. Further, the deficit is
expected to increase substantially in the subsequent years
Based on this forecast, GUVNL has signed a long term power purchase agreement with
EPGL for the quantum of 800 MW. The balance power shall be supplied to other
prospective consumers connected to STU/CTU through short term / Medium term open
access. Since power sale for major capacity is tied up, installation of Phase II super
critical imported coal based thermal power plant nearby Nana Mandha, Kajurda Dist.
Devbhumi Dwarka, Gujarat is justified.
LOCATION
5
The proposed site is located nearby Nanda Mandha, Khajurda Dist. Devbhumi Dwarka,
at about 44 km from Jamnagar city.
SITE FEATURES
6
The complete land required for the project is Government Land and in name of Essar
Power Gujarat Limited. The identified area consists of non-agricultural land. The ground
level is at 31.5 MSL. The proposed site area belongs to seismic zone-5. Geo-technical
investigation reports are available for the proposed power plant location.
CLIMATOLOGICAL FEATURES
7
The normal annual rainfall is about 537.5 mm with 88% of total rainfall receiving during
monsoon season from June to September. The yearly average temperature is about 33
0
C and humidity in the locality is as high as 27-96% during monsoon with a decreased
humidity of 15-35% during summer season. The annual mean wind speed of the region
is about 15.37 m/s with winds blowing in the east direction predominantly.
These
specific climatologically data pertaining to site is available, climate data related to
existing (under construction) power plant site has been considered as representative of
the metrological conditions of the site and mentioned above.
13
ACCESS TO SITE
8
The site is accessible by road from Jamnagar – Okha state highway no.25. The plant
site is located adjacent to the Jamnagar – Okha road as shown in Exhibit-1. Nearest
railway station is Jamnagar, which is at a distance of about 44 kms from site.
LAND AVAILABILITY
9
A total land area of 125 hectares is been identified for the project which is adequate for
the power plant including green belt, common facilities like water complex, coal stock
yard, conveyor other O&M and administrative facilities. The complete land required for
the project is Government Land and in name of Essar Power Gujarat Limited. The same
facility being built for Phase-I (1200MW) will be utilized to meet the requirement of
Phase-II (1320MW).
FUEL REQUIREMENT
10
Imported design coal having an calorific value of 4900 kCal/kg would be used as the
main load carrying fuel. The annual coal requirement for 2x660 MW units is estimated to
be about 4.5 million tones considering a plant availability factor of 85%. The secondary
fuel would be HFO as per IS 1593 and the start-up fuel would be LDO as per IS 1460,
1995. The monthly requirement of HFO would be about 1071 cu.m.
MAIN PLANT EQUIPMENT
11
For the 660 MW unit, the rated inlet steam conditions for steam turbine would be 247 bar
(a) steam pressure at 567C and the reheat steam temperature would be 5930C. The
steam turbine would be a multi cylinders tandem - compound machine, driving a turbogenerator at 3000 rpm to generate 660 MW output at 0.85 power factor at the generator
terminals. The MCR evaporation of the steam generator would be superheated steam at
about 250.7 bar (a) pressure and 569C temperature and steam temperature at reheater
outlet would be 594C. The steam generators would be designed as semi- outdoor
equipment while the turbine generator sets with all auxiliary and feed cycle equipment
14
would be located indoors. The parameters indicated above are preliminary and subject to
confirmation by the selected main equipment suppliers.
COAL HANDLING SYSTEM
12
It is envisaged that coal for this project would be imported would be (Approx) 4900 k Cal
/ kg of calorific value. The annual requirement of coal for the power plant would be about
4.5 million tones. The coal handling system envisaged would be capable of handling
coal from plant junction tower J NT-2 to SG bunkers at rated capacity 1000TPH
(1W+1S).
.
ASH HANDLING SYSTEM
13
The ash content in coal would be about 24 %. Hence 2,13,730 tons of bottom ash and
8,54,919 tons of fly ash would be generated annually per unit when the plant is operating
with a PLF of 85%.
Bottom ash would be collected in a dry type bottom ash hopper. This bottom ash shall
the conveyed to bottom ash silos using scraper chain conveyors passing through clinker
grinder and set of belt conveyors.
The fly ash handling system would be designed to collect fly ash in dry form in silo using
pressure type pneumatic system. The fly ash collected in the storage silo would be
unloaded into the trucks either in conditioned form or in dry form, if required for utilization
or conveyed in high concentrated slurry form to disposal area.
Alternatively provision would be given to dispose BA and unused FA through High
Concentrated Surry disposal (HCSD) system.
FUEL OIL
14
Both fuel oil (HFO) and Light diesel oil would be required at site by road tankers from
ESSAR refinery depots close to the Power plant.
15
WATER AVAILABILITY
15
The source of consumptive water for the thermal power plant would be Arabian sea,
which is at a distance of 15 km from site. The total requirement of sea water make for
each (i.e. one unit of 660MW) is around 1 6 5 0 9 0
m3/day. For both of 2X660MW
unit water makeup is around 330180 m3/day. Sea water is proposed to be pumped
from the existing sea water intake pump house to the cooling tower forebay for makeup
of closed
loop circulation system.
15.1 For the condenser cooling, closed circuit re-circulation system with seawater make-up
using induced draught cooling towers has been proposed. The makeup water for the
condenser cooling would be drawn from the sea by pumps and discharged into the
common CW forebay. From the CW pump house the cooling water would be pumped to
the condenser through individual MS conduits. The discharge would be led partially to the
cooling tower basin through similar MS conduits with suitable lining or GRP pipes and
balance back to sea. 1.3 COC shall be maintained and the discharge to the sea shall
have less than 5 deg C differential temperature.
15.2
Fresh water required for other services viz. DM plant, fire protection system, cooling
water make up for air-conditioning & ventilation system and plant potable water system,
service water, auxiliary cooling (bearing cooling) etc. would be supplied from
Desalinated plant.
15.3
Feed cycle makeup and cooling water for steam generator and turbine generator
auxiliaries would be met from the DM plant.
POWER EVACUATION
16
The power would be evacuated on 400 kV double circuit twin/triple moose conductors.
Out of 1320 MW, 800 MW shall be supplied to GETCO, for which GETCO shall
construct the line from power plant bus bar i.e battery limit of EPGL for power
evacuation, to one of their nearest 400kV Substation. For balance power EPGL will take
16
Open Access (OA) for requisite amount of power from GETCO, alternatively a separate
transmission line will be constructed to evacuate the balance equivalent amount of
power, which shall connect to nearest PGCIL Substation. The proposed scheme for
power evacuation is presented in the single line diagram Exhibit – 08.
ENVIRONMENTAL ASPECTS
17
The power plant is proposed to use imported coal. One (1) Bi flue chimney for phase II is
proposed with a height of 275 m high RCC chimney (stack). This Bi Flue Chimney will be
common for both the steam generator units to meet the requirements of the
environmental regulations. The steam generators would be provided with low NOx
burners and hence the emission of oxides of Nitrogen from the steam generator would be
as per environmental regulations. EPGL shall initiate the application for necessary
Chimney clearance to be obtained from Ministry of Defence in similar manner as done for
Phase-1 project.
The steam generators would be provided with electrostatic precipitators to limit the
particulate matter in the flue gas within 30 mg/Nm3 .This is also within the stipulations of
Central Pollution Control Board /State Pollution Control Board.
Environmental clearance for the proposed project needs to be obtained from MOEF and
from State Pollution Control Board. Rapid environmental impact assessment (REIA) and
comprehensive environmental impact assessment (CEIA) studies have to be completed
and report submitted to MOEF and also to State Pollution Control Board for Their
Clearances. it is also proposed to reserve space for installing FGD in case it is required to be
installed to control SO2 emission in line with environmental norms.
Adequate provisions are proposed for neutralizing the effluents from the water treatment
plant.
Effective ash management plan for utilization of fly ash would be planned and
implemented to ensure proper disposal and use of generated fly ash. The ash utilization
would be progressively increased to achieve 100 %.
Rain water harvesting measures would be adopted in the proposed plant for
17
conservation of rain water. Rain water would be collected from the buildings roofs would
be collected in a collection tank of suitable capacity. This water would be used for
gardening purposes.
All necessary measures would be taken to limit the noise levels within the permissible
limits in the premises and at the plant boundary.
Provision has been also made for the Green belt within the premises.
In view of the above measures no significant impact on environment is expected due to
the installation of proposed power project.
PROJECT COST AND COST OF GENERATION
18.
Estimated cost of proposed 1320 MW project is Rs. 6971 Crores, including interest
during construction (IDC) and financial charges. The cost per MW works out to be Rs.
5.28 (approx) Crores per MW of installed capacity.
19.
LOI received from GUVNL for supply of 800 MW Power at a levelised tariff of Rs. 2.80 /
kwhr for phase II.
PROJECT SCHEDULE
20
Based on expected deliveries of main plant and balance of plant equipment, project
implementation period is considered as 39 months for commercial operation date (COD)
from zero date for the first unit and 3 months thereafter for the second unit as indicated
in preliminary project milestone schedule, Exhibit- 09.
18
RECOMMENDATIONS
21
To ensure timely completion of the proposed project, it is recommended that early action
on the following activities be initiated by EPGL:
a)
Approval of Civil Aviation Authority for installing 275 m high chimney. As explained by
EPGL the same has already been initiated.
b)
Preparation of EIA reports for environmental clearance from state and central pollution
control authorities. As explained by EPGL the same has already been initiated.
c)
Discussions with prospective Indian financial institutions, foreign financial institutions,
external commercial borrowing agencies, Indian commercial banks and reputed main
plant equipment suppliers.
d)
Appointment of project consultant for carrying out detail engineering.
e)
EPGL to identify suitable buyers for ash generated from the power plant.
19
CHAPTER – III
NEED AND JUSTIFICATION FOR THE PROJECT
1.
The State of Gujarat is part of the Western Region comprising the states of Chhattisgarh,
Gujarat, Madhya Pradesh, Maharashtra, Goa, Dadra and Nagar Haveli and Daman & Diu. By
the end of the Jan ‘2016 the installed / available generation capacity in Gujarat was 23,972
MW and the total installed capacity in Western region was 1,02,300 MW
2.
DEMAND FOR ELECTRICAL POWER
Rapid industrialization and increase in commercial and domestic use of electricity are the main
reasons for increase in power consumption. In addition, the government policies like rural
electrification, electricity to all by 2020, development of irrigation sector, minimum per capita
consumption of 1000 units / year, etc are also contributing in increasing the future power
demand. To meet the above requirements, the additions in the power generation capacity
would have to match with the future power demands.
Demand for electrical power in Gujarat State has been increasing due to rapid industrial
growth. In spite of the steps taken by Gujarat Urja Vikas Nigam Ltd (GUVNL) to set-up new
power plants, the demand for power exceeds the availability.
20
3.
Table III.1 and III.2 presents the peak power demand and the energy requirement of
Gujarat state and Western region from Year 2016-17 to 2021-22 as per National Electricity
Plan of Dec ‘2013 issued by Ministry of Power, Govt of India.
Table - III.1
Projected Peak Power Demand and Energy Requirement of Western Region
Sl no.
1
2
3
4
5
6
Projected Peak Power Demand and Energy Requirement of Western Region
Projected Peak Power
Year
Projected Energy requirement (MU)
demand (MW)
2016-17
62015
394188
(Projected )
2017-18
65871
417342
(Projected )
2018-19
70383
444735
(Projected )
2019-20
75223
474042
( Projected )
2020-21
80441
505534
( Projected )
2021-22
86054
539310
( Projected )
Table - III.2
Projected Peak Power Demand and Energy Requirement of Gujarat
Sl no.
1
2
3
4
5
6
7
Projected Peak Power Demand and Energy Requirement of Gujarat
Projected Peak
Projected Energy
Year
Power demand
requirement (MU)
(MW)
2015-16
17538
101479
2016-17
(Projected )
2017-18
(Projected )
2018-19
(Projected )
2019-20
( Projected )
2020-21
( Projected )
2021-22
( Projected )
19091
108704
20486
116649
21942
124937
23503
133825
25177
143360
26973
153582
21
Table - III.3
Sl. No
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
Installed Power Capacity of Gujarat
Installed Generation Capacity for
Gujarat State till March 2015
PLANT NAME
Installed Generation Capacity in Gujarat
THERMAL POWER PLANTS
GANDHINAGAR
870
WANAKBORI
1470
UKAI(TH)
1350
SIKKA
490
PANANDHRO
290
TORRENT POWER
400
SURAT LIGNITE
500
AKRIMOTA
250
APL
2640
Essar Vadinar
1200
OPGS
160
Sub Total ( MW )
9620
GAS POWER PLANTS
DHUVARAN GAS
219
Dhuvaran Expansion
374
UTRAN
520
GIPCL-I
145
GIPCL-II
165
TORRENT POWER GAS
100
ESSAR POWER
515
CLPIPL
655
GSEG Stage-1
156
SUGEN
1148
GPCC Pipavav
700
Sub Total ( MW )
4697
HYDRO POWER PLANTS
UKAI(HY)
300
UKAI LBCH
5
KADANA
240
PANAM
2
PVT HY.
8.6
Sub Total ( MW )
556
Wind Power
5850
Solar Power Plants
1587
Captive Power Plant
299
Bio Mass Plant
41
Gujarat Share out of Central Sector Power
5659
plants
Total ( MW )
28308
22
Table - III.4
Power Scenario at Western Region
Installed Capacity
Units
2014-15
2013-14
Hydro
MW
7448
7448
Gas
MW
10915
10139
Thermal(Coal)
MW
65807
58020
Nuclear
MW
1840
1840
Total (H+G+T+N)
MW
86010
77446
Diesel
MW
17.48
17.48
RES
MW
12795
9925
Grand Total
MW
98822
87389
Net Increase Over Previous in installed Capacity
Year
%
13.08%
11.52%
Peak Demand
Max. Peak Load Catered
MW
45283
42253
Increase Over Previous Year
%
7.17%
3.33%
Max. Unrestricted Demand
MW
46490
43215
Min. Demand
MW
25460
24713
Shortage (MW)
MW
182 to 2481
40 to 1377
0.1 to
Shortage (%)
%
0.40 to 5.83%
3.2%
Energy Generation & Requirement
Energy Gen ( H+G+T+N)
Mus
358926
320317
Increase Over Previous Year
%
12.05%
10.58%
Wind & Solar Energy
Injection
Mus
13531
9416
Increase Over Previous Year
%
43.70%
1.56%
Energy Gen(H+G+T+N+ wind +Solar)
Energy Gen
372457
329733
( H+G+T+N + Wind + Solar)
Mus
Increase Over Previous Year
%
12.96%
10.30%
Net Energy Availability
Mus
332278
299152
Net Unrestricted Energy Req.
Mus
334712
302057
Energy Shortage (%)
%
0.73%
0.96%
Peak Demand Met (MW)
Gujarat
MW
14005
12577
Madhya Pradesh
MW
10050
9972
Chattishgarh
MW
3770
3459
Maharastra
MW
20424
18803
Goa
MW
489
489
Daman & Diu
MW
331
283
DNH
MW
721
653
ESIL
MW
621
618
23
2012-13
7448
9185
50879
1840
69352
17.48
8987
78356
18.86%
40890
7.40%
41478
25139
244 to 2422
0.65 to 6.71%
289666
4.51%
9271
27.37%
298937
5.10%
28165
301213
6.66%
12348
9692
3320
17268
418
278
652
NOTE: The peak power demand and Energy requirement for the year 2016-2017 to 2021-2022 is
estimated based on the projected growth rate as per the National electricity Plan of
Dec‘2013 issued by Ministry of Power.
4.
INSTALLED GENERATING CAPACITY
The Installed generating capacity and availability of power to the state of Gujarat from
various sources for the year 2014-2015 are tabulated in Table III.3.
Considering that Wind Power, Captive power, Biomass and Hydro Power generation is not
stable across different seasons and time of the day, we need to rely on sustainable power
from reliable sources of thermal Plants and partly on Solar plants.

Considering 80% Availability of Thermal plants ( 9620 MW )
- 7690 MW

Considering 80% Availability of Central Sector ( 5690 MW )
- 4530 MW

Out of Gas based Power Plants of 4690 MW, Operational Load
- 1400 MW.

Out of 1587 MW Solar Power & PLF of 20% – Operational Load
- 320 MW.
13940 MW
For the Year 2015,
Out of Total 13940 MW Reliable power Source in Gujarat and
Peak demand of 17538 MW ( Refer Table III.2 ), deficit Power will be 20% at Peak
Load demand in Gujarat not considering the Wind Power & Hydro Power
generation.
Already
PPA is signed between GUVNL and EPGL for the 800 MW Power
Evacuation from the Plant Site considering the future high Power demand in
Gujarat State and Few
New thermal Power Projects being commissioned from
Year 2015 to 2020.
5.
MINISTRY OF POWER’S BLUEPRINT FOR POWER DEVELOPMENT:
The Ministry of Power, Government of India (GOI) has developed a blueprint to address
the power shortage Situation in the country and strategies to overcome it in a time
bound manner. Based on the demand additional generation Capacity needs to be added
in the country in the 12th five year plan by 2017. To achieve the target, already steps
have been taken by different electricity boards to set up new power plants
24
CHAPTER IV
SITE FEATURES
LOCATION OF THE SITE
1
The proposed site for 2x660 MW Super critical imported coal based thermal power
station as phase II nearby Nana Manda, Khajurda, Dist Devbhumi DwarkaGujarat.
ACCESSIBILITY TO SITE
2
The site proposed for 2x660MW units has the following features:
(a)
The proposed site is accessible by road from Jamnagar, which is on the Jamnagar –
Okha state high way.
(b)
The land required for the power plant is under the possession of Essar Power Gujarat
Ltd.
(c)
Sea water make up shall be drawn from the Arabian sea and fresh water required for
power plant will be available from Essar Oil desalination plant.
d)
The coal would be transported by sea route and would be unloaded at Stock yard, and
further transported through conveyors.
AVAILABILITY OF LAND
3
Based on topographical survey drawing furnished by M/S EPGL, about 125 hectares of
land is available for the proposed project at Salaya. This excludes about 25 hectares of
land for ash disposal (considering 24% ash content and 85% PLF) which is adequate for
disposal of 100% ash generated in 4 years. The site identified for the project is mainly
non agricultural with barren land generally with minimum undulations. The land for
corridors of coal transportation and sea water supply pipe line from Arabian Sea to plant
site are not considered in the above.
25
AVAILABILITY OF WATER
4
The makeup water shall be drawn from the Arabian sea located at about 15 km from the
plant boundary. Fresh water requirement of 20640 m3/day would be supplied from
the desalination plant located in Essar Oil Refinery. The makeup requirement of CW
system from sea water requirement for the proposed power plant is 330180
m3/day Thus adequate and reliable quantity of water is available for the proposed
power plant. The analysis of sea water is presented in Appendix-2.
COAL SUPPLY
5
The annual coal consumption of the power plant would be about 4 . 5 million tonnes
considering an average GCV value of coal to be 4900 kCal/kg, annual plant availability
factor (PLF) of 85% and plant heat rate of 2130 kcal/kWh.
Coal would be mainly
received from Indonesian mines through ship using cap size vessels each of capacity of
150000 lakhs tonnes.
POWER EVACUATION
6
Considering the capacity of plant and that a 400kV system is already available at close
proximity to the plant, power evacuation is proposed to be done at 400 kV level. For this
purpose, an outdoor type 400 kV switchyard, with two main breaker schemes, has been
proposed at the power station. The 400kV switchyard would be GIS considering the fact
that the site is closer to sea and will consume less space. The proposed scheme for
power evacuation is presented in the single line diagram Exhibit – 08.
ENVIRONMENTAL ASPECTS
7
The site proposed for the power plant is situated away from the nearby major cities,
isolated and environmentally non-sensitive area. Also, since necessary pollution control
measures are being proposed for the power plant, it is expected to meet the requirement
of environmental authorities.
26
Thus the site has all the infrastructure requirements for the proposed power plant
expansion. It is therefore considered that this site is suitable for the installation of the
proposed power plant.
TRANSPORTATION OF EQUIPMENT
8
All power plant equipment and construction materials would be transported by
rail/road/ship to the power plant site.
SUITABILITY OF SITE
9
Considering adequacy of available land, availability of river water for plant requirements,
coal supply arrangements /, facilities proposed, access to site, feasible power
evacuation scheme and environment aspects, it is concluded that the identified site is
suitable and land is more than adequate for installation of 2x660 MW units.
27
CHAPTER V
FUEL LINKAGE AND TRANSPORTATION TO SITE
TYPE OF FUEL
1
Imported coal would be used for load carrying. LDO would be used for light up and
initial warm up of units and heavy fuel oil (HFO) for start-up and flame stabilisation at low
loads.
SOURCE OF COAL AND QUALITY
2
Coal for the project would be Imported, supplied from Indonesian coal fields coal having
about 24 % max. of ash content and with an average gross calorific value (GCV) of
about 4900 kCal / kg. The analysis of coal is given at Appendix-3.
ANNUAL COAL REQUIREMENT AND COAL LINKAGE
3.
The annual consumption of coal for the power plant is estimated at 4.5 million tonnes considering
average GCV of Imported coal as 4900 kCal / kg with an annual plant availability factor (PLF) of
85% and total heat rate of 2130 Kcal.kWh.
TRANSPORTATION OF COAL TO SITE AND STORAGE
4
Coal will be received by large cape size cargo ships (1.5 lakhs tones) and unloaded at
the existing jetting of phase-I. Coal from the jetty is envisaged to power plant by closed
conveyors.
FUEL OIL SUPPLY
5
The fuel oil system would be designed for the use of light diesel oil (LDO) for start-u p
and heavy furnace oil (HFO) for flame stabilization purpose The secondary fuel would
be HFO as per IS : 1593 and LDO as per IS 1460 : 1995.
28
Based on the statistical average oil consumption of 1 ml per kWh for normal operation &
2 ml per kWh during stabilization period at a PLF of 85%, the quantity of HFO required
per month is approx 1200 cu.m and LDO would be 400 cu.m respectively
Oil is envisaged to be supplied from nearest Essar refinery terminal by using road
tankers to the site. Approximately 7 days of oil storage is considered adequate during
trial operation.
29
CHAPTER VI
PLANT LAYOUT AND CIVIL ENGINEERING ASPECTS
PLANT LAYOUT
1.
The layout of the main plant along
with
all the auxiliary systems has been shown in
Plot Plan (Exhibit - 1). In laying out various facilities consideration has been given to the
following general principles :
(a)
Least disturbance to existing habitation and vegetation, if any.
(b)
Flexibility to have future expansion units with particular reference to the switch
yard and main plant.
(c)
Predominant wind directions as gathered from the wind rose to minimize
pollution, fire risk, etc.
2.
(d)
Power evacuation corridor for connection to state grid
(e)
Sea water intake pump house
(f)
Approach road to the power plant from the main highway
(g)
Availability of adequate space for fabrication / construction equipment.
(h)
Availability of adequate space for labour colony during construction stage.
All facilities of the plant are laid out in close proximity to each other to the extent
practicable so as to minimize the extent of land required. The layout also facilitates
communication of men and movement of materials between the various facilities both
during initial construction and also during subsequent operation and maintenance.
3.
Besides taking into consideration the above aspects, the Plot Plan is made to permit coal
receipt by conveyors from jetty. Fuel oil would be received by road tankers.
30
CIVIL ENGINEERING ASPECTS
Site Topography and Grade Level
4.
Site terrain is almost flat without significant undulations. The main plant, auxiliary
buildings and coal stockyard etc. would be located at suitably higher level of than the
general grade level.
Station Building: General Arrangement
5.
The steam turbine generator and auxiliary equipment would be located in the main bay of
the building having 29.0m span. Each unit is accommodated in a length of 10.0m x 9
bays. Total length of station building for both the units would be 220 m which includes
two unloading / maintenance bays each of 10.0 m wide at the end of the station building.
The heaters are accommodated in the auxiliary bay (Heater bay) having a span of 10.0
m. The control room / electrical building is located on the side of the station building to
accommodate switch gear, electronic panels and control room in a space of 50.0 m x
41.50 m.
6.
The turbine - generator bay would be serviced by three floors - ground floor at 0.0 M
level, mezzanine floor at +6.9 M level and operating floor at +13.7 M level. Localized
O&M platforms at required levels would be provided. The Deaerator would be located at
EL+ 26.00 M in the BC bay (heater bay). Road access would be provided to the
unloading and maintenance bays for unloading TG components and auxiliary equipment.
7.
The superstructure would be of structural steel framing with RCC floor slabs. The roof of
the TG bay would consist of sandwiched panels (with insulating material). The turbine
generator pedestal would be reinforced concrete and would be isolated from the building
foundations and super structure. All structures would be designed to cater to applicable
wind/seismic forces in the area as per relevant Indian Standards.
Steam Generator Area and Mill Bay
8.
The mill bay would be of structural steel-framed construction, supporting the steel
bunkers. The 14 m wide bay would have mill maintenance platform at ground level and
31
floors for the feeders and for the bunker feeding conveyors provided with trippers. The
bunker bay would be located at the front side between the furnace in the steam generator
area and the T-G building. Concrete paving would be provided in the steam generator
area with necessary drains and trenches. Pipes and cables in this area would, in general,
be routed on overhead pipe / cable racks.
Chimney
9.
One (1) Bi-flue chimney with common wind shield for the two units has been envisaged
for the proposed thermal power plant. The total height of reinforced concrete chimney is
275 mtr, and Diameter of flue can is 7.6 mtr. This would meet the requirement of Indian
Emission Regulation. The chimney windshield shall be of RCC slip form construction.
Miscellaneous Buildings
10.
Table - VI.1 below indicates list of major buildings / structures planned in the power plant
and type of construction :
Table -VI.1
Major Buildings / Structures
Sl. No.
1.
Building / Structure
ESP control room
2.
Air washer rooms
3.
Ware house and
Workshop
4.
D.G house
Remarks / Type of Construction
Ground plus three floor; common for two units.
Structural steel construction with brick walls.
Floors and roof would be of RCC.
Two per unit; Each having ground plus one
floor. Structural steel construction with brick
walls. Floors and roof would be of RCC.
Structural steel columns with bricks for side
cladding.
Pre-coated galvalume sheet
supported
on
structural
steel would be
provided for roof.
Structural steel construction with pre- coated
galvalume sheet for roof. Sides are kept open.
32
5.
6.
7.
8.
9.
10.
11.
12.
Hydrogen cylinder
shed
CW pump house
& MCC room
Clarified water
pump house
D.M Plant
Coal handling
switch gear cum
control room
Switch yard
control room
DM plant control
room cum switch
gear room
Ash handling
compressor
room + MCC
room
Structural steel construction with pre- coated
galvalume sheet for roof with 1.8 m high brick
dwarf walls for the sides.
Structural steel construction with brick walls
Structural steel construction with brick walls.
Structural steel columns with pre-coated
galvalume sheets for roof. Roof is supported
on structural steel trusses. Sides are kept
open.
Structural steel construction with brick walls
Structural steel construction with brick walls
Concrete construction with brick walls
Compressors would be provided with metallic
containers and covered shed would be
provided for protection.
13.
Admin Building
Concrete construction with brick walls
14.
Canteen Building
Concrete construction with brick walls
15.
Service Building
16.
Fire Station Building
17
Car / Scooter parking
Structural steel construction with brick walls.
Floors and roof would be of RCC.
Structural steel construction with pre- coated
galvalume sheet for roof. Sides are kept open.
Fire office space would be of concrete
construction with Brick walls
Structural steel construction with pre- coated
galvalume sheet for roof. Sides are kept open.
Soil Profile and Foundations
11.
Details would be furnished after the detailed geo-technical investigation of the proposed
area is carried out. However the net safe bearing capacity of 40 t/m2 at 3.0 m below the
existing ground level is considered for the purpose of this report.
Machine Foundations
33
12.
All equipment would be supported on conventional block / framed type RC foundations
and would be separated from the building foundations and superstructure. All variable
speed machines would be supported on vibration isolation system with springs and
viscous dampers.
Roads, Drains & Boundary Wall
13.
The roads would initially be of water-bound macadam type with shoulders on either side
of carriage width.
After major construction activities are completed, these would be
surfaced with bituminous carpet. All major roads would be 7.0 m wide and other
approach roads would be 4.0 m wide. Storm water drains would be provided on either
side of the roads. The storm water drains would be of RCC construction. The storm
water drains would be connected to the nearest water body or would be treated suitably
and reused for gardening and other purposes. The power plant boundary wall of 3.0 m
height with anti-climbing device would be constructed from locally available stones.
Design Basis
14.
Dead and live loads would be considered as per relevant IS codes and standard
engineering practices. The basic wind speed of 50 m / s is considered for design of
buildings / structures as per IS : 875 : Part III. The power plant is located in Seismic Zone
V as per IS : 1893 and seismic forces would be considered accordingly for the structures
/ buildings. All designs would be carried out in SI units and would be as per relevant IS
codes.
Sewage Disposal
15.
Sewage from various buildings would be lead to STP
located close to the
buildings by means of CI pipes laid underground. The treated water will be used for
green belt.
34
Landscaping
16.
The various services / utility areas within the plant would be suitably graded to different
elevations. Natural features of the plant site would be retained as far as possible to
integrate with the buildings to form a harmonious / pleasant environment. Areas in front
of various buildings and the entrance of power plant would be landscaped with ground
cover, plants, trees based on factors like climate, adaptability etc. The green belt would
consist of native perennial green and fast growing trees. Trees would also be planted
around the coal stock pile area and ash disposal area to minimize the dust pollution.
35
CHAPTER VII
MAIN PLANT EQUIPMENT AND SYSTEMS
PLANT CAPACITY
1
EPGL have awarded for installation of 1320 MW (2x660 MW) coal based thermal power
project nearby Nana Manda, Khajurda Devbhumi Dwarka Dist, Gujarat.
UNIT SIZE
2
Two (2) units each of 660 MW have been considered for the project. This is based on
request for proposal (RFP) document requirement.
TURBINE CYCLE HEAT RATE
3
The generally adopted supercritical pressure (turbine throttle pressure) is about 247 bar
(a). For the purposes of the present DPR, following options of throttle steam and reheat
steam parameters for the 660 MW units have been considered to prepare heat balances
and to compute turbine cycle heat rates using the software STpro:
a)
4
247 bar (a), 567°C/593°C
Based on the above as superheater/reheater steam temperatures increase for the same
pressure, the turbine cycle heat rate decreases which means plant efficiency improves.
5
Leading supercritical boiler manufacturers in the world have proven experience in
designing and manufacturing boilers for above mentioned which are in operation for long
time.
6
The relevant turbine cycle heat balance is presented in Exhibit-2. Indicative parameters
for both the options have been mentioned in Table VII.1.
36
STEAM GENERATOR AND ACCESSORIES
8
The steam generator (SG) would be once through type and would be designed for firing
100% Imported coal. The SG would be radiant, two pass design, single reheat, balanced
draught and semi outdoor type.
9
The water wall would be spiral wound plain tubes with vertical tubes over the spiral water
walls or vertical rifled tubes type.
10
Indicative design parameters for the steam generator for the 660MW unit would be as
below.
Table-VII.1
Indicative Parameters for the Steam Generator
i
Superheater outlet pressure
ii
Superheater outlet temperature
iii
Superheater outlet flow
1966.7 TPH
iv
Re-heater outlet pressure
51.51 bar(a)
v
Re-heater outlet temperature
Feed water inlet temperature to
vi
11
economizer
250.7bar(a)
569°C
594.4°C
297°C
The steam generator would be corner fired or front and rear wall burners mounted type.
The furnace would be appropriately sized to avoid slagging in the pendant/platen
superheaters and reheaters and in the heat transfer surfaces in convection pass.
12
The coal burners would be of proven advanced design to reduce NOx production and
the furnace would also be provided with over fire air ports to further reduce NOx
production.
13
The SG would be provided with circulation system comprising steam separators to
remove water moisture from the evaporator outlet and to recirculate water into
economizer inlet, for use during startup and shut down. The SG and steam turbine
generator (STG) would be designed for sliding pressure operation, which would increase
turbine cycle efficiency and reduce boiler feed pump power consumption. The load
range for sliding pressure operation would be from about 40% STG maximum
37
continuous rating (STG MCR) to 90% STG MCR. This modified sliding pressure
operation would be employed to provide facility of temporary load increase even before
the fuel handling and firing system can be loaded to support any sustained higher load.
14
The SG would consist of water cooled furnace, radiant and convection superheaters,
reheaters, economizer, regenerative air heater, steam coil air preheaters. Smart soot
blower system would be provided with soot blowers located at strategic locations for
cleaning the slagged and fouled heat transfer surfaces during operation.
15
The SG would be provided with vertical spindle medium speed coal mills, which would
be located in the boiler front or between the boiler and the ESP depending upon the
manufacturer’s standard. The milling system would be designed such that one(1) mill
would be standby and other mills would take care of MCR with worst coal and two(2) mill
would be standby with design coal. The coal mills would be provided with dynamic
classifiers to control the fineness of the ground coal thereby controlling the unburnt
carbon losses. The coal mills would be provided with gravimetric coal feeders.
16
Sampling arrangement at mill outlet would be provided for the purpose of establishing
the average gross calorific value of coal as well as coal fineness. The coal mills would
be provided with steam blanketing system for the purpose of fire protection.
17
The SG would be designed to handle and burn HFO as secondary fuel upto about
22.5% SG MCR for start- up and for flame stabilization during low load operation or
during mill change over. For unit light up and warm–up purposes, LDO system having
7.5 % SGMCR firing capability would be used with air atomization.
18
The SG would be provided with fuel oil pumps and fuel oil heating equipment along with
high- energy electric arc ignitors to ignite the fuel oil guns.
19
The draught plant would comprise primary air fans, forced draught fans and induced
draught fans. The primary and forced draught fans would be of axial blade pitch
controlled axial type. The induced draught fans would be axial blade pitch controlled
axial type or speed controlled (VFD) centrifugal type, which would reduce power
consumption during power plant operation at TGMCR and part load operations.
38
20
Electrostatic precipitators (ESP) would be provided for the collection of fly ash. The ESP
would be provided with microprocessor control system to optimize and for minimum
electric power consumption. The ESP would be so designed that for worst coal firing
with an ash content of about 25 %, an outlet dust concentration of 30 mg/Nm3 as
stipulated by
World bank group on pollution prevention and abatement / State/Central Pollution
Control Boards, would be achieved.
STEAM TURBINE GENERATOR AND ACCESSORIES AND CYCLE EQUIPMENT
Steam Turbine Generator
21
The steam turbine generator (STG) would be rated for about 660 MW maximum
continuous output at generator terminals, with throttle steam condition of 247bar(a) at
567°C/593°C reheat ,0.01 bar(a) condenser back pressure with 0% make up. The STG
output at valve wide-open (VWO) condition would be about 693 MW, which is 5% above
the maximum continuous rating of 660MW to enable increased output required during
low frequency operation and drop in efficiencies over years of operation.
22
The steam turbine would be a multi cylinder, reheat extraction and condensing turbine.
23
The turbine generator would be complete with all accessories such as protection system,
lube and control oil system, seal oil system, jacking oil system, seal steam system,
turbine drain system, electro-hydraulic control system, automatic turbine run up system,
on-line automatic turbine test system and turbine supervisory
instrumentation. A
continuous bypass (60 % capacity) method of lube oil purification is proposed to be
adopted for purification of lubricating oil.
24
The turbine generator would also have all necessary indicating and control devices to
permit the unit to be placed on turning gear, rolled, accelerated and synchronized
automatically from the control room. Other accessories of the turbine generator would
include an external oil purification unit with transfer pumps and oil storage tank of
adequate capacity.
39
PLANT CYCLE
25
The condensing plant would comprise two condensers, one each for the two LP
turbines. Vacuum pumps of 3x50% capacity would be provided to create vacuum in the
condenser during start-up and to remove the non-condensable gases liberated during
normal operation.
26
The regenerative cycle would consist of low pressure heaters, a variable pressure
deaerator, three high pressure heaters and one gland steam condenser.
27
Under normal operating conditions, drains from the high pressure heater would be
cascaded to the next lower pressure heater and finally to the deaerator. Drains from the
low-pressure heaters would be cascaded successively to the next lower pressure heater
and finally to the condenser hot well or pumped forward to the condensate line. Heaters
would be provided with drain level controllers to maintain the drain level automatically
throughout the range of operation of the heaters. The system would consist of splitrange control valves to take the drain to a lower pressure heater or to the condenser
through a flash box under exigent conditions.
Bypass system
28
The STG unit would be provided with a suitable HP-LP bypass system.
a)
To prevent a steam-generator trip in the event of a full export load throw-off and
to maintain the unit in operation at base load
b)
To prevent a steam-generator trip following a turbine trip and enable quick restart
of the turbine generator set
c)
To minimise warm restart duration of the unit after a trip
d)
To conserve condensate during start up
e)
To facilitate quick load changes in both directions without affecting the steam
generator operation during start-ups.
Condensate Pumps
40
29
The condensate from the condensate hotwell would be pumped by 3x50% capacity
condensate pumps, two working and one stand by to the deaerator through the gland
steam condenser, drain cooler and low-pressure heaters. The pumps would be vertical,
cannister type, and multistage centrifugal pumps driven by AC motors.
Boiler Feed Pumps
30
The feed water would be pumped from the deaerator to the steam generator through the
high pressure heaters by means of 3 x 50% capacity boiler feed pumps i.e. two steam
turbine driven and one motor driven type. The motor driven BFP would be used as
standby and during start-up. The boiler feed pumps would be horizontal, multistage,
centrifugal pumps of barrel type.
Low Pressure Heaters
31
The low pressure (LP) heaters would be of shell and tube with stainless steel U-tubes
(seamless) welded with their ends rolled in carbon steel tube sheets. The LP heaters
would be provided with condensing zones and also with drain cooling zones.
Deaerator
32
The deaerating feed water heater would be a direct contact, variable pressure type
heater with spray-tray type or spray type of deaearation arrangement. The feed water
storage tank would have a storage capacity adequate to feed the steam generator for 6
minutes when operating at SG MCR conditions.
High Pressure Heaters
33
The high-pressure (HP) heaters would be of shell and tube with stainless steel U-tubes
(seamless) welded with their ends rolled in carbon steel tube sheets. The HP heaters
would be provided with de-superheating zones and a drain cooling zones in addition to
condensing zones.
Gland Steam Condenser
41
34
A surface type gland steam condenser would be used to condense the gland steam
exhausted from turbine glands. The gland steam condenser would be of single-pass
type with the main condensate flowing through the tubes to condense the steam.
Exhausters would be provided to evacuate the air from the shell side and maintain the
shell at the required negative pressure.
Condensate Polishing Unit
35
In order to maintain high purity of the feed water, 2x50% capacity condensate polishing
units (CPU) are envisaged in the condensate system.
Chemical Dosing System
36
Ammonia dosing system would be provided to ensure chemical conditioning of the
condensate/feed water for controlling the alkalinity. The ammonia solution would be
injected into the condensate at the condensate extraction pump discharge. The lowpressure ammonia dosing system would comprise solution preparation-cum metering
tanks with motorized agitators, two positive displacement type-dosing pumps, piping,
valves, instruments and local control panel. Each dosing pump would be sized to cater
to the 100 % dosing requirement of each of the 660 MW units.
Oxygenated Treatment
37
To reduce iron pick up from the boiler, during normal operation of the plant, oxygenated
treatment is also proposed. Under this treatment gaseous oxygen would be injected at
CPU outlet and at BFP suction to maintain about 150-250ppb.Feed water pH is
maintained in the range of 7.0-8.5.
Fuel Oil system
42
38
The annual requirement would be about 1071 cu.m based on consumption of 2ml/kWh
(CERC guidelines) of power generation and 85 % PAF.
39
HFO would be supplied by road tankers from Essar refinery terminals located at near to
site. Two tanks each of capacity 4000 KL are proposed which are adequate to meet the
normal requirement including peak requirements during commissioning and trial
operation of units.
40
The HFO tanks would be fitted with steam heated floor coil heaters for initial heating and
to supply fuel oil at the required temperature to the inlet of pumping and heating units. All
HFO lines would be heat traced and insulated.
43
CHAPTER – VIII
INSTRUMENTATION AND CONTROL SYSTEM
1.
DISTRIBUTED MICROPROCESSOR BASED INSTRUMENTATION AND CONTROL
SYSTEM (I&C)
Microprocessor based distributed control system with state of the art Human Machine
Interface (HMI) is proposed for the 2 x 660 MW to provide a comprehensive integrated
instrumentation and control system including the functions of Data Acquisition System
(DAS) to operate, control and monitor the steam generator and auxiliaries, steam turbine
generator and auxiliaries and the balance of plant systems including electrical system
with a hierarchically distributed structure.
Distributed control system (DCS) has been envisaged for the main plant comprising of
Boiler and auxiliaries, turbine and auxiliaries. PLC based control has been envisaged for
Coal handling, Ash handling, DM plant, Fire detection & Alarm and Fire Fighting system
(control for the sea water intake, CW system etc.. shall be included appropriately) .
SCADA would be used for Switchyard controls. All PLC, SCADA & DCS shall be OPC
compliant supporting open architecture for homogeneous connectivity & uniform
operation by plant DCS operating station.
The distributed microprocessor based system proposed is to be geographically
centralized. In the geographically centralized microprocessor based system, electronic
cubicles would be located in a centralised location with centralised operation from the
control room.
2.
SALIENT FEATURES OF DCS
2.1
The Distributed Control System (DCS) would use the state of the art technique of
functional distribution of control and monitoring defining redundancy at appropriate level
to reduce the risks associated with failure of any single controlling unit. The DCS shall
have complete control capabilities that include closed loop control, open loop control,
computation and interfacing for data acquisition, graphic displays, logging, annunciation,
sequence of events recording, data storage, retrieval, performance calculations and
management information system. The system shall allow for operation from the control
room through operator work station (OWS) with TFT monitors. The communication from
the control desk operators’ interface to the electronic hardware shall be over a high
44
speed data highway. The system will be based on open system architecture to facilitate
interface with third party software. MIS will have interface with both DCS and all PLCs.
2.2
The microprocessor based system proposed is functionally distributed with electronic
hardware located in a centralized location designated as Control Equipment Room
(CER) and plant operation to be undertaken from the Central Control Room (CCR).
2.3
The instrumentation and control system would integrate the functions of plant
monitoring, control and information systems. All equipment and processes in the unit
would be controlled and monitored from Central Control Room. The Central Control
Room shall house unit control desk while related power supply and system cabinets
shall be mounted in Control Equipment Room. The operating stations (OWS) shall be
functionally interchangeable. TFT display screen with keyboard control for OWS will be
provided for operation and maintenance. Also dedicated software for Vibration
Monitoring system (VMS), Flame monitoring system, Boiler tube detection System,
Performance analysis of Plant & equipment, Diagnosis and optimization system is
envisaged. LVS (Large Video Screen) has been envisaged for overview information &
operation of the plant.
2.4
The DCS shall have adequate redundancy features. The system shall be provided with
the redundancy at various levels.
a)
Processors, I/O bus, Data bus, Communication bus, power supply
b)
I/O module redundancy would be for critical open loop and all closed loop
services only. However, TMR had been detailed separately.
c)
Triple redundant sensors would be considered only for critical services like boiler
trip, turbine trip, furnace draft control, governor control, steam temperature, hot
well level controls and bypass controls. Less-critical controls would be
considered with dual redundant sensor. No redundancy would be considered for
non-critical measurement system.
3.
CONTROLS INCLUDED IN DCS
A Microprocessor based DCS of modular hardware with state-of-the art HMI covering
the following is envisaged:
45
a)
Steam generator (SG) start-up / shutdown sequence, integral controls like burner
management system, secondary air damper control, soot blowing, high pressure
by-pass system and controls for boiler and auxiliaries and closed loop controls
like combustion control and SH / RH steam temperature control.
b)
TG integral controls like Automatic Turbine Run-up System (ATRS), Turbine
Protection (TP), Electro-hydraulic Turbine Controls (EHTC), Automatic Turbine
Tester (ATT), Turbine Stress Evaluator, turbine supervisory system and LP & HP
by-pass system and gland steam controls, Lube oil temperature control system.
c)
Balance of plant control includes auxiliary steam system, condensate system,
feed water system, HP/LP Dosing system, cooling water system, auxiliary cooling
water system and makeup water system.
d)
Coordinated master control.
e)
Generator Auxiliaries Control.
f)
The Furnace Safeguard and Supervisory System (FSSS) and the Turbine
Protection System (TPS) is proposed to be implemented through triple modular
redundant (TMR) control system conforming to SIL 3 with certification from an
authorised agency. Where the DCS Vendor does not have this system in their
product range, independent TMR system with integration to DCS through
communication links is proposed.
The DCS envisaged is independent for each unit except at Management Information
System (MIS) level and at the shift charge engineers level which is common for both the
units.
4.
CONTROL LOOP GROUPING PHILOSOPHY
The following critical loops would be implemented in separate dedicated TMR/redundant
controllers of the same DCS system:
a)
Boiler protection and BMS in SIL 3 Certified Dual redundant or TMR (Triple
modular redundant) system in line with latest NFPA guidelines.
b) Turbine protection in TMR mode
c) Electro-hydraulic governing control in TMR mode
d) Furnace draft
(
Redundant
)
e) Steam temperature
(
“
)
f)
(
“
)
HP / LP Bypass controls
g) Hot well controls.
(
“
)
46
h) Boiler start-up / shutdown sequence logic including BMS, Mills etc. ( ‘’ )
i)
Turbine start-up / shutdown logic ( ‘’ )
All other loops would be grouped suitably without
compromising availability
requirements. The TMR systems will be preferably of the same family of the DCS,
otherwise TMR systems will be interfaced with DCS through bi-directional OPC link with
Ethernet based TCP-I/P Protocol.
5.
LOCAL OPERATION
Local push button station for stop facility shall be provided for all motorised drives except
for solenoid valves. The motorised valve with integral starter will have LPB operation on
the actuator itself.
6.
UTILITY PACKAGES
6.1
Utility packages are proposed with dedicated stand-alone control system. Condensate
Polishing unit, (if applicable) Coal handling system, ash handling system, water
treatment plant, CW plant, sear water Pump House system, Effluent treatment system
and fire protection system will be provided with independent Microprocessor based PLC
control systems with VDU/KB based OS operation and will be located in the respective
local control room (Common for 2 units).
6.2
Serial communication will be provided with the Plant DCS system in the main control
room for monitoring. All the offsite unit control systems shall be networked with the main
plant DCS so that the offsite plant information is available in plant DCS.
6.3
PLC-based control system will also be provided for Air conditioning and ventilation
system and fire detection & alarm system. Sea water pump controls would be PLC
based control having local control panel located in the sea water pump house &
interfaced with DM Plant PLC to facilitate operation from DM plant operator station.
Chemical dosing system would be relay based. Compressor package will be provided
with integral microprocessor based control system with hardwired connection / serial link
to DCS.
6.4
The control of the packages is proposed from dedicated PLC / microprocessor based
systems that will be located in a control room nearer to the respective equipment.
Suitable interface (hardwired and /or serial) would be provided with the plant I & C
system in the main control room for status monitoring.
47
7.
Operation Philosophy
All equipment/system associated with main plant viz. SG, STG and their associated
auxiliaries, other balance of plant systems like chemical dozing systems (HP & LP) etc.
& Plant electrical system of each unit, and plant common systems like compressed air
system, plant common station electrical system shall be operated / monitored from
VDU/Keyboard based Operator stations (OS) mounted on central Control Desk (UCD)
and from Large Video Screen displays (LVS).
The Central control room shall be common for both the units & layout shall be
accordingly planned.
8.
UNIT CONTROL DESK
The unit, functional group / drive level control and operation of all main plant equipment
would be from a set of console type TFT monitors along with the keyboard / mouse.
9.
The Control desk (CD) for each unit would house the following items:
a)
Operator work stations (TFT Monitors) for operation, control and monitoring of
steam generator, turbine generator and the balance of plant.
10.
b)
Telephone handsets
c)
Annunciation windows
d)
Emergency push buttons for SG, TG ,HT and critical LT devices
The operator can perform the following operations of main plant and balance of plant
from monitors in the UCD through key boards:
a)
Operation of all control valves, control dampers, motor operated valves,
interlocked isolating valves and dampers, non-interlocked isolating valves &
dampers, motor operated bypass valves of control valves, warm-up valves, drain
valves and vent valves in the steam generator, turbine generator and auxiliaries
and auxiliary electrical systems.
b)
Operation of pumps and fans associated with the steam generator, turbine
generator, feed cycle and other auxiliary systems.
c)
Call for plant overview, group display, individual loop display, etc. and carry out
associated control operations.
11.
All the monitors are supported by the following peripherals, which are located in the
control room:
48
12.
a)
Colour Inkjet printer (Operator’s action)
b)
Dot matrix printers (logs and reports).
c)
Colour Inkjet printer (History).
d)
Colour Inkjet printer (Engineering station).
e)
Dot Matrix printer (SER).
In addition to the above, monitors / peripherals would be provided for following:
a)
2 no’s of Maintenance engineer's equipment (MEE): Monitor and Laser printer. If
TMR is not part of the DCS, then separate ES or programming unit will be
provided (1 No. MEE for each unit )
b)
Historian and Plant Performance calculation monitor. Historian hardware will be 2
x 100% type.(for each Unit)
c)
Shift in charge Engineer's equipment (SCE) will comprise of Monitor and Laser
printer (1 No common for 2 Units)
d)
Management information system: Monitors and printers.
However, the plant operation shall be carried out only through the Operator Stations.
Backup between the Operator Station shall be defined for Plant operation in case of one
station failure.
13.
CONTROL ROOM
The control room of the unit is partitioned into different rooms to house the following
equipment:
a)
Control Desk (CD) and printers in the main common control room.
b)
DCS system cabinets, Marshalling cabinets, electrical auxiliary cabinets, steam
generator and turbine auxiliaries system cabinets in the electronic cubicle room.
c)
Cabinets in the Control Equipment Room.
d)
Shift Incharge Engineer’s monitor with key board and printers in Shift Incharge
Engineer’s room. ( 1 no. common for 2 units )
e)
Maintenance Engineer’s monitor with key board in MEE room and printers of
I&C, steam generator and turbine system in auxiliary electronics room (common).
f)
LVS: The size will be 2x3 matrix (each 67” size) for each unit & 1 number for
offsite plant unit comprising of CHP, AHP, DM plant etc (common for 2 Units).
g)
Electrical panel room in main control room
h)
Uninterrupted Power Supply System (UPS) in UPS room (separate).
49
14.
FEATURES OF THE I&C SYSTEM
14.1
Smart transmitter maintenance facility
A PC based dedicated smart transmitter maintenance facility, common for both units,
would be provided for complete diagnostic, record keeping, calibration and configuration,
event and log reports, historical data base records of all transmitters.
14.2
Computerised Maintenance Management System (CMMS)
Computerised Maintenance Management System (CMMS) suitable for use with
maintenance management of a modern power generation utility’s equipment and
systems would be provided. It shall be common for both units and shall perform tasks
such as asset and inventory management, preventive maintenance scheduling, job plan,
work order generation, purchase and personnel functions, etc.
14.3
Performance analysis, diagnostics and optimisation system (PADO)
The PADO system would provide critical analysis of the plant performance and guidance
for optimisation on continuous on-line basis. The system shall analyse dynamically the
status of the process and the equipment of the power generating units and generate
operator guidance instructions for remedial actions for maintaining the process and the
system / equipment in the plant to their optimum performance.
14.4
Sequence of Events Recording System
Sequence of events recording system (SER) of 1 millisecond resolution with an input
capacity of 512 points would be provided as an integral part of DCS to log trips, cause of
trips and other important faults to diagnose the cause of plant trips. This shall also
include switchyard inputs. The system will be provided with a dedicated printer located in
the main control room.
14.5
Annunciation System
A Stand-alone microprocessor based annunciation system (AS) would be provided with
ISA sequence ring back feature. The system has the features of standard ISA
sequences. A limited number of annunciation windows for critical alarms of process and
electrical are proposed to be provided in the unit control desk. Alarm prioritisation is also
50
envisaged. A set of annunciation push buttons would be provided in the unit control
desk.
14.6
Analytical Instruments
Adequate number of analytical instruments would be provided for continuous monitoring
of steam, condensate & feed water system. The analytical instruments proposed are for
measurement of specific conductivity, cationic conductivity, pH, dissolved oxygen, silica
and hydrazine.
14.7
Steam and Water Sampling System (SWAS)
Various steam and water samples (with suitable sample coolers) would be routed to a
centralised place and cooled to the required temperature before passing through the
respective analytical sensors. The complete hardware associated with this sampling
system and Flow cells with sensors are mounted in a sampling rack with facility for grab
sampling. The analysers are located in a separate panel near the sampling rack in an
air-conditioned environment. The SWAS room will be suitably located in the station
building for each unit.
14.8
Control Valves
All control valves shall be considered to handle 15% excess capacity over and above the
maximum flow value. The control valve design shall be suitable for the required fail safe
conditions of process / equipment. Anti-cavitation trim with controlled, staged pressure
reduction shall be used for high pressure drop application.
14.9
Final Control Element Actuators
All final control elements (control valves and control dampers) would have actuators of
pneumatic / hydraulic type. The control system design shall be suitable for the required
fail-safe conditions of process / equipment.
All actuators would be sized so that the final control elements operate properly even
when the upstream pressure exceeds 110% of maximum value. Pneumatic actuators
would be provided with air failure lock and remote release, limit switches, adjustable
minimum and maximum stops, load position indicators, positioners, electronic position
transmitters and solenoid valves in accordance with the system requirements.
51
14.10 Boiler tube leak detection system
A microprocessor based Boiler tube leak detection system (24 channel) with high grade
audio electronic microphone type audio detectors, display unit, etc. would be provided to
generate alarms on occurrence of tube leakage and to display the level of leakage in the
form of bar charts.
14.11 Furnace flame monitoring system
The flame monitoring and analysis system would provide flame condition monitoring and
thermo-graphic analysis of the flame for each burner and guide the plant operation
personnel regarding the nature of fault and the corrective action required. The system
would comprise video cameras, signal conditioning cards, amplifiers, special cables, etc.
with all necessary equipment and accessories.
14.12 Field Instruments
Field transmitters, switches and temperature elements with adequate redundancy would
be provided to meet the interlock/control requirements of the power plant.
Local indicators are envisaged wherever indicating type transmitters are not provided to
enable local operators to supervise and monitor equipment / process operation.
Separate switches would be considered for unit and equipment trips and also for alarm /
interlock purpose wherever transmitters are not envisaged. All transmitters shall be
smart transmitters with integral indicators. Also smart transmitter maintenance facility will
be provided.
14.13 Air Supply for Pneumatic Equipment
Oil free, dry instrument air from instrument air header at a pressure of 6 - 8 bar (g) would
be drawn for various instrument auxiliaries like positioners for control valves & control
dampers, I/P converters, etc. Each of these pneumatic equipment which requires air
supply at different pressures would be provided with an air-filter regulator.
14.14 Power Supply
A redundant uninterrupted power supply (UPS) system would be provided at 230V AC,
single phase, 50 Hz, 2 wire for power supply requirements of instrumentation and control
systems viz. DCS man-machine interface equipment, analysers and instruments
52
mounted on the unit control panel. Any other voltages required including control system
supply of + 24 VDC would be derived from the 230V AC UPS. Conversion from 230V AC
UPS power to 24V DC power shall be done in redundant mode.
14.15 Testing and Calibration Instruments
Necessary testing and calibration instruments required for the complete I&C system for
commissioning & maintenance during operation of the plant shall be considered.
(Common for Both Units).
14.16 Cables
Individual / pair shielded and overall shielded twisted pair copper cables would be used
for analog signals and overall shielded cables would be used for digital signals. All these
cables shall be armoured. The inner sheath shall be PVC and the outer sheath shall be
FRLS PVC. The size of the wire would be 1.5 sq.mm. 2.5 sq.mm copper control cable
would be used for cabling for services like field solenoid valve to the control system.
Compensating cables will be provided for connecting the thermocouple inputs to the
measurement system of DCS and up to temperature transmitters for closed loop control
system. The interconnecting cables between any two cabinets and between cabinets
and panels would be of prefabricated type.
14.17 Instrumentation Pipes / Tubes and Fittings
For remote located instruments like transmitters, tubes and fittings of appropriate
material and rating would be used. Open type transmitter racks with canopy would be
provided to group and mount all pressure, flow, level transmitters and temperature
transmitters in the Turbine area and closed transmitter racks would be used in Boiler
area. Junction boxes would be provided for termination of all field switches like pressure,
temperature and level.
For all pipe mounted instruments, pipes and fittings of appropriate material would be
used. For all high pressure and temperature services (above 62 bar (g) or 425°C), two
isolating valves of NB25 size would be used. For level and flow instruments NB25 size
isolating valves would be used. For other services and measurements NB15 size valves
would be used.
53
14.18 Vibration Monitoring and Analysis System (VMS)
A microprocessor based vibration monitoring and analysis system along with sensors
would be provided for steam turbine Generator and for all HT drives. STG vibration
measurement will be part of standard Turbovisory package and shall be suitably
interfaced with the centralized vibration analysis and diagnostic system. Sensors
provided for vibration measurement will be proximity / velocity pick-ups/ acceleration
pick-ups along with key phasor measurement. This VMS will be interfaced with Plant
DCS.
14.19 Pollution Monitoring
Analysers for continuous monitoring of CO, SO2, NOx, Mercury, SPM, monitoring
are envisaged in the stack, to comply with the statutory requirements of respective
Pollution Control Board. Oxygen measurement is envisaged in the flue gas duct for
oxygen trimming in combustion control to ensure efficient combustion. Ambient Air
Quality Monitoring System (AAQMS) is envisaged..
14.20 Instrumentation Earthing
Separate electronic earthing system with dedicated earth- pit would be provided for DCS
equipment.
14.21 Master Clock
A stand-alone master clock system common for both the units with suitable time formats
is envisaged for synchronizing with the clock system of DCS, annunciation system, PLC
systems of utility plants , Sequence of events Recorders, Disturbance Recorders, Tariff
metering equipments, etc . The system shall receive time formats from the Remote GPS
satellite through antenna. The master Clock shall also have No. of slave clocks at
various locations in the Plant
54
CHAPTER – IX
ELECTRICAL SYSTEMS
GENERATOR
1.
The key one line diagram (Exhibit - 08) describes the plant electrical system.
The generator would be rated to deliver 776.5 MVA (660 MW), at 21 kV, 50 Hz,
0.85-power factor, at 3000 rpm. The generator rating shall not be a limiting
factor for total power evacuation, and the rating shall be suitable for steam
turbine VWO rating of 690 MW. The generator winding would be star connected
and will deliver rated MVA output under +5% variation in voltage and -5 to +3%
variation in frequency.
2.
All generator components, rotor winding, stator core, end region flux shield
structures and lead box, except the stator winding, are hydrogen cooled. The
stator coils, parallel rings, main leads and terminal bushings are cooled directly
with water.
Hydrogen coolers would be built into the stator frame of the
generators and would be sized to ensure at least 75% of the rated output when
one hydrogen cooler is taken out for maintenance.
3.
The generator would be provided with either brush-less or static excitation
system. Suitable fast acting non-dead band type continuous acting digital type
automatic voltage regulator would be provided. The AVR will have the required
redundancy feature built in to ensure reliable operation.
4.
The generator winding would be provided with Class – F insulation. However,
temperature rise would be limited to Class – B limits.
GENERATOR CIRCUIT BREAKER
5.
The generat or circuit breaker will be provided in the run of the generator main
connection to the generator transformer to connect or disconnect the generator
during the startup or shutdown period of the plant or on generator fault
conditions.
One generator circuit breaker will be provided for each turbine generator
complete with all accessories and a local control panel.
The rated continuous current and rated voltage will be coordinated with the
Insulated Phase Bus duct (IPBD) rating. The main current carrying parts will be
55
designed to withstand without damage for a period of one second, the effects of
a short circuit due to a fault at either the generator transformer LV side or the
generator side.
6.
The generator circuit breaker with SF6 insulated poles (single pole construction)
will be built on a common base frame with ganged operating mechanism and
local control panel for test and maintenance operation, assembled to form a
three phase unit.
GENERATOR BUS DUCT
7.
The terminals of the generator will be connected to the generator transformer
through a Generator Circuit Breaker (GCB) using Isolated Phase Bus Duct
(IPBD). Short circuit withstand capability of IPBD will be decided based on the
fault level contribution from the Generator and grid transformer and rated for 1
sec. The bus duct will be natural air cooled and will run partly indoor and partly
outdoor.
The bus duct installation will be complete with generator line side and neutral
side current transformers and line side voltage transformers, required for
protection, metering and voltage regulation. Surge protection equipment
consisting of lightning arrestors and surge capacitor with suitable discharge
characteristics to suit the generator basic insulation level will be provided.
Generator Isolated Phase Bus Duct (IPBD)
Sl.
No.
Particulars
Rating
1.
Type of Bus Duct
IPBD / Natural air cooled
2.
Nominal Service Voltage / frequency
21 kV / 50 Hz
3.
Rated voltage
24 kV
4.
Continuous current rating
22,000 A
Basic impulse insulation level (1.2/50
5.
6.
125 kV peak.
micro-sec)
Bus bar conductor material
Aluminium
56
7.
(a) VT & SP cubicle
(b) Voltage transformer
3 kV / 110 /
21000 /
110 /
3 V/
3 V, 3 nos., 100 VA /
ph.
(c) Lightning Arrestor
24 kV Metal oxide type, with
nominal discharge current of
10 kA.
8.
Bus bar material as per
IS 5082
GENERATOR TRANSFORMERS (GT)
8.
The GT will be either 3 Nos. 270 MVA, 2 winding, single-phase banks or one
three phase 810 MVA rating transformer, ONAN / ONAF / OFAF cooled and will
be provided with on-load tap changer having taps in steps of 1.25%. In case of
single phase option, one additional limb (single phase bank) will be procured as
spare for the station. The HV side neutral will be solidly earthed. Lightning
arrestors will be provided near the generator transformer. The HV terminals of
the transformers will be connected to the associated bays in 400 kV GIS thru
busbars.
9.
The rating and details of the generator transformer are as in Table–IX.1 below :
Table – IX.1
Generator Transformers
Sl.No
Particulars
Rating
1
Type of cooling
ONAN / ONAF / OFAF
2
Rating
3x1 Phase 165/220/275 MVA or
3 Phase 486/648/810MVA
(ONAN/ONAF/OFAF). *
3
No load voltage ratio
21 kV / 420 kV
57
Sl.No
Particulars
Rating
4
Vector group
YNd1
5
Percentage impedance
16% *
6
Type of tap changer
On Load
7
Tap range
+10% in steps of 1.25%. *
8
Impulse voltage withstand
(1.2/ 50 micro-sec)
1300 kV peak for 400kV and
9
125 kV peak for 21kV
Terminal connection
HV side Terminals on
HV side
bushings for 400kV GIS
MV Side
connection.
Throat
type with matching
flanges for connection to IPBD.
10
Applicable standard
IS 2026 / IEC 60076
Note : * - final values to be firmed up during detailed engineering.
EVACUATION OF POWER
10
Considering the capacity of plant and as 400kV system is available at close
proximity to the plant, power evacuation is proposed to be done at 400 kV level.
Hence 400 kV Gas Insulated Substation will be installed in the plant. The start
up power would be supplied to the unit and station transformers from 400 kV
GIS by back charging the generator transformer.
11
The enclosed key one line diagram shows the arrangement of circuits in the 400
kV GIS. The 400 kV GIS will have the following bays:
a) Two Generator Transformer Bays
b) Four line bays.
12
The power generated in the power plant is proposed to be evacuated on 400 kV network
through double circuit triple moose conductor from power plant to GETCO 400 kV
substation which is about 140 km from the plant. For this purpose, GETCO shall have to
carry out the required studies for augmentation or up gradation of the existing 400 kV
network for reliable power evacuation. It is also proposed to evacuate power to CTU
network through PGCIL 400 KV line to Bhachau.
58
Space shall be provided in the proposed power plant switchyard for one additional bay
for future use.
400KV GIS DESIGN
13
Two main busbar -switching scheme is proposed for 400 kV GIS considering its
high reliability, flexibility of operation and maintenance and keeping in view the
general practice followed for 400 kV GIS System.
14
SF6 circuit breakers are proposed because of its proven performance and world
wide experience.
15
The 400kV switchyard will be a Gas insulated indoor type considering the fact
that the location is not highly polluted
GIS communication and Protection Philosophy:
16
To ensure reliable operation of the various feeders/bays such as Generator
Transformer bays, line bays etc. state of the art numerical protection will be
provided with required redundancy. In order to communicate between
substations both at power plant and remote grid substation either conventional
PLCC or optical fibre ground wire (OPGW) would be provided in line with the
practice being followed at the remote grid substation.
17
For each of the outgoing lines in 400 kV GIS, precision energy metering will be
provided.
The technical parameters of 400 kV switchyards are indicated in
Table – IX.2
Table-IX.2
400 kV GIS
Sl.
No
Parameters
400 kV GIS
1.0
Technical Data
1.1
Design Voltage Levels
(a)
Nominal Voltage
400 kV
(b)
Highest system voltage
420 kV
(c)
Basic impulse level
1425 kV peak.
(d)
Fault level (kA rms
for 1 sec)
50 kA rms
59
Sl.
No
Parameters
400 kV GIS
2.0
Circuit Breakers
2.1
Type of breaker
SF6
2.2
50 kA rms / 125 kA peak.
2.3
Short circuit
breaking and making
current
Applicable standards
3.0
Isolators
3.1
Type of mounting
and execution
Centre break,
horizontal upright
3.2
Applicable Standards
IS 9921 / IEC 129
4.0
Current Transformers
4.1
Type
Indoor
4.2
Accuracy class metering cores
0.2S for revenue
metering 0.5 for
other.
4.5
Applicable standards
IS 2705 / IEC
60044-1
5.0
Voltage Transformer
5.1
Type
Indoor
5.2
Revenue metering
Electro Magnetic
Voltage
Transformers
(EMVTs)
5.3
Other purpose
Capacitive Voltage
Transformers
(CVTs)
5.5
Applicable standards
IS 3156/ IEC
60044-1
6.0
Lightning Arrestor
6.1
Type
Metal oxide, gap
less
6.6
Applicable standards
IEC – 60099
7.0
Line traps
60
IEC – 60056
Sl.
No
Parameters
400 kV GIS
7.2
Quantity
Depending on the
scheme (PhasePhase or Phase Earth)
7.3
Applicable standards
IEC 60353
8.0
Coupling devices
8.1
CVT will serve this purpose.
IEC 60481
AUXILIARY POWER SUPPLY SYSTEM
18
The proposed auxiliary power supply system is shown in enclosed key line
diagram. The auxiliary power supply required for the various drives like Boiler
Feed Pumps (BFP), ID/FD fans, CW pumps ranges from 200 KW to several
Megawatts. Based on the techno-economical studies, the voltage level of 11 kV
and 3.3 kV are proposed for these drives.
19
Various auxiliaries will be supplied at the following nominal voltages depending
upon their ratings and functions:
a) 11000 V,  10%, 50 Hz, -5 to +3%, 3 phase, 3 wire, medium resistance
grounded AC supply for motors rated above 1500 kW.
b) 3300 V,  10%, 50 Hz, -5 to +3%, 3 phase, 3 wire, medium resistance
grounded AC supply for motors rated above 200KW and up to 1500KW.
c) 415 V,  10%, 50 Hz, -5 to +3%, 3 phase, 3 wire, solidly grounded AC
supply for motors rated 200 kW and below and other L.T. services.
d) 230 V,  10%, 50 Hz, -5 to +3%, 1 phase AC supply for lighting, space
heating of motors and panels, single phase motors, etc.
e) 220 V, ungrounded DC supply for emergency power to critical loads of
electrical system.
f)
220 V, ungrounded DC supply for protection, control and indication.
g) 110 V, 1 phase, grounded AC supply for AC control circuits.
h) 24 V DC supply for instrumentation and control systems such as closed loop
controls and open loop controls.
61
i)
230 V, 1 phase AC Uninterruptible Power Supply for plant instrumentation
and control system.
j)
415 V,  10%, 50 Hz, -5 to +3%,, 3 phase, 4 wire Diesel Generator for
emergency back-up.
20
At this stage for the evaluation, auxiliary power consumption is considered as
6.5% of the unit capacity. The auxiliary loads will be segregated as unit loads
and common station loads. 2 x 100% rating Unit Transformers (UTs) will cater to
unit loads 100% rating station transformer (ST) will cater to station loads under
normal operating conditions. The start-up power for the auxiliaries will be
supplied
through
generator
transformer,
station
transformer
and
unit
transformers. Once the unit is started and the generator picks up rated speed
and voltage, the unit will be synchronised with grid supply by closing generator
circuit breaker.
One Motor driven BFP and two turbine driven BFPs will be
provided for each unit. The motor driven BFP will be used as a standby and also
will run during starting of the unit.
STATION TRANSFORMERS (ST)
21
Two station transformers of three – winding, three phase, 65/40/25 MVA, 21/
11.5/34.5kV, with off circuit changer ±10% in steps of 1 . 2 5 % will provided.
These STs will be connected through GCB to Generator Transformer. Each ST
will be sized to cater to 100% station loads + outage of one UT. The ratings and
details of the station transformers proposed are as given in Table–XIII.3.
Table–IX.3
Station Transformers
Sl.
Particulars
Station Transformers
No.
1
.
2
.
3
.
4
.
5
.
6
.
Type of cooling
ONAN / ONAF
Rating
65/40/25 MVA*
No load voltage ratio
20/11.5/34.5kV
Vector group
Dyn11yn11
Type of tap changer
Off-Circuit
Tap range
± 10% in steps of 1.25%
62
7
.
8
.
BIL
950 kV peak
Terminal connections:
20kV Side
Throat type with matching
flanges for connection to IPBD.
11kV side
Throat type with matching
flanges for connection to SPBD.
9
Applicable standard
IS 2026
. Note : * - final values to be firmed up during detailed engineering
UNIT TRANSFORMERS (UT)
22
Two (2), two winding unit transformers will be provided for each unit. These will
be 63/31.5/31.5 MVA rating, 21/11.5/11.5 kV, 3 phase, 50 Hz, with +10% offcircuit taps in steps of 1 . 2 5% on the HV side. The transformers will be
ONAN/ONAF cooled with a vector group of Dyn11yn11, The 11kV side will be
medium resistance earthed. The details of UT are indicated in Table–IX.4.
Table–IX.4
Unit Transformers
Particulars
Sl.
Unit Transformer
No.
1
Type of cooling
ONAN/ONAF
2
Rating
63/31.5/31.5 MVA*
3
No load voltage ratio
21kV / 11.5 / 11.5 kV
4
Vector group
Dyn11yn11
5
Type of tap changer
OCTC
6
Tap range
+10% in steps of
1.25% *
7
Impulse withstand (1.2/50
125 kV peak for
micro- sec)
21 kV and 75 kV
peak for 11.5 kV
8
Power frequency withstand HV/LV
63
(rms)
70 kV for 21 kV
Particulars
S
Unit Transformer
l.
N
and 28 kV for 11.5
o
KV (rms)
.
9
Applicable Standards
IS
2026
/
IEC
60076
Note : * - final values to be firmed up during detailed engineering.
23
The unit transformers will supply power to the 11kV unit switchgear as shown in
the enclosed key line diagram. As far as possible, the unit loads will be
distributed equally on each 11kV unit switch gear so that in case of outage of
any one bus, it would still be possible to operate the unit at partial load.
UNIT AUXILIARY TRANSFORMERS (UAT)
24
Two (2) no.s , unit auxiliary transformers will be provided for each unit to feed
3.3kV unit auxiliary motor loads. These will be 16 MVA, 11/3.45 kV, 3 phase, 50
Hz, with +5% off-circuit taps in steps of 2.5% on the HV side. The transformers
will be ONAN cooled with a vector group of Dyn1. The 3.3kV system would be
medium resistance earthed.
The required number of 11kV feeders from station switchgear would be provided
for Coal Handling system, Ash Handling System, AC & Ventilation System &
Other systems as required to the plant.
AUXILIARY / SERVICE TRANSFORMERS
25
The required number of transformers will be provided depending on service /
location / segregation of the loads, though the service transformers are indicated
in the enclosed key one line diagram tentatively. These transformers will be
rated at 2500 / 2000 / 1600 / 1000 kVA, 11kV/433V with a vector group of Dyn11
as per actual requirement. They will supply power to the 415 V auxiliaries of the
unit and station loads. The neutral of these transformers will be solidly earthed.
The transformers will be provided with + 5% off-circuit taps in steps of 2.5% on
64
the HV side. The service transformers may be dry type and will be finalised
during detailed engineering.
11 kV SWITCHGEAR
26
The 11kV switchgear will comprise draw-out type Vacuum / SF6 circuit breakers
housed in indoor, metal-enclosed cubicles and will cater to all 11kV motors,
11kV/433V transformers. The switchgear will be equipped with control,
protection, interlock and metering
communication features as required.
Technical parameters of 11kV switchgear are given in Table-IX.5.
3.3 kV SWITCHGEAR
27
The 3.3 kV switchgear will comprise draw-out type Vacuum / SF6 circuit
breakers housed in indoor, metal-enclosed cubicles and will cater to 3.3 kV
motors. The switchgear will be equipped with control, protection, interlock and
metering features as required. Technical parameters of 3.3 kV switchgear are
given in Table-IX.5.
Table-IX.5
11 kV and 3.3 kV Switch Gear
S.No
Particulars
11 kV
Switchgear
3.3 kV
Switchgear
1.0
Switch gear
1.1
Nominal system voltage
11kV, 3 Ph., 50 Hz
3.3kV, 3Ph., 50 Hz
1.2
System Neutral Earthing
1.3
Power frequency withstand
/impulse withstand voltage
Medium resistance
earthed
28 kV rms / 75kV peak
Medium resistance
earthed
10 kV rms / 40kV
peak
1.4
Short time rating ( 1 sec)
40kA rms /100kA peak
1.5
Applicable standards
IS 3427
40kA rms / 100kA
peak
IS 3427
65
S.No
Particulars
2.0
Circuit breaker
2.1
2.2
Type
Operating duty
2.3
2.4
Rated current
Rated breaking/making
current
Short time rating
Mechanism
2.5
2.6
3.0
3.1
3.2
Contactors
Type
Application
4.0
4.1
HRC Fuses
Type
4.2
Application
4.3
Symmetrical Breaking
capacity
Applicable standards
4.4
11 kV
Switchgear
Vacuum / SF6
0–0.3sec-CO3min-CO
As required
40kA rms/100kA peak
40 kA for 1.0 sec.
Motor charged
spring closing
3.3 kV Switchgear
Vacuum/SF6
0–0.3sec-CO3min- CO
As required
40kA rms/100kA
peak
40 kA for 1.0 sec.
Motor charged
spring closing
Vacuum
Motors in CH
system
Current limiting HRC
fuses
Short-circuit
protection of 3.3
kV motor feeders
with vacuum
contactors
40 kA rms
IS 9224
66
415 V SYSTEM
28
The 415V, 3 phase, 3 wire power for the 415V auxiliaries will be obtained from
11kV/433V transformers. The system will be a solidly earthed system. For
maximum reliability, duplicate power supplies with auto changeover facility will
be provided for the essential power and motor control centres. The 415V
switchgear will be of metal enclosed design with a symmetrical short circuit
rating of 50 kA for 1 sec.
All power and motor control centres will be compartmentalised. The switchgear
will be of single / double front execution depending on final layout and will be
finalised during detailed engineering. They will be of fully draw-out design. The
circuit breakers will be of air break type.
Motor starting will be direct on line. All LT motors will be controlled by MPCB,
electro-magnetic
type
contactors
provided
with
ambient
temperature
compensated, time lagged, hand reset type thermal overload relays, having
adjustable setting with built-in single phase preventer backed up by HRC fuses
for protection against short circuits. The technical particulars of 415V switchgear
are as given in Table–IX.6.
Table-IX.6
415 V Switchgear
Sl.
Particulars
Rating
No
.
1.0
Switchgear
1.1
Rated voltage/No. of phases/frequency
415V / 3 Ph / 50 Hz
1,2
System neutral earthing
Solidly earthed
1.3
One minute power frequency
withstand voltage
1.4
(a) Power circuit
2500 V
(b) Control circuit
1500 V
(c) Aux. Circuits connected to CTs
2000 V
Maximum allowable Temperature of
Bus bars
900C
67
Particulars
Sl.
Rating
No.
1.5
Short circuit withstand of Bus bars
50 kA for 1 sec.
1.6
Dynamic rating of busbars
100 kA peak
2.0
Circuit breakers
2.1
Type
2.2
Operating duty
2.3
Rated breaking current / Making current
2.4
Short circuit withstand current
3.0
Starters
3.1
Type
DOL
3.2
Continuous & Intermittent
3.3
Contactor rated duty as per IS 2959 & IS
8544
Utilisation categories as per IS 2959
4.0
Applicable standards
IS 2516
Air break, motor
charged spring closing
mechanism
0 – 3 min – CO3 min – CO
50 kA at 415V AC &
0.25 pf / 100 kA
50 kA for 1 sec.
AC 3 & AC 4
DC SYSTEM
29
DC loads will be divided into two categories ie, Unit DC loads and Station DC
loads. Each category of loads will be catered by separate battery and charger
system. Two (2) nos. 220V 100% rated batteries with associated float cum
boost chargers will be provided for each system. Each battery will be capable of
catering to 100% of power and control loads of Unit and Station systems
respectively.
A separate DC system will be provided for 400kV GIS. GIS DC system will have
two (2) nos. 220V 100% rated batteries with associated float cum boost
chargers.
Separate 48V battery and chargers will be provided in the GIS control building to
cater to the PLCC loads if PLCC is provided.
68
The batteries will be of stationary lead acid Plate type complete with battery
racks, porcelain insulators, inter-cell and inter-tier connectors. The chargers will
be of silicon rectifier type with automatic voltage control and load limiting
features.
EMERGENCY POWER SUPPLY
30
To enable the unit to shutdown safely during complete A.C supply failure in the
station, certain important plant auxiliaries will be provided with a reliable A.C
power supply through a separate source. For this purpose, one (1) 415V quick
starting diesel generator set with automatic mains failure (AMF) will be provided
for each unit. The tentative rating of the DG set will be 1500 kVA.
31
The diesel generator will feed a separate emergency 415V switch gear, to which
all the essential loads such as the A.C emergency bearing lube oil and seal oil
pumps, turning gear motor, battery chargers, emergency lights, and essential
instrument power supply feeders will be connected. When the normal A.C
supply is healthy, the emergency switchgear will be fed through a tie from the
unit service switchgear. When the normal A.C supply fails, the DG set will start
automatically and will feed the loads connected to the emergency switchgear.
When the normal A.C supply is restored, these essential loads will be manually
changed over to the normal power supply.
UN-INTERRUPTIBLE POWER SUPPLY SYSTEM
32
230 V single phase A.C uninterruptible power supply will be provided for the
Plant DCS/Instrumentation system. This power supply will be derived from
parallel redundant with static bypass un-interruptible power supply system
having two (2) sets of converters, inverters with a back up battery. Also a
standby AC supply will be provided as a back up to the inverters, which will be
switched on through static switch in case of inverter failure.
GENERATOR AND GIS PROTECTION AND CONTROL
33
The details of the protections that will be provided for the various electrical
equipment viz., Generators, Generator transformers (GT), Unit / Station
transformers, unit / station service transformers, 400 kV switching equipment,
400 kV lines, motors, switch gear etc., are indicated below.
69
34
The selection of the protective scheme will be based mainly on reliability,
sensitivity, selectivity and technical merits. All main protections will be of fast
acting type in order to isolate the faulty system from the healthy system in the
shortest possible time, to minimise damage to the equipment and ensure
continuity of power supply, if possible.
Generator Protections
35
Two multifunction numerical Generator protections operating on different
principles and housed in generator relay panels (GRP) will be provided for each
unit. The panels will be located in the unit control room / Relay room. The
following minimum protections are proposed to be provided in the GRP and the
protections will be divided into two groups; each group being 100% redundant.
so that even if one group of protections is not available or under maintenance,
the generator is protected by the other group.
a) Generator differential protection (87G1)
b) Generator stator 0 – 95% earth fault protection (64 GI)
c) Generator stator earth fault (95 – 100%) protection (64G2)
d) Generator back-up stator earth fault (0-95%) protection (64G3)
e) Rotor earth fault protection (2 stage) (64F1 and F2)
f)
Generator negative phase sequence protection (46GI 46G2)
g) Generator reverse power protection (32G1 32G2)
h) Generator loss of excitation protection (40G1 40G2)
i)
Generator pole slipping protection (78G)
j)
Generator under frequency protection (81G1 81G2)
k) Generator over-voltage protection (59G1 and G2)
l)
Generator backup impedance protection (21G)
m) Generator stator overload protection (50GS)
n) Generator VT fuse failure protection (60G)
o) Dead machine protection (61B)
p) Generator field over-voltage protection (59F)
q) Generator, Generator Transformer and Unit Transformers over-fluxing
protection (99G).
70
r) In case of static excitation, excitation transformer protection will be a part of
the excitation system.
Generator Transformer Protections
36
The following protections will be provided for the Generator Transformer:
a)
Generator transformer HV winding restricted earth fault protection (64GT)
b)
Generator, generator transformer and unit transformers overall differential
protection (87 0A)
c)
Generator transformer differential protection (87GT)
d)
Generator transformer over-current and earth fault protections (51GT,
51NGT)
e)
Generator Transformer Over fluxing protection (99GT-1 99GT-2)
f)
Differential protection for 400kV Busbar line from GT to GIS.
g)
Buchholz (63), winding temperature (49 WT) and oil temperature (49 0T)
protections, OLTC buchholz
h)
Generator transformer pressure relief protection (63PTX)
i)
Generator transformer fire protection trip, oil level low, cooler trouble
alarms.
21kV /11.5kV Unit Transformer, 11kV /3.3kV Unit Auxiliary Transformer
Protections
37
The protections that will be provided for the unit transformers/ unit auxiliary
transformers:
a) Differential protection (87) and short circuit protection (50)
b) Back-up over current protection on HV side (51)
c) Instantaneous phase overcurrent protection on HV side (50)
d) Back-up over current protection on LV side (51)
e) Back-up earth fault protection on LV side (51N)
f)
Buchholz (63), winding temperature (49 WT) and oil temperature (49 0T)
protection
g) Pressure relief protection (63PTX)
71
h) Fire protection trip (63 RTX)
Station Transformer Protections
38
The following protections will be provided for the station transformers:
a) Differential protection (87T)
b) Instantaneous phase overcurrent protection on HV side (50)
c) IDMT phase overcurrent protection on HV side (51)
d) IDMT earth fault protection on HV side (51N)
e) IDMT phase overcurrent protection on LV side (51)
f)
IDMT earth fault protection on LV side (51N)
g) Restricted earth fault protection (64REF)
h) Neutral displacement protection (64N)
i)
Buchholz (63 AX 63TX), winding temperature (49WT AX 49WT TX) and oil
temperature (49 OAX 49 OTX) protection.
j)
Pressure relief protection (63 PTX) and Oil level (63 OLAX).
k) Fire protection and trip (63 FRTX)
11000 V / 433V Service Transformer Protections
39
The following protections will be provided for service transformers:
a) Over current protection on HV and LV sides (51) and short circuit protection
(50) on HV side
b) Earth fault current protection on HV and LV sides (50N 5IN).
c) Buchholz (63), winding temperature (49 WT) and Oil temperature (49 0T)
protections.
400 kV Line Protection
40
The 400 kV lines will have the following protections:
(a) Distance protection (21-1)
(b) Distance protection (21-2) and Directional inverse time phase over current with
high set unit (67 / 50)
72
(c) Fuse fail relay (FFR) for each secondary of CVT
(d) Directional inverse time earth fault protection (67N)
(e) Under voltage relays for live – line / dead bus and dead – line / live bus closing
and safe grid establishment (27-1, 27-2, 27S)
(f) Fault locator (FL)
(g) Fault recorder (FR)
(h) Neutral impedance replica of distance relay (21NTR)
(i) No voltage protection
400 kV Bus Bar Protection
41
Redundant type high-speed bus fault numerical relay is proposed for detecting
the fault on 400 kV buses. The bus bar protection scheme will have detecting
elements for each of the main bus and one check zone element. The main and
check zone elements will be connected two different secondaries of CTs and
tripping will be initiated only when respective bus element and check zone
elements operate. Bus wire supervision relays to guard against faults in the CT
secondary wiring and bus wire shorting relay to short CT secondary bus wires
on fault are also proposed. The scheme shall be expandable to accommodate
future lines.
Local Breaker Back-up (50 LBB)
42
All 400 kV circuit breakers including generator transformer breaker will be
provided with local breaker back-up protection. For generator transformer
breaker, an additional relay will be provided to detect breaker failure for ground
and phase fault in the generator circuit and other low magnitude faults also.
43
The local breaker back-up protection relay will be numerical relay.
This will
provide protection against stuck breaker condition for the 400 kV system. This
protection will be initiated by primary fault detecting relays and time delayed to
permit the breaker to trip.
Circuit Breaker Protection
73
44
All the trip coils of the circuit breakers will be supervised.
The following
protections will also be included:
a)
Pole discrepancy protection
b)
Trip coil supervision relay for each trip coil (98L1 to L6)
c)
Anti pumping device for breaker closing (94).
Protection of 11 kV and 3.3 kV Motors
45
All 11 kV and 3.3 kV motors will be provided with the following protections:
a)
Thermal overload protection
b)
Overload alarm protection
c)
Instantaneous over current protection
d)
Locked rotor protection
e)
Negative sequence protection
f)
Differential protection (For motor ratings of 1000 kW and above)
g)
Earth fault
h)
Bus under voltage
i)
Bearing temperature monitor
j)
Water flow monitor for CACW motors(if applicable)
k)
Lube oil pressure monitor
l)
Winding temperature monitor
Protection of 415 Volt Motors
46
Motors rated below 100 kW will have bi-metallic relays for thermal overload
protection and HRC fuses for short circuit protection. Motors rated 100 kW to
200 kW will be provided with motor protection relays inclusive of locked rotor
protection in addition to above. Composite motor protection relay comprising of
thermal overload, short circuit, locked rotor, instantaneous over load, IDMT
earth fault protection, negative phase sequence protection, self diagnostic
monitoring & trip circuit supervision will be provided.
74
Power Supply and Lighting Circuits
47
The power supply feeders will have properly rated HRC fuses for short-circuit
protection. Lighting circuits will be protected by miniature circuit breakers.
48
400 kV GIS CONTROL
SCADA (Supervisory Control And Data Acquisition) system comprising of
various controls, metering, indication, annunciation, synchronising, remote
control functions, mimic diagram, sequence of events recording, etc., shall be
provided for GIS.
The controller shall be configured with redundant CPU. The redundant CPU
shall be configured to operate as hot standby.
All the SCADA switches and
servers shall be located in switchyard control room. All SCADA servers Front
End Processor servers (if any) shall be rack mounted.
One (1) no. Operator Station for SCADA (for control and monitoring of complete
400 kV GIS equipment) shall be located in Central Control Room (CCR) of
power plant and one (1) no. in GIS Control Room. One (1) no. Engineering
Station shall be provided in the CCR to make the SCADA configuration changes
and system settings.
The Engineering Station shall also be configured as
Operator Station to act as standby in case of failure of the Operator Station in
CCR.
The location for the GIS control shall be central control room (CCR) by default.
But provision shall be made available in the SCADA to control the GIS from GIS
control room also. It shall not be possible to control the GIS from two locations
simultaneously. The required selection shall be provided in the operator station
of CCR.
The SCADA system shall be based on a de-centralised concept with bay
oriented distributed intelligence devices, for safety and availability reasons. The
offered SCADA system shall be of latest state of art design with capability to
interface with bay control units (separate for each bay).
75
Relay panels pertaining to switchyard would be located in the switchyard relay
room, which would be kept locked. The communication between the numerical
relays and SCADA system shall be with fibre optic cable.
CABLING SYSTEM
49
Power cables would be selected based on the following minimum criteria:
a)
Continuous circuit current rating
b)
De-rating factors for ambient temperature and grouping
c)
Short circuit rating of the circuit (not applicable for MV/LV fuse protected
feeders)
50
d)
Voltage dip
e)
Standardisation of cable sizes to reduce inventory
The following types of cables will be used:
a)
For 11 kV system
11kV unearthed grade, stranded aluminium conductor, cross linked
polyethylene (XLPE) insulated, extruded black PVC inner sheathed,
galvanized steel wire armoured for three core or aluminium wire
armoured for single core or unarmoured* and overall FRLS extruded
black PVC sheathed cables conforming to IS : 7098.
b)
For 3.3 kV system
3.3kV unearthed grade, stranded aluminium conductor, cross linked
polyethylene (XLPE) insulated, extruded black PVC inner sheathed,
galvanized steel wire armoured for three core or aluminium wire
armoured for single core and overall FRLS extruded black PVC
sheathed cables conforming to IS : 7098.
(c)
For medium and low voltage system
Power cables of 1100V grade, stranded aluminium conductor, cross linked
polyethylene (XLPE) insulated, extruded black PVC inner sheathed galvanized
steel wire armoured for three cores or Aluminum wire armoured for single core
and overall FRLS extruded black PVC sheathed cables conforming to IS : 7098.
(d)
For control applications
76
1100 V grade annealed high conductivity stranded copper conductor, PVC
insulated, PVC inner sheathed armoured and FRLS extruded black PVC outer
sheathed cables conforming to IS : 1554. Conductor cross section will generally
be 1.5 mm2. CT, PT and switchyard control circuits will use 2.5 or 4 mm2 copper
conductor cables.
(e)
For instrumentation applications
Stranded high conductivity annealed tinned copper conductor, multicore, PVC
insulated, flexible, twisted pair / triplets, individually and overall shielded (for low
level analog signals) and only overall shielded for digital signals, PVC inner
sheathed, steel wire armoured and overall FRLS PVC sheathed cables.
Conductor cross section will be 0.5 mm2.
Individual / pair shielded and overall shielded twisted pair copper cables would be
used for analog signals and overall shielded cables would be used for digital
signals. All these cables are armoured. Overall sheath would be FRLS quality.
The size of the wire would be 0.5 mm2 FRLS, 1.5 mm2 copper control cable
would be used for cabling between MCC and Control system.
Compensating
cables will be provided for connecting the thermocouple inputs to the control
system.
51.
Cables would be laid in fabricated steel ladder type or perforated type cable trays in the
station and other auxiliary buildings and upper elevations of the steam generator area.
Between buildings, the cables would be laid in built-up trenches. Cables to other plant
areas located far off from the station building would be directly buried in soil or carried on
overhead racks.
LIGHTING SYSTEM
52
Suitable illumination necessary to facilitate normal operation and maintenance
activities and to ensure safety of working personnel would be provided. This
would be achieved by artificial lighting using normal, emergency and DC
lighting.
77
53
For yard illumination, floodlights would be installed at suitable locations to
provide the requisite level of illumination. Pole-mounted high-pressure sodium
vapour fixtures would be used for approach roads.
54
Generally, energy efficient fluorescent fixtures would be used for indoor
illumination. A combination of high pressure sodium vapour and fluorescent
fixtures would be used for the turbine building. For steam generator area and
pumps area, high-pressure sodium vapour lamp fixture will be provided.
55
The illumination levels at different places would be maintained as per accepted
norms. The lighting system would be designed to ensure uniform illumination.
56
Power distribution from the lighting transformers would be through 415V, 3
phases, 4 wire distribution boards. A suitable number of lighting panels would
be located in each area. Power to the lighting panels would be supplied from
the 415V, 3 phase, 4-wire distribution.
57
About 80% of the total light fittings would be connected to the normal 240 V AC
lighting supply and the balance 20% to the station emergency bus fed from the
DG set in the station building and steam generator areas.
58
Installite type DC emergency lights are envisaged at strategic points in the
power station viz., near entrances, staircases, control rooms, etc. These would
be provided with local battery back up for 3 hours, which would be normally off
when AC power is available. These would be automatically switched on when
the normal / emergency AC supply fails. In critical areas like control room, the
DC lighting will be fed from the station DC supply.
SAFETY EARTHING AND LIGHTNING PROTECTION
59
A safety earthing system comprising buried steel conductor earthing grid would
be provided for the switchyard and other outlying areas.
This would be
connected to the earth grids in various buildings. The buried earth grids would
be further connected to earthing electrodes. The selection of earth conductor
sizes would be based on the applicable fault levels.
60
Lightning protection system comprising roof conductors, vertical air termination
and down-comers would be provided for all structures whose calculated risk
index requires protection as per applicable standards.
78
COMMUNICATION SYSTEM
61
For effective communication in the plant, public address system, private
automatic branch exchange system (EPABX) and CCTV systems will be
provided:
Public Address System
a)
This system will have paging and party channels comprising handset
stations with amplifiers, transmitters, receivers, sound proof booths, and
loud speakers. This system will facilitate paging, communication and also
private conversation as in conventional telephone.
EPABX System
b)
The EPABX will be a state of the art digital system capable of interfacing
with ISDN network. The ISDN network or PSTN network available at the
project site would be suitably interfaced and the communication
facility/feature would be extended to individual extension as required. The
number of extension will be decided during detailed engineering.
Walkie-talkie System
c)
Walkie-talkie systems with necessary repeater / booster station will be
provided for mobile communications.
CCTV System
d)
Closed Circuit Television (CCTV) system shall be provided for monitoring
plant facilities for fire, confirmation of calamities, and security check. The
CCTV system will include required number of Pan-Tilt-Zoom (PTZ)
cameras and Fixed cameras. PTZ cameras will be installed in the suitable
locations of all over the plant area and fixed cameras will be installed along
the fence. CCTV Monitors will be located in the various control room in the
plant and CCTV control units will be located in the central control room.
79
FIRE DETECTION / ALARM AND FIRE PROOF SEALING SYSTEM
62
Addressable type multi criteria detector based fire detection and alarm system
would be provided to facilitate visual and audible fire detection at the incipient
stage of fire in strategically important areas of the power station. This system
will comprise manual call points located at strategic locations in areas which are
normally manned and automatic addressable type multi-criteria detectors
located in plant areas, such as control room, switchgear room, battery rooms,
etc., to detect fire at an early stage. Linear heat detectors will be provided for the
cable gallery and conveyors. Infrared type amber detector will be provided for
the conveyor gallery. Fireproof sealing will be provided for all cable penetrations
through walls and floors to prevent spreading of fire from one area / floor to
another.
ELEVATORS
63
One freight-cum-passenger elevator of capacity 1360 kg and speed of 0.75
m/sec will be provided in each of the steam generator areas to serve major
platforms of the steam generators. A separate 8 passenger (550kg), 1m/sec
elevators will be provided for catering to the station building
and electrical
switchgear buildings. This elevator will have access to different floors.
CATHODIC PROTECTION
64
Based on the water and soil analysis, cathodic protection will be provided for all
requisite equipment. The type of cathodic protection (sacrificial or impressed
current) will be finalized during detailed engineering.
80
CHAPTER – X
PLANT WATER SYSTEMS
1
The scheme of water systems for the proposed 2x660 MW unit at Salaya is shown in
Exhibit-03. Sea water would be used for condenser cooling, cooling of SG and TG
auxiliaries and various other requirements like SG makeup, service and potable
water. The water systems consist of various sub-systems listed below and discussed
in the subsequent paragraphs of this chapter.
2
a)
Sea water Intake system
b)
Condenser cooling water system
c)
Cooling water (CW) make up system
d)
Auxiliary cooling water (ACW) system
e)
Water treatment (WT) systems
f)
Service and potable water system
g)
Fire protection system
h)
Effluent disposal system
i)
Chemical laboratory equipment
SEA WATER INTAKE SYSTEM
The daily seawater requirement is estimated to be about 330180 m3/day ( for phase
II). The main source of water for the plant is from the Arabian sea, which is about 15
km from the power plant site. The seawater will be pumped by 4 Nos seawater intake
pumps. (3 working + 1 standby). Each of capacity 7500 m3/hr. These seawater intake
pumps will be located in the offshore seawater intake pump house, which is a
common facility for existing phase -I and proposed phase -II
81
3
PLANT WATER REQUIREMENT
The total plant water requirement is summarized in Table –X.1
TABLE-X.1
Plant Water Requirement
Sl.
No
Description
1
Cooling Tower Blow down
8690
208560
2
Evaporation & Drift Loss
2659
63816
3
Cooling water makeup for
condenser and SG & STG
auxiliaries with margin
11350
272400
4
Sea
water
as
to desalination plant
2408
57792
5
Water requirement for coal
and ash handling system
HVAC
makeup,
Misc.
requirements
Total Makeup for Sea
6
water requirement
x660 MW units
Estimated
quantity for 2x660
MW
M3/hr
M3/day
feed
for
-
13758
2
82
Quality
Sea Water
Sea Water
Desalinat
ed water
330180
Sea Water
6
CONDENSER COOLING WATER (CW) SYSTEM
An open type recirculation type of cooling system with cooling tower is proposed for
CW system. The system will consist of two induced draught cooling tower (IDCT) for
each unit, CW pumps, CW conduits (with valves, expansion joints and instruments as
required) and CW treatment system.
6.1
Cooling Water (CW)Pumps
5 x 50% capacity CW pumps (2 x 50% pumps for each unit) each of capacity 42,600
m3/hr are proposed for the 2 x 660 MW units to meet the CW flow of 77400 m3/h with
10 % margin towards impeller wear. The type of pump would be mixed flow type
with concrete volute, SS316L/ Duplex SS impeller/shaft. These pumps would be
installed
in individual chambers connected to the CW forebay. Each pump chamber would
have provision for installing coarse screens and stop logs. The pumps would be
located indoors in a pump house. CW chemical dosing system will be housed in a
room adjoining the CW pump house. Handling of pumps would be through an EOT
crane of suitable capacity. Handling facilities would also be made available for
screens and stop logs.
6.2
Cooling Towers
It is proposed to install two (2) induced draught cooling towers, for each unit of
660MW, each capacity 42600 m3/hr. The cooling water would be collected in a RCC
basin. The cooling tower would be designed for a cooling range of 100C. The cooling
tower shall be complete with basin associated supporting structure and foundation
etc.
6.3
RC Channels
The total CW flow of 170400 m3/hr from all the cooling tower basins is proposed to be
83
conveyed by gravity to the common CW forebay and CW pump chambers through
RC rectangular open channels. The channels will be designed to accommodate
maximum level fluctuations expected under transient flow conditions.
6.4
CW Forebay and sumps
The total CW flow of 170400 m3/hr from all the units would be discharged from the
open channel to a common forebay and CW pump chambers. The forebay will be
designed to ensure equal distribution of flow to the CW pumps as well as to limit the
entrance velocity at the CW pump chambers. The top level of the forebay walls will
be fixed on the basis of maximum upsurge expected in the forebay, when all the CW
pumps trip under normal water level condition. The sump level of the pump chamber
is fixed so as to ensure adequate submergence for the CW pumps as per HIS
standards.
6.5
CW Inlet and outlet conduits
From the CW pump house, cooling water would be pumped to the condensers
located in the station building, through mild steel conduits with internal lining.
Expansion joints and motor operated butterfly valves will be provided on these
conduits at CW pump discharge, as well as at condenser inlet/outlet. The hot water
from each condenser to cooling tower will be conveyed through similar independent
mild steel conduits. Both, cold and hot water conduits will be laid underground.
6.6
Valves and Specialities
Motor operated butterfly valves would be provided at the discharge of the CW pumps
and at the condenser inlet / outlet piping to facilitate isolation and control. Expansion
joints are proposed in the CW pump discharge lines and condenser inlet and outlet
lines to take care of any misalignment, thermal expansion etc., and also to facilitate
erection and maintenance. CW pumps and their respective discharge valves would
be suitably interlocked to facilitate coordinated operation.
6.7
Condensor On Load Tube Cleaning System ( COLTCS)
Condenser on-load tube cleaning system (COLTCS) using sponge rubber balls would
be provided to keep the condenser tubes clean by removing the scaling.
84
6.8
CW Blow Down and Make-Up Water Requirement
Make up water requirement of CW system is obtained as the sum of drift and
evaporation losses from the cooling tower and blow down from the CW system (by
way of water drained from the hot water conduit of the CW system).Table-X.2
indicates the CW blow down / make up water requirements for the cooling water
system.
Table –X.2
CW System Make-up Requirement
Sl. No.
Item
Quantity
Quantity
(m3/hr)
(m3/day)
1
Cooling Tower (Evaporation + Drift Losses)
2659
63816
2
Condenser CW System Blow down
8690
208560
3
CW Make-up requirement (item 1 + item 2)
11350
272400
4
Concentration Ratio ‘C’ (item 3 / item 2)
1.3
1.3
The analysis of sea water (make up water) is presented in Appendix-2. The cooling
water system is proposed to operate with a COC of 1.3. Suitable chemical dosing
system will be provided for control of water chemistry in the CW system. Chemicals
will possess anti scaling, anti corrosive and anti dispersant properties. The blow down
requirements and the total make up water requirement is estimated based on same
COC. Blow down water from the CW system would be led to the blow down weir tank
from where the sea water would be led in to the sea by gravity.
Make up water requirement of CW system would be about 11350 m3/hr. Four (4) (3
Working and 1 standby) Sea Water pumps would be provided to cater the makeup
water requirements. These pumps would directly draw water from the sea.
7
AUXILIARY COOLING WATER (ACW) SYSTEM
The ACW system will meet the cooling water requirements of all the auxiliary
85
equipment of the TG and SG auxiliary coolers.
The total estimated cooling water (passivated DM water) requirement for the above
auxiliaries for one unit of 660 MW plant is 3500 m3/hr. A closed loop system using
passivated DM water is proposed for the ACW system. The DM water will be
circulated through the auxiliary coolers by 3 nos (3x50%) closed loop cooling
water (CCW) pumps, each of 2860 m3/hr capacity. The hot water from these
auxiliaries will be cooled in the 3 x 50% capacity plate type ACW heat exchangers by
the circulating water tapped from the main CW circuit and pressure boosted by ACW
Booster pumps. 3 nos. of ACW Booster pumps (3x50%),each of 3300 m3/hr capacity,
would be provided for each 660 MW unit.
A CCW overhead tank will be provided to ensure positive suction to the CCW pumps
and also serve as the source of make-up to the ACW system. Normal make-up to the
CCW over head tank will be provided from the condensate extraction pump
discharge. Initial fill for the tank will be provided from the boiler fill pumps discharge.
8
WATER TREATMENT (WT) PLANT
8.1
DM plant would meet the requirement of steam generator (SG) feed water make up,
and ACW system make-up. DM water
requirement is calculated based on SG feed water make up at 1% MCR. DM plant
would consist of mixed bed (MB) units. The period between regenerations
for each stream of the MB units would be 72 hours.
MB units would be of mild steel construction with five (5) mm thick rubber lining
internally and all associated piping / valves of the unit would be either rubber lined or
SS. DM water from the mixed bed unit would be stored in DM water storage tanks.
DM water transfer pumps would be used to transfer DM water up to the condensate
storage tank. The condensate storage tanks would be sized to meet maximum
requirement of DM water when one unit is under start-up. The MB unit would be
designed to limit the silica less than 0.02 ppm.
86
8.2.5
Regeneration System
33% hydrochloric acid/98% Sulphuric acid and 48% sodium hydroxide would be used
as regenerants for the purpose of regeneration of MB units. The equipment of
regeneration system shall comprise bulk acid and alkali storage tanks (the tanks
would be sized for storing acid and bulk alkali for regeneration requirements for both
the streams of MB unit for 30 days), acid / alkali unloading pumps, 2x100 % mixed
blowers, acid / alkali solution preparation cum measuring tanks and regeneration
pumps, etc. Regeneration equipment for Condensate Polishing Units(CPU) would
also be located in the same area of MB regeneration system.
8.2.6
Neutralising System
The acidic and alkaline effluents from DM plant/CPU would be led to the neutralising
pit, which would be in two (2) compartments to facilitate maintenance and cleaning.
Acid or alkali would be added to the neutralising pit depending on nature of effluents
from DM plant to neutralise the effluent collected in the neutralising pit. Two (2 x
100% capacity) nos. of neutralising pumps, each of 50 cu.m / hr. capacity and of SS
316 material of construction are proposed to re-circulate and dispose the neutralised
effluents to the central monitoring basin (CMB). The neutralising pit would be RCC
lined with acid alkali proof tiles.
8.2.7
Mode of Operation of DM Plant
The complete mode of operation of DM plant and Sea water Pre treatment plant
would be automatic for which a Programmable Logic Control (PLC) based system
would be provided.
9
SERVICE AND POTABLE WATER SYSTEMS
Service water system will supply water required for ventilation, HVAC system, coal
handling system and other miscellaneous water requirements such as canteen,
toilets etc. Two (2) horizontal service water pumps (1 W + 1 S) each of 25 m3/hr
capacity are proposed. Service water pumps will pump water from the desalinated
water storage tank to a overhead tank from where water would be led to consumer
points by gravity. The desalinated water storage tank caters to the water
87
requirements of 2x660 MW units.
Potable water would be made available by EOL to the Potable water tank from where
the potable water would be distributed by gravity.
10
FIRE PROTECTION SYSTEM
The fire protection system will be common for the entire plant. The plant is designed
to provide a safe operating environment for equipment and personnel. This is
achieved by laying out equipment with sufficient separation and segregation to
minimize the risk from fire and explosion, and by selection of suitable equipment and
materials
Hazardous areas like oil, coal storage yard and cable areas are identified and
suitable equipment is selected for use in such areas. A manual and automatic fire
detection and alarm system is provided, with detection device selected to suit
particular risks. A control system designed to provide operating and fire brigade staff
with sufficient information to identify and respond correctly to any fire detected.
Automatic and manual extinguishing systems will be provided to limit the
consequences of fires in major items of plant and to minimize consequential
reductions in generating capacity. Hydrants are provided at strategic locations.
Internal hydrants (wall hydrant cabinets) are provided within building where
appropriate. Combined foam water hydrant cabinets are provided where necessary
near oil risks. All equipment and escape routes will be clearly marked in the plant.
The Fire protection system shall consist of the following
a)
Hydrant system covering all areas of the plant.
b)
High velocity water spray system for the protection of generator transformers
and turbine lube oil tanks, Lube oil system equipment, unit auxiliary
transformers inside the steam turbine building.
c)
Automatic deluge (medium velocity water spray) system for the protection of
cable vaults/ cable galleries and coal conveyors.
d)
Portable extinguishers and hand appliances for extinguishing small fires in
different areas of the plant.
e)
Mobile fire tender
The fire protection system will be designed to confirm generally to the rules and
88
regulations of the TAC/LPA. Four (4) hydrant pumps cum spray pumps(2 motordriven + 2 Diesel engine driven) of horizontal, centrifugal type, of 273 m3/hr capacity
will be provided. Two (2) jockey pump (motor-driven) of horizontal, centrifugal type, of
25 m3/hr capacity will be provided to keep the system pressurized. The diesel engine
provided will be utilized in case of power failure to the main motor driven pumps.
Hence even during emergency conditions also the fire water pumps can be switched
on to meet any adverse effects. All the above pumps will be located in the
desalinated water pump house. Starting of the pumps will be automatic and stopping
of the pumps is manual. The desalinated water storage tank will have a dead storage
of 3000 m3 of water for the fire protection system, in line with the regulations
stipulated by TAC/LPA. The emergency fire water line would be tap off from the
seawater intake pumps and connected to the desalinated water storage tank.
Portable extinguishers will be provided in all the buildings of plant premises. Portable
trolley mounted CO2 extinguisher of capacity 22.5 kg will be provided for control room
11
EFFLUENT DISPOSAL SYSTEM
The liquid effluents will be collected and treated/recycled generally as per the
following:
a) The waste effluents from the DM plant and CPU regeneration waste will be
collected in neutralizing pit and neutralized before pumping it to the Central
Monitoring Basin(CMB).
b) The oil water separator will collect water from the areas where there are
possibilities of contamination by oil (transformer yard and fuel oil storage
area) and the drains from such areas will be connected to an oil separator.
From the oil separator the clear waste water will be led to the Central
Monitoring Basin, while the oily waste sludge will be collected separately and
disposed off. Other plant drains can also be led into the CMB.
c) All the effluents collected in the Central Monitoring Basin(CMB) will be mixed
and diluted. A portion of the water from the CMB would be pumped to be
utilized for the ash disposal system. The balance quantity of water from the
CMB would be utilized for gardening,
89
CHEMICAL LABORATORY EQUIPMENT
12
A suitable chemical laboratory shall be provided in the power plant to enable testing
of coal, fuel oil, water, flue gas, etc. as required for normal operation of the power
plant. The equipment to be provided shall be decided during the contract stage. In
addition to equipment, the laboratory shall also be equipped with necessary
laboratory glassware, reagent chemicals and laboratory furniture, as may be
required. Metrological data recording facility would also be provided.
90
CHAPTER –XI
COAL HANDLING SYSTEM
GENERAL
1
This chapter covers the provisions for the coal handling system for the proposed 2x660
MW supercritical thermal power plant. It covers proposed & existing facilities for receipt
of coal by ships, stacking near the power plant area, reclaiming from stockpile, crushing
and conveying coal upto the steam generator bunkers. Flow diagram proposed is
enclosed as Exhibit-4.
DESIGN CRITERIA AND ASSUMPTIONS
2
The design criteria for coal transportation from berth conveyor, stacking, reclaiming, and
conveying is based on the following functional requirements and assumptions:
a)
Coal handling system would be designed for the proposed 2 x 660 MW units only.
b)
Coal handling system has been designed based on TGMCR worst coal
requirement of 300 TPH having a calorific value of 4900 kCal / kg.
c)
The plant load factor would be considered as 85%.
d)
The maximum lump size of the coal expected to be received at power plant would
be around (-) 50mm. Hence crushing of coal not considered.
e)
In the existing facility, coal received from the berth is conveyed at the rate of 5000 TPH
to stockyard and then reclaimed from stockyard at the rate of 1850TPH and conveyed
by closed belt conveyors to the plant junction tower (JNT-2). Further from the JNT-2,
one additional stream of belt conveyor of capacity 1000 TPH will be conveyed to
phase-II and one stream of existing two conveyors of phase-I will be used as a
standby for phase-II as well for phase-I
f)
A coal stockyard for stacking of coal required for a minimum period 30 days for 2
units existing unit (2x 600MW) and proposed unit (2 x 660MW) has been
considered.
g)
Coal handling system would be designed based on 24 hours of operation per day.
91
3
3.1
SYSTEM CAPACITY
The maximum daily requirement of coal for two units of phase II would be about 14391
tones. Coal would be conveyed to SG bunkers at the rate of 1000TPH rated capacity
(1W+1S).
4
4.1
SYSTEM DESCRIPTION
The system description furnished below is to be read with reference to exhibit no 1 and
5 (Plot plan and coal handling flow diagram).
5.0
SALIENT FEATURES OF THE SYSTEM
The following are the salient features of the coal handling system:
5.1
Belt Conveyors
All conveyors would be provided with Nylon-Nylon belting with fire retardant (FR) grade
covers of 5mm thickness at top and 3 mm thickness at bottom. The belt width of BCN1A/1B will be 1200 mm. Troughing angle will be 350. The belt speed would be about
2.63m/s.
5.2
Conveyor Galleries
All above-ground conveyors would be provided with enclosed galleries with colour
coated sheeting on side and top. Seal plates at required locations like road crossings
and above buildings would be provided.
5.3
Junction Towers
All junction towers would be of structural steel with chequered plate covered / RCC
floors. Side cladding and roof would be provided with colour coated sheets.
5.4
Feeding of Coal to Bunkers and Bunker Ventilation System
Coal would be fed to the bunkers from conveyors through motorized travelling trippers.
The coalbunkers would be of circular type and the openings on the top would be covered
with bunker sealing belt to avoid dust nuisance. The bunkers would be adequately
ventilated to keep the bunkers free from accumulation of volatile gases, thereby
eliminating fire hazard and also avoiding dust nuisance in the tripper floor. The dustladen air would be passed through bag filters before being let out to the atmosphere.
92
5.5
Metering of Coal
Adequate number of electronic belt scales would be provided on conveyors at
appropriate places to monitor the quantity of coal received at the plant, quantity of coal
available in the stock pile and quantity of coal consumed by the steam generator.
5.6
Tramp Iron Detection and Removal
Tramp iron and other magnetic materials would be removed by means of in-line
magnetic separators provided above the head pulleys of conveyors leading to the
crusher house and conveyor before the coal bunkers.
Metal detectors would be
provided on other conveyors at appropriate locations to detect non-magnetic metal
pieces and heavy iron pieces that may be present in the coal being conveyed.
5.7
Dust Control
Plain water spray dust suppression system would be provided for all transfer points in
the junction towers. Plain water type dust suppression system would be provided all
around the stockpile to suppress the dust generated and to keep dust nuisance to the
minimum. The bunker ventilation system would be provided with bag filters to trap the
dust generated while loading coal into bunkers and to vent out dust free gases/air.
5.8
Fire Protection
Fire hydrants would be provided at all tunnel entry points, junction towers, and bunker
gallery and along the overhead conveyors. Fire hydrants would also be placed along the
periphery of the coal stockpile for fire fighting.
5.9
Coal Yard Drainage
Drainage channels would be constructed to take all the effluent from the coal stock yard,
which would be ultimately led to a coal pile run-off pit. The coal pile run off pit will have
two compartments. The coal particles will settle down in the first compartment and
relatively clean water will over flow to the second compartment. A sump pump would be
provided to pump the water to the plant drains.
5.10
Controls
Operation of the complete coal handling system, except traveling trippers over SG
bunkers would be monitored from the coal handling control room. Traveling trippers
would be controlled locally. The control and protection system would be microprocessor
based with redundant CPU and colour monitor. Telemetered integrated readings would
93
be provided for accounting of coal consumed by the SG units. Also, annunciation would
be provided in the Unit control room to indicate low level of each bunker.
94
CHAPTER-XII
ASH HANDLING SYSTEM
1
GENERAL
1.1
This chapter covers the design criteria and salient features of the ash handling system
for the proposed 2x660MW supercritical thermal power plant. The following data has
been considered for the design of ash handling system:
a)
Hourly coal firing rate at 100 %MCR condition
per unit for worst coal
:
300 T
b)
Ash content
:
25
c)
Distribution of total ash produced as
-
Bottom ash
:
20 %
-
Fly ash(evacuation design)
:
90 %
-
Fly ash (disposal design)
:
80%
of ash in storage area
:
1.3 m3
e)
PLF
:
85%
f)
The system proposed for bottom ash removal would be dry type. Fly ash removal
d)
Volume occupied by one tonne
system would be two stage pneumatic conveying system. Disposal of ash would
be in high concentrated slurry form.
g)
The water required for high concentrated slurry formation would be met from CW
blow down. However, service water would be used for fly ash dust conditioners,
jacket cooling of air compressors and silo / ESP aeration blowers cooling etc.
2
CAPACITY AND TIME CYCLE
2.1
The scraper chain system will operate continuously to evacuate bottom ash generated
on combustion of coal. The capacity of bottom ash removal and will be 20 TPH for each
unit. The system bottom ash generated is only about 12.19 TPH. Bottom ash silo has
been considered of 750 tones common for both units total bottom ash generation.
95
2.3
Fly ash formed in a shift of eight (8) hours would be evacuated from the fly ash hoppers
of the steam generator unit up to ash storage silo in 4 hours by two stage pneumatic
conveying system with a system capacity of about 150 TPH per unit. However FA would
be evacuated continuously under normal conditions. It is proposed to provide two (2) fly
ash silos each of 3000 tones capacity common for both units with One (1) intermediate
storage silo of 3000 tones. Details of these silos would be worked up during detail
engineering stage.
2.4
Unutilized fly ash and bottom ash would be disposed into ash disposal area by HCSD
pumps. Fly ash and bottom ash collected from the respective bottom ash and fly ash
silos would be disposed in to ash disposal area. In a shift, FA & BA disposal from both
the units would be carried out simultaneously.
3
SYSTEM DESCRIPTION
3.1
The ash handling system would include complete bottom ash (BA) evacuation system,
fly ash (FA) evacuation system, fly ash storage silos, BA&FA disposal systems up to the
ash pond. The ash handling system shall be as per the system description and flow
diagrams enclosed.
Ash formed due to combustion of coal in the pulverised fuel steam generator (SG) would
be collected as bottom ash in the bottom ash hopper and as fly ash in the fly ash
hoppers.
The fly ash would be collected in the economiser hoppers, air-preheater
hoppers and electrostatic precipitator (ESP) hoppers provided along the flue gas path.
3.1.1
Bottom Ash (BA) Handling (Refer Exhibit - 5)
3.1.1.1Bottom ash (BA) hopper would be provided below furnace with four hour storage
capacity. The bottom ash collected in the BA hopper would be evacuated using scraper
chain conveyor (one working + one standby). The bottom ash discharged into the water
trough of the scraper chain conveyor would be crushed in a clinker grinder (one working
+ one stand by) the crushed bottom ash from the clinker grinder would be conveyed to
the bottom ash silo by a series of belt conveyors
.
96
3.1.2
Fly Ash Handling (Refer Exhibit - 6)
3.1.2.1 The fly ash handling system would be designed to collect fly ash in dry form in silo using
two stage pneumatic conveying system.
FA from ESP hoppers of each unit, FA would be conveyed up-to intermediate storage
silo by first stage pneumatic conveying system.
Hoppers in each field would be connected to common conveying line and fly ash
removal from all hoppers in that field would be done one after the other. The clearance
from any hopper would continue cycle after cycle till the level in the hoppers reaches low
level. The removal of fly ash from any particular hopper would be initiated whenever the
level in the hopper reaches predetermined level. Therefore, the removal and transfer of
the fly ash to the intermediate storage silo would be done in cyclic manner on a
continuous basis.
Generally, the fly ash conveying system would operate continuously but with time gaps
between cycles. The fly ash removal system would be designed on a continuous basis
with 15 cycles of operation per hour, and during emergency with 20 cycles of operation
per hour. The level probe would be provided in each hopper in such a way that the ash
collected in the hopper would be equal to the volume of the ash transmitter vessel.
There would be one (1) manually operated isolation valve (knife gate type) below each
fly ash hopper which would be used during maintenance of the ash transmitter vessel.
FA from intermediate storage silo would be conveyed by second stage pneumatic
conveying system up-to the FA silos.
The fly ash collected in the storage silos would be unloaded into the trucks either in
conditioned form or in dry form, if required for utilization or conveyed in high
concentrated slurry form into disposal area.
4
AUTOMATIC SEQUENTIAL CONTROLS FOR ASH REMOVAL SYSTEM
4.1
To automatically control all the compressors, pumps, valves, etc., in the
fly
ash
handling system, a centralized control panel with microprocessor based PLC would be
provided in the control room for the ash handling system. The PLC system would
97
provide for continuous cyclic operation of fly ash evacuation system. The opening and
closing of the valves below fly ash hoppers would be controlled with the help of level
switches provided on the transmitter vessel / fly ash hoppers in various streams. The
hopper from which fly ash is being removed would be indicated on the monitor or mimic
panel.
The equipment and valves in the bottom ash handling system would be controlled
automatically through a separate PLC system provided in boiler area. The status of
operation of bottom ash handling system would be available on the monitor or mimic
panel in ash handling system control room.
Silo unloading system would be controlled from the local control panel located at silo
unloading floor.
5
ASH DISPOSAL AREA
5.1
The BA and unutilized FA in high concentrated slurry form from both the units would be
pumped to ash disposal area / ash pond by HCSD pumps. About 25 hectares is
identified for ash disposal. The ash disposal area would be lined with geo-membrane
material to avoid percolation of water into earth’s surface.
98
6
ASH POND AREA ESTIMATION
The ash pond area is estimated as given below based on the following inputs and
assumptions.
1
Coal firing rate
:
300 TPH
2
Ash content
:
25 %
3
Percentage of Fly Ash
:
80%
4
Percentage of Bottom Ash
:
20%
5
Area of ash pond
:
25 hectares
6
Height of ash bund
:
4m initial height.
Subsequent increase of 4m
in three phases upto
ultimate height of 20 m.
7
V lume occupied by one tonne of
ash in storage area
:
1.3 cu.m
8
Total ash generated per hour per :
unit
60.99 T
9
BA ash generated per hour per :
unit
12.19 T
Fly ash generated per hour per :
unit
48.79 T
10
BA ash generated per year for
proposed phase-II units
(with PLF 85%)
:
2,13,730 T
11
:
8,54,919 T
12
FA ash generated per year for
proposed phase-II
(with PLF 85%)
The area available for ash disposal can accommodate 100% Bottom Ash generated by 2
units in 4years, and 100% Fly Ash generated by 2 units in 1 years.
99
7
7.1
POSSIBLE AREAS OF ASH UTILISATION
The environmental regulations are becoming stringent on the ash disposal aspect. The
present regulation stipulate for atleast 50%, 75% and 100% fly ash utilization in 1year,
2year and 3year respectively from date of commissioning. Hence it is necessary to find
out the areas where ash can be utilized without harming the environment. Presently the
ash based products are at developmental stage and need to be made more
environmental friendly. Some of the areas of ash uses include:
a)
Brick/ Block/ Tiles manufacturing
b)
Cement manufacturing
c)
Roads and embankment construction
d)
Structural fill for reclaiming low lying areas
e)
Mines fill
f)
Agriculture, Forestry and Waste land development
g)
Part replacement of cement in mortar and concrete
h)
Hydraulic structure (Roller compacted concrete)
i)
Ash dyke raising
j)
Building components – Mortar, Concrete, concrete hollow blocks, aerated
concrete blocks etc.
k)
Other medium & high value added products (Ceramic tiles, wood, paints)
pavement blocks, light weight aggregate, extraction of alumina, cenospheres etc.
100
CHAPTER XIII
MISCELLANEOUS SYSTEMS
COMPRESSED AIR SYSTEM
1
Three centrifugal compressors (one working for each unit and one common stand by),
each having suitable capacity to cater to the plant at a discharge pressure of 9.97 kg /
cm2 (g) would be provided for 2x660 MW units. The centrifugal compressors proposed
would meet the instrument and service air requirements of the plant. The requirement of
the compressed air for the fly ash conveying and coal handling system would be met
through separate dedicated compressors.
2
The compressed air system would include accessories such as moisture separators and
air receivers. The discharge lines of all the three compressors would be branched. Two
air driers (one operating and the other stand by) for each unit of suitable capacity would
be provided.
AIR CONDITIONING SYSTEM
3
It is proposed to air-condition the unit control room, electronic cubicle room, shift charge
engineer’s room, printer room, maintenance engineer’s room, UPS room, ESP control
room, static excitation cubicle room, analyser panel room, coal handling control room,
DM plant control room and switchyard control room. Inside design conditions of 24.5 

1.50C dry bulb temperature and relative humidity not exceeding 60% would be
maintained in all air-conditioned areas.
4
Two independent centralised chilled water systems are envisaged for air-conditioning
the unit control room / electronic cubicle rooms and ESP control rooms. Each centralised
system would consist of three (two working and one standby) water chilling units. The
system also consists of chilled water pumps, condenser cooling water pumps, induced
draught FRP cooling towers, adequate number of air handling units for circulating the
conditioned air through air distribution system to the room.
101
5
For air conditioning of all other rooms, packaged air conditioners or room air conditioners
of suitable capacity would be provided.
VENTILATION SYSTEM
6
For the ventilation of the station building, evaporative cooling system (Air washer type) is
envisaged. This system consists of air washers, supply air fans, air washer circulating
water pumps, centrifugal fans and air distribution system for distributing the supply air
inside the station building. The exhaust of hot air out of the station building would be
achieved by provision of roof extractors and wall mounted exhaust fans.
7
For ventilation of other buildings, supply air fans or louvers, exhaust air fans, roof
extractors or a suitable combination of these complete with louvers, filters, ducting
grilles would be provided.
HYDROGEN GAS SYSTEM
8
Hydrogen gas with a purity of 99.9% (by volume) is required for cooling of the
generators. It would be required for the initial filling and continuous make-up during
normal operation for maintaining the required purity in the generator. The normal
hydrogen gas requirement for two units is about 50 Nm3 / day. This requirement would
be met by procuring the hydrogen gas cylinders from external sources
CRANES AND HOISTS
Station Building EOT Cranes
9
One overhead, cabin operated electric overhead travelling (EOT) crane of 115/25 ton
capacity, Class M5, spanning 29 m in AB bay for TG building would be installed in the
turbine hall for handling various equipment, except generator stator, during erection and
maintenance. The generator stator would be erected by employing temporary erection
facilities such as derrick / hydraulic jacks, or strand jack arrangement.
Miscellaneous Lifting Tackles / Hoists
102
10
For equipment, which weighs above one ton, electrically operated type of hoists and
trolleys would be provided. For equipment weighing less than one ton, manually
operated hoists and trolleys would be provided.
11
The areas / equipment for which the lifting tackles are proposed to be provided are in
warehouse, all equipment in the station building which are not accessible to station
building EOT crane, steam generator area (all fans, gear boxes, mill components, etc.),
DM plant (to load the chemicals in to the tanks), coal handling junction towers and ash
water pump house , HCSD pump house, cooling tower area, ESPs, sea water/clarified
water pump houses, fuel oil pump house, etc.
WORKSHOP EQUIPMENT
12
The power plant would be equipped with a work shop capable of catering to the routine
maintenance requirements of the plant. Considering the type of jobs likely to be carried
out at the workshop, all or some of the following equipment are proposed to be provided.
The availability of the maintenance facilities in the vicinity of the site may be taken into
consideration while finalising on this aspect.
a)
Machine Shop Equipment
i) ii)
One general purpose lathe
iii)
One shaping machine
iv)
One universal milling machine
v)
One radial drilling machine
vi)
One bench drilling machine
vii)
One portable hand drill gun
viii)
One surface grinding machine
ix)
One double-ended pedestal grinder
x)
One flexible shaft grinder
xi)
One power driven hacksaw
One set of balancing equipment
103
xii)
Work benches, hand lamp sets
(with transformer), hydraulic jacks,
general tools, surface plates and measuring tools.
b)
Welding Equipment
i)
One AC transformer welding set
ii)
One rectifier welding set
iii)
Two oxy-acetylene gas cutting and welding sets
iv)
One electrode drying oven
v)
Welding tables, soldering irons, welding masks, etc.
CHEMICAL LABORATORY EQUIPMENT
13
A chemical laboratory as per the requirement would be provided in the power plant to
enable testing of fuel, water, flue gas, etc. for normal operation of the power plant and
as stipulated by MOEF and GSCB.
14
Chemical laboratory would be equipped with all or some of the following equipment. In
addition to these equipment, the laboratory would also be equipped with necessary
laboratory glassware, reagent chemicals and laboratory furniture. A portion of the
chemical laboratory housing equipment such as the spectrophotometer would be airconditioned. Necessary meteorological and environmental equipment would also be
provided.

Conductivity meter

Alfoc test kit for oxygen

pH meter

Turbidity meter

Spectrophotometer

Jar test apparatus (laboratory flocculator)

Muffle furnace

Vacuum oven

Ordinary oven
104

Bomb calorimeter

Sieve shaker

Sieves, cover receiver

Mechanical jaw crushers

Grinder

Jar ball mill

Electric oven for coal analysis

Hard grove grindability tester

Apparatus for oxidation stability test

Coal analyser for proximate analysis

Redwood viscometer

Appa atus for water in oil by Dean and Stack method

Interfacial tension apparatus

Pensky-Martens flash point apparatus

Three-bulb orsat

Explosimeter (Combustible gas analyser)

Ultimate analysis apparatus hydrometer.

Hydrogen purity test apparatus

Magnetic stirrer

Balance (chainomatic) with weight box

Atomic absorption spectrophotometer

Triple beam balance

Single pan balance

Water bath

Gas heating assembly

Hot plate

Distilling still

Vacuum pump
105

Heating mantle

Kipp’s apparatus

Flame photometer

Lovibond comparator

Hot plate-cum-magnetic stirrer

Laboratory centrifuge

Potentiometric titration apparatus

Atomic absorption spectrophotometer (AAS)

Gas chromatograph with data processor (GS)

Noise level meter

Wind anemometer and wind vane

Dial type barometer

Stack monitoring kit

Hygrometer

Dry wet bulb thermometer

Dew point tester

BOD incubator

COD incubator.
106
CHAPTER XIV
ENVIRONMENTAL PROTECTION AND WASTE MANAGEMENT
TYPES OF POLLUTION
1
The technical details and emission parameters mentioned in this chapter refer to
proposed 2 x 660 MW Phase II super critical imported coal based thermal power plant
near by Nana Manda & Khajurda, Dist Devbhumi Dwarka, Gujarat. This chapter details
out the following environmental impact aspects:
a) Air pollution
b) Water pollution
c) Noise pollution
d) Sewage disposal.
AIR POLLUTION
2
The air polluting emittants from the power plant are as follows:
a) Dust particulates in flue gas, from chimney
b) Sulphur dioxide (SO2) in flue gas
c) Nitrogen oxides (NOx) in flue gas
d) Mercury (Hg)
e ) Coal dust particles while handling of coal
f ) Dust in the ash disposal area.
REGULATIONS FOR LIMITING AIR POLLUTION
INDIAN STANDARDS
3
As per notification by Ministry of Environment and Forests dated
19 May 1993, the
emission limits are as follows:
a)
b)
Suspended particulate matter (SPM)
emission (dust particulate from fly ash) :
< 30 mg/Nm3
Sulphur di-oxide *
<100 mg/Nm3
:
107
c)
Nitrogen oxides
:
< 100 mg/Nm3
d)
e)
Mercury (Hg)
Coal dust particles during
:
< 0.03 mg/Nm3
:
Not specified
:
Not specified
Storage/handling of coal
f)
Dust in the ash disposal area
Note : *Sulphur di-oxide emission would be controlled by specifying minimum
stack height limit which is as follows :
Power Generating Capacity
Minimum Stack Height
500 MW and more
275 m
200 MW and above to less than 500 MW
220 m
Less than 200 MW
H = 14 (Q) 0.3
Where
H = stack height in M
Q = SO2 emission rate in kg / hr
4
As per notification by
Central Pollution Control Board dated 16 Nov 2009, for the
ambient air quality, the permitted limits of ground level concentrations of pollutants
considering Industrial, Residential, Sensitive areas is furnished in Table- XIV.1 below :
Table –XIV.1
Pollutant
National Ambient Air Quality Standards
Concentration in Ambient Air
Time Weighted
Average
Annual Average*
Sulphur Dioxide (SO2)
Oxides of Nitrogen as
NO2
Particulate matter (size
less than 10um) or
PM10 ug/m3
Particulate matter (size
less than 2.5um) or
PM2.5 ug/m3
g/m3
Industrial Residential,
Rural Other areas Area
50
Sensitive Area
20
24 hrs**
Annual Average*
80
24 hrs**
Annual Average*
80
60
80
60
24 hrs**
100
100
Annual Average*
40
40
24 hrs**
60
60
108
40
80
30
Table – XIV.1
Pollutant
National Ambient Air Quality Standards
Concentration in Ambient Air
Time Weighted
g/m3
Average
8 hours**
100
100
1 hours**
180
180
Annual Average*
0.50
0.50
24 hrs**
1.0
1.0
8 hours**
02
02
1 hours**
04
04
Annual Average*
100
100
24 hrs**
400
400
Benzene (C4H6) ug/m3
Annual Average*
05
05
Benzo (a) pyrene (BaP)
Particulate phase only
ng/m3
Annual Average*
01
01
Arsenic (As) ng/m3
Annual Average*
06
06
Nickle (Ni) ng/m3
Annual Average*
20
20
Ozon (03) ug/m3
Lead ug/m3
Carbon Monoxide mg/m3
Ammonia ug/m3
*
**
Annual arithmetic mean of minimum 104 measurements in a year taken twice a week – 24
hours at uniform interval.
24 hourly / 8 hourly values should be met 98% of the time in a year. However, 2% of the
time, it may exceed but not on the consecutive days.
109
Notes:
1.
National Ambient Air Quality Standard:
The levels of air quality
necessary with an adequate margin of safety to protect the public
health, vegetation and property.
2.
Whenever and wherever two consecutive values exceed the limit
specified above for the respective category, it would be considered
adequate reason to institute regular / continuous monitoring and
further investigations.
Dust Particulates from Fly Ash in Flue Gas
5
As per the above norms the particulate matter (PM) emission applicable to this project
would be 30 mg / Nm3. But considering prevailing international trend of limiting the PM
emission to 30 mg / Nm3 as per the stipulation by the World bank group on pollution
prevention and abatement (July 1998), the electrostatic precipitators (ESP) for the
project would be designed to limit the emission level of PM to be within
30mg / Nm3 .
Sulphur Dioxide (SO2) in Flue Gas
6
As per the above norms, the minimum stack height shall be 275m. A common twin flue
Stack for two units has been proposed for effective dispersal of SO2.
Space for FGD is also proposed to be considered and can be installed if required for SOx Control.
Nitrogen Oxides (NOx) in Flue Gas
7
The steam generators would be fitted with low NOx burners. To reduce NOx emissions,
over-fire air system would also be installed in the furnace. The NOx ground level
concentrations (GLC) would be checked during preparation of EIA report for the project.
110
8
Emissions
CO2 , SO2 and NOX Emission
8.1
Since supercritical units have been considered for the proposed project the CO2 , SO2
and NOX emission would be about 6-7 % less compared to sub critical unit of 660MW.
The quantitative description for CO2 emission is given below. The SO2 and NOX emission
will be in similar line.
CO2 Emission
8.1.1
The pressure and temperature at the inlet of the steam turbine for 660 MWe supercritical
unit would be 247 bar (a) and 567 oC / 594.3 oC reheat, whereas the same for a sub
critical 660 MW unit would be typically 166.7 bar (a) / 537 oC/ 537 oC. Due to the high
initial pressure and temperature conditions, the gross station heat rate (estimated at 0 %
make up and condenser pressure 0.093 bar (a)) for a 660 MW super critical unit would
be lower, i.e.2130 kcal/kWh compared to the 2444.20 kcal/kWh for the sub critical unit.
Therefore the coal consumption rate at MCR conditions would be lower for a super
critical unit. The details of the coal firing rates and CO2 productions are furnished in the
enclosed Table-XIV.2. Since the coal firing rate for the sub critical 660 MW unit would be
high, the CO2 emissions would also be higher ( i.e about 6.66 % ) compared to a super
critical unit of the same capacity.
111
Table-XIV.2
660 MW TPS - CO2 Emission for Super Critical and Subcritical Unit
660 MW Super
Critical unit
Sl.No.
Para
Gross stationmeter
heat rate at TG
MCR, kcal/kWh
Coal Firing rate ( GCV 4900
kcal/kg), kg/hr
CO2 emission , kg/ kg of fuel
CO2 emission tonnes/ MWh
CO2 emission,
million
tonnes/year variation in CO2
Percentage
emission
1
2
3
4
5
6
8.2
660 MW
Sub Critical
unit
2130
2444.20
299808
1.9481
0.8468
8.46
358673
1.9481
0.9717
9.71
Base
( + ) 18.24
Stack Emission (Preliminary)
: One twin flue stack for two 660 MW units
a)
Number of stacks
b)
Number of flues per stack
: Two flues in one bi-flue stack
for (Unit 1 and 2) of 660 MW
c)
Physical stack height (m)
: 275 m
d)
Plume diameter at exit (m)
: 7.6 m (flue exit diameter) approx
e)
Flue gas exit velocity (m/s)
: 22 m/sec approx
f)
Flue gas exit temp (°C)
: > 125 (at stack outlet) approx
3
g)
Flue gas density (kg/NM )
h)
Emission rate per flue of
: 1.114 approx
i)
SPM (mg/Nm3)
:
ii)
SO2 (kg/h)
: 321 per each stack approx
iii)
NOx (kg/h)
30
322
112
COAL DUST PARTICLES DUE TO HANDLING OF COAL
9
Coal dust would be generated generally at the conveyor transfer points, coal unloading
area and coal stockpile area. Hence, coal transfer points and coal stockyard would be
provided with dust suppression / dust extraction facilities. Further, in order to arrest the
coal dust generation, all conveyors would be provided with enclosed galleries. The
bottom portion of all the conveyor galleries would be provided with seal plates with in the
power plant area and at road crossing.
10
Dust collection system would also be provided in coal bunkers to evacuate dust and
hazardous gases like methane from the coal bunkers. Collected dust would be returned
to either the associated belt conveyor or to the coal bunker.
FLY ASH DUST PARTICLES FROM ASH SILOS AND ASH DISPOSAL AREA
11
Two fly ash storage silos, one for each unit are proposed to be provided, two
intermediate fly ash silo common for both units to be provided. Fly ash evacuated from
the ESP collecting hoppers would be transported in closed pipelines by pneumatic
means. At the time of unloading fly ash in to the silos, some ash laden air would get
vented out. However, In order to restrict the fly ash dust particles to the limit, a vent filter
would be installed on top of each of the fly ash silos at the vents.
113
12
The following pollution control measures would be installed for ash disposal:
a)
Maximum utilization of fly ash in dry form is envisaged. Closed trucks and
containers would be used for this purpose, as far as possible. Provision would be
made to dispose the unutilized fly ash through HCSD system.
b)
To reduce the dust nuisance while unloading the ash into the open trucks from fly
ash silos, the fly ash would be conditioned with water spray
c)
Water sprinkling system would be provided in the ash disposal area to restrain
flying of fine ash due to wind
d)
The ash disposal area would be lined with impervious lining to prevent seepage
of rain water from the disposal area in to the ground and pollute ground water.
WATER POLLUTION
13
The water pollutants applicable for this plant are:
a) Cooling tower blow down water
b) Water treatment plant effluent
c) Effluent from ash disposal area
d) Effluent from coal pile area run off
e) Air pre-heater wash water effluent
f)
Plant wash down water
114
g) Floor and equipment drainage effluent
h) Rain water drainage
i)
Sewage from various buildings in the plant.
REGULATIONS FOR LIMITING WATER POLLUTION: INDIAN STANDARDS
14
Environmental (Protection) Rules 1986 issued by Ministry of Environment and Forests Schedule-I, stipulates the following limits for effluent disposal:
a)
Ash pond effluent:
i)
pH
: 6.5 to 8.5
ii)
Suspended solids
: < 100 mg/l
iii)
Oil and grease
: < 10 mg/l
b)
Effluent from WT plant
c)
Steam generator blow down:
d)
: Not Specified
i)
Suspended solids
: < 100 mg / l
ii)
Oil and grease
: < 20 mg / l
iii)
Copper (total)
: < 1.0 mg / l
iv)
Iron (total)
: < 1.0 mg / l.
Cooling tower blow down:
a)
Free available chlorine
: < 0.5 mg/l
b)
Zinc
: < 1.0 mg/l
c)
Chromium (total)
: < 0.2 mg/l
d)
Phosphate
: < 5.0 mg/l.
115
15
As per the notification issued by the Ministry of Environment and Forests dated 19 May
1993, the Schedule-VI specifies the quality of effluent permitted to be discharged. The
qualities of effluents have been specified under the following categories:
a) Inland surface water
b) Public sewage
c) Land for irrigation
d) Marine coastal areas.
16
For the proposed power plant, the category to be considered would be under inland
surface waters. The major effluent limits under category are:
a) Suspended solids
:
100 mg / l (max).
b) pH
:
5.5 to 9.0
c) Temperature
:
Shall not exceed 10oC above the
receiving water temperature.
:
d) Oil and grease
17
10 mg / l.
The quantity of effluents would confirm to the limits indicated above and also those limits
prescribed by Gujarat State Pollution Control Board (GSPCB).
REUSE OF PLANT EFFLUENTS
18
Following measures are proposed for reusing plant effluents:
116
a) Cooling Tower Blow Down
The cooling tower blow down does not require treatment but relies on minimizing the
level of pollutants by operating at reduced cycles of concentration to prevent the buildup
of contaminants and through proper selection of treatment chemicals which do not
introduce additional pollutants such as zinc and chromium.
b) Water Treatment Plant Effluents
The effluent from the regeneration of the cat-ion resin units in the water treatment plant
(DM Plant) is generally acidic in nature and from the anion resin units are alkaline in
nature. The combined waste water from the DM plant would be neutralized in a
neutralizing pit. The neutralized effluent is expected to have suspended solids less than
5 ppm and pH in the range of 6.5 to 8.5. This would be led to the guard pond.
c) Coal Pile Area Run- Off
The coal pile area runoff water during monsoon season would be led to a separate pond.
Coal particles would settle down in the pond and clear water would be allowed to flow
into the ash pond.
d) Effluent from Bottom Ash Handling System
The drain and overflow water from the bottom ash handling system would be collected at
the bottom ash sump where the ash would settle down and clarified ash water overflows
to clear well section of the basin. This clear water would be sent to the ash water sump.
e) Plant Wash Down Water
117
In the power plant, some specific locations require washing to maintain good plant house
keeping and prevent build up of dirt and waste material. The waste water would be led to
the guard pond.
f) Floor and Equipment Drainage System Effluent
i) Means would be provided for collecting and draining water from floors in process areas
of the plant and collecting and disposing of water and other liquids from process
equipment, discharged fire protection water and oil storage tanks.
ii) In the turbine building, the ground floor slabs would be sloped to drain out floor drains.
The equipment drains are piped directly to the drain system. Drains are collected and
directed to sumps outside the buildings from where it would be pumped to the guard
pond through a oil water separator.
RAIN (STORM) WATER DRAINAGE
19
The rain (storm) water removed from the building roofs would be collected to a rain
water collection tank. The rain water which falls on the yard area grade level surfaces
would be directed through the open ditches and culverts to the storm drainage. All
ditches would be concrete lined and located along the roads. All drainage ditches would
be located to provide the shortest practical drainage path while providing efficient
drainage for the yard. Grade level would be contoured such that storm water run off is
directed on the ground by sheet flow, to well defined drainage paths leading to the
ditches.
SEWAGE FROM VARIOUS BUILDINGS IN THE PLANT
20
Sewage from various buildings will be by sewers connecting to the nearest manholes.
The concentrated sewage will be led to a sewage treatment plant. A network of sewers
with manholes located at all junctions and at a spacing of 50 m will be provided to cover
all the buildings in the project.
MONITORING OF GROUND WATER
118
21
Four bore-wells would
be identified inside / outside the plant premises to monitor the
ground water quality as per IS: 10500 (1991).
NOISE POLLUTION
22
The source of noise in the proposed power plant are:
-
Steam turbine generator
-
Other rotating equipment
-
Combustion induced noises
-
Flow nduced noises
-
Steam safety valves
REGULATIONS FOR LIMITING NOISE POLLUTION: INDIAN STANDARDS
23
As per the Environmental (Protection) Rules 1986 as well as MSPCB, the limits in the
noise levels are:
Industrial area
24
:
75 dB (A) in day time (6 AM to 9 PM)
:
70 dB (A) in night time (9 PM to 6 AM)
The Occupational Safety and Health Administration Standards (OSHA), USA indicate
the following permissible noise.
---------------------------------------------------------------Duration per Day (Hours)
Sound Level (dBA)
---------------------------------------------------------------8
90
6
92
4
95
3
97
2
100
1.5
102
1
105
0.5
110
0.25
115
119
25
All the equipment in the power plant would be designed / operated to have the noise
level not exceeding 85 - 90 db (A) measured at a distance of 1.5 m from the equipment.
Also, all the measures would be taken to limit the noise levels at the plant boundary
within the stipulated limits.
POLLUTION MONITORING AND SURVELLIANCE SYSTEMS
26
The emission and gas monitoring systems installed in this Project consist of the
following:
a) Flue Gas O2 and CO Monitoring: These would be measured at the economizer
outlet. In addition, O2 would be monitored at the air pre heater outlet. For this
purpose, CO and O2 monitor probes and analyzers would be installed separately.
b) Stack emissions: Flue gas exiting into the atmosphere would be monitored for CO2,
NOx, SO2 and Opacity. Stack emission readings would be sent to the DCS for
monitoring. For this purpose, dilution probes, associated gas analyzers and support
equipment, sample lines and Opacity sensor / transmitters would be installed. The
Opacity sensors would be equipped with a blower to protect the optics from coating
by flue gas particles.
The system operation would be continuous. Stack gas analysis for SO2, CO2 and
NOx would be performed by extracting a gas sample from the flowing stream in the
stack, filtering to remove particulate droplets, diluting with scrubbed instrument air
and conveying the sample to the analyzers.
One sampling system per unit would be provided.
Air Monitoring
27
Air Monitoring Stations (AMS) would be set up to monitor the air quality in the
neighboring villages. The parameters being monitored are suspended particulate matter
120
(SPM), respirable particulate matter (RPM), Sulphur di-oxide (SO2), Nitrogen Oxide
(NOx), Carbon monoxide (CO) and Hydro carbons (HC). The air quality monitoring
would be carried out continuously including the times during which power plant boiler
firing with 100% coal as test firing is done.
GREEN BELT
28
In the proposed power plant, for raising plantation adequate saplings would be planted
inside the power plant.
IMPACT OF POLLUTION/ENVIRONMENTAL DISTURBANCE
29
Since all necessary pollution control measures to maintain the emission levels of dust
particles, sulphur dioxide and nitrogen oxides within the permissible limits would be
taken and n cessary treatment of effluents would be carried out, there would be no
adverse impact on either air or water quality in and around the power station site on
account of installation of the proposed plant.
ENVIRONMENTAL CLEARANCE
30
Appendix - 6 gives the environmental appraisal for the proposed power plant in the
format required by the National Committee on Environmental Planning and Coordination.
121
CHAPTER XV
PROJECT SCHEDULING AND IMPLEMENTATION
PROJECT SCHEDULE
1
The project milestone schedule is presented in Exhibit-09. It is envisaged to put the first
unit into commercial operation in 39 months, reckoned from the date of award of boiler
and turbine generator (BTG) contract for the project. The second unit would be put into
commercial operation 3 months thereafter. The synchronization of each unit would be
three months ahead of their commercial operation date (COD).The time between
synchronization and COD would be utilized for the following activities.
a)
Trial operation of steam generator (SG) and turbine generator (TG)
including
submission of report upon successful completion 4 Weeks. Trial operation would
include.
i)
Trial operation of the unit for 72 hours at full load on auto mode
ii)
Operation of the unit at various load regimes for sufficient duration on auto
b)
Stable operation of unit and notice for performance guarantee (PG) test for SG
and TG – 2 Weeks
c)
Performance guarantee test including shutdown for removal of instruments and
unit characteristics tests inclusive of VWO test, house load operation test, ramp
rate test, demonstration of cold, warm and hot start-up times – 2 Weeks
d)
PG test for balance of plant systems like WT plant, water clarification
plant,
cooling towers, coal handling etc. – 2 Weeks
e)
Review/approval of PG tests and take over for commercial operation – 2 Weeks
HANDLING OF EQUIPMENT
2 The following mode of handling heavy equipment at site is envisaged for at the erection
stage:
122
a)
All steam generators parts would be brought to the SG area and hoisted to the
erection points using tower crane and other types of lifting devices
b)
The generator stator would be unloaded from the carriers by means of hydraulic
jacks or mobile cranes in the maintenance bay of the station building. At the
time of erection, the stator would be placed on the TG pedestal using the
hydraulic jacks or mobile cranes
c)
All equipment in the station building, except the generator stator, would be
erected
using one (1) no 115/25 ton E.O.T. crane installed in the station
building. The transport carriers would be
brought into the maintenance bay of
the station building to facilitate handling by the E.O.T. cranes
d)
The generator transformer would be jacked up and unloaded on the railway
track
provided for transformers close to the foundations and moved to the
position by means of the bi-directional
rollers provided. Smaller transformers
would be skidded into position using winches.
O&M PERSONNEL
3
To ensure adequate technical competence in operation and maintenance of the power
station, the following measures would be taken:
a)
Personnel identified for O&M functions would comprise
having
the required
background
and
a cadre of engineers
experience in commissioning,
operation and plant maintenance functions for a coal fired thermal power plant
of similar capacity
b)
These O&M personnel would be recruited at an early stage and would be
given
adequate training
at
the manufacturer's works,
at site, at other
similar power stations and/or in training simulators so as to familiarise them
with the necessary O&M functions relating to plant and equipment specific to
this project.
123
PRELIMINARY AND OTHER WORKS
4
To ensure timely project execution within the cost envisaged, several project
developmental activities are to be completed before the date of award of BTG contract.
However, apart from obtaining necessary approvals and clearances, some of the
important site-related works such as site enabling works viz. temporary site office,
storage sheds, construction water and power supply would be taken up and completed
early.
RISKS PERCEIVED DURING PROJECT PHASES
5
The risks perceived during various phases of project, primarily would be in brief as
below:
a)
Pre-construction phase
The primary aspects which need attention during pre-construction phase would
be related to:
i) Availability of land:
Adequate land is identified for installation of this project which is well connected
by road and railways. Serious impact on land availability for commencement of
project activities and hence on project scheduling.
ii) Availability of fuel:
The supply of 5.5 million Tons of imported coal for both the projects of 2x660
MW Phase-II coal would affect the plant operation.
iii) Availability of water:
Implementation of water supply scheme needs to be taken up early so as to
ensure availability of water for project on schedule.
124
iv) Approvals and permits:
The suitable actions needs to taken-up with various agencies to obtain the
statutory / non- statutory clearances. Non availability of any clearances would
affect the smooth functioning of project execution. The list of permits and
clearances generally required to be obtained is furnished in Chapter- XVI.
v) Finalization of contracts:
Well documented contracts with reputed suppliers/contractors along with well
defined technical/commercial terms and conditions and involvement of reputed
technical consultant need to be firmed up. Loosely documented contracts would
cause cost and time over run of the project
b)
Construction
phase
i) Financial strength of project
developer:
Sound financial strength of project developer is essential to infuse required
equity part of project cost at right time so as to obtain smooth flowing of debt
portion from lenders. Inability of this, would lead to fund crunch causing
payment
ii)
default
to
in
project
Delay
contractors
thereby
completion
and
affecting
increase
project
in
schedules.
project
cost:
This could happen due to improper selection of contractors/equipment
suppliers. While selecting the contractors/equipment suppliers, at- most care
needs to be taken to evaluate their financial as well as technical capabilities and
heavy penalties to be enforced in case of dilution of contractual conditions.
Services of reputed technical consultant need to be employed for monitoring the
technical
iii)
qualities,
Delay
in
cost
over-run
construction
and
of
timely
power
completion
evacuation
of
project.
facilities:
Creation of power evacuation facilities generally need more time considering its
nature of execution. Inadequate planning would lead to delay in availability of
evacuation facility. This would delay the operation phase of project causing loss
of revenue.
125
c)
Post
i)
construction
operation
availability
Fuel
and
phase
transportation:
Inadequate availability of fuel and/or inadequate fuel transportation facilities
would lead to adverse effect on functioning of plant causing revenue loss.
Hence, proper agreements related to supply and transportation of fuel need to
rightly
placed
ii)
and
monitor
Equipment
closely.
performance:
Proper selection of equipment/systems during contracting stage and operation
& maintenance of the same as per manufacturer’s recommendation s is very
essential. Dilution of this would lead to deterioration of the equipment
performance causing loss of power generation. Hence, operation and
maintenance of the plant to be carried out with well equipped and by well
qualified
iii)
O&
Escalation
staff.
M
in
O&M
cost:
This can happen in case of improper selection of spares, non adherence to
manufacturer’s recommendations and unskilled O&M personnel. Proper
attention needs to be given to these aspects to keep the plant in sound
condition.
d)
General
Other risks involve would be political, economical, change in law, revenue
collection etc. which would be addressed suitably.
126
CHAPTER - XVI
PROJECT APPROVALS AND PERMISSIONS
CHECK LIST FOR PERMITS, CLEARANCES AND LICENSES FOR POWER PROJECTS
SL.
NO.
CLEARANCES
AUTHORITY
1.1
Environmental clearance
Ministry
of
Environmental
Forest, Government of India
1.2
No objection for tallest structure
Airport Authority of India,
Delhi.
1.3
Registration of Company
Companies Act, 1950)
Registrar of Companies
1.4
Rehabilitation & resettlement of
displaced families by land acquisition
MoEF, Government of State
1.5
Import licenses & formalities
Controller of Imports & Exports
1.6
Foreign investment approval
Reserve Bank of India (RBI)
1.7
Final financial package
CEA
1.8
External borrowings
Reserve Bank of India, Ministry
of Finance, Government of India,
Income Tax Authorities.
2.0
NON-STATUTORY CLEARANCES
2.1
Land availability
Government of State / Private
Land
2.2
Fuel linkage and approval of fuel
supply agreement
Department of Petroleum and
Natural Gas
2.3
Transportation of Fuel
Department of Petroleum and
Natural
Gas,
Ministry
of
Railways, Shipping and Surface
Transport
(Indian
127
New
SL.
NO.
CLEARANCES
AUTHORITY
2.4
Approval
of
Contractor,
O&M Reserve Bank of India
Contractor and other financial and
legal advisors, including payment of
their fees, services, etc., in foreign
currency.
2.5
Real Estate, Rights & right to access
and use of Site, including Right of
Way for all corridors to the Facility
3.0
OTHER CLEARANCES/ APPROVALS
3.1
Approval as per Explosives Act and Chief Controller of Explosives
Rules
3.2
Approval as
Regulation
3.3
Approval as per Indian Electricity Act Electrical Inspectorate
and Rules for Electrical Installation
3.4
Approval as per Indian Petroleum Act Chief Controller of Explosives
and Petroleum Rules for storage and
transport of Petroleum Products
3.5
Approval as per gas cylinder rules and Chief Controller of Explosives
handling and transport of compressed
gases
3.6
Approval of weigh bridge and weigh Inspector
scales
Measure
3.7
Allocation of Liquid Petroleum Gas
per
Indian
Government
of
State
Concerned
Authorities
Relevant Village Panchayat
/
/
Boiler Chief Inspectorate of Boilers
128
of
Weights
and
Director
of
Industries,
Government of State
SL.
NO.
3.8
CLEARANCES
AUTHORITY
(a)
Collection, storage and
disposal of waste
(b)
Site clearances, safe report
and safety audit
SPCB
3.9
Approval
Scheme
of
Fire
Protection
3.10
Confirmation
of
Collector
/
Directorate of Town and Planning
for the use of the site for the
construction and operation of the
Power Station and Fuel Facility
3.11
Consent of relevant Panchayat for
the development of Project Site and
the Township site
3.12
Approval of Chief Inspector of
Factories of the proposed design
and construction of power station
and fuel facility
(a)
(b)
Fire Brigade
Tariff Advisory
Committee
Directorate
Planning of
State
of
Town
and
Government of
Directorate
of
Town
and
Planning of Government of State
Chief Inspector of Factories of
Government of State
SEB
3.13
Allocation / approval of electric
supply for construction power and
Contractor’s township in colony area
SEB
3.14
Allocation
for
Owner’s
township
3.39
of
electric
supply
Approvals / clearances for labour / Concerned Authorities
man power like License from labour
commissioner for Construction labour,
Registration of workers or exemption
to be claimed if group insurance taken
for some, etc
129
CHAPTER – XVII
PROJECT COST ESTIMATES
1. PROJECT COST
The total project cost including IDC is estimated at Rs. 6 9 7 1 Crores (about Rs. 5.28
Crores / MW) for the 1320 MW capacity. This cost is at par with industry standard. The
Project Cost Break-up is given as under:
Total Cost
Description
Land, Site Development including water storage
EPC contracts
Customs Duty @ 25%/ Excise Duty @ 12.5%
Total Hard Cost
Preliminary and Pre‐operative expenses
4870
933
5803
200
Margin Money for working capital
IDC & Financing Costs
Contingencies @ 5% of Hard Costs
Project insurance
Total Project Cost
204
648
94
22
6971
PRE-OPERATIVE AND PRELIMINARY EXPENSES
Preliminary
10 crs
Insurance
15 crs
Admin & Personal Cost
60 crs
Start up & Other Expense
60 crs
MFA
20 crs
PMC
35 crs
130
2. INTEREST DURING CONSTRUCTION PERIOD
Interest on loan during construction (IDC), which is part of the project cost has been
calculated based on debt-equity ratio of 75: 25 and weighted average interest rate.
3. TARIFF
Power Purchase Agreement for 800 MW is to be signed with GUVNL for a period of 25
years. The cost per kWh based on standard evaluation criteria works out to Rs. 2.80
(levellised) and Balance power will be on Merchant sale.
4. ASSUMPTIONS CONSIDERED IN FINANCIAL PROJECTIONS
The two-part tariff model as per the guidelines of Government of India has been adopted
to calculate the cost of generation :
Debt – equity ratio
:
75 : 25
Cost of coal as received at site
:
USD 50.00 per ton
Cost of fuel oil as received at site
:
Rs.17,000 / KL
Interest rate on domestic debt
:
11.5%
per
annum
construction & 11.5%
operations.
Depreciation
:
Depreciation at 5.28
Straight line Method.
Operation and maintenance
charges
:
18.38 Lacs/MW escalated at 4%
p.a.
Gross heat rate
:
2130 Kcal/ kWh
Gross calorific value of coal
:
4900 k Cal / kg
Repayment period for loans
:
Moratorium of 1 year from COD
and thereafter repayment in 40
equal quarterly instalments.
during
during
%
Details of working capital
(a)
Margin money
:
25 % of total working capital
(b)
Interest rate on balance of
working capital
:
11 % per annum
131
on
Auxiliary power consumption:
Conservatively considered 6.5%
5. FIXED CHARGES
The items of cost forming a part of the fixed charge component are :
a) Operation and maintenance charges
b) Interest on loan becoming due during the year
c) Interest on working capital
d) Deprecia ion/Repayment
e) Return on equity
f)
Income Tax.
6. VARIABLE CHARGES
The variable charge component of the tariff includes the cost of primary fuel which is
imported coal and secondary fuel which is fuel oil. Based on government of India norms,
the following are considered while computing the annual running cost for periods beyond
the initial stabilisation period:
(a)
Annual cost of fuel oil
(b)
Annual cost of coal.
(c)
Annual cost of water
132
APPENDIX - 1
PROJECT SITE DATA
1.
Location of the plant
Nearby Nana Manda Khajurda
Village,
Dist Devbhumi Dwarka
,Gujarat.
2.
Elevation above mean sea level
31.5m
3.
Climatic conditions
3.1
Temperatures : Monthly basis
Highest Temperature Recorded
Minimum Temperature Recorded
Average Ambient Temperature
Wet buld Temperature
48 deg.C
5 deg.C
34 deg.C
28 deg.C
3.2
Relative humidity
Varies between 27% and 96%
3.3
Annual average rain fall
Annual average rainfall is about
535.7 mm (most of which occurs
during the monsoon season from
June to September)
3.4
Wind speed
- Maximum
- Aveg. Wind speed
50 m / s.
15.37 m/s
Seismic data (as per IS : 1893)
Zone V
4.
133
APPENDIX - 2
SEA WATER ANALYSIS
Sr.No
Test Parameters
Unit
Result
1
Color
APHA
5
2
Oil & Grease
ppm
ND
3
BOD
ppm
<5
4
COD
ppm
32
5
Suspended Solid
ppm
6
Turbidity
NTU
10
<
16.1
7
Calcium Hardness as CaCO3
ppm
1011
8
Magnesium Hardness as CaCO3
ppm
6714
9
Chloride as Cl
ppm
23716
10
Sulphate as SO4
ppm
3450
11
Sulphide as S
ppm
ND
12
M-Alkalinity as CaCo3
ppm
126
13
P-Alkalinity as CaCo3
ppm
6.0
14
Nitrate as NO3
ppm
3.5
15
Nitrite as NO2
ppm
50
16
Silica as SiO2-Dissolved
ppm
1.43
17
Iron as Fe-Dissolved
ppm
0.5
18
Iron as Fe-Suspended
ppm
ND
19
Total Dissolved Solids
ppm
37542
20
Conductivity at 25°C
µ-mho/cm
56034
21
pH at 25°C
22
Dissolved Oxygen as O2
8.1
ppm
134
7.0
APPENDIX - 3
ANALYSIS OF IMPORTED COAL
Proximate analysis
Worst
Design
Best
TOTAL MOISTURE
39
11.5
5
ASH
3
24
24
VOLATILE MATTER
30
25.6
19.2
FIXED CARBON
29
38.9
51.8
4000
4922
6060
GCV (ARB)
APPENDIX - 4
ANALYSIS OF FUEL OIL
Unit
Sl.
No.
Particulars
1.
Flash point
Deg. C min.
66
2.
Viscosity @ 150C Maxi.
Cst
180
3.
Power point
0
21
4.
Ash content by weight
% max.
01
5.
Free Water content by volume
% max.
1.0
6.
Sediments by weight
% max.
0.25
7.
Total sulphur by weight
% max.
4.0
8.
Calcium
PPM
30.5
9.
Sodium
PPM
10
10.
Lead content
PPM
0.2
11.
Vanadium
PPM
40.50
12.
Carbon residence (Rams bottom)
% wt
7.74
13.
Approximate gross calorific value
Kcal/kg
14.
SP gravity at 150C Max.
C
Furnace
Grade MV2
: 1593)
10,000
0.933
135
Oil
(IS
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
1.Name /Title of the project
: 2 x 660 MW, Imported coal based thermal
power plant at Nana Manda & Khajurda, Gujarat.
2.Name and address of the project
: Mr. Ramesh kumar
proponent
Essar Power Gujarat Limited (EPGL)
44th KM Jamnagar-Okha Highway,
Village Kajurad, Dist Devbhumi Dwarka.
3.Site where proposed plant would
be located (Site map, Land
: Nana Manda & Khajurda,
Dist Devbhumi Dwarka, Gujarat
layout plan to include 25 km
radius zone around the site )
4.Capacity of the project under
: 2x660 MW supercritical
consideration
5. Whether alternative sites were
: No, since this site was found most suitable
explored? If so, give details for
each site (Maps to be enclosed)
6.Land use pattern of the land
: Mostly non agricultural land, some land
occupied by salt pans, balance low productive
agriculture land.
7. Cost of land
: Covered under project cost
8.Govt. land / private land/ others
: 100 % Government land.
9. Topographical features,
: Generally flat drawing towards north (Refer
demographic profile and
Chapter - VI of the Report)
physiography.
10.Nature of soil
: Sandy, Murram
136
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
11.Distance from the nearest
: 11 km from Khambhalia town
town/city/major human
settlement
12. Population to be displaced
: None
13. Distance from water source
: 15 Kms
14. Area of forest land, if involved
: Nil
15.Distance of forests from the site
: NA
16. Give basis for selection of site
:
i) The land is barren and is not inhabited
ii) The site is 500 m from State Highway.
Nearest railway station is about 11 km from
site.
iii) Availability of adequate land
iv) Availability of adequate quantity of sea
water from arbian sea
: Yes, operational 2 x 600 MW as Phase- I
17.Is this an extension? If so
indicate capacity of the existing
plant
18. What is the ultimate capacity?
19. Name and address of
the consultant, if any
: 2x660 MW
:
Tata Consulting Engineers Ltd.
St. Mark’s Road, Banglore - 560001
137
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
GENERAL ENVIRONMENTAL INFORMATION
20. Details of major industries,
: Within 10Km area- There are a number of stone
thermal power plants, mines,
crusher, one ceramic making plant and other
quarries etc. Existing within
small mills. Ship building activity takes place at
a radius of 25 km of your
nearby Salaya port (minor port).
plant
Within 25km area- Refinery of Essar oil and
Reliance refinery.
21. What is the total human
population of 25 km of the
: There are 21 villages in 10km area of the site. The
total population is approximately 88934.
plant site indicate the pattern
of population dispersal.
22. Give a broad description
of the site. Attach map
: Refer Exhibit-1. The site is approachable from
Khambhalia state highway.
showing topographical
features
23.Nature of soil
: Refer Chapter VI
24.Area of the land proposed to
: Already in possession of total land of 330 Ha
be acquired (Attach layout
plan)
138
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT

Area required for plant
: For Phase- II (BTG & BOP) 125 hectares
Green belt : as per MOEF norms

Ash disposal

Colony (indicate separately
for departmental staff,
contractors (if any)
iv) Transmission corridors and
power evacuation system
v) Approach road, railway
bridges etc.
: Existing ash pond 25 hectares
: Not envisaged. Existing Essar oil refinery colony
would be used
By 400kV switchyard. Evacuating to 400kV
: GETCO / PGCIL substation.
: Jamnagar –Okha state highway, Widening and
strengthening of existing village roads & bridges.
No railway network
25.Present use of land
: Not Applicable
26.Area proposed to be built-up
: Refer Exhibit –I
or developed
27.Specify site characteristics
: Coastal
River basin/estuarine/
coastal/others
139
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
28.Is the site situated in the
: No
forest area? Give following
details:i) Area
: Not applicable
ii)Type of forests
: Not applicable
iii) If site is situated nearer to
: Not applicable
the forests? Give the
distance from the site
iv) Give a description of the
:
flora within 10 km of your
plant site under the following
heads:a)
Crops
b) Forest
c) Grassland
d) Endangered species
Maize, Bajra and wheat are the main crops
Not Applicable
Community level grassland are present.
Mangroves along the coast line on muddy patches
of land
e) Other (Specify)
v) Give a general description of
: The national park exists within 25km of site.
the fauna, especially wildlife, endangered species,
etc., within a radius of 25 km
140
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
vi) Give details of the following
:
features, if they exist, with-in
a radius of 25 km of the
proposed site?
Yes
Marine Sanctuary /
Marine national Park
i) Fisheries
ii) Sanctuary / natural park /
Biosphere rese ves
None
iii) Lakes / ponds / reservoir
Small streams/nalla are present
Yes
iv) Stream / river
v) Estuary / sea
None
vi) Hill / mountains
vii) Historic / cultural /tourist /
archaeological/scenic sites /
None
defense installations
29.Human Settlement
Total
number
of
: Refer Exhibit-10
persons
proposed to be employed.
i ) During construction
3000 (peak construction)
ii) During operation
400 Plant personal
30.Do you propose to build a
: Existing colony of Essar. Refinery at Vadinar
township / housing quarters
would be used to accommodate power plant
for
your
personnel also.
employees/contractor's
workers?
31.Area required for above
: Not applicable
141
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
32.Population to be
:
During detail engg
accommodated
33. Distance and direction of
Within a radius of 25km from plant
township from plant site
Service provided in
township.

Daily consumption of water
: 150lt /person/day

Power system
: 1KW/person /day

Sewage treatment
: The sewage (120lt/person/day) will be treated in STP

Drainage
: The treated water will be used for green belt.

Any other
:
Market, school, bank, post office, police station,
telephone, transport, hospital recreation halls
34.Number of persons to be
:
displaced along with details
of their occupation and
income
i) Number of persons who do
:
not own property, but, derive
their sustenance from the
No rehabilitation and resettlement is envisaged
land to be acquired
ii) Details of rehabilitation plan :
for the oustees
iii) Site where they would be
resettled
:
142
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
iv) Compensation to be paid
:
v) Authority responsible for their :
resettlement
FUEL
35 .Has fuel linkage been
established.
i)Type,
and : For coal characteristics refer Appendix – 3.
quantity
characteristics of fuel used
ii)
Has
the
linkage
been : Established
established?
iii)Name of Mine/Block
: Imported coal
iv) Is it a working mine or : working
yet to be opened?
v) Is the mine situated in the : Not applicable.
forest area?
vi)Please furnish a fuel analysis
: Refer Appendix - 3
report from a recognized
laboratory (Details to include
percentage contents of C, H,
N, S and Oxygen (if any) and
gross calorific value)
vii) Indicate the type of fuel : Pulverized coal firing
firing to be adopted
143
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
viii) Air to fuel ratio to be : During detail engineering stage
specified
WATER
36.Water use and liquid wastes
(provide
a
detailed
: Refer Exhibit- 3
water
balance diagram)
37. What is the source of
: Arabian sea water (Gulf of kutch)
Water? Would it be adequate
for the future use? Do you
propose
any
measures
to
augment the water supply and
how it affects other users
38.Lean season flow
: During detail engineering stage
39.Give details of the receiving : Arabian sea water (Gulf of kutch)
water body
40.Average daily approx.
quantity of Water required for
i)
Cooling tower blow-down
: Refer Exhibit- 3
ii)
Evaporation and drift loss
:
ii)
Cooling tower makeup(i+ii)
:
Total daily water requirement
:
144
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
41.What type of cooling system
:
Open cooling system with natural draught cooling
towers
is proposed once
through/closed

Give temperature difference
: Temperature rise across condenser is 10C
between inlet and outlet

Annual temperature profile
: Normal raw
of the receiving water
water
temperature variation
is
expected.
42.Quantity and expected
:
characteristics of the waste
water discharged per day from
the plant
i) Cooling
: Not applicable
ii ) Cooling Tower Blow-down
:
8690 m3/hr
iii) Process
:
1548 m3/hr
iv) Others
:
v) Total
:
43.Type
treatment
of
waste
proposed
10238 m3/hr
water : The effluent from DM plant and plant drains led to
to
adopted for each stream
be
guard pond, which would be used for plant
washing, gardening and miscellaneous services
The CW blow down would be returned back in to
the sea
44.Applicable standards
: MOEF / CPCB/ GSPCB regulations
regulations for the Effluents
145
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
45.Point of final discharge land
:
Sea.
/ sewer / river / lake /bay /
estuary / sea
46.Mode
Open
of
final
channel
/
discharge : Mode of final discharge is through pipeline with
pipeline
/
diffuser arrangement
covered drains
47.If the liquid effluents are : Not applicable
finally
discharged
to
river/pond/lake, the impact on
the quality of Water at the
nearest
human
settlement
should be mentioned
48.Details of
the reuse of : Cooling tower will be installed.
waste water
AIR EMISSIONS
49.Please
furnish
for
your : Refer Chapter XIV
location
50.Wind rose
i)Mean,
maximum
: Refer plot plan
and :
minimum temperature for every
month of the year
ii)Mean wind speed
:
iii)Humidity
:
iv)Mean cloud cover
:
Refer project details
146
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
v)Percentage(frequency)
:
occurrence of inversions and
heights
vi)Please specify the following:
:
vii)Number of stacks
: One Twin flue stack for two units
viii)Number of flues in each : Two
stack
ix)Inter-stack distance
: -
x)Stack height
: 275m
xi)Internal
diameter
of : 7.6 m (Approx.)
each flue at the top
xii)Gas velocity
: 20 – 25 m / sec approx. (at exit)
Flue gas characteristics
:
i) Volume (through each stack)
: During detail engineering
ii) Temperature
: During detail engineering
iii) Density
: 1.286 kg/Nm3
 Size distribution of
: During detail engineering
particulates
v) Gas composition (by Vol. )
: Typical
CO2
: 13.7%
O2
: 9.2 %
SO2
: 0.01 %
147
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
N2
H2O
: 74.5 %
: 2.6 %
vi)Heat emission rate of gases : During detail engineering
from each stack
: SO2 : During detail engineering.
Particulates < 30 mg / Nm³ per boiler with worst
each
coal firing and ash content of 24%
vii)Emission rate of SO2, NOx
and
particulates
stack in milligm/ m3
from
.
viii)Back ground pollution levels
of SO2, NOx and particulates
microgram/m3
: SO2 – Less than 80.0
NOx -Less than 80.0
(within 10km area)
148
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
a) What kind of stack emission : Flue Gas Monitoring: These are measured at the
monitoring is proposed
economizer outlet. For this purpose, O2
CO
monitor probes analyzers are installed separately
Stack emissions: Flue gas exiting into the
atmosphere is monitored for CO2, NOx, SO2 and
opacity. Stack emission readings are sent to the
DCS for monitoring. For this purpose, dilution
probes, associated gas
analyzers
support
equipment, sample lines and opacity sensor/
transmitters are installed. The opacity sensors
equipped with a blower to protect the optics from
coating by flue gas particles. The
system
operation is continuous. Stack gas analysis for
SO2 , CO2 and NOx is performed by extracting a
gas sample from the flowing stream in the stack,
filtering to remove particulate droplets, diluting
with scrubbed instrument air and conveying the
sample to the analyzers
b) What equipment is proposed
: Same as above
to be acquired or used for
this purpose
c)Give
pollution
details
control
of
the
air : High Efficiency electrostatic precipitator to limit
equipment
proposed to be installed
particulate emission to 30mg / Nm 3 at ESP outlet
with worst coal firing and ash content of 24%
149
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
d)Give
details
organization
of
the : There would be an experienced and qualified chief
set-up
for
chemist in charge of analytical measurements and
maintenance of pollution control
equipment
and
level
expertise
pollution control
of
and
authority of person in charge
e)Emission rate of particulates
and
sulphur
dioxide to
released
when
: SPM- < 30 mg/Nm3
be
SO2 and NOx will be dispersed through 275m
control
tall stack.
equipment is :
f)Functioning normally
SO2
:
Particulates
: With worst coal firing and ash content of 24%
Wet type FGD (limestone based) is proposed.
< 30 mg / Nm3 (with all fields of ESP in operation).
g) Not functioning
SO2
: Not applicable as the plant would be shut down
Particulates
: -
h)What special procedure do : Adequate design margins and standby capacity
you propose to lay down for the
are
provided
air pollution control during the
precipitators to forestall such problems
period when emission exceeds
prescribed limits for any reason
including
malfunction
of
pollution control equipment?
150
for
proposed
electrostatic
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
51.Other types of pollution
: Water
sprinkling
measures to reduce fugitive
dust emissions
a)Details of measures to control : All equipment would be designed / operated to
noise
have a total noise level not exceeding 85 to 90 dB
(A) measured at a distance of 1.5 m
b)Details regarding prevention
and
control
of
fire
and
explosion hazards
: All equipment vulnerable to explosion or fire would
be designed to relevant IS codes statutory
regulations.
Suitable
fire
protection
system
comprising hydrants and spray systems are
provided for fire protection
TRANSPORTATION OF FUEL:
52. Proposed mode of transport : Imported coal /
of coal/ oil/ gas.
Essar refinery near to site.
i)By sea
: Coal
ii)By Road
: Fuel oil
iii)By Pipe / Rope ways
: Nil
iv)By Rail/Road
: Coal
v) By Others
: Nil
151
Oil from
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
Coal and Ash Handling:
53. What procedure would be : Coal would be received by ships, transported from
adopted for coal handling at the
the jetty to plant site through closed conveyors to
plant site?
the stock pile. Coal within the plant from stockpile
yard to coal bunkers would be transported through
series of belt conveyors and traveling trippers.
i)Give
details
suppression
equipment
of
dust : Dust extraction system at all coal transfer points,
/
collection
bunker ventilation system for coal bunkers would
for
reducing
be provided and dust suppression system in the
pollution from coal fines and
stock yard is provided.
other fugitive emissions from
coal
handling
(conveyor
transfer points, storage, Bunker
filling etc.)
Ii) How do you propose to
: Not applicable
prevent /treat the run-off from
the coal storage/ handling area
?
iii) What quantity of fly ash And : Total ash expected: 1464 t/day per unit ( with 24%
bottom ash would be produced
ash content)
per day
Fly ash: 1171 t / day per unit
Bottom ash:
152
2 9 3 t / day per unit
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
iv)
Indicate the
method
of : Fly ash: Fly ash collected in various hoppers
collection, transportation and
would be pneumatically (pressure) conveyed to
disposal of the ash
the silos. From silos it would be either conveyed to
the disposal area in the form of high concentrated
slurry or collected in dry form for commercial use
Bottom ash : would be disposed off in dry / wet
form
Provision has been kept to dispose off the Ash
generated in high concentrated slurry form
v) What efforts have been
: Arrangements would
be
made with
private
made or you wish to make
entrepreneurs for utilizing fly ash for commercial
towards utilization of fly ash for
purposes
Bricks /cement/ road
construction/land fill/soil
stabilization/ other forms of
disposal or use
vi)
What
precautions
are : As high concentrated slurry disposal is envisaged
proposed to be taken to prevent
,ash disposal pond would be completely lined with
pollution of water source and
impervious liner to prevent ground water pollution.
ground water from solid waste
disposal, especially with regard
to coal particles and ash slurry?
153
APPENDIX - 5
BASIC INFORMATION FOR ENVIRONMENTAL APPRAISAL
GENERAL INFORMATION ABOUT THE PROJECT
vii) What land area is available
: Around 25 hectares of land has been identified for
for ash disposal? Would it be
ash disposal which is adequate for the expected
sufficient for the expected life of
plant life in the existing facitilty.
the plant ?
154
54.0 CONSTRUCTION MATERIALS
i) Indicate source of supply of : Construction materials would be available with in
stones and location of quarries
in
the
site
map
with
radius of 50 km.
the
alignment of the roads to the
projects site and its distance
from the site
ii) Source of supply of sand and
: Local available services within 50kms
its distance from the site
iii)
If new roads are built : Widening & strengthening of existing village roads
whether
their
alignment
is
outside the plant
through agriculture land /forest/
grazing
land/human
settlement/fallow land
iv) Mode of transportation of : All power plant
equipment and construction
heavy equipment, cement steel
materials would be transported by Sea/ road to
i.e. by road or rail or sea
the power plant site
v)Name of the nearest rail head
: The nearest Railway station (Khambhalia)
is
where they would be off loaded
located at a distance of 20 Km from the proposed
and its distance from the site
site
vi)If a new road is to be built : Not required
from the rail head, the details of
land to be acquired should be
given
OCCUPATIONAL SAFETY AND HEALTH
55.Health status of workers : In coal handling areas suitable dust control
especially those engaged in the
/collection equipment are provided to ensure a
coal handling, ash collection
clean and healthy environment. No problems are
and ash disposal area
envisaged in ash disposal area where slurry
disposal has been envisaged
155
56.Whether any adverse health
effect
due
to
noise
: Noise level would be limited to 85-90 dB (A) in
were
these areas and hence no adverse health
observed among the workers
engaged
in
compressor
the
turbine,
room,
crushing
problems anticipated
mills etc
57.If the plant is new, precau-
: Adequate measures would be taken as required.
tionary measures proposed to
be taken for safety and health
protection of workers may be
mentioned
ENVIRONMENTAL MANAGEMENT
58.Give
details
organizational
of : Qualified Engineer would be given responsibility of
set-up
you
have
for
propose
to
pollution
monitoring
the pollution monitoring and control.
and
control ?
59.What
is
the
expertise of
the
level
of : Qualified engineers would be
job
person in
charge of pollution control ?
60.Briefly outline the proposed
:
environmental monitoring
programme, mention No. of
observation sites and frequency
of observations addressing to
the following parameters:
i)Air
: Refer Chapter – XIV
ii)Water
: Refer Chapter – XIV
iii)Ground water
: Refer Chapter – XIV
iv)Stack Monitoring
: Refer Chapter – XIV
156
employed for the
v) Have you been asked by the
: Refer Chapter – XIV
Central State Pollution Control
Boards to take any special
Environmental control
measures and how do you
Propose to carry out these
obligations?
vi) Raising of green belt(Area
: The
area
may be indicated in a map)
allocated for the Green belt would be developed in
and around 250-300 acres of the power plant
DETAILS OF EXISTING UNITS
61.If it is an extension, Please
:
Phase-I of 2 x 600MW (Under operation)
furnish the following details in
respect of the existing units:
Existin g
units and
their
capacity
2 x 600
MW
Efficien
cy
of
ESP in
%
99.8
Fuel
consumpti
on(coal/oil
/gas)tonne
s/day
Sulphur
content
in %
11568
0.01
62. Have there been public
:
No
complaints or questions
in the Parliament or State
assembly regarding the
environment problems posed by
the existing Units. If so, give
details
157
Stack
height
in m
275
Heat
emission rate
in kcal/hr
from stack
NA
Particulates
SO2
NOx
NA
NA
63.Have there been any
:
Nil
representation / protests from
the Public/voluntary
organizations against the
setting up of the new units/plant
at the Proposed locations if so,
give details
64.Economics
of
Pollution :
Control
Excluded from the scope of this report. During
detail engg
65.What is the total project cost
:
During detail engg
66.Indicate costs of pollution :
During detail engg
?
control
under
the
following
heads
Capital / Recurring (annual)
:
Included above
Air
:
Included above
Fly ash control
:
Included above
Sulphur dioxide control
:
Included above
Oxides of Nitrogen control
:
Included above
158
PRODUCED BY AN AUTODESK EDUCATIONAL PRODUCT
PRODUCED BY AN AUTODESK EDUCATIONAL PRODUCT
PRODUCED BY AN AUTODESK EDUCATIONAL PRODUCT
PRODUCED BY AN AUTODESK EDUCATIONAL PRODUCT
AEGIS LTD - ESSAR ENGINEERING SERVICES DIV., HAZIRA
750
750
3000T
3000T
3000T
3000T