Coega CCGT Power Plant Project
By: Black & Veatch / Eskom
25 July 2006
Table of Contents
A.
B.
Introduction
1.
Need
2.
Project background
Power plant
1.
Gas Turbine Technology
2.
Cycle Configuration
3.
Equipment, systems & facilities
4.
Site buildings
5.
Emissions
6.
Noise levels
7.
Cooling System
8.
Water Supply
9.
Wastewater & Sewage Treatment Systems
10. Fire Protection
C.
Site Layout & LNG Integration
D.
Project Milestones
A. Introduction
1. Need
• In March 2006, Eskom Board supported the Combined Cycle Gas
Turbine (CCGT) project strategy to have the first 800MW available
in the first quarter of 2009.
• Project seen as a potential option to:
– Help resolve the Cape problems
– Strengthen regional supply
– Stabilise the grid
– Anchor project for IDZ
2. Project Background
• Coega CCGT Project under evaluation since 2004.
• Project being developed jointly with iGas (a subsidiary of CEF, also
a state owned entity):
– iGas developing the LNG import and regasification terminal
– Eskom developing the power station
• Provision for a maximum of 3200MW has been made at the current
site.
• First 800MW to be commissioned prior to the LNG regasification
terminal being commissioned; therefore liquid fuel firing would be
used in the first 12 to 18 months until the terminal is ready to supply
natural gas.
B. Power Plant
1. Gas Turbine Technology
• Project Requirements:
 800 MW by March 2009.
 Eventual 2400 MW Combined Cycle & 800MW open
cycle. Total will be 3200MW.
 Initial operation on distillate fuels until LNG available
in 2011.
 First 800 MW will be Open Cycle to accommodate
schedule.
1. Gas Turbine Technology (continued)
• Turbine Technologies
 F-Class: Best fit for combined cycle (CC); higher
efficiency and proven reliability in CC operation with
natural gas. Also good match of MW output to
project.
 E-Class: Good when burning primarily liquid fuels.
1. Gas Turbine Technology (continued)
• Gas Turbine Suppliers:
 General Electric (GE), Mitsubishi Heavy Industries
(MHI) and Siemens are all viable options.
 Alstom has expressed concerns over long term
operation on distillate fuels. Difficult to operate GT in
Open Cycle.
 All four vendors are able to execute project as an
equipment only supplier (complete Power Island) or EPC
Turnkey.
2. Cycle Configuration
• Recommended Coega Cycle Configuration
 Two blocks of 3x1 configuration using F-Class CTs.
 First block will be initially in Open Cycle mode to meet
goal of 800 MW by March 2009. It will produce 1200MW
by the end of 2009 in combined cycle mode.
 First block will be operated on liquid fuel until LNG
available.
 Second 3x1 block will be completed in time for 2011
operation on LNG.
3. Equipment, systems & facilities
 The following is a list of major equipment, systems and
facilities:
 2 blocks of 3 x 1 Combined Cycle units, Combustion Turbines with HRSGs
 Each block – 400 MW steam Turbine
 Once through sea water cooling – Surface condenser with Titanium tubes.
 Desalination System.
 Air Compressors and dryers
 Fuel Oil Storage tanks and unloading facility
 Demin Water Tank
 Firewater/Service water Tank
 Condensate Storage tank
 Intake cooling water structure with Pumps, screens
3. Equipment, Systems & Facilities (continued)
•
The following is a list of major equipment, systems and facilities (continued):
 Intake cooling water pipe and discharge canal
 Auxiliary Boiler.
 Wastewater Treatment System
 Emergency Diesel Generators
 8 MW Black start Diesel Generator
 2 – 100 Ton Bridge Cranes with aux Hoists.
 Hydrogen Generation system
 Hypochlorite Generation System
 Demin water system.
 Condenser Tube Cleaning System.
 CEMS
3. Equipment, Systems & Facilities (continued)
• Heavy haul:
– Steam turbine generator stator: LxWxH = 12m x 5.5m x 4.85m,
shipping weight = 314,000 kg
– Steam turbine step-up transformer: LxWxH = 8m x 4.2m x 5m, shipping
weight = 270,000 kg
– HRSG HP drum: LxDia = 13m x 3.1m (including shell projections),
shipping weight = 143,000 kg
– Largest HRSG tube bundle section (probably the HP economizer or
evaporator section): LxWxH = 25m x 4.3m x 3.4m, shipping weight =
218,500 kgs
•
Note: Transportation of equipment may be an issue.
4. Site buildings
 The HRSG does not include duct firing.
 Pilings are assumed for all major foundations, and spread
footers of other foundations. Further stabilization of the existing
subgrade is also not included.
 The following Site Constructed buildings are included:
 ST Generation and CT Buildings
 Three story Admin/Maint/warehouse building
 Demin Water Treatment Building
 Desalination Building
 Water Treatment Building
5. Emissions
• Air emission sources will be the combustion turbines (6),
emergency diesel generator (1), and auxiliary boiler (1).
• The World Bank NOx emission limit for combustion turbines burning
diesel is 165 mg/Nm3 with a provision for increase to 400 mg/Nm3 if
there are technical difficulties, such as scarcity of water for
injection.
• World Bank standards will be met when burning diesel or natural
gas.
• SO2 emissions are dependent on fuel sulfur content.
• Water injection may be required to meet combustion turbine NOx
emission requirements when burning diesel.
6. Noise levels
• Imposing requirement of 85 dBA at 3 feet from individual
equipment.
• Can impose site boundary limitations if necessary to
meet NPA, CDC, or national standards.
• Installing silencers on steam relief valves and startup
vents to minimize noise during startup and upset
conditions.
7. Cooling system
• Once through cooling using seawater with a maximum 7oC
temperature rise.
• Performing a heat rejection comparison between once through
cooling and cooling tower to confirm once through cooling is the
most economical option.
• A portion of the circulating water effluent may be used for LNG
vaporization.
• Thermal modeling to be performed to confirm no impact on
environmentally sensitive areas.
8. Water supply system
• Installing a desalination system to serve as the primary
make-up water supply and CT water injection.
• A connection to the city water system will be used as
backup.
9. Wastewater & Sewage treatment Systems
•
Sanitary waste will be discharged to the local wastewater treatment plant.
•
An oily water separator will be used for any waste streams coming from potentially
contaminated areas.
•
All process water collected on site, including effluent from the oily water separator,
will be treated by a wastewater treatment system and re-used.
•
Oil collected in the oily water separator will be pumped out and disposed of off-site.
•
A false start drains tank will collect liquid fuel resulting from an unsuccessful
combustion turbine start on diesel. This waste will be disposed of off-site.
•
Combustion turbine off line water wash waste will be collected and disposed of offsite.
•
Purge water from the performance fuel gas heater will be collected and sampled to
determine whether there is hydrocarbon contamination. Uncontaminated water can
be processed in the wastewater treatment plant and re-used. Contaminated water
will be disposed of off-site.
10. Fire protection
•
An inert gas system (CO2) will protect the combustion turbine
compartments.
•
Sprinkler systems will be used to protect the turbine areas, control room,
and other sensitive electrical rooms.
•
A motor driven fire pump and backup diesel driven fire pump will be
provided.
•
A combined raw / fire water storage tank will be used as the primary fire
water source.
•
Standpipes inside the fire tank for raw water use will ensure a dedicated
fire water source.
•
An additional dedicated fire water tank will be provided to serve as a
backup fire water source if the city water source does not meet NFPA
reliability requirements.
•
A ring header around the site with fire hydrants will be used for general site
protection.
11.Fuel supply
• Liquid fuel usage rate is 1,367 l/min per combustion turbine at base
load. This assumes a diesel heat content of 42.33 MJ/kg (LHV) @
25oC.
• Bulk storage facility will have 6 tanks each sized at 47.7 million
liters, each to provide 21 days storage for 6 combustion turbines
operating at base load.
• Capacity of the on site diesel storage tank should be 13.5 million
liters with a usable capacity of not less than 11.8 million liters,
assuming 6 CTs operating at base load for 24 hours.
• Two 160,000 m3 LNG tanks with a third tank in the future are
assumed.
• LNG terminal availability will be assumed at 98%
Site Layout
C. LNG Integration
C. LNG Thermal Integration
• LNG-CCGT Thermal Integration will be
evaluated. Following options will be studied.
–
–
–
–
Cooling water integration
Gas turbine inlet air chilling
Base case – no integration.
As back-up both open rack vaporizers (ORV) and
submerged combustion vaporizers (SCV) will be
considered.
D. Project Milestones
D. Project Milestones
• 28 July 06 – Specs for long-lead items
• Sept 06 – Concept Design / Prep EPC Specification
complete
• Oct 06 – EPC Bid Issue
• Jan 07 - Submit bids
• 15 April 07 – EPC LNTP Award
• 31 May 07 – Prelim EPC Design complete
• 31 Aug 07 – ROD/EPC NTP award
• Mid Sept 07 – Start construction
• 01 Feb 08 – Start foundations
• 01 Aug 08 – Port available
D. Project Milestones (continued)
•
•
•
•
•
•
•
•
•
30 Nov 08 – Tank farm complete
01 Jan 09 – Diesel available
Mid April 09 – Backfeed
Mid May 09 – First Fire CT-1
1st June 09 – First Fire CT-2
Mid June 09 – First Fire CT-3
01 Sept 09 – Steam blow
01 Dec 09 – Planned commercial operation (CC)
01 March 10 – Guaranteed commercial operation (CC)