DETAILS OF CALCULATIONS:
POWER OUTPUT
= 660 MW
TOTAL ENERGY DELIVERED @ 660 MW FOR A PERIOD OF ONE HOUR =
660MWH
Taking Efficiency = 37.96 % and 90 % PLF
Input = 660* 103 x 0.9 x 860 kcal / 0.3796
= 1345732.35 Kcal
(1 KWH = 860kcal)
Design calorific value of coal = 3300 Kcal/ kg
Coal requirement per hour
= 1345732.35 / 3300 = 408 T
At efficiency 38.96 % coal requirement per hour = 397 T
Yearly saving of coal by increasing
efficiency of 1 % = 11 x 24 x 365 days = 96,360 MT
Total value of the coal saved @ Rs 650 / MT = Rs 626 lakhs
If the efficiency increases by 2.5 % = Rs 626 x 2.5 = 1565 Lakhs
Considering the life time as 30 Years, the savings in Fuel cost
will be Rs 46950 Lakhs ~ 470 Crores
For three units = 470 x 3 = 1410 Crores
INDIRECT SAVINGS
Assuming Auxiliary Power consumption as 8 %
Estimated reduction in auxiliary power consumption = 0.3 %
For 660 MW units savings of auxiliary power
= 8 % x 660 x 0.003 = 0.158MW
Yearly savings in MW
= 0.158 x 365 x 24 x 0.9 = 1248 .825
= 1248825 units
Taking the unit cost as Rs 2.50 per unit
Savings
= 32.00 Lakhs
Total for three units
= 32 x 3 = 96.00 Lakhs
~ 1.0 Crores
For life time = 30. Crores
TOTAL = 1410 + 30 = 1440 CRORES
ASSUMING THE LIFE AS 30 YEARS, THE APPROXIMATE SAVINGS WILL BE
RS 48 CRORES PER YEAR FOR ALL THREE UNITS TOGETHER.
INCREASE IN PLANT EFFICIENCY by SUPER
CRITICAL PARAMETERS
Efficiency Increase
1.5
6
5
4
0.6
0.9
3.2
3 .
2
1
167 bar 250 bar
250 bar 250bar
250 bar
538/538’c 538/538
540/560’c 566/566 ‘c 580/600’c
Comparison of BHEL V/s Doosan Units
Doosan Units
BHEL Units
• Total Weight- 27960
MT
• Total
MT
–
–
–
–
–
Structure – 6924 MT
Pr. Parts – 7080 MT
P C Piping – 3032 MT
P F System – 3823 MT
Draft System – 5004
MT
– Refractory/Insulation
C&I/Misc – 2097 MT
–
–
–
–
–
–
Weight-
28585
Structure – 10801 MT
Pr. Parts – 5800 MT
P C Piping – 1445 MT
P F System – 2342 MT
Draft System – 5680 MT
Refractory/Insulation
C&I/Misc – 2517 MT
COMPARISION OF 660 MW Vs 500 MW BOILER
Description
unit
660
T/HR
2225
1625
KG/CM2
256
179
0C
540
540
T/HR
1742
1397.4
0C
303.7
338.5
RH STEAM TEMP OUTLET
0C
568
540
RH STEAM PRESS INLET
KG/CM2
51.17
46.1
FEED WATER TEMP
0C
291.4
255.2
S/H STEAM FLOW
SH
STEAM PR
SH STEAM TEMP
RH STEAM FLOW
RH STEAM TEMP
INLET
500
Tonnage Comparison
Description
660 MW
500 MW
Structural Steel Erection
7383
9200
Boiler Proper & Accessories (Pre. Parts)
7080
5300
Refractory, Insulation & Cladding
1410
2000
Power Cycle Piping
3032
2200
54
76
Coal Firing System
3573
2000
Draft System
5275
5200
62
200
Miscellaneous System
130
280
Electrical & Instrumentation
282
380
28281
26836
Soot Blowing System
Fuel oil system
TOTAL
Material Comparison
Description
660 MW
500 MW
Structural Steel
Alloy Steel
Carbon Steel
Water wall
T22
Carbon Steel
SH Coil
T23, T91
T11, T22
RH Coil
T91,Super 304 H
T22, T91,T11
LTSH
T12
T11
Economizer
SA106-C
Carbon Steel
Welding Joints (Pressure Parts)
42,000 Nos
24,000 Nos
Structural Comparison
Slno
660 MW
1
STRUCTURALS
500 MW
a
b.
Remarks
Entire structural is bolting typeentire structure is bolted. Holes
are drilled on the columns and
gusset plates, and supplied with
matching plates.
Structural is
assembled at site
with welding
Advantages (660MW) of
Bolting structure:
oFast in erection.
oClean environment
oNo Welding network required
oSafety at site
oPainting finish is good
o( No Weld surface)
No Welding work involved in
assembly/ Erection , except
Walkway rail post welding
Assembly is carried
out with Welding
Can be dismantled if required
( For Maintenance purpose)
Material supply is tier wise
including staircases, railing,
gratings etc.
Material is supplied
as per the erection
sequence.
Erection completion tier wise,
including gratings, platforms ,
staircases etc.
c
COST COMPARISON
1 Cost of SG Package
1970.73 Cr
1020.54 Cr with ESP
2 Cost of ESP
183.54Cr
3 Total cost of Boiler + ESP
2154.27 Cr
1020.54 Cr
4 Cost of Boiler per MW with ESP
1.09 Cr
1.02 Cr
5 Cost of TG for entire stage
1204.72 Cr
634.31 Cr
6 TG cost per MW
0.6Cr
0.63 Cr
BOILER SPECIFICATION
Description
unit
S/H STEAM FLOW
T/HR
2225
KG/CM2
256
0C
540
T/HR
1742
0C
303.7
RH STEAM TEMP OUTLET
0C
568
RH STEAM PRESS INLET
KG/CM2
51.17
FEED WATER TEMP
0C
291.4
SH
STEAM PR
SH STEAM TEMP
RH STEAM FLOW
RH STEAM TEMP
INLET
= Boiler Efficiency
Quoted Turbine Heat Rate
100% TMCR
86.27%
100% Load 1904 Kcal / KWH
80% TMCR
86.60%
80% Load
1924 Kcal / KWH
60% TMCR
86.68%
60% Load
1973 Kcal / KWH
50% TMCR
86.91%
50% Load
2065 Kcal / KWH
Net Plant Heat Rate = NTRH
= 2207 KCal / KWHR ( at 100% TMCR)
80% TMCR
60% TMCR
50% TMCR
= 2222 Kcal / KWHR
= 2276 Kcal / KWHR
= 2376 Kcal / KWHR
Plant Efficiency at 100% TMCR = 38.96%
80% TMCR = 38.7 %
60% TMCR = 37.78%
50% TMCR = 36.19%
SUPERCRITICALTHERMAL CYCLE
ADVANTAGES
•
•
•
•
(1)
Improvements in plant efficiency .
Decrease in Coal Consumption
Reduction in Green House gases.
Overall reduction in Auxiliary Power
consumption.
• Reduction in requirement of Ash dyke
Land & Consumptive water.
SUPERCRITICAL – ADVANTAGES
(2)
• Sliding pressure operation because of Once
through system .
• Even distribution of heat due to spiral wall
arrangement leading to less Boiler tube
failure, thereby improving system continuity
and availability of the station.
• Low thermal stress in Turbine .
• The startup time is less for boiler.
SUPERCRITICAL – DISADVANTAGES
• Higher power consumption of BFP
• Higher feed water quality required.
• More complex supporting and framing in Boiler due to
Spiral Wall tubes.
• Slight higher capital cost.
• Increased dependency For Spares and services.
IMPORTANCE OF EFFICIENCY
• The cost of operating the Plant of 3 x 660 MW, one
percentage point below the design point, will incur
additional fuel cost of Rs. 16 Crores in a year.
• The indirect costs for Maintenance, APC, Ash Dyke land
etc. will give additional burden of Rs. 1Crores in a year.
• The environment will benefit on account of reduction in
GHGs like Co2, NOX & SOX.
• The life time savings of Rs.550- 600 Crores can be
achieved by increasing efficiency by one percentage .
• At Sipat, we gain an efficiency of 2.5 percentage by
adopting super critical technology in 1980 MW station,
thus saving Rs. 1440 Crores in its life time.
REDUCTION IN CO2 EMMISSION
• CONSIDERING AVG COAL CONSUMPTION OF AT
FULL LOAD OPERATION
:
400T/HR
• IMPROVEMENT IN EFFICIENCY
FOR SUPER CRITICAL TECHM
COMPARED TO 500 MW BOILER
:
1.5%
• REDUCTION IN COAL FLOW
:
6 T/HR
• REDUCTION IN CO2 EMMISSION
(FIXED CARBON CONTENT IN COAL 30%) : 6 T/HR
• REDUCTION IN CO2 EMMISSION
PER YEAR
: 52560 TONS