1. DETAILS OF CALCULATIONS:
POWER OUTPUT = 660 MW
TOTAL ENERGY 660 MW FOR A PERIOD OF ONE HOUR = 660MWH
Taking Efficiency = % and 90 % PLF
Input = 660* 103 x 0.9 x 860 kcal / = Kcal
(1 KWH = 860kcal)
Design calorific value of coal = 3300 Kcal/ kg
Coal requirement per hour = / = 408 T
At efficiency % 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 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 Lakhs ~ 470 Crores

2. INDIRECT SAVINGS For three units = 470 x 3 = 1410 Crores
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 = 0.158MW
Yearly savings in MW = x 365 x 24 x 0.9 =
= units
Taking the unit cost as Rs 2.50 per unit
Savings = Lakhs
Total for three units = 32 x 3 = Lakhs
~ 1.0 Crores
For life time = 30. Crores
TOTAL = = 1440 CRORES
ASSUMING THE LIFE AS 30 YEARS, THE APPROXIMATE SAVINGS WILL BE RS 48 CRORES PER YEAR FOR ALL THREE UNITS TOGETHER.

3. INCREASE IN PLANT EFFICIENCY by SUPER CRITICAL PARAMETERS
Efficiency Increase
1.5 6 5
0.9
0.6 4
3.2 3 . 2 1
167 bar
538/538’c
250 bar
538/538
250 bar
540/560’c
250bar
566/566 ‘c
250 bar
580/600’c

4. Comparison of BHEL V/s Doosan Units
Total Weight 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
BHEL Units
Total Weight MT
Structure – 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

5. COMPARISION OF 660 MW Vs 500 MW BOILER
Description
unit
660
500
S/H STEAM FLOW
T/HR
2225
1625
SH STEAM PR
KG/CM2
256
179
SH STEAM TEMP 0C
540
RH STEAM FLOW
1742
1397.4
RH STEAM TEMP INLET
303.7
338.5
RH STEAM TEMP OUTLET
568
RH STEAM PRESS INLET
51.17
46.1
FEED WATER TEMP
291.4
255.2

6. 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
Soot Blowing System 54 76
Coal Firing System
3573
Draft System
5275
5200
Fuel oil system 62
200
Miscellaneous System
130
280
Electrical & Instrumentation
282
380
TOTAL
28281
26836

7. Material Comparison Carbon Steel T11, T22 T22, T91,T11 T11 24,000 Nos
Description
660 MW
500 MW
Structural Steel
Alloy Steel
Carbon Steel
Water wall
T22
SH Coil
T23, T91
T11, T22
RH Coil
T91,Super 304 H
T22, T91,T11
LTSH
T12
T11
Economizer
SA106-C
Welding Joints (Pressure Parts)
42,000 Nos
24,000 Nos

8. Structural Comparison
Slno
660 MW
500 MW
Remarks 1
STRUCTURALS a
Entire structural is bolting type- entire 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:
Fast in erection.
Clean environment
No Welding network required
Safety at site
Painting finish is good
( No Weld surface) b.
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) c
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.

9. COST COMPARISON 1.09 Cr 1.02 Cr 0.6Cr 0.63 Cr 1 Cost of SG Package
Cr with ESP 2
Cost of ESP
183.54Cr 3
Total cost of Boiler + ESP Cr Cr 4
Cost of Boiler per MW with ESP
1.09 Cr
1.02 Cr 5
Cost of TG for entire stage Cr Cr 6
TG cost per MW
0.6Cr
0.63 Cr

10. BOILER SPECIFICATION S/H STEAM FLOW T/HR 2225 SH STEAM PR KG/CM2 256
Description
unit
S/H STEAM FLOW
T/HR
2225
SH STEAM PR
KG/CM2
256
SH STEAM TEMP 0C
540
RH STEAM FLOW
1742
RH STEAM TEMP INLET
303.7
RH STEAM TEMP OUTLET
568
RH STEAM PRESS INLET
51.17
FEED WATER TEMP
291.4

11. = Boiler Efficiency
100% TMCR
86.27%
80% TMCR
86.60%
60% TMCR
86.68%
50% TMCR
86.91%
Quoted Turbine Heat Rate
100% Load
1904 Kcal / KWH
80% Load
1924 Kcal / KWH
60% Load
1973 Kcal / KWH
50% Load
2065 Kcal / KWH
Net Plant Heat Rate = NTRH
= KCal / KWHR ( at 100% TMCR)
80% TMCR = Kcal / KWHR
60% TMCR = Kcal / KWHR
50% TMCR = Kcal / KWHR
Plant Efficiency at 100% TMCR = 38.96%
80% TMCR = 38.7 %
60% TMCR = 37.78%
50% TMCR = 36.19%

12. 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.

13. 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.

14. 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.

15. 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 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 Crores in its life time.

16. REDUCTION IN CO2 EMMISSION
CONSIDERING AVG COAL CONSUMPTION OF AT FULL LOAD OPERATION : T/HR
IMPROVEMENT IN EFFICIENCY
FOR SUPER CRITICAL TECHM
COMPARED TO 500 MW BOILER : %
REDUCTION IN COAL FLOW : T/HR
REDUCTION IN CO2 EMMISSION
(FIXED CARBON CONTENT IN COAL 30%) : 6 T/HR
PER YEAR : TONS