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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
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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 0.9 5 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
Doosan Units Total Weight- 27960 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- 28585 MT 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 Comparison of BHEL V/s Doosan Units
Net Plant Heat Rate = NTRH = 2207 KCal / KWHR ( at 100% TMCR) 80% TMCR = 2222 Kcal / KWHR 60% TMCR = 2276 Kcal / KWHR 50% TMCR = 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