CEA PRESPECTIVE ON Energy Efficiency in Coal Fired Power Stations CHANDRA SHEKHAR DIRECTOR,CEA

CEA PRESPECTIVE ON Energy Efficiency in Coal Fired Power Stations CHANDRA SHEKHAR DIRECTOR,CEA

ALL INDIA PLANT LOAD FACTOR OF COAL BASED POWER PLANTS (%) 11-12 FO 11.46 pm 5.93 Av. 82.61 12-13 FO 13.59 pm 5.71 AV. 80.69 13-14 FO 17.65 pm 5.01 Av. 77.34

GROWTH OF GENERATION GWH 1947 to 2014 2500000 generation Gwh 2000000 1500000 1000000 500000 0 4073 5106 9662 16937 32990 47434 66689 102523 104627 156859 245438 287029 395889 517439 624495 789013 876885 912000 967150

Installed Capacity as on 31-12-14 (Type Wise) Hydro, 40798.76, 16.00% [CATEGORY NAME], [VALUE], [PERCENTAGE] Nuclear, 4780, 1.87% Diesel, 1199.75, [CATEGORY 0.47% NAME], [VALUE], [PERCENTAGE] Coal, 153570.9, 60.22% Installed Capacity = 255012.8MW

Installed Capacity as on 31.03.2014 (Type Wise) Nuclea r 2% Diesel 1% R.E.S 12% Hydro 18% Gas 9% Coal, 130370.89, 58% Installed Capacity = 243028.95MW

GENERATION Gen. 13-14 -967BU (14-15) upto 31 st Dec.793.7BU 722 last year Comprises Coal/lignite based 746.1 BU (77.14% of total Gen.) on 60% Capacity Gas = 44.52 BU(4.6% of total Gen.) on 9% Capacity, Hydro= 134.84 BU (13.9% of total Gen.) on 17% Capacity In 2014-15 upto December,2014 COAL/Lignite 75.28% on 60.22% capacity Gas 4% on 9% Capacity Hydro 13.44% on 15.99 % Capacity

Power position in the country (2013-14) HYDRO, 134.85, 14% 17% DIESEL, 1.85, 0% GAS, 44.52, 5% 9% NUCLEAR, 34.23, 3% BHUTAN IMP., 5.6, 1% COAL, 746.1, 77% 60% CAP.

CAPACITY ADDITION DURING 11 TH PLAN (2007-2012) (in MW) Capacity addition target during 11 th Plan 78,700 Capacity Commissioned during 11 th Plan 54,964 MW 43384 MW coal 5156MW gas 5544MW hydro

CAPACITY ADDITION DURING 12 TH PLAN (2012-2017) (in MW) Capacity addition target during 12 th Plan 88,537 Capacity already Commissioned during 12 th Plan (as on 31 Dec., 2014) Total- 49058.2 42845 COAL 4318.2 GAS 1895.02 Hydro State 10011.1 Pvt. 29776.5 Central 9270.62

Major Unit Sizes and Steam parameters Size Steam Parameter Design Efficiency MW ata/c/c (%) Year 30-50 60/ 482 ~31 1950 60-100 90/ 535 32-33 1960 110 to150 130/ 535/535 35-36 1970 200/210 130,150/535/535 36.3,37.8 1977 250 150/535/535 38.3 1995 500 170/ 538/538 38.5 1984 500 170/535/565 38.7 2010 660 247/535/565 ~39.5 2010 660/800 247/565/593 40.5 2012 Efficiency on HHV basis

PLF of Power Plants PLF 2012-13 2013-14 State sector 65.57% 59.13 % Central Sector 79.18% 76.11% Pvt - 64.12% 68.67% ALL INDIA - 69.93% 65.55% Loss of Generation due to Coal shortage 15.84BU 4.3BU Receipt of poor coal quality 16.41 6.75 Backing Down 23.39 48.95 Transmission constraints 4.1 0.23 Gas Shortage 73.09 107.15

ALL INDIA Thermal PS last Five Years Efficiency Trend Capacity Analysed 82973.47 MW (13-14) 73 Stations Design Efficiency 36.75% 34.50 Efficiency 34.00 33.75 33.84 33.91 33.50 33.49 EFFICIENCY 33.00 32.50 32.54 Efficiency 32.00 31.50 YEAR 2009-10 2010-11 2011-12 2012-13 2013-14

BOILER LOSSES to be taken care off seriously of COAL FIRED STATIONS

The major factors to be looked into in TURBINE SIDE LOSSES Main steam and reheat steam inlet parameters (For every 1 drop in Main Steam/ R H temperature than the designed value of 537 C, causes a heat loss of approx 0.67 KCal/KWh 1 KG/CM2 drop in Main Steam Pressure at Turbine Inlet than the design value i.e 150 KG/CM2 causes a heat loss of approx. 1.31 KCal/KWh) Turbine exhaust steam parameters Reheater and super heater spray Passing of high energy draining Loading on the turbine Boiler loading and boiler performance Operations and maintenance constraints Condenser performance and cooling water parameters Silica deposition and its impact on the turbine efficiency Inter stage sealing, balance drum and gland sealing Sealing fins clearances Nozzle blocks Turbine blade erosion Functioning of the valves Operational status of HP heaters

The major TURBINE CYCLE LOSSES

Major Possibilities for Condenser and Water pumping and Cooling tower

Heat rate GAURENTEED BY EQUIPMENT MANUFACTURER

Sl. Capacity Group(MW) PLF% Groupwise 2013-14 No. of Units Cap. in MW PLF% in 13-14/12-13/11-12 1 660-800 21 14600 67.92/57.52/44.31 1 450-600 87 45130 67.66/71.97/78.38 2 300-350 26 8020 62.82/70.45/72.26 3 250 51 12830 71.96/77.91/81.75 4 210 143 30030 68.76/76.91/78.67 5 195-200 25 4990 73.23/76.62/74.98 6 100-150 101 12145 46.36/50.23/49.11 7 25-99 85 4880 47.85/54.39/55.46 8 Total 539 132625 65.56/69.93/73.32 * No of units reviewed (Total commissioned 539/490 Cap.132624 Stations 143

VARIOUS FACTOR EFFECTING HEAT RATE Measurement System COAL CONSUMTION GCV CALCULATION GROSS & AUX Power OIL Consumption COOLING TOWER CT Efficiency CW Flow Partial Load Tie up LOSS Evacuation LOSS Load Throw off/loss BOILER EFFICIENCY APH Seal Leakage Mill Fineness Soot Blowing Loss Boiler Blow Down H2 in Coal Loss Moisture in Coal Loss Moisture in Air Loss Water Chemistry O2 Control Flue Gas Exit Temp. Dry Flue Gas Loss SWAS steam Draining Air Ingress Insulation Missing Attemperation Loss Unburnt Loss TURBINE Heat Rate Low Rated MS/RH Temp & Pressure Gland and Drain Valve Leakages HL in Drip System Failure Heat Loss in Drip Pump Failure/NA Air Ingress High Dissolved O2, D/A Vent HP/IP/LP Cylinder Efficiency Missing Insulation TDBFP Efficiency HP/LP Heater Performance Condenser Low Vacuum, Tube Cleaning Sub cooling COAL H2 in Coal Moisture Coal Burning in Yard Sulphur in Coal Coal Blending

Efforts towards improvement in Efficiency of Thermal Power Generation

Adoption of Supercritical Technology Efficiency gain of about 2 % is possible over sub critical units First Supercritical unit of 660 MW Commissioned in Dec- 2010, 800 MW in July,12 33 Units with total capacity 22700 MW operating Supercritical to constitute ~40%(~25000MW) coal fired capacity addition in 12 th Plan (2012-17) 100% coal fired capacity addition in 13 th Plan and beyond to be supercritical

EFFICIENCY IMPROVEMENT THROUGH RENOVATION AND MODERNISATION Programme To restore rated capacity and design parameters such as Heat Rate, APC, SOC etc.. To make the operating units well equipped with modified/ augmented latest technology. To overcome technological obsolescence and non-availability of spares. To improve the performance parameters in terms of PLF, Efficiency, Forced Outages, Availability and Reliability. To reduce maintenance requirements and enhance the ease in maintenance. Compliance of stringent environmental norms, safety and other statutory requirements.

Renovation & Modernization of old thermal power stations is an economical option to supplement capacity addition programme for increased power availability and Efficiency Extension of useful economic life of generating units by another 15-20 years. To focus on full load operation of the unit beyond their original design life. Uprating of Generating Unit. Improvement beyond design parameters.

Drivers for E E R&M Availability of Coal, Land & Water is becoming more difficult for new power projects. Coal is an exhaustible natural resource. Hence, its saving through efficiency enhancement is desirable. R&M results in lower Specific Coal Consumption. R&M is one of the most cost effective measure for getting additional generation. Additional generation from old units becomes available in very short duration. 24 ( Contd--)

The benefits expected from Comprehensive R&M in a typical 200/210 MW unit include : - - Increased output by about 4-8% - Improved Unit Heat Rate by 10-15% - Extended Plant Life by about 15-20 years. There is a shift from Generation Maximisation to Generation Optimisation with efficiency enhancement. Efficiency enhancement of about 8-10% is feasible in the existing LMZ units. Increased emphasis on Environment for clean technology. The environmental norms are getting more and more stringent.

11 th Plan R&M Programme & Achievements (2007-12 ) Programme (MW) Achievement (MW) Life Extension Programme (LEP) 7318 (53 units) 1291 (13 Units) R&M Programme 18965 (76 units) 14855 (59 units) Total 26383 (129 units) 16146 (72 units) 26

12 th Plan R&M Programme (20012-17 ) Programme (MW) Achievement (MW) Life Extension Programme (LEP) 12066 (70 units) ( 30-09-2014 ) 1347.19 ( 12 Units ) R&M Programme 17301 (65 units) 1060.5 ( 09 units ) Total 29367 (135 units) 2407.69 ( 21 units ) 27

RETIREMENT OF POWER PLANTS Retirement in a systematic manner an ongoing activity with focus on closing down Small and Old units Units of non-reheat type Units having very low design efficiencies Units having very low actual efficiency

Present Methodology for Retirement of units Units deviating more from design to retire first Retirement is linked to commissioning of new units In case of Gas based, Technology changing rapidly. Faster retirement could be considered to keep abreast with technology development

RETIREMENTS OF OLD UNITS Details of Retirements : 11 th Plan - 2398 MW has already been retired comprising mainly of small size ( <100 MW),old and non reheat units 12 th Plan12-17( Planned)- 4075 MW (< 100 MW coal units, > 35 years old Gas stations) till date 771 MW 13 th Plan (Planned) about 4000MW

Efforts under IGEN Programme Mapping of 85 Thermal units done and all the recommended measure have been implemented Guided for adoption of Better O&M Practices 55 Ebsilon Professional Professional Software Licenses provided to 15 Utilities GSECL, HPGCL, PSPCL, MAHAGENCO, CSPGCL, MPPGCL, RRVUNL, NLC, TANGEDCO, OPGCL, TVNL, DVC, APGENCO, UPRVUNL, and GIPCL

TRAINING on USE OF EBSILON.under IGEN TRAINING TO 100 ENGINEERS HAS BEEN IMPARTED ON EBSILON PROFESSIONAL SOFTWARE (This training has been imparted by GERMAN and Indian EBSILON EXPERTS)

IGEN contd.. Introduction of Online BPOS and Other Activities for OLDER TPS for 200MW and Above The Boiler Performance Optimization System (BPOS) is an online computer system which monitors and optimizes boiler operation. Module for soot blowing management. In the closed loop mode of operation at Suratgarh TPS INTRODUCTION to energy efficiency through Efficiency measure and Better Operation and Maintenance Practices

85 Units MAPPING STUDIES Capacity range of units No. of units Average Design Gross Heat Rate (kcal/kwh) Average Operating Gross Heat Rate (kcal/kwh) Average Deviation (%) Range of operating GHR (kcal/kwh) 100-110 MW 8 2434.9 3016.8 19.0 2696-3601 120-125 MW 9 2395.4 2921.9 18.5 2690-3730 140 MW 4 2360.2 2824.1 19.7 2750-2905 195-200 MW 5 2399.6 2989.1 24.4 2393-3962 210 MW 49 2361.6 2714.4 14.9 2384-3064 250 MW 5 2339.1 2687.2 14.9 2546-2773 500 MW 5 2254.6 2566.2 13.8 2508-2647

MAJOR REASONS FOR THE HIGH OPERATING GROSS HEAT RATE 1. Low combustion efficiency due to improper air-fuel ratio. 2. Poor performance of milling system to meet new demand. 3. Low turbine cylinder efficiency 4. High dry gas losses due to poor heat transfer 5. Poor sealing and heat transfer in air pre-heaters 6. Low condenser vacuum. 7. High air ingress in the boiler and high heat loss due to poor insulation 8. Improper mill maintenance due to poor spare availability 9. Poor quality of coal 10.High auxiliary power consumption

Section wise Unit Heat rate losses in a particular unit

Saving Potential of Coal Based State Power Plants emerged out through current case studies on 70% plf Million tonnes of Oil equivalent (MToe) 6 5 4 3 2 1 0 0.46 1 2 Case Studies 5.07 All State Utilities

Comparison of average Unit Heat Rate of different unit sizes 2700.00 2600.00 2500.00 2400.00 2300.00 2200.00 2100.00 2000.00 1900.00 2633.38 2557.80 2542.80 2497.30 2532.30 2353.21 2343.00 2311.60 2268.60 2195.00 120MW 125MW 210MW 250MW 500MW Average Design Load Average Operating

Variations in Boiler Efficiency Boiler Efficiency (%) 90.00 88.00 86.00 84.00 82.00 80.00 78.00 76.00 74.00 72.00 88.93 88.13 87.40 86.03 86.61 85.70 83.91 81.37 78.61 78.12 120MW 125MW 210MW 250MW 500MW LOAD Design Average Operating Average

Total 563906.18 Parameters 120 MW (2) 125 MW (1) 210 MW (12) 250 MW (1) 500 MW (1) Total (toe) Short Term Potential ( 139317.67 toe) MS pressure 438.72 0 4449.8 0 63.29 4951.81 MS Temp 41.82 0 1641.34 893.52 0 2576.68 RH Temp 387.78 0 2723.90 186.15 878.63 4176.46 Condenser Vacuum 839.91 1673.07 50004.95 4573.15 0 57091.08 UBC in Fly Ash 679.07 0 16418.47 0 0 17097.54 UBC in bottom ash 415.49 0 6594.78 404.88 362.99 7778.14 Makeup 0 0 18814.98 0 2498.13 21313.11 Excess air 3615.05 988.22 18846.78 0 882.80 24332.85 Long Term Potential ( 424588.52 toe) RH Spray 0 915.21 7177.84 0 1556.96 9650.01 SH Spray 10.5 22.59 347.87 0 93.82 474.78 Exit Gas Temp 3002.22 2028.04 32193.89 0 4467.60 41691.95 Change in FW temp 1554.28 0 4867.69 0 6515.25 12937.22 HPT Efficiency 2799.52 4112.85 27154.21 5888.86 4411.76 44367.2 IPT Efficiency 3727.8 769.26 24527.67 749.44 6404.30 36178.47 LPT Efficiency 5052.32 0 197972.48 7491.05 20796.68 231312.53 HPH TTD 3784.42 0 23077.46 851.08 2338.79 30051.75 HPH DCA 0 7.73 2080.06 97.73 0 2185.52 LPH TTD 101.33 0 11784.78 1139.24 308.26 13333.61 LPH DCA 0 0 767.36 0 1638.12 2405.48

PAT Scheme Perform, Achieve and Trade scheme- aim is to improve Efficiency of the thermal plants both coal & gas based. Total Target Set for thermal power stations= 3.2 MTOE out of total 6.686 MTOE Threshold limit to be DC = 30,000 tons of oil equivalent (TOE) per annum ( all power plants above 11-12 MW will be covered in PAT scheme) MOP notified net heat rate reduction targets to 144 Thermal power Stations. Stations to achieve the targets within 3 years from date of notification i.e by 31.3.2015 Penalty for non achievement

Thermal Power Plant Groups under PAT Scheme Thermal Power Plants [144 Nos] Coal/Lignite [97] Gas [40] Diesel [7]

Target Setting for Reduction of NHR Deviation in Net Station Heat Rate from Design Net Heat Rate Reduction Target for Deviation in Net Station Heat Rate (%) Up to 5 % 10 % More than 5% and Up to 10 % 17 % More than 10% and Up to 20% 21 % More Than 20 % 24 % TARGET SET ARE UNDER NORMALISATION

Actual Heat Rate Deviations S.No. Particulars 2013-14 1. No. of Stations in the range of 27% SHR deviation(below 5%) 2. No. of Stations in the range of SHR deviation(5-below 10%) 3. No. of Stations in the range of SHR deviation(10-20%) 4. No. of Stations with SHR deviation of more than 20% 32% 26% 15% (ALL INDIA HEAT RATE DEVIATION wrt Design 10.04% (Huge potential)

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