SGTPS, M.P. POWER GENERATING CO. LTD, …steag.in/sites/all/.../Session1/Experience_of_Generating_company_in... · 210MW. 27-03-1994; ABL/ BHEL. 85.3/43.20; 2333. 3; 210MW. ... 1

SGTPS, M.P. POWER GENERATING CO. LTD, BIRSINGHPUR

Unit No.

Unit Capacity

Date of commissioning

Boiler/ Turbine Make

Boiler/Turbine Efficiency

Designed Unit

Heat Rate

1 210MW 26-03-1993 ABL/ BHEL 85.3/43.20 2333

2 210MW 27-03-1994 ABL/ BHEL 85.3/43.20 2333

3 210MW 28-02-1999 ABL/ BHEL 86.1/43.20 2311

4 210MW 23-11-1999 ABL/ BHEL 86.1/43.20 2311

5 500 MW 18-06-2007 BHEL/ BHEL 87.99/44.07 2216

SGTPS, UNITS OVERVIEW

4

Year Station Heat Rate

Sp. Coal Consumption

Sp. Oil Consumption P.U.F.

FY 09 3126 0.798 1.063 67.89%

FY 10 3022 0.7843 1.037 65.99%

FY 11 2823 0.7503 1.436 65.78%

FY 12 2784 0.7088 1.543 70.00%

FY 13 2888 0.7264 1.370 73.52%

FY 14 2828 0.7403 0.900 67.21%

(80.77% Incl Backing Down)


Performance of Last Five Years


Efficiency Improvement Opportunities A study revealed that average 1.5% increase in efficiency of Thermal Power Plants in India could result in: • CO2 reduction: 4.5% per annum (over 10 Million

Ton/ annum) • Coal savings: 9 Million tons per annum • Coal savings worth Rs. 630 Crore • Higher productivity from same resources;

equivalent to capacity addition. • Lower generation cost per KWh.

ENERGY CONSERVATION IN THERMAL POWER STATION

Market based mechanism Additional incentive for improving Energy Efficiency Improves the cost economics of Energy Efficiency projects

Increases the profitability Benefits to industry irrespective of their present level of energy efficiency Creates a healthy competition on energy efficiency across industry Ultimately facilitates natural resource conservation

PAT –Perform Achieve and Trade

Covers 685 designated consumers in 9 sectors All DCs consume about 240 mtoe energy i.e. about 60%

of total energy consumption of the country Targets were given to all DCs to achieve the same

within a time frame • Achievement > Target E-certs • Achievement < Target Purchase E-certs / Penalty

National Target = 10 mtoe at the end of 1st PAT Cycle

PAT –Perform Achieve and Trade

National level target -10 MTOE -Apportioned to individual sectors based on their energy consumption -Target for individual Thermal power plants-depending upon the performance of a unit in the sector & potential for energy saving. S. No.

Variation in Net Station Heat rate From Design Net Heat

Rate.

Reduction Target for % Deviation in Net Station

Heat Rate 1 Up to 5 % 15% 2 More than 5 % and up to 10 % 20%

3 More than 10 % and up to 20 % 27%

4 More than 20 % 34%

PAT Scheme –Target setting Methodology

Consumption- 16820917 MT Specific cons - 0.858 kg/kWh GCV - 3966 kcal/kg Energy Input - 66707736 Mcal

Consumption- 8662 MT Specific cons - 0.442 ml/kWh GCV - 10000 kcal/liter Energy Input - 86619 Mcal


Electricity Import

Electricity – 0 Million kWH

Electricity Generation

Electricity – 19601 Million kWH Gross Heat Rate – 3088 kcal/kWH

Electricity Export to Grid & other

Auxiliary Consumption

Electricity to Grid – 17789 Million kWH Net Station Heat Rate – 3402kcal/kWH

Electricity – 1812 Million kWH Percentage – 9.24 %

SGTPS

CALCULATION OF PAT TARGETS FOR SGTPS (Based on Av. Energy Cons. 2007-08 to 2009-10 SGTPS

CALCULATION OF PAT TARGETS FOR SGTPS

Design Gross Station Heat Rate of PH- 1 & 2 2700 kcal/kWh

Auxiliary Power Consumption target 8.25 %

Design Station Heat Rate of PH- 1 & 2 2943 kcal/kWh

Design Gross Station Heat Rate of PH- 3 2425 kcal/kWh

Auxiliary Power Consumption target 6.00 %

Design Station Heat Rate of PH- 3 2580 kcal/kWh

Overall Design Station Heat Rate 2807 kcal/kWh

Actual Net Station Heat Rate Adjudged by Auditor 3402 kcal/kWh

Deviation in Net Station Heat rate 595 kcal/kWh

Deviation in net station heat rate 29.75 %

Deviation in Net Station Heat rate 595 kcal/kWh

Deviation in Net Station Heat rate 29.75 %

Target Saving 210 kcal/kWh

PAT Target Net Station Heat rate 3192 kcal/kWh

CALCULATION OF PAT TARGETS FOR SGTPS

PAT TARGET FOR THE STATION- SGTPS BIRSINGHPUR

PLAN/ METHODOLOGY DEVISED TO ACHIEVE THE TARGETS OF PAT

REGULAR MONITORING OF PLANT PERFORMANCE

IDENTIFIATION OF AREAS OF EFFICIENCY LOSS

PRIORITIZING THE ISSUES

ACTION PLAN TO PLUG THE LOSS OF EFFICIENCY

MONITORING OF SUCCESS PLAN

QUANTIFICATION OF DATA

REGULAR MONITORING OF PLANT PERFORMANCE VIS-A-VIS TARGETS

REGULAR MONITORING OF PLANT PERFORMANCE VIS-A-VIS TARGETS

MAJOR REASON FOR DEGRADATION IN NET STATION HEAT RATE

LEAKAGE IN AIR PREHEATERS THROUGH FLUE GAS O2 ANALYSIS

AIR INGRESS IN BOILER DUCT AND CASING

HIGH LEVEL OF COMBUSTIBLES IN BOTTOM AND FLY ASH

LOW LEVEL OF CONDENSER VACUUM DUE TO DIRTY CONDENSER

TUBES

LOWER FEED WATER TEMP. DUE TO OUTAGE OF HP HEATERS IN

UNIT NO. 1 & 2

INTERNAL LEAKAGE IN BFP RECIRCULATION VALVES

PARTIAL LOADING DUE TO CAPACITY REDUCTION OF ID FANS

IDENTIFICATION OF AREAS OF IMPROVEMENT UNDER ACTION PLAN

S. Equipment/ Then Recommendation Saving No. System existing status Potential 1 Boiler Leakages in APH, Attend APH leakages 186837 Tons of systems high unburnt , Change burners coal/year, HR 98.7 high excess air reduce excess air in boiler kcal/kWh

High loading of Reduce air ingress in ID Fan furnace 2 Condensers Cleanliness factor Improve cleanliness factor Increased 4.87MW

45 to 71% to 75% by improving on- Load, HR 14.5 line cleaning and elimin- kcal/kWh ating air ingress 3 Aux. Cons. BFP Recirculation Replace valve/ seat Reduction in aux. valves and control cons by around valves passing 1.1 MW 4 Unit Repeated blr Replace Eco & R/H coils Estimated gain tube leakages Replace faulty instrument HR 18.6 Kcal/Kwh Repeated unit trip Causing high oil & aux. consumption

MEDIUM TERM ACTION

MEDIUM & SHORT TERM ACTION- (Operation & Maintenance Practices)

BOILER Fineness analysis to be checked and if the bottom ash un-burnt carbon is more, the +50 mesh size coal may be controlled

Regularly Implemented

A routine check up of un-burnt carbon in bottom ash and fly ash may be done and corrective action taken

Regularly Implemented

Air velocity of Primary air is to be reduced. Done in AOH

Temp. of Secondary air is to be increased. A/H replaced in unit 1 & 2

SADC •Regular maintenance of SADC power cylinders •Ensuring proper inside flap operation and condition.

Done in AOH

EXCESS AIR •Regular monitoring of O2 in flue gas & maintaining secondary air flow accordingly.

Immediately Implemented


SHORT TERM ACTION- (Operation & Maintenance Practices)

Air Pre-heater •Plugging the failed tubes in air heaters at every opportunity. •Improved quality of coal to reduce the erosion of air heater tubes due to high ash content. • Performance evaluation of Air preheater by analysis of oxygen content at the out let of APH to be carried out.

Implemented


Mills •Proper preventive maintenance and adjusting the grinding media clearances and spring assembly loading can improve the mill performance. •Operating the mill at rated parameters so as to improve the performance of the mills.

Implemented

• Clean air flow and dirty air flow test velocity of coal air mixture, this help to balance the coal flow in each PC line. Clean air flow and dirty air flow test velocity of coal air were done.

Implemented


SHORT TERM ACTION- (Operation & Maintenance Practices)

The data for the design model is extracted from the HBD Diagram & PPD of Boilers. The data for operating models taken on two respective time schedule . One on 08th May, with five readings in each hour. The operating model is created by simulation and model gap-analysis is performed. Accordingly, short term & long term recommendations are advised. Since, the unit was under shut-down for 15th May to 30th May’2013 due to Low-system–Demand. The Opportunity was availed to implement short term recommendations. The readings were again taken on 20th Jun and operating model again created. The models of these activities are given in next slides. The overall performance improvements are tabulated in subsequent slide.

EBSILON SIMULATION METHODOLOGY

USE OF EBSILON IN IDENTIFICATION OF AREAS OF DEFICIENCY

Figure 1: Design Model of the Unit 4 (100% Load condition)

Figure 2: Operating Model of the Unit 4 (Before Improvement Work) USE OF EBSILON IN IDENTIFICATION OF AREAS OF DEFICIENCY

IMPROVEMENT WORKS CARRIED OUT DURINTG SHORT SHUT DOWN

•AIR HEATERS: SLEEVE PLACEMENT IN TUBE ENDS • BURNERS : INSPECTION OF COAL BURNERS AND REPLACEMENT OF DAMAGED ONES • CONDENSER : 1. TUBES PARTIAL CLEANING 2. DETECTION OF AIR INGRESS AND ATTENDING THE SAME •LP HEATERS : 1. ATTENDING THE PASSING OF BYPASS AND DRAIN VALVES 2. ADJUSTMENT OF DRIP LEVEL CONTROLLER

Figure 3: Operating Model of the Unit 4 After Improvement Work

USE OF EBSILON IN IDENTIFICATION OF AREAS OF DEFICIENCY

Sl No.

Description Unit Design Oper. After Recommended

work

Oper. Before Recommended

work

% Improvement After Mapping

1 Load MW 210 167.25 164.56 1.9473

2 Unit Gross Heat Rate kcal/kwh 2426.2 2412.9 2461.4 -2.01

3 Turbine Heat Rate kcal/kwh 1990 2113.0 2147.0 -1.609

4 Boiler Eff. % 86.1 84.11 83.33 0.927 5 GCV kcal/kg 3500 3715 3710 0.135 6 Sp.Coal Cons. kg/kWh 0.64 0.65 0.66 -1.538

Main Steam Parameters 7 MS Flow at turbine inlet t/h 627.88 498 500 -0.401 8 MS Temp. °C 535 530 530 0.0 9 MS Pressure kg/cm2 150 98.1 99.0 -0.917

10 Condenser Pressure mmHg 75.98 80.6 80.91 0.384 11 Feed water flow t/h 627.88 455.3 457.3 -0.439 12 HPT Efficiency % 90.00 89.3 88.5 0.896 13 IPT Efficiency % 90.77 81.36 81.36 0.0 14 LPT Efficiency % 88.51 87.4 87.36 0.0458 Flue gas/ Air temp.

15 Flue gas temp. at APH I/L °C 339 265.00 265 0.0 16 Flue gas temp. at APH O/L °C 145 110.3 102 7.529

17 Super Heater spray t/h 0 38 42.7 -12.368 18 Reheater spray t/h 0 12 14.2 -18.33 19 Make up water % 0 0.38 0.45 -18.421

UNIT 4 PLANT PARAMETERS DESIGN AND ACTUAL

FACTS ABOUT LP HEATER

The performance of LP Heaters can be analyzed by monitoring • The Terminal Temperature Difference (TTD) • Pressure drop on the feed-water side & • Temperature rise across the heater For a closed feed water heater, the Terminal Temperature Difference (TTD) is defined as: TTD= Sat. Temp. of bled steam–Water Temp. at Heater O/L If the value of TTD is too large, the cycle efficiency will be reduced.

FAULT ANALYSIS

An increase in the TTD and/ or a decrease in the temperature rise indicate the problem could be the result of any or all of the following causes: - Fouled heater tubes (either steam or water side or both). Internal leakage (leakage through the water box

partition plate resulting in a partial internal bypassing of the heater, or, tube-to-tube sheet leakage resulting in feed water leaking to the steam side).

External leakage (through the bypass valve). Plugged tubes (reducing the heat transfer area, while

increasing tube velocity)

In present case, TTD of LPH-2 & LPH -3 were maintaining high. The Problems could be of:- (1) Not maintaining of heater optimum level, (2) Higher pressure drops in the heaters, (3) Passing drain valves/ bypass valves, (4) Presence of non-condensable gases in the heaters

OBSERVATION

Units Load TTD DCA OUTLET TEMP. Net Heat Rate

MW LPH-3

(ºK)

LPH-2 (ºK)

LPH-

1(ºK)

LPH-3

(ºK)

LPH-2

(ºK)

LPH-1 (K)

LPH-3 (ºC)

LPH-2 (ºC)

LPH-1 (ºC)

Design 210.00 2.87 2.95 3.39 0 0 5.90 120 90 57.1 2333.0

Previous Mapping

164.57 7.49 12.79 3.75 0 0 3.28 110 80 55 2556.0

Later Mapping

167.24 2.49 11.29 3.56 0 0 3.45 115 82 55 2498.3

PERFORMANCE IMPROVEMENT TABLE

CASE STUDY-2

CONDENSER PERFORMANCE

The condenser is of two pass, water cooled type condenser having 19208 number of tubes (with 17902 tubes in condensing zone and 1316 tubes in air cooling zone) and total surface area of 9656 m2. Design inlet cooling water temperature is 33ºC and outlet is 41.33 ºC. Design volume flow of cooling water is 7.91 M3/s.

CONDENSER

A small worsening of the back pressure is expensive in terms of the extra heat required for a given output. There are three important parameters: • The CW inlet temperature • Flow of Cooling water • The terminal temperature difference (TTD) For a given input parameters of CW inlet temperature and flow, the back pressure in the condenser also depends in part upon the TTD, which indicates of the heat exchanger condition. Ebsilon Software gives condenser performance in terms of TTD, LMTD & Condenser effectiveness.

FACTS ABOUT THE CONDENSER PERFORMANCE

CONDENSER ANALYSIS THROUGH EBSILON SOFTWARE- DESIGN MODEL

CONDENSER PERFORMANCE BEFORE IMPROVEMENT WORK

CONDENSER PERFORMANCE AFTER IMPROVEMENT WORK

TTD CW Temp. Rise

Cond Pr.

LMTD Effectiveness

Design(A) 3.10 11.5 ºC 0.1033 6.89 0.7656

Previous Mapping (B1) 6.2 11.0 ºC 0.1096 10.8 0.6386

Later Mapping(B2) 5.9 11.0 ºC 0.1078 10.4 0.6509

Deviation (A-B1)/A in % 100% --- 6.07%

56.75%

` 16.59%

Deviation (A-B2)/A in %

90.3% --- 4.35% 50.94% 14.98%

CONDENSER ANALYSIS THROUGH EBSILON SOFTWARE

TABLE INDICATING PERFORMANCE IMPROVEMENT

Conclusion- There has been improvement in condenser performance data after the work

USE OF NEW ENERGY EFFICIENCY SOFTWARE- EBSILON

1. THE EBSILON SOFTWARE IS QUITE USEFUL IN IDENTIFICATION OF DEGRADAING COMPONENTS IN THE POWER PLANT CYCLE

2. IT IS ALSO USEFUL IN DATA VALIDATION 3. IT HELPS IN EARLY DETECTION OF FLAW AND

PRESENT STATUS OF STATION HEAT RATE FAIRLY ACCURATELY.

MONITORING OF

SUCCESS PLAN: OTHER TESTS

AND ANALYSIS

Many of the tests were regularly conducted by the energy efficiency cell to achieve the targets of PAT. Some of these tests include the following- •Energy efficiency test of each unit every quarter •Regular dirty pitot test of coal mills- in order to balance the coal-air flow and to optimize the combustion so as to bring about desired improvement. •Condenser performance test- to address the problems of this vital component •Performance test of Air Pre-heaters, including leak test.

OTHER TESTS CONDUCTED REGULARLY TO ASSESS THE PERFORMANCE FOR

CORRECTIVE ACTION

TURBINE PERFORMANCE CALCULATION AND ANALYSIS PICS FROM EXCEL FORMAT

HP HEATER PERFORMANCE CALCULATION AND ANALYSIS PICS FROM EXCEL FORMAT

HP HEATER PERFORMANCE CALCULATION AND ANALYSIS PICS FROM EXCEL FORMAT

FINDINGS BASED ON TESTS AND ANALYSIS- ACTION PLAN

UNIT NO.

DEFICIENCY OBSERVED IMPACT ACTION

1, 2 & 3

Passing in HPBP BP-1 & 2, even in full closed position temp downstream of the valve is maintaining above 400 Deg C.

Efficiency loss, further damage to valve spindle and seat.

Attended in unit overhauling.

1 Air ingress in flue gas duct Higher loading of ID Fan, partial loading

Repair work taken up in next opportunity.

1 & 2

Leakage across the air heater

Removal of air heater, duct repair, wind box replacement along with modified register was done in AOH.

3 Both Main ejectors were in service, vacuum is maintaining -.92, with one ejector vacuum is maintaining -.88.

Adversely affecting the heat rate.

Cause identified and corrected

1 & 2 TDBFP-A has recirculation valve passing of 90T/h and TDBFP-B has a recirculation valve passing of 150T/H.

High aux. Consumption

Attended in AOH

S. No.

Major works undertaken Period Cost of works

Gain

UNIT # 1: 210 MW

1 Replacement of H.P. heaters 5 & 6 in 210 MW 2009-10 Rs. 550 Lacs HR reduced by 42 Kcal/Kwh

2 Replacement of Air heater complete 2010-11

Rs 85 Lacs HR reduced by 27 Kcal/Kwh

3 Replacement of 60 coils of R/H banks and int. banks

2012-13 Rs 10 Lacs

Tripping avoided

4 Replacement of ID Fan runner 2010-11 Rs. 40 lacs Partial loading avoided

UNIT # 2: 210 MW

1 Replacement of H.P. heaters 5 & 6 2010-11 Rs. 550 Lacs HR reduced by 42 Kcal/Kwh

2 Replacement of Air heater complete 2011-12 Rs 85 Lacs HR reduced by 27 Kcal/Kwh

2 Replacement of wind box & modified air registers

2011-12 Rs . 242 lacs Better combustion

3 Replacement of ID Fans runner 2010-11 Rs. 40 lacs Partial loading avoided

4 Replacement of R/H coils of bottom int. banks, front & rear cage wall

2011-12

Rs 1000 Lacs

Tripping avoided

MAJOR WORKS TAKEN FOR IMPROVEMENT IN HEAT RATE OF SGTPS:

MAJOR WORKS TAKEN FOR IMPROVEMENT IN HEAT RATE OF SGTPS:

S. No.

Major works undertaken Period Cost of works

Gain

UNIT # 3: 210 MW

1 Replacement of Air heater tubes 7000 Nos.

2013-14 Rs. 9.0 Lacs

HR reduction by 11 Kcal/ Kwh

UNIT # 4: 210 MW

1 Replacement of Air heater tubes 20000 Nos.

2013-14 Rs. 14.0 Lacs

HR reduction by 16 Kcal/ Kwh

ACHIEVEMENT OF

FIRST CYCYLE PAT TARGET


ACHIEVEMENT OF PAT TARGETS BASED ON AV. ENERGY CONS. & HEAT RATE

PRESENT STATUS

2010-11 to 2013-14 FOR SGTPS

Consumption- 23806718 MT Specific cons - 0.731 kg/kWh GCV - 3855 kcal/kg Energy Input - 91774897 Mcal



Electricity Import






Electricity to Grid – 29933 Million kWH Net Station Heat Rate – 3080 kcal/kWH

Electricity – 2634 Million kWH Percentage – 8.088 %

SGTPS

ACHIEVEMENT OF PAT TARGETS BASED ON AV. ENERGY CONS. & HEAT RATE

PRESENT STATUS

2010-11 to 2013-14 & FY 14-15 UP TO DEC’14 FOR SGTPS

Consumption- 27795250 MT Specific cons - 0.734 kg/kWh GCV - 3827 kcal/kg Energy Input –106364947946 Mcal

Consumption- 19384ML Specific cons - 0.512 ml/kWh GCV - 10000 kcal/liter Energy Input - 193832 Mcal

Consumption- 30572 ML Specific cons - 0.807 ml/kWh GCV - 10000 kcal/liter Energy Input - 305710 Mcal

Electricity Import






Electricity to Grid – 34774Million kWH Net Station Heat Rate – 3059kcal/kWH

Electricity – 3084.9 M kWH Percentage – 8.148 %

SGTPS

FUTURE PLANNING- FURTHER REDUCTION IN NSHR

•Energy audit is being conducted in all the units along with BOP to explore areas of further improvement and possible benefits thereof. • Renovation and modernization for adoption of recent technologies along with necessary retrofitting for 4X210 MW Units. (Activities are underway) • Potential of further reduction in auxiliary consumption are being explored. • Reduction in auxiliary consumption of coal and ash handling system through low ash coal.

FUTURE PLANS LED BASED

ILLUMINATION FOR

POWER STATION

PROJECT- USE OF LED ILLUMINATION FOR POWER STATION

CONCLUSION- LED BASED ILLUMINATION

• THE ABOVE IS A MODEL CALCULATION FOR LED LIGHTING FOR ONE CONTROL ROOM OF 2X210 MW PH-1 OF SGTPS. • SIMILAR CALCULATIONS HAVE BEEN DONE IN RESPECT OF OTHER POWER HOUSES AND INSTALLATIONS OF SGTPS • THE SAVINGS ARE HUGE AND THE PAY BACK PERIOD IS OF THE ORDER OF 2 TO 3 YEARS. • LOOKING TO THE QUANTUM OF SAVINGS VIS-À-VIS INVESTMENT, THE PROPOSAL TO TOTALLY SHIFT TO LED BASED ILLUMINATION FOR THE POWER STATION IS A VIABLE SCHEME. • THE ABOVE IS A HEALTHY ENERGY CONSERVATION OPPORTUNITY AND THE SAME MAY BE MADE MANDATORY FOR THE POWER STATIONS.

POINTS FOR BRAIN STORMING

1. UNITS HAVE TO BE RUN ON PARTIAL LOAD DUE TO LOW SYSTEM DEMAND: IT IS WELL KNOWN FACT THAT IN PARTIAL LOADING, HEAT RATE IS

HIGHER THAN DESIGNED. PARTIAL LOADING IS NOT BEING CONSIDERED IN DECIDING THE PAT TARGETS. (SGTPS HAS SUFFERED 13% LOSS OF GEN DUE TO LOW SYSTEM DEMAND DURING YEAR 13-14).

2. UNIT STAND BY DUE TO LOW SYSTEM DEMAND: UNITS HAVE TO BE KEPT AS STAND BY AND CONSUMPTION OF FUEL OIL

OCCURS DURING START UP. THIS ADDS TO THE HEAT RATE AND AUXILIARY ENERGY CONSUMPTION. IT IS NOT BEING CONSIDERED IN DECIDING THE PAT TARGETS.

PLEASE THINK OVER IT

Thank you for

your kind attention

Documents

SGTPS, M.P. POWER GENERATING CO. LTD, …steag.in/sites/all/.../Session1/Experience_of_Generating_company_in... · 210MW. 27-03-1994; ABL/ BHEL. 85.3/43.20; 2333. 3; 210MW. ... 1