Energy Conservation - Case study

Transcription

1 Energy Conservation - Case study Sachin S Gurao Tata Power Company 2009, Mumbai 1

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4 Energy Conservation Initiatives Press Releases Tata Power flagship Energy Conservation campaign Energy Club attains a critical milestone Tata Power takes the next big leap in Energy Conservation; Empowers It s harbingers (Energy Champions) for a greater role Aug May Tata Power Organizes Energy Champions Meet Jan 2009 Tata Power takes its energy conservation to the youth Sept 17,

5 Energy Conservation in Power Utility A power plant produces electrical energy and also consumes a substantial amount of energy in the form of auxiliary consumption required for various plant equipments and services Management attitude -The top management of the company is committed to, and has the right attitude towards energy conservation. This is passed on to the the plant staff for ensuring success by Quality Management Systems such as Tata Business Excellence Model and ISO 5

6 Trombay Generating Station Installed Capacity MW ISO 9001:2000 Certified Perception has changed to strike a balance between reliability and energy conservation 6

7 Energy Conservation in Power Utility Energy conservation in Power Utility is achieved mainly by- 1) Operating the equipments at maximum efficiency. 2) Reduction of Auxiliary Power Consumption Energy Conservation Measures adopted at Tata Power have taken both these factors into consideration 7

8 Factors affecting Auxiliary Consumption Unit Generation and Load Pattern Operation of Plant Auxiliaries Service auxiliary such as Illumination, Air Conditioning etc Unit startups / shutdowns 8

9 Energy Saving Techniques Energy saving Techniques adopted are classified in the following categories - Design and Conceptual Stage Techniques developed through O&M experience Energy auditing by external agencies 9

10 Design and Conceptual Stage 2009, Mumbai 10

11 Design and Conceptual Stage Use of Steam Turbine driven Boiler Feed Pumps. ( 2 X 9 MW) Pioneered concept of using Variable Speed Drives for Large Motors by using LCI drives for 4 X 2 MW ID Fan Motor of 500MW Unit Use of Fluid Coupling for Motor Driven Boiler Feed Pump 11

12 Techniques developed through O&M Experience 2009, Mumbai 12

13 Techniques developed through O&M Experience In addition to techniques adopted at design stage various initiatives have been taken over the years to optimise the Auxiliary Power Consumption. These are Modification in Operation Strategy to achieve Optimisation Installing energy efficient devices Monitoring of Aux Power Consumption continuously improving the levels and accuracy Knowledge sharing and benchmarking with other power utilities 13

14 Modification in Operation Strategy to achieve Optimisation 2009, Mumbai 14

15 Optimisation By Modifying Operations Efficiency enhancement of ACW pumps by coating of casing and impeller Totally 6 pumps have been coated Power saving KWh ( Rs 6,57,000) annually Flat belt drive for ventilation fans ( reduces transmission losses) Implemented for 2 fans Saving achieved : KWh (Rs 1,53,300) annually 15

16 Optimisation By Modifying Operations Previous system System modification Saving achieved O&S building AC(110 TR) - 3 compressors running in the day and 2 in the night All 26 AHU in 13 locations in service for 24 Hrs. Air washer system Unit-6 East side- X3 air washer pumps (55KW): 2 pumps running to cater for system requirement Timer based running of 1 compressor from 17:15 Hrs to 08:00 hrs Timer based switching OFF 1 AHU in each location from 19:00 Hrs to 08:00 Hrs Running 1 pump is adequate during monsoon and winter seasons ( 6 months) Rs 13.5 Lacs annually ( KWH) Rs 11.5 Lacs annually (424787KWH) Rs 5.9 Lacs Annually ( KWH) 16

17 Optimisation By Modifying Operations Previous system System modification Saving achieved Air washer system Unit- 6 west side- 2X3 air washer pumps(37.5kw): 2 pumps running to cater system requirement Air washer system east and west side - 2X3 air washer pumps running to cater system requirement Running 1 pump is adequate during monsoon and winter seasons ( 6 months) Running 1 pump is adequate during monsoon and winter seasons ( 6 months) Rs 8.1 Lacs ( KWH) Annually Rs 8.1 Lacs ( KWH) annually 17

18 Installing Energy Efficient Equipments 2009, Mumbai 18

19 VFD for Heater Drip Pump OF 2 Units Idea Description Earlier case : Heater drip pump was loaded up to only 40 % of its capacity & header pressure is 20 % higher than the design value with control valve throttled at 69 %. Present case : Risk Factors Required header pressure & control cannot be controlled at lower loads Risk Mitigation Operate control valve at lower loads VFD installed to operate the pump at lower RPM with control valve fully open to meet the flow requirement. KPI Impact Specific Power Consumption Savings Rs. 40 Lacs Investments Rs. 80 Lacs 19

20 VFD FOR HEATER DRIP PUMP : Earlier Condensate system LPH-2 Drain receiver LIC 0.5 Bar 26.7 Bar 69% Open Case with 500 MW Flow: 20 Kg per Sec RPM: 1450 AMP: KW:

21 VFD FOR HEATER DRIP PUMP : Present Condensate system LPH-2 Drain receiver L I C Vary RPM 0.5 Bar 14 Bar 100% Open Case with 500 MW Flow: 20 Kg per Sec RPM: 1060 KW:

22 VFD for CRP & BFP CRP - Condensate Recirculation Pump : CRP is provided for recirculation condensate water of feed water tank through CPH (Condensate pre-heater). Its main function is to maintain cold end temperature of CPH. Normally when it operates its control valve is throttled up to 65% indicating power loss in form of throttling losses. Reduction in speed results in increase in control valve opening & thereby energy saving. Low Pressure Boiler feed Pump : LPBFP is provided for feeding water to LP drum. Normally when it operates at full speed its control valve is 55 % open in full load condition indicating power loss due to throttling. Reduction in speed results in increase in control valve opening & thereby energy saving. 22

23 VFD FOR CRP FWT CPH outlet to Feed water tank CPH CPH inlet line CRP discharge to CPH inlet VFD C/V 22 Bar / 3000 RPM CRP 35 % Open BEFORE AFTER Flow: 14 Kg/Sec Flow: 14 Kg/Sec RPM: 3000 RPM: 2535 KW: 50 KW: 31 Benefit : Rs. 12 lacs Annually 23

24 VFD FOR LPBFP LP Drum FWT VFD 28 Bar / 3000 rpm 55 % Open at full load BEFORE Flow: 12 Kg/Sec RPM: 3000 KW: 50 AFTER Flow: 12 Kg/Sec RPM: 2279 KW: 31 Benefit : Rs. 12 lacs Annually 24

25 BENEFITS The main benefit is the electrical energy saved which is ~ 2 MUs per annum. Also the project has pay back period of less than 2 years. This project can qualify for CDM ( Clean development mechanism) for getting Carbon Credits. Reduction in throttling of control valves increases its life & reduces corresponding maintenance cost. Due to soft start of the 415 V motor its high inrush current during starting is prevented. This reduces the motor heating & increases its life. 25

26 ENCON ACTIVITY Optimization of auxiliary power consumed in Lighting and Air Conditioning Optimizing & Switching OFF unwanted Lighting Optimizing AC temperature set points. WITH DUE RESPECT TO PLANT OPERATION & SAFETY Minor modification can lead to large saving Easy to implement No large investment required 26

27 LIGHTING ENERGY CONSERVATION DONE IN TWO MAIN PARTS Operation Area -Operation staff 24 hours -Light required whenever Operator takes round or when there is an emergency -Implemented by using Push Button Station at all entrances Office and Service Area & street lighting -Staff in General shift and some staff waits back. Not there on Holidays - Implemented by installation of timers -Timers give Off command every 1 hour after office timing 27

28 Battery Room BEFORE AFTER 28

29 Switchgear Room BEFORE AFTER 29

30 Locker Room BEFORE AFTER 30

31 TG Deck Entrance From O & S building BEFORE AFTER 31

32 Background Large lighting load at Trombay Project done Use of 25 KVA Escosaver Optimise system impedance to save power Power Saving Energy Saver for Lighting Upto 40% Features Has bypass facility Enhances lamp life 32

33 Savings before and after operation of Energy Saver Parameter Direct Mode R phase Y phase B phase Power-Saver Mode R phase Y phase B phase Current (A) Cos φ KW KVA KVAR Initial energy consumption / day (Without Power-Saver) = 254 kwh / day Energy Consumed / day (With Power-Saver) = 147 kwh / day 33

34 Other Modifications Replace Filament Lamps with LED Lamps Replace Conventional Ballast of tube lights with Electronic Ballast Timers for exhaust fans Increased Chilled Water Set Temperature in O & S A/c plant Lighting system based on Timers All A/C systems and Window A/Cs set at 24 0 C Trombay Housing Colony Lighting Total Savings due to Energy Conservation at Trombay Plant & Colony Monthly Saving (KWH) : Monthly Saving (Rs) :

35 Proposed Activities Sr No. 1 Proposed activity Timer settings of other external locations viz. Coal yard, Station A switchyard etc are to be modified 2 Energy savers to be shifted from LDB's to major energy guzzlers 3 Connecting photo sensitive devices to the lighting panels which are operated manually 4 Conducting awareness programs in residential colony 5 Optimising street lighting in colony 6 7 Reducing operating voltage by adjusting lighting transformer tap ( where-ever possible ) To change the timer setting of O&S building Centralised AC so as to switch it OFF earlier during evening peak 8 Replacement of colony household incandescent bulbs by CFL 9 Utilise solar heater for daily hot water requirement in the housing colony 35

36 Energy auditing by external agencies 2009, Mumbai 36

37 Energy audit of the AC system by Voltas 2009, Mumbai 37

38 Conclusion Comparison of auxiliary power consumption of Thermal Power Utilities India benchmark 6.33% International benchmark 3.99% Tata Power 4.33 % Tata Power s Auxiliary Power Consumption has been acknowledged by CEA as one of the best in India 2009, Mumbai 38

39 Nothing worthwhile is ever achieved without deep thought and hard work. J R D TATA 39