A CASE STUDY TO REDUCE THE SPECIFIC WATER CONSUMPTION IN NSPCL ROURKELA PP-II (2×60 MW)

1. ROURKELA A CASE STUDY TO REDUCE THE SPECIFIC WATER CONSUMPTION IN NSPCL ROURKELA PP-II (2×60 MW) PARMJIT (DEPUTY MANAGER, O&M) RUPAK KUMAR TOPPO (ENGINEER , O&M)

2. ROURKELA INTRODUCTION NSPCL ROURKELA CPP- II draws water from tarkera pump house through a common header, which is then divided into the following sections. • CCW SUMP IN CW PUMP HOUSE • RAW WATER SUMP IN RAW WATER PUMP HOUSE • DM PLANT • ASH WATER SUMP IN ASH HANDLING PLANT

3. ROURKELA STATEMENT OF THE PROBLEM • MINISTRY OF ENVIRONMENT , FORESTS AND CLIMATE CHANGE (MoEFCC) ON 7 DEC 2015 notified new regulations for TPPs ,As per these regulations . • All existing plants to achieve a maximum specific water consumption of 3.5 Cubic meter / MWh. • NSPCL ROURKELA SP. RWC IN 2015-16 around 6.47 Cubic meter / MWh.

4. ROURKELA YEAR WISE RAW WATER CONSUMPTION 8.94 9.16 8.42 7.13 6.47 5.20 4.68 4.55

5. ROURKELA ACTION PLAN • A Committee formed in NSPCL ROURKELA Dated 16.01.16 to meet the new guidelines of MINISTRY OF ENVIRONMENT , FORESTS AND CLIMATE CHANGE (MoEFCC) “3 R” methodology was adopted . 1. REDUCE- Raw water consumption reduced in processes • like CW water, Ash handling system and Raw water system. 2. REUSE- Reuse of waste water e.g. DM plant waste water . • 3. Recycle- Recycle of water from plant drains ,dyke.

6. ROURKELA action plan continues……. • Some of the suggestions of the committee were as follows. • Reduction of ash water consumption . • Reduction of DM water consumption. • CT losses to be brought down by renovation. • Reuse of DM plant waste water and all other process waste water. • Recycle the toe drain and all the drains inside and around plant. • Installation of flow meter on strategic locations for monitoring. • Reduction of portable water wastages by installing push and use taps and floats on overhead tanks.

7. ROURKELA WATER BALANCE OF PLANT • In June2016 water balance study done by NPC Bhubaneswar AND NSPCL ROURKELA. • To draw overall picture of the water consumption in plant . • To find out scope of improvement by knowing the flow in each field. RAW WATER INFLOW/OUTFLOW DISTRIBUTION SP. WATER CONSUMPTION IN JUNE 2016

8. ROURKELA 1. REDUCE

9. ROURKELA ACTIONS TAKEN TO REDUCE SP. WATER CONSUMPTION IN CW AND ASH WATER 1. CW MAKE UP WATER REDUCTION • CW make up-536 m3/hr and CT evaporation losses are 402 m3/hr . • CW make up= CT losses + blow down • Blowdownlosses were 536-402=134 m3/hr • COC limit increased from 3.5 to 4.0 that reduce blow down losses by 25m3/hr. 2. ASH WATER REDUCTION • Dry ash handling system was installed to collect fly ash from first 3 fields. • Due to low ash collection in last three fields fly ash removal is being done once in a shift. • Ash water flow to Rotary Vane Feeders are being monitored as per ash flow. • All damaged Rotary Vane Feeders mixing chamber were replaced. • ASH dyke recirculation to reuse in ash water sump.

10. ROURKELA ACTIONS TAKEN TO REDUCE SP. WATER CONSUMPTION IN RAW WATER PUMP HOUSE • 3. RAW WATER REDUCTION • RAW WATER = SERVICE WATER+ FF WATER+ PROJECT WATER • To reduce leakages and undue uses of FF water system during routine check up FF water leakages and wastages are noticed and corrective action are taken. • Service water over head tank overflow line is put back to raw water sump . • Flow meters installed at each tapping of raw water pump house. FF FLOW METER SERVICE WATER FLOWMETER PROJECT WATER FLOWMETER

11. ROURKELA REDUCING THE DM WATER CONSUMPTION • Dm water consumption of both units was around 4.5 T /hr. • Following actions taken to reduce the dm water consumption. • Drain lines of all boiler drains are collected in one vertical drain as it is easy to monitor one drain header . • Heating steam control to FO heaters changed from manual to auto control. • CBD opening schedule was made, once in a week for one hour in normal running of units . • Charging of HP bypass system during unit light up and long time islanding. • DM water consumption of both units running is < 3.0 T /hr.

12. ROURKELA REDUCING BOTTOM ASH WATER CONSUMPTION • Earlier bottom ash hopper deashing was done twice in a shift. • Now it is done once in a shift if coal flow is less than 65 TPH. • Ash water pressure reduced to reduce raw water consumption by operating one ash water pump in normal and additional one pump during bottom hopper deashing which was earlier two fly ash water pump in normal and additional one pump for bottom hopper deashing. • This saves raw water consumption as well as auxiliary power and increases equipment availability.

13. ROURKELA 2.REUSE

14. ROURKELA REUSE OF WASTE WATER IN DM PLANT • DM intake = unit 1& 2 dm water + waste in a processes like backwash of ac filter ,pressure filter etc. • A pit called neutralizing pit to collect such wastes and water in this pit after chemical treatment now put to ash water sump. Neutralising pit in dm plant

15. ROURKELA REUSE OF WASTE WATER IN RAPH BEARING COOLING • In RAPH ACW water is used. • RAPH bearing and oil cooler ACW outlet drain water is being collected in Hot water Tank instead of draining to ash slurry sump. RAPH bearing cooling system Outlet drain collected in funnel Outlet drain fed into HWT

16. ROURKELA 3. RECYCLE

17. ROURKELA RECYCLING OF PLANT DRAINS Toe drain pump house to collect toe drain water • All plant toe drains were visited and their condition monitored. • All toe drains were cleaned and their water was collected in toe drain pump house . • 3 pumps are installed in toe drain sump . • Chemistry department checks parameters like PH,TSS,TDS. • Output of toe drain pumps after these parameters found within limit is fed in CT-2 sump. Toe drains toe drain pump house auto set point (start 1.6m/stop 0.8m)

18. ROURKELA RECYCLING OF PLANT DRAINS • Guradihnala pump house • A submersible pump of 30 m3/hr in front of ash silo in guradihnala. • Pump outlet is fed to ash water sump in ash water pump house. guradihnala submersible pump house

19. ROURKELA RECYCLING OF PLANT DRAINS • TG HALL PUMP HOUSE • TG hall drains that includes TG ground water drains pit pump outlet, condenser pass drain and vent, deaerator drain etc are collected in TG hall sump. • 2 pumps one dewatering pump and one submersible pump are installed . • Output of these pumps fed to ash water sump. TG hall pump house TG hall and guradihnala discharge to ash water sump

20. ROURKELA RECYCLING OF PLANT DRAINS • Ash brick plant drains collection • Three pumps are installed in front of ash brick plant to collect water from drains . • Fourth pump is installed at back side drain of ash brick plant to collect the drain water. • All these drains outlet fed ash water sump through ash dyke recirculation line. 3 no of pumps 4th ash pump water outlet to ash dyke recirculation

21. ROURKELA RECYCLING OF PLANT DRAINS • HOT WATER TANK WATER RECYCLING • HOT WATER CONTAIN WATER FROM BOTH UNIT IBD + SH DRAINS +BOILER VERTICAL DRAIN(SH VENT+SAMPLE COOLER DRAIN+FRS DRAIN+SAFETY V/V PASSING+PRDS DRAIN ) • WATER COLLECTED AT HOT WATER TANK IS FED BACK TO CT OUTLET . • THIS PUMP IS MADE OPERATIONAL FROM DCS WITH ALARM,HW TANK LEVEL AND AUTO STOP FACILITY. HW TANK AND PUMP HW PUMP

22. ROURKELA OVERALL DIAGRAM • PLANT WATER INLET AND RECYCLED WATER

23. ROURKELA INSTALLATION OF FLOW METERS • Instalation Of Flow Meter At Different Points To Find Water Flow In Each Section. • RAW WATER INLET AT PLANT • SERVICE WATER • FF WATER • ASH RECIRCULATION LINE • ASH WATER DISCHARGE HEADERS (3 NO.S ) • PROJECT WATER FLOW METER IN ASH RECIRCULATION LINE

24. ROURKELA STEPS TO SAVE PORTABLE WATER CONSUMPTION • PUSH AND USE TYPE FLOW METER IN ALL WASHROOMS IN PLANTS.

25. ROURKELA DAETP WASTE WATER RECOVERY • In DAETP vacuum pump seal water drains are collected in ct through hot water tank. • DAETP WASTE WATER COLLECTION HEADER

26. ROURKELA WASTE WATER RECOVERY IN ASH HANDLING PLANT • ASH SLURRY PUMPS SEAL WATER LEAKGES AND OTHER WATER COLLECTION FROM LEAKAGE IN SERIES SLURRY PUMPS ARE COLLECTED IN A PIT AND FED BACK TO ASH SLURRY SUMP. ASH PLANT DRAIN PIT PUMP

27. ROURKELA RAW WATER CONSUMPTON DURING CURRENT FINANCIAL YEAR • * This is lowest ever monthly sp. Raw water consumption.

28. IN FINANCIAL TERMS • Rate of water is 10119 rupee per 1000 cu. m

29. ROURKELA WAY FORWARD • All drains in the plant vicinity should be look into for repair / reconstruction after project completion for proper recycling of the water. • More pumps to be installed at guradih nala to recover waste water. • As unaccounted losses 54 m³/hr which is 8% of total water consumption .Flow meter should be installed at more places of water distribution. • Ensure 100 % dry ash utilization by coordinating with M/s NHAI & OCL. • Exploring possibility of water treatment plant and sewage treatment plant and emergency water pond construction. • Separate drains for raw water and process water drains.

30. ROURKELA THANK YOU Thanks to…….. BMD , TMD ,CHEMISTRY DEPARTMENT,C&I CIVIL DEPARTMENT,FINANCE DEPARTMENT AND OPERATION DEPARTMENT