MOTOR DRIVEN BOILER FEED PUMP OPERATION PROCEDURE FOR MDBFP:-
a) ISOLATION PROCEDURE FOR MDBFP: (STEPWISE PROCEDURE) 1. Stop the pump to be isolated after unloading it 2. Deselect it from standby. 3. Close its discharge valve and its IBV . 4. press it’s EPB 5. Isolate power supply of MDBFP main motor (Breaker racked out and DC control supply off ) 6. Isolate the power supply of discharge valve and its IBV. 7. Close the Super heater and Reheater spray manual valves at 8.5M . 8. Close the Recirculation manual valve at Deaerator floor . floor . 9. Close the booster pump suction isolation valve . 10. Open suction strainer vent, booster pump pump casing vent and booster pump pump discharge line vent 11. Open suction strainer drain valve and main pump casing drain valve
12. Check for the complete depressurization depressurization of Feed Water side by observing observing the booster pump pressure. pressure. 13. After complete draining (observe: (observe: No water is coming coming from drains) drains) stop its AOP and block the power supply of AOP. Do if required for maintenance work: a) Open DE/ NDE jacket cooling line inlet / outlet valve of booster pump b) Open DE/ NDE jacket jacket cooling cooling line inlet / outlet valve of main pump c) Open inlet / outlet valves of DE/ NDE mechanical mechanical seal line of booster pump valves of DE/ NDE mechanical d) Open inlet / outlet valves mechanical seal line of main pump pump e) Open cooling water line inlet / outlet valve of working oil cooler f) Open cooling water line inlet / outlet valve of Lub oil cooler b) LINE UP PROCEDURE FOR MDBFP: (STEPWISE PROCEDURE) 1. 2. 3. 4. 5.
6. 7. 8.
9. 10. 11. 12.
Check lub oil tank level normal normal and Restore power supply of AOP AOP Run AOP and check for any oil leakage Close suction strainer drain valve and main pump casing drain valve Open the recirculation manual valve at Deaerator floor . Crack open the booster pump suction isolation valve Close the suction strainer vent, booster pump casing casing vent and booster pump discharge line vent when sufficient water comes through the vents. Open booster pump suction isolation valve fully Open the SH /RH spray manual manual valves at 8.5m Restore the power power supply of discharge discharge motorized valve and its IBV Open the recirculation control valve from DCS Open cooling water line inlet / outlet valve of working oil cooler Open cooling water line inlet / outlet valve of Lub oil cooler .
Ensure the following: a) Open DE/ NDE jacket cooling line inlet / outlet valve of booster pump b) Open DE/ NDE jacket jacket cooling cooling line inlet / outlet valve of main pump c) Open inlet / outlet valves of DE/ NDE mechanical mechanical seal line of booster pump valves of DE/ NDE mechanical d) Open inlet / outlet valves mechanical seal line of main pump pump
e) Line up one mechanical mechanical seal cooler for for DE/ NDE of booster pump pump f) Line up one mechanical mechanical seal cooler for for DE/ NDE of main pump
CONEDENSATE EXTRACTION PUMP OPERATION PROCEDURES FOR CEP:a) ISOLATION PROCEDURE FOR CEP: (STEPWISE PROCEDURE) 1. Stop the pump to be isolated after unloading it 2. Deselect it from standby. 3. Close its discharge valve and its IBV . 4. press it’s EPB from local 5. Isolate power supply of CEP main motor (Breaker racked out and DC control supply off ) 6. Isolate the power supply of discharge valve and its IBV. 7. Close the pump Suction valve and the strainer relief line valve . 8. Close the recirculation control valve and its manual isolating valve . 9. Close the casing vent to LPDFT.(Solenoid and manual valve) 10. Close the vacuum balancing line valve to condenser . 11. Close thrust bearing cooling water (ECW) inlet and outlet valves. ( Depending on the isolation required) 12. Open the strainer vent. (Monitor Condenser vacuum in CCR while doing so and coordinate the activity with the person in control room.) 13. Open the strainer drain. Observe that pump draining is completed. 14. Now CEP is ready for giving PTW after proper Mechanical and Electrical isolation . b)
1. 2. 3. 4. 5. 6. 7. 8. 9.
10. 11. 12. 13. 14. 15.
LINE UP PROCEDURE FOR CEP: (STEPWISE PROCEDURE) Maintain the hot well level is normal ( i.e. slightly above adequate level) Close the drain valve of suction strainer . Close the strainer vent. Open thrust bearing cooling water (ECW) line inlet and outlet valves . Open strainer relief line valve. (Monitor condenser vacuum in CCR while doing so.) Open the casing vent to LPDFT . Open the vacuum balancing line valve. Open recirculation line manual valve . Slowly open suction valve.( Monitor Condenser vacuum in CCR while doing so and coordinate the activity with the person in control room. If any abnormality is found close it immediately). Ensure that thrust bearing oil level is greater than 40% . Restore the power supply of Discharge valve and its IBV . Its discharge valve is kept open in standby condition. Restore the power supply of CEP main motor Release local EPB of CEP main motor Select the pump as standby
c) CHECKS BEFORE STARTING THE PUMP: 1. 2. 3. 4. 5. 6.
7. 8.
Check the hot well level is normal i.e 470 MM . CEP is in normalized condition as stated above . Confirm from the operator that local line up is normal and ensure that thrust bearing oil level is greater than 40% . Pump can be started in standby mode with discharge valve open OR in normal mode with discharge valve closed . Pump recirculation valve is to be kept open at above 40% & in manual Start the CEP and open the recirculation valve to establish minimum recirculation flow and observe current, flow, vibration, bearing temperatures, winding temperatures and see that discharge pressure very low switch for tripping has been reset . Confirm from the operator that all parameters are normal in local . When we charge condensate lines from hot well to deaerator during initial periods of start up, ( we run only one CEP with its recirculation valve full open and proper venting of all lines will be done slowly by just opening the IBV of its discharge valve . )
d) START PERMISSIVES OF CEP:1. 2. 3. 4. 5. 6. 7. 8. 9.
Suction valve Hot well level not low set at +220 mm Pump thrust bearing temperature not high set at 80 0C Motor bearing temperature not high set at 75 0C Motor winding temperature not high set at 100 0C Recirculation valve 40% open . Vent valve to LPDFT in open condition. Discharge valve open in standby condition OR closed in deselected condition . Switchgear Not Disturbed
e) PROTECTIONS OF CEP:1. 2. 3. 4. 5. 6. 7.
Hot well level very low set at -1479 mm Suction valve not open CEP On and discharge pressure very low (< 18Kgf/cm 2 ) CEP On and discharge flow very low (< 300 T/hr and time delay of 120 sec) Pump Thrust brg. temperature very high at 90 0C (from two RTD s and time delay of 10 sec) Motor bearing temperature DE/ NDE very high at 90 0C (from RTD s and time delay of 10 sec) Motor Electrical protection operated
f) CHECKS DURING NORMAL RUNNING OF THE PUMP:1. Check the Current, Flow, Bearing Temperatures, Vibration and winding temperatures of motor etc. in the control room. 2. Check the values of suction pressure, discharge pressure, DP across suction strainer, 3. Thrust bearing oil level, and Thrust bearing oil temperature at local from the o perator . 4. Confirm from the operator that thrust bearing oil level is > 40 % and pump are normal . 5. Any possible air ingress into the system through the CEP system .
Function of Economiser Recirculation 1. Eco Recir. Valve must be open a) To maintain flow in economiser to prevent steaming in it b) To avoid any overheating of economiser tubes which can occur at high flue gas temp. 2. Eco Recir. Valve must be closed when sufficient continous water flow through economiser is established (i.e. after charging HP/LP Bypass System(>25%) or after unit synchronisation)
BOILER CHEMICAL DOSING a) TSP (Tri sodium Phosphate- Na3PO4) b) Hydrazine (N2H4 ) c) Ammonia (NH3) d) Sodium hydroxide a) Main purpose of phosphate treatment: 1. React with salts of Mg&Ca to form sludge and is drained through CBD 2. To increase the PH in boiler
b) Hydrazine (N2H4 ): to remove oxygen (Oxidation of metal takes place in presence of oxygen) N2H4= N2+H2O (But at higher temp. >2000C , hydrazine is converted into ammonia) c) Ammonia(NH 3): to increase PH d) Sodium hydroxide (NaOH) : to increase PH
CRITICAL ITEMS TO BE CHECKED BEFORE BOILER LIT UP COMMON ACTIVITIES 1.
BEFORE BLU
ACW System is charged with one self cleaning strainer in service & one running ACW pp (one ACW Pump for Full load operation) Two Turbine PHE and one Blr PHE should be charged with ACW side & ECW side. And other one Turbine PHE and one Blr PHE should be Isolated from both side (ACW & ECW side)
2. CW System is established with atleast one CW Pump running and both condenser water Boxes are charged (three CW PPs for Full load operation) and maintain feed pool level normal by CT Make up pumps. 3. Instrument & service air systems are charged ♦ ♦ ♦ ♦
TG side charged & Pressure is adequate Instrument air to Boiler side charged & Pressure is adequate Plant air to Blr side is charged Monitor Instrument air & service air pressure in DCS Instrument air to
4. DM Make Up System is charged with adequate DM Storage Tanks level ♦ Check adequate no of DM makeup pump is running in DM plant and 2 ♦ Discharge Pressure = 5 Kgf/cm ♦ Normal make up is lined up for Hotwell & ECW O/H Tank (SG&TG) and Maintain normal Hotwell level (i.e. + 450 mm) & ECW O/H Tank (SG&TG) level - from 1000 to 1500 mmwc (Do Not Increase Hotwell Level Too Much Otherwise Condenser Springs May Damage) 5.
Emergency Make Up System is charged Emergency make up is lined up & charged for Hotwell & ECW O/H Tank (SG&TG) CST tank level - adequate One CT Pump - running
6. ECW System for boiler & 7. Turbine are in charged condition ♦ Maintain ECW O/H Tank (SG&TG) level - from 1000 to 1500 mmwc ♦ Line up of Supply & Return Lines of both ECW System ♦ (Drain v/vs closed & Vent v/vs closed after proper venting) ♦ Two Turbine PHE and One Blr PHE - in lined up condition ♦ Two ECW Pumps (TG) and one ECW Pumps(SG) - Running
Boiler side 1. 2. 3. 4. 5.
Eco I/L Valve (E-2) is i n opened condition Eco recirculation Valve (E-17) is open with its manual isolating valves CBD - Motorised valves are closed EBD (B81,82) and IBD (B96,97) valves - closed Open Boiler Drum, SH,& RH vents Boiler Drum vents - a) B1, B2, b) B3, B4 c) B25, 26 d) B28, 29 SH vents - a) S-15, 16 b) S-17, 18 c) S-26, 27 d) S-28, 29 e) S-31, 32 RH vents - R-9, 10
6. Open SH start up vent valves
a) S-34,35
b) S-36,37
7. open SH Drain valves (i.e. Master drain) and open common O/L valve to IBD tank and close SH filling valve & RH filling valves 8. Ensure bottom hopper and trough seal over flow from ash handling plant 9. Spray line of IBD Tank is line up 10. Drum level is normal & one BCW Pump is running and second BCW pump will run at boiler drum pr. 3 to 5 kgf/cm 2 11. AC Scanner Air Fan is running and Discharge pr is >230 mmwc and check Starting of DC Scanner Air Fan and make it stands available. 12. SH & RH spray- motorised and Pneumatic valve must be closed 13. Secondary Air, Flue Gas and Primary Air Path are lined up 14. Fire hydrant system is charged condition 15. Lined up oil guns ,LDO ,HFO,Air atomising sytem and Steam atomising station at burner floor. 16. Open SH/RH spray manual isolation valve at 8.5M
Turbine Side 1. 2. 3. 4.
MOT level is normal (i.e. 840 mm). Turbine Duplex Filter and jacking oil Filter are in cleaned condition. Generator Seal oil filter ( Air side and H2 side) are in cleaned condition. Turbine lub oil system and Generator seal system are established. SLC of all oil pumps (seal & Lub oil) and Gate valve gearing are ON condition. TCV of Lub oil is in auto. a) Seal oil DP (Air side) both T E & EE is 1.7 Kgf/cm2 b) Seal oil DP (H2 side) both T E & EE is 1.7 Kgf/cm 2 c) H2 pressure >3.2 Kgf/cm2 d) N2 pressure in Primary Water Sytem > 0.3 to 0.5 Kgf/cm2
5. Turbine is on barring gear. 6. Test by actual running of Standby DC EOP, ,DC JOP, DC SOP, AC AOP and AC SOP(Air side), and record pressure & current . 7. Primary Water Sytem is established , Tank level - normal and SLC of pumps is ON. Check availability of standby pump. 8. All Turbine & Generator Protections are in service. 9. ACW ,CW System and ECW System are established. 10. One CEP is in service on recirculation and other CEPs stands available. 11. Condensate system: Valve Gland sealing header - charged & put control valve in
auto. 12. MS Strainer drains (MSV#105 & #106) and HPBP warm up line drain valves (BPV #101 & #102 ) to UFT are in open condition. 13. Spray Water of UFT is in opened condition. 14. Open CRH atmospheric drain valve ( closed this CRH atmospheric drain valve before vacuum pulling) 15. All PRDS Drain and manual isolating valves are opened. PRDS spray manual isolating valves are closed. 16. HP Heater #5A & #6A and HP Heater #5B & #6B are in charged condition from water side and isolated from steam side. 17. Main Turbine: gland sealing root valve (at 8.5 m) is in closed condition and gland sealing root valve at PRDS floor is opened. Main Turbine gland sealing drain valve ( at 8.5 m) is in open condition. 18. Both TDBFP Exhaust valves and gland sealing valves are closed. 19. Fill Feed Water line by opening vent at HPH outlet and close vent after water coming from vent and Run MDBFP on recirculation before boiler purging. 20. LP BYPASS spray & GSC minimum Recirculation are in lined up condition. 21. HPBP System: spray root valve is closed , its power pack oil level is normal and its power pack oil pumps stands available. 22. Check LPBP Oil Unit and its oil level is normal. 23. Check Control Fluid System of Main Turbine.
a) Turbine Lub oil system :One AOP, One AC JOP#1 & one OVEF are running. Lub oil temperature controller valve (TCV) is ON and its temp set point is 45 0C. Actual temp is maintaining around 45 0C. Standby Oil pumps are available. SLC of All oil pumps are ON and SGC oil system - ON and auto. Running oil pumps discharge pressure are normal.
b) Generator Seal Oil system :One AC SOP(Air side), One AC SOP(H 2 side ) & One BC Exhaust Fan are running. Standby seal oil pumps are available, SLC of All Seal oil pumps are ON Seal oil DP (Air side) both T E & EE is 1.7 Kgf/cm2 Seal oil DP (H2 side) both T E & EE is 1.7 Kgf/cm 2 H2 pressure >3.2 Kgf/cm2 c) Oil Cooler of Turbine Side:Turbine Lub oil cooler, Seal oil cooler (Air side), Seal oil cooler (H 2 side), Primary water cooler, Control Fluid Cooler, TDBFP #A &B oil cooler are charged from water side as well as oil side, And standby coolers (above said) are in isolated condition.
