Standard Operation Procedure of Oil filter & oil Cooler change over

 

SOP: Oil Filter Change Over

Follow the below mentioned steps for changeover of filter.

This procedure is valid for duplex filter.

  • Ensure Filter DP is high enough to change the running filter to stand by filter.
  • Ensure that stand by filter is provided with filter element, which is cleaned or replaced with a new one.
  • Open the vent of the standby filter.
  • Crack- open the filter equalizer line.
  • See that air is coming out of filter, close vent as soon as full bore liquid comes out of it.
  • Operate change over mechanism.
  • Observe that filter DP has come down to minimum DP position in the indicator.
  • Close the equalizer line.
  • Clean the choked filter & keep ready for immediate use.

SOP: Cleaning of Choked oil Filter Element

Follow below steps to clean or replace filter element.

  • Open drain and vent of choked filter.
  • Ensure complete draining of filter body.
  • Open the filter flange and remove the filter element(s).
  • Clean the filter body from inside.
  • Clean the filter element with fresh water/ petrol and dry it with dry air, if it is a reusable filter or use new cartridge if it is a non-reusable one.
  • Close the filter flange.

Oil Cooler Change Over

This procedure is valid where duplex type oil cooler is provided. When running cooler is required to do maintenance due to leakage, non-performing etc., it needs to change over to standby one. Proceed as per below mentioned steps for cooler change operation.

  • Ensure stand-by one ready for operation.
  • Ensure stand-by oil cooler vents on both tube and shell side of the cooler is open.
  • Ensure the cooler drains are closed.
  • Charge Cooling water in the cooler and close waterside vents after removing entrapped air.
  • Open cooler oil equalizer line. It takes some times to fill a cooler.
  • Close oil vent once entrapped air is completely removed.
  • Operate change over mechanism.

Check all the parameters of oil and cooling water.

Control oil temperature by operating CW valve.

Power plant equipments standard operating procedures (SOP)

 











SOP: Standard Operating Procedures

SOP is to provide a harmonized organizational framework for the operation of equipments and system.

Objectives of SOP

SOPs are detail-oriented documents and provide step-by-step instructions as to how employees within an organization must go about completing certain tasks and processes.

SOP of Centrifugal Pumps:

START:

For starting of a centrifugal pump proceed as stated below. However, when a pump is put on remote & auto, its suction and discharge valves are normally kept open unless specific logic and protection is implemented.

  • Ensure there are no work permits on equipment & equipment is in normalized condition.
  • Ensure tank level is normal.
  • Ensure suction valve is open & suction pressure is normal.
  • Ensure field all instruments are in service.
  • Ensure proper lubrication for pump bearing
  • Ensure cooling water flow & pressure to bearings & mechanical seal (If provided)
  •  Ensure Discharge valve is closed.

Note: For high discharge head pumps, normally discharge valve is in closed condition and there will be minimum recirculation valve. And low discharge head pumps discharge valve is in open condition

  • Ensure that all the protection and interlocks are in service.
  • Prime the pump by opening air vent from pump body or discharge vent.
  • Give start- command by operating LPB or from DCS.
  • Once pump achieves normal speed, open discharge valve slowly.
  • Check current, vibration, bearing temperature, any noise etc. and record.

SOP STOP:

  • To stop a centrifugal pump follow below mentioned steps.
  • Keep integral by pass open & close discharge valve, .
  • Issue stop command either from local push button or from DCS.
  • Keeps cooling water flow some more time to gland cooling etc.
  • If the pump is kept as stand by, don’t close CW line valve
  • If the pump is stopped for maintenance, isolate suction valve, discharge integral bypass, minimum re-circulation line valve and balancing leak off line valve.
  • Stop cooling water flow to pump gland.

SOP of positive displacement pumps:

Plunger pump, reciprocating pump, screw pump& gear pump are such pumps in this category. MOP, LDO pump are gear pumps, lime dosing pump etc. are of screw pumps.

Pumps like HP/LP dosing pumps are plunger pump which are normally used in power plant.

START:

  • Follow the steps below for startup of such pump.
  • Ensure there are no work permits on equipment & equipment is in normalized condition.
  • Ensure normal tank level.
  • All field instruments are in service.
  • Ensure proper lubrication for pump bearing.
  • Ensure suction & discharge valves are open.

Note: Positive displacement pumps should be always started with discharge valve open

  • Ensure that integral pump relief valve & that of on discharge line are not gagged.
  • Ensure that all the protection and interlocks are in service.
  • Prime the pump by opening air vent from pump body or discharge vent.
  • Give start- command by operating LPB or from DCS.
  • Check current, vibration, bearing temperature, any noise etc.. and record the data.

SOP STOP:

 Switch off keeping all the valves on.

Reference books for power plant O&M

Cooling Water Pump/Tower

To take cooling tower in service, proceed as stated below.

  • Ensure that Cooling Tower sump is filled with makeup water up to operating level.
  • Tower distribution header valves are opened.
  • CW return water line valves are open.
  • CW pumps are available for operation and free to rotate.
  • CT fans are available for operation.
  • CT fan gearboxes are filled with requisite lube oil (LO) and up to operating level.
  • Protections for CWP and CT fan are in service.
  • Ensure field instruments are in service.
  • Open suction valve for selected pump, keep discharge valve close.
  • Prime pump by opening air release valve on pump.
  • Start CW pumps and gradually open the discharge valve.
  • Charge cooling water in condenser, lubricant oil (LO) cooler, and generator cooler.
  • Check discharge pressure, vibration, bearing temperature and motor current.
  • Check distribution of cooling water in tower and adjust deck valve to make it uniform.
  • Maintain sump level. Put other cooling water pump on auto.

Note:

 Before putting any pump on auto, ensure that pump’s suction and discharge valves are open and priming of the pump is done.)

SOP Lube Oil cooler & Oil filter change over

SOP Boiler Feed Water Pump start up

Follow the steps given below 

  • Ensure there are no work permits on equipment & equipment is in normalized condition.
  • Ensure Deaerator level is normal
  • Ensure pump suction pressure is normal
  • Pump and Motor bearings are properly lubricated and oil cups contain oil.
  • Ensure suction strainer differential pressure is normal
  • All protection and interlock are in service.
  • All field instruments are in service.
  • CW line for bearing cooling & gland water cooling is open.
  • Open suction valve, keep discharge valve close.
  • Ensure minimum re circulation and balancing leak off line valves are open.
  • Start pump by operating Local start Push Button or from DCS.
  • Ensure pump has reached 50% RPM in just 10 seconds to avoid bearing failure & rubbing of balance & counter balance discs.
  • Gradually open discharge valve. If integral by pass valve is provided, open by pass valve first. Once Feed line is pressurized, main discharge valve can be opened fully.
  • Check all parameters, bearing temperature, vibrations, suction / discharge pressure, balance leak off pressure, motor winding temperature etc.
  • Put other pump(s) on auto.

SOP Instrument Air Compressor (Reciprocating)

Follow the steps given bellow to start a compressor

  • Ensure there are no work permits on equipment & equipment is in normalized condition.
  • All protection and interlock are in service.
  • All field instruments are in service.
  • Sufficient lubricant oil (LO) is present in crank sump.
  • CW is charged in compressor and after cooler and flow switch is reset.
  • Moisture Traps are in service.
  • Suction air filter is cleaned.
  • Discharge valve is open.
  • Start compressor.
  • Check loading and unloading of compressor.
  • Record loading unloading current and pressure.
  • Check discharge temperature.

Pump Change Over SOP:

  • Ensure that stand by pump is available for operation.
  • Prime the pump after opening its suction valve. (Where minimum re circulation line is provided, open re circulation line valve).
  • Start pump either from local or from remote.
  • Open discharge valve and close minimum re circulation line valve.
  • Gradually close discharge valve of previous pump. (where minimum re circulation line is provided , open re circulation line valve before closing discharge valve)
  • Ensure that incoming pump is maintaining all parameters like discharge pressure, bearing temperature & vibrations.
  • Switch off the previous pump.

Boiler Gauge Glass Operation

Initial line up SOP

  • Crack open the steam cock. Wait for some time till the gauge glass is heated slowly.
  • Crack open the water cock.
  • Close the drain cock & vent valve.
  • Open the steam cock and water cock fully.

SOP for Gauge glass flushing

  • Close the water cock and open the drain cock for some time.
  • Close the drain cock and open the water cock.

Note: Water should return to its normal working level quickly. If this does not happen, then there is a blockage in the waterside

  • Then Close the steam cock and open the drain cock for some time.
  • Close the drain cock and open the steam cock.

Note: If the water does not return to its normal working level quickly, then there is blockage in the steam side.

Charging of Main Steam Line

This procedure is applicable when main steam line is depressurized and first boiler is coming into service. Proceed as follows for charging main steam line.

  • Ensure that boiler has achieved at least 60% of its rated pressure
  • (for detail operations of boiler refer boiler operation from OEM manual).
  • Ensure that that all the drain line valves are open along with stream trap by pass.
  • Open MSSV by pass partially so that line steam pressure is at 5 kg/ cm2.
  • Heat up line at least for 10 min.
  • Increase pressure up to 10 kg/ cm2 for another 10 min. To control main steam pressure line, warm-up vent can be opened and regulated.
  • Once dry steam is observed  coming out from all the drains, close the steam trap by pass and keep all the traps in service.
  • Increase pressure of the steam line near about the boiler pressure and open MSSV. Before operating MSSV, care to taken that steam pressure before and after MSSV is more or less same. To match the steam pressure warm up vent can be throttled.
  • Increase pressure and temperature as required for turbine start up.
  • It is to be noted that increase of temperature up to 300 deg C should be 3-5 deg C per minute. Above 300 degC the increase of main steam line should be 5-7 degC per minute.

SOP Ejector System

Normally ejector system consists of one set of Hogger and 2 main ejectors. For ACC ejector system there is

One set of Hogger system and 2 set of service ejector. Each service ejector set consists of 2 nos of ejectors, 1 in 1st stage and 1no ejector in 2nd stage.

To take Hogger ejector in service follow following guidelines

  • Ensure auxiliary steam is available at desired pressure and temperature
  • Ensure vacuum breaker valve fitted on steam condenser is closed
  • Ensure cooling water is circulating in the condenser and the turbine gland is charged fully at 0.1 kg/cm2
  • Note: During cold start up gland sealing is charged after taking hogger into line (after vacuum pulling) i.e say at vacuum -0.2 to -0.5 kg/cm2 & During hot start up gland sealing is charged before taking hogger into line (before vacuum pulling).
  • Ensure live steam line to ejector steam lines drain are kept open.
  • Charge the main steam line to ejector steam & temperature control valve.
  • Ensure the rated pressure (10 kg/cm2 or as specified by OEM) and temperature.
  • Once the rated parameters are reached open the steam valve of starting or hogger ejector.
  • Observe the steam is vented to the atmosphere.
  • Then open the ejector airline valve.
  • Observe vacuum inside the condenser increasing slowly and will reach 60 to 70% of rated vacuum within 20 minutes

 Read More SOPs.

Emergency operation guide in power plants

Slop fired Boiler SOP

Turbine oil flushing SOP

Coal handling plant SOP

Boiler refractory dry out SOP

Boiler feed pump start/stop SOP

Steam turbine cold, warm & hot start up SOPS

Boiler Alkali Boil out SOPs

Boiler Hydraulic test SOP


15-Emergencies in power plant operation

 

Emergencies in power plant operation: Following are some of the emergencies that are normally faced during operation of power plant.

1.Tripping of boiler: Following are the main cause of tripping of boiler

  • Low drum level
  • High furnace pressure
  • High/ low bed temperature
  • Tripping of boiler due to failure of FD, PA, SA  and ID fan
  • Electrical fault in Boiler MCC

2.Tripping of Boiler; Case: 2 Boilers & 2 Turbines

Actions to be taken:

  • Reduce load at turbines so that inlet pressure to turbine maintains at operating value.
  • Share load equally on both the turbines.
  • Close main steam stop valve of the tripped boiler.
  • Ensure that all coal feeders (fuel feeding system) and fans are stopped on tripping of boiler.
  • Maintain drum level.
  • If required stop one boiler feed pump (BFP).
  • Check the cause of tripping of boiler and try to rectify the fault.
  • If boiler fault is rectified, start the boiler with startup compartment and gradually increase boiler pressure and temperature (Follow hot/warm start up curve)
  • Synchronize the boiler with the running boiler.
  • Start one more BFP
  • Take compartment one by one into line and increase the load
  • Maintain the equal load on both turbines as per requirement
  • Finally stabilize the power plant operation.
  • If the boiler fault cannot be rectified immediately, decision of stopping of one boiler can be taken after due consultation with station manager.

3.Tripping of Turbine

Followings are some of the causes of tripping of turbine

  • Any one of the protections or interlocks of turbine or generator generally initiates tripping of turbine.
  • In some of the cases spurious tripping is caused due to mal functioning of instruments.
  • Due to mal operation of the operating staff.

4.Non-availability of Fuel (Normal Shut Down): (Case: 2 Boilers & 2 Turbines)

Take planned shutdown of power plant in following ways.

  • Reduce station load by switching off export feeders.
  • Stop one turbine and put it on turning gear once turbine speed comes to zero.
  • Stop one boiler by slumping the compartments one by one. Slumping of compartment is done in the reverse direction i.e. 5th compartment is slumped first and so on.
  • Reduce further load by switching off the auxiliaries.
  • Finally, one turbine runs on auxiliary power load. If STG running on synchronized condition, generator breaker can be opened on auxiliary load. If STG runs on islanding mode, synchronize STG with DG or grid and transfer auxiliary load to DG or grid before opening Generator breaker at minimum STG load.
  • Stop the turbine and put on turning gear in due time.
  • Stop ACC fans or CT fans, CEP etc. in due time.
  • Keep open main steam line & other process steam line drains.
  • Once fuel is made available, restart power plant as per cold start up procedure

5.Non-availability of DM Water

  • Plan for normal shut down.
  • Build up DM water in DM storage tank and restart Power plant as per start up procedure

6.Fuel handling / Fuel feeding system Break down

  • Causes of Fuel handling & fuel feeding system failure
  • Belt cut
  • Mechanical equipments like gear box, coupling & pulley failure
  • Electrical equipments like motor & feeders failure

Take following actions

  • Inform the station Manager & reduce the steam demand
  • Switch off the export feeder
  • Trip the Turbine & put it on turning gear as per SOP
  • Stop the other fuel feeding & fuel handling system
  • Stop the fans sequentially
  • Hot box up the Boiler as per SOP
  • Attend the breakdown
  • Re-start the plant as per SOP

7.Boiler feed pump incomer supply failure

  • Causes of incomer supplier failure,
  • Breaker trip
  • Relay malfunction

Take following actions

  • Reduce the steam demand, trip the export feeders
  • If supply is not restored within minute,trip the Boiler & Turbine manually
  • Hot box up the Boiler
  • Put STG on turning gear as per SOP
  • Stop the fuel handling system
  • Identify & troubleshoot supply failure
  • After restoring the BFP incomer power supply, stat the Boiler feed pump & maintain drum water level
  • Start the Boiler as per SOP (Hot or Warm)

8.Main steam line leakage

  • Probable Causes of main steam line leakage,
  • Leakage in welding joint due to corrosion & rusting
  • Uneven expansion
  • Water hammering

Take following actions

  • If leakage is heavy inform the station Manager & reduce the steam demand
  • Switch off the export feeder
  • Trip the Turbine & put it on turning gear as per SOP
  • Stop the fuel feeding & fuel handling system
  • Stop the fans sequentially
  • Hot box up the Boiler
  • Identify & arrest the leakage
  • Analyze the causes of leakage
  • Start the Boiler & STG as per SOP

9.Turbine HP valve gland leakage

Probable Causes of HP valve gland leakage,

  • Turbine Load hunting
  • Ageing
  • Poor fitment of gland packings during overhauling

Take following actions

  • If leakage is heavy inform the station Manager & reduce the steam demand
  • Switch off the export feeder
  • Trip the Turbine & put it on turning gear as per SOP
  • Stop the Boiler as per SOP
  • After cooling, attend the gland leakage
  • Start the Boiler & Turbine as per SOP

10.Tripping of Auxiliary Transformer

  • Following are the probable cause of tripping of auxiliary transformer.
  • Heavy earth fault in any of the LT drives.
  • Tripping on transformer protection like low oil level, high oil/winding temperature, Buchholz relay operation etc.

On tripping of auxiliary transformer, total power plant will trip. Proceed as follows to tackle the emergency.

  • Resume auxiliary power immediately.
  • Ensure STG have got tripped and shutdown safely
  • Ensure boilers are tripped.
  • Close MSSV.
  • The drives, which were put on auto, take all of them on manual.
  • Close all the control valves.
  • Once auxiliary power is available, start one BFP and take water into boilers.
  • To resume auxiliary power stand by Auxiliary transformer can be taken to service if HT voltage available in bus or by closing PCC bus coupler.
  • Put STG on turning gears after starting AOPs.
  • Start the power plant as per hot start up procedure.

11.Tripping of Export Transformer

  • Following are the probable causes of tripping of export transformer.
  • Heavy earth fault in any of the LT drives.
  • Tripping on transformer protection like low oil level, high oil/winding temperature, Buchholz relay operation etc.

On tripping of export transformer,power plant will come to Island mode operation. Proceed as follows to tackle the emergency

  • Ensure Turbine has not tripped on high pressure
  • Maintain Boiler operating pressure by controlling start up vent control valve
  • Operate Boiler & STG on home load
  • If process needs steam, charge the steam from PRDSH as per SOP
  • Maintain Boiler load as per steam process demand
  • After troubleshooting the transformer, synchronize the Turbine with grid & start to export the power
  • Slowly cut off the PRDSH steam to process & charge the process steam line through Turbine extraction steam.

 12.Tripping of Export Feeder

Probable cause of tripping of feeders are,

  • Over load
  • Earth fault
  • Maintain main steam header pressure
Take following actions

  • Ensure that dumping system has acted to cope up increase in pressure. If dumping system is not available, maintain Boiler pressure by operating start up vent CV & also take combustion system in manual mode to reduce firing as per requirement
  • Reduce load on boiler, if required slump one compartment of a boiler or both the boilers.
  • Ensure that dumping system ceases to operate and system is stabilized at reduced load.
  • Analyze the cause of tripping of feeder and rectify.
  • Once problem is sorted out and rectified, take export feeder in service after due consultation with consumer.
  • Gradually increase load on power plant and stabilize.

13.Turbine Oil Leakage

  • Causes of oil leakage in turbine area,
  • Leakage in oil line caused by failure of joints or flanges or due to vibration in oil line.
  • Spillage through centrifuge due to seal break.

Take following actions

  • If it is in Lube oil (LO) oil or hydraulic oil line, plan for safe shut down.
  • Try to attend leakage under emergency plan.
  • Analyze the cause for oil leakage to avoid future leakages
  • Do leak testing and restart the turbine
  • If it is in other area like in Centrifuge, isolate centrifuge.
  • Top up oil in MOT, if required.

 14.DCS failure

  • Probable Causes of DCS failure,
  • DCS power supply failure
  • DCS controllers failure
  • DCS other accessories like card, switch & SMPs etc failure

Take following actions

  • During DCS failure, DCS operators cannot judge the plant operating condition so need to take following actions.
  • If Turbine not tripped automatically, trip it manually through emergency push button provided in Governor panel.
  • Trip the Boiler manually (Stop Fuel feeding system, Boiler fans & fuel handling system) & close MSSV manually
  • Start Turbine Lube oil pump manually & put STG on barring gear.
  • Start BFP manually & operate the control valves manually in field.
  • Observe drum level from local level gauge glass
  • Analyze the cause of DCS failure.
  • After troubleshooting start the DCS as per SOP
  • Then start the plant as per SOP (Hot or warm)

15.UPS  failure

  • Probable Causes of UPS failure,
  • UPS battery failure
  • UPS cards failure

Take following actions

  • After UPS failure, DCS also gets fail & DCS operators cannot judge the plant operating condition so need to take following actions.
  • If Turbine not tripped automatically, trip it manually through emergency push button provided in Governor panel.
  • Trip the Boiler manually (Stop Fuel feeding system, Boiler fans & fuel handling system) & close MSSV manually
  • Start Turbine Lube oil pump manually & put STG on barring gear.
  • Start BFP manually & operate the control valves manually in field.
  • Observe drum level from local level gauge glass
  • Analyze the cause of UPS failure.
  • After troubleshooting of UPS start the DCS as per SOP
  • Then start the plant as per SOP (Hot or warm)

 

 Read: POWER PLANT && CALCULATIONS

 

 

 

 

Steam Turbine standard operating procedures (SOPs)

 

Lube oil system operation

Pre-checks

  • Ensure lube oil tank level is normal
  • Ensure lube oil pumps are healthy to operate
  • Ensure lube filter & cooler are in service
  • Ensure lube oil inlet and outlet valve provided at filters & coolers are open
  • Ensure cooling water inlet & outlet valves provided for oil coolers are in closed condition
  • Ensure suction & discharge valve of the pumps are in opened condition

Operation

  • Start the oil pump (AOP)
  • Ensure no abnormal sound & vibrations
  • Observe the discharge pressure
  • Ensure header pressure is normal, if not adjust with PRV or recirculation valve
  • Check the oil filter DP, if high change over the filter
  • Check overhead oil tank is getting filling
  • Ensure lub oil is supplying to each bearing & adjust the oil pressure to each bearing as per desired requirement
  • Maintain the oil temperature by adjusting cooling water inlet & outlet valves.

Note: Keep open cooling water inlet valve 100% open & adjust the temperature by adjusting outlet valve
  • Ensure the over head oil tank is full
  • Keep stand by lube oil pump & EOP ready

Barring gear operation

  • Ensure lube oil system is in service and oil is circulating at the bearings at a desired pressure
  • Ensure barring gear motor is healthy to start & its all interlocks are in place
  • Engage the barring gear clutch
  • Start the barring gear motor
  • Observe the rotor is rotating at barring speed without increase in bearing vibrations & temperature
  • Ensure there is no any abnormal sound

Cooling water system operation

Pre-checks

  • Ensure the cooling tower level is normal
  • Ensure cooling water pump is healthy to operate & their protections & interlocks are in place
  • Ensure cooling water pump (MCWP) suction valve is open & discharge valve is closed
  • Ensure all the field instruments are healthy & inline
  • Ensure surface condenser inlet & outlet cooling water line valves are open
  • Ensure Condenser water box vents are open
  • Ensure cooling tower inlet cooling water line valves are open

 15-Emergencies in Power plant

Operation

  • Start the pump from DCS at 70% RPM
  • Open the discharge valve slowly
  • Observe discharge pressure is increasing gradually
  • Ensure the pump’s vibration & bearing temperatures are normal
  • After venting air from condenser water box close the vent valves
  • Observe cooling water is falling in cooling water
  • Increase the pump’s speed as per requirement
  • Note down cooling water inlet & outlet water temperature of condenser
  • Start cooling tower fans one by one as per requirement

 SOP Lube oil & Oil cooler change over

Condensate system operation

  • Ensure the hot well level is adequate. Otherwise make the hot well level with DM water
  • Ensure the CEP is healthy & its all interlocks are in place
  • Ensure pump’s suction & discharge valves are open
  • Ensure ejector & gland sealing steam condenser inlet & outlet cooling water line valves are open
  • Start the pump, ensure the water will flow from ejector & Gland steam condenser (GSC)
  • Ensure gland steam outlet control valve to deaerator is close & cooling water is recirculating through recirculating control valve
  • If the hot well level increases, then GSC discharge valve can be opened
  • Once the Turbine comes into line,GSC outlet control valve should be kept in auto mode to maintain hot well level
  • Vacuum pulling & Vacuum killing
  • Pre-checks
  • Ensure auxiliary steam is available at desired pressure and temperature
  • Ensure vacuum breaker valve fitted on steam condenser is closed
  • Ensure cooling water is circulating in the condenser and the turbine gland is charged fully at 0.1 kg/cm2
  • Ensure live steam line to ejector steam lines drain are kept open
  • Ensure Hogger & main ejectors steam and air valves are in closed condition

Vacuum pulling through hogger ejector

  • Charge the main steam line to ejector steam & temperature control valve
  • Ensure the rated pressure (10 kg/cm2) and temperature (220 deg C) for ejector vacuum pulling
  • Once the rated parameters are reached open the steam valve of starting or hogger ejector
  • Observe the steam is vented to the atmosphere
  • Then open the ejector airline valve
  • Observe vacuum inside the condenser increasing slowly and will reach 60 to 70% of rated vacuum within 20 minutes

SOP to put main ejector into line

  • Ensure CEP is running
  • Ensure cooling water inlet and outlet valves of main ejector which is to be taken into line
  • Vent out air from water box of the ejector
  • Then open the drain valve of inter condenser and after condenser of ejector
  • Open the steam valve of after condenser ejector
  • Open the steam valve of inter condenser ejector
  • Observe the condensate is drained out from both the condensers
  • Slowly open the air valve & observe the vacuum is increasing
  • When vacuum reaches rated, then stop the hogger or starting ejector

Vacuum killing or Taking out of main ejector

  • Close the air valve of the ejector
  • Close the steam valve of inter condenser
  • Close the steam valve of after condenser
  • Close the drain valves of after & inter condensers
  • Close the cooling water inlet & outlet valve once the ejector is cooled

 Read

Power plant & Calculations

Slop fired Boiler start up procedure

 

Pre-checks

  • Ensure DM water storage tank, feed tank & Deaerator  level are normal
  • Ensure availability of start up fuel (wood) & main fuel (coal) and power supply with DG backup
  • Ensure maintenance & trial runs (healthiness) of all equipment including fuel handling, ash handling / auxiliaries, motorized valves, actuators, control valves and PRDS controls are completed successfully
  • Ensure that all interlocks / protection and controls are checked & taken in line.
  • Ensure expansion pointers are cleaned & tramps are in good condition.
  • Ensure Boiler manholes and flue gas path system manholes are boxed up.
  • Ensure availability of chemical dosing system and readiness of drum level gauge glass with illuminator assembly.
  • Ensure availability of cooling water, instrument air and service air.
  • Ensure Coal bunker is filled with required level
  • Ensure all rotary air lock valves of evaporator, economizer & bag filters are open
  • Ensure healthiness of all dampers and keep them in open/close marked positions as per requirement
  • Open all air releases/vent valves in boiler drum and open super heater header drains and its vent valves.
  • Ensure all boiler bottom ring header drains, blow down valves and main steam stop valves including its bypass valves are closed.
  • Ensure Boiler feed pump’s bearings oil level normal, minimum recirculation, balancing leak off valves & suction valves are open, cooling water pressure normal.

Boiler start up

  • Start the ACW pump, Instrument Air & Service Air Compressor
  • Start BFP from control room. Ensure suction pressure, balancing pressure & discharge pressure normal. Bearing temperature & Vibrations normal. Ensure motor draws current normal & sound normal. Shut the BFP immediately if any abnormal condition and check thoroughly before restart.
  • Start water filling the boiler drum through 30 % control valve and maintain the drum level up to 30%.
  • Start the Ash handling plant prior to light up the Boiler. Then start all hoppers RAV.
  • Ensure bag filter main damper is closed & bypass damper is open
  • Maintain the drum level about 40%.
  • Drum vent, super heater vent and main steam line drain should be kept open.
  • Start wood firing by spraying small quantity of diesel & slowly raise the furnace temperature
  • At furnace temperature > 150 deg C start ID & FD fans at minimum speed
  • Close drum air vent at 2.5 kg/cm2
  • At 3 kg/cm2, gibe blow down to CBD, IBD & bottom headers one by one for 30 sec to 45 seconds
  • At pressure > 4 kg/cm2, open start up vent 10% initially & close the top header drain valves & go on increasing the pressure
  • At furnace temperature around 250 deg C, start coal feeding by starting SA fan
  • Now slowly increase fuel feeding & FD air
  • When boiler pressure reaches 6 kg/cm2 & 150 deg C, charge the main steam line. Before charging the main steam line, open all the drains at 100 % and warm up vents at minimum opening and then open the MSSV bypass valve.
  • Start HP & LP dosing and maintain recommended drum water parameters of boiler. Keep the CBD at minimum opening to maintain recommended residual PO4 & conductivity of drum water
  • Check & record thermal expansion of boiler pressure parts and record the bearings temperature & vibrations of auxiliary equipment’s associated with Boiler
  • After ensured all condensate removed & color less steam comes through drains, keep all the drains in crack position, then open main steam stop valve and close the bypass steam valve
  • At Boiler pressure 9 kg/cm2 & temperature 180 deg C, charge Deaerator & SCAPH through PRDSH
  • At flue gas temperature > 180 deg C take bag filter into line
  • Observe seal air pressure, conveying air vessel pressure of AHP is normal.

Slop firing:

  • Ensure sufficient quantity of slop with required brix is available in slop tank
  • Ensure tank coil heater & steam tracing lines are charged & tank slop temperature is 70 to 80 deg C
  • Ensure slop pumps are healthy & agitator is running condition
  • After ensuring above all are normal, start slop transfer pumps & keep slop in recirculation mode for at least 2 to 3 hours before taking into boiler
  • As the Boiler reaches 50 to 60% of MCR & furnace temperature is 450 to 500 deg C open the atomizing steam line, slowly introduce the slop into furnace by opening SOV
  • Note: Before introducing slop into nozzle, keep open the steam connection line provided with respective nozzle.
  • Quantity of slop fired at MCR is 3.91 TPH & slop quantity should be reduced as the load demand reduces
  • Always maintain 20 to 25% supporting fuel on heat basis. Never start the Boiler with slop
  • During slop firing ensure supplement fuel is supplying continuously to avoid clinker
  • The soot blowers provided in economizer, evaporators are operated once in a shift & wall blowers twice in a shift

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