boiler & aux operation pmi

8/12/2019 Boiler & Aux Operation PMI

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3 June 2014 PMI Revision 00 1

POWER PLANT

OPERATIONBOILER &

AUXILIARIES




Presentation outline

OPERATING PROCEDURE

APH

ID, FD AND PA FAN

FURNACE PURGE

BOILER LIGHT UP

MILLING SYSTEM




Before starting any

quipm nt…

ENSURE

No PTW is pending on the equipment which is to be

normalized .

Equipment is properly boxed up and no maintenance staff

working.

Local operator is informed before the equipment is started.




Pre start checks

before light up




Equipment cooling water is charged in boiler side and

proper venting is done.

Service water /filter water for sealing in the boiler bottom

is charged .Get the clearance from AHP for sealing of

bottom hopper.

Service and instrument air is charged and air for SADC

and burner tilt are charged .

Fire water/ sprinkler water is available in boiler area.

Before Light up……




DM water is available .

Ensure the availability of aux. steam .

Ensure 6.6 kv, 415 volt , 220 volt DC,110 V AC, 24 V DC

SUPPLIES are normal . Ensure that all MCC s are

charged. Both buses are charged independently and Buscoupler is in OFF position .ensure all chargers are in

charged condition and all the batteries are in healthy

condition .

All unit protections/interlocks ( boiler ,turbine & generator )

are checked and recorded in the protection register .





Start LDO PUMP or charge LDO line upto firing floor if

other units are running.

Start HFO pump or charge charge HFO line upto firing

floor on long recirculation if other unit is running. also inform

other units .

charge atomising air and atomising steam lines.

Keep boiler drum vents,SH vents , SH drains ,CRH drains,

HRH drains open.

Ensure all low point drains are closed .





Inform shift chemist to take water sample before water

filling in the boiler and take clearance from shift chemist.

Inform him to prepare hydrazine , ammonia and phosphate

solution for dosing . Check availability of all LP and HP

dozing pumps .

Fill water in the boiler upto normal level by running oneBFP .

Ensure at least two ESP passes are clear and their inlet /

outlet gates are open. Elect. Supply of fields are kept off .

Inspect the boiler up to drum floor . Ensure that all

manholes /peepholes are closed.





Ensure start up vent and ECO recirculation valve are open.

Charge the SCAPH LINE .

Keep the burner tilt at 0 deg ( horizontal )

Ensure boiler and auxiliaries areas are clean , safe and

properly illuminated .





AIR PRE-HEATER OPERATION

PRE START CHECKS

• Support bearing/ guide bearing lub oil pumps RUNNINGand lub oil coolers are CHARGED.

• Bearing temperature NOT HIGH (less than 60oC)

• Electrical supply to APH motor is AVAILABLE.

• Local operation - Isolating valves of air motors are 'OPEN'and bypass valves of air motor solenoids are 'CLOSED'.

• 'Air motors' lub oil level ADEQUATE

• Service air pressure is ADEQUATE (> 5 Kg/cm2)




APH STARTING PROCEDURE

• WHEN BOTH APHS ARE OFF

• START air motor of APH.

• Air motors ON indications come on

• Isolating dampers of APHs start opening.• INSTRUCT local operator to check, locally for any

abnormal sounds from bearings/seals.

• START air heater electrical motor.

• Breaker CLOSED & its indication comes on UCB• Associated air motor stops.

• Starting current shoots up and comes down to normal load

current.






•Isolating dampers of the air heater remain open.

•Isolating dampers of the other air heater, not in service, startclosing if its air motor is not ON.

•INSTRUCT local operator to check, locally for any abnormal

sounds from bearings/seals.

•There should be no abnormal hunting in air heater amperesmeter readings.

•There should be no abnormal sounds from air pre-heater

seals or bearings.

•Bearing temperatures must be within the normal range (650C -75 0C)





• SHUT DOWN PROCEDURE

• CHECK Corresponding ID & FD Fans are running.

• UNLOAD associated ID/FD fans, gradually.

• The other pair of ID/FD fans (if running) starts loading up onauto.

• STOP the associated FD fan. Maintain desired oxygen

percentage.• Furnace total airflow indication drops slightly. Reduce firingif required.

• STOP the associated ID fan.

• Furnace pressure increases slightly. Maintain furnace draft

between -5 to - 10 mm wcl.• STOP air heater electrical motor.

• With a few seconds time delay, the isolating dampers of theair heater are closed, if the other AIR HEATER is in service.




FURNACE

PRIMERY AIR HEATER

SECONDRY AIR HEATERMILLS

FD FAN A

PA FAN BPA FAN A

FD FAN B

ESP

ID FAN A

ID FAN B

CHIMNEY

Atmospheric air

Atmospheric air




ID FAN OPERATION

PRE START CHECKS

WHEN BOTH THE FANS ARE OFF

• Fan lub oil pressure is ADEQUATE (1.2 Kg/cm2).

• Fan bearing temperature is NOT HIGH (< 60 0C .)

• All permissive for the fan AVAILABLE. ''Inlet guide vanesmin.'' & Inlet/outlet dampers closed''

• Local operator is informed before the fan is started.




ID FAN OPERATION

START fan.

• Inlet/outlet dampers start closing. Inlet vanes come tominimum.

• The fan breaker is CLOSED after inlet/outlet dampers closefully.

• Inlet/outlet dampers open up after a time delay.

• Inlet/outlet dampers of the other fan closes and regulatingvanes comes to minimum position.

• ADJUST inlet guide vanes to maintain furnace draught between - 5 mm.to -10 mm.

• INSTRUCT the local operator to check for abnormal bearing vibrationand temperature.




ID FAN OPERATION

• WHEN ONE FAN IS RUNNING

• All pre-start checks are OVER.

• START fan motor

• Fan motor current settles down at no load current.

• Inlet/outlet dampers start opening.

• Maintain furnace draft -5 to - 10 mm wcl.

• Maintain desired airflow.• ADJUST bias to 50% and furnace draught set point to 45%.

• Check furnace draught is maintained between 5 mm wcl to-10 mm wcl.

• TRANSFER vane controllers of both fans to ''AUTO''.

• Inlet vanes modulate to maintain set value of furnacedraught.




ID FAN OPERATION

• SHUT DOWN PROCEDURE

• Reduce the coal firing and air flow so as to sustain with one ID fan.

• SELECT IGV controls of fan to manual.

• IGVs control transfers to manual.

• REGULATE IGVs of the ID Fan to minimum.

• ID fan discharge pressure decreases.

• ID fan current come to minimum, other fan loading increases.

• STOP the ID fan.

• Total airflow drops slightly avoid Boiler trip.

• The inlet and outlet dampers close on interlock.

• REGULATE the inlet guide vanes of the running ID fan to desired

loading.• Maintain furnace draught at -5 mm wcl.

• Note : If associated FD fan is in service it will be necessary to unload FDfan and stop it before stopping ID fan;




FD FAN OPERATION

• CHECK before starting the FD fan, all start permissive is satisfied.

• Fan control oil temp is NORMAL (<55 oC)

• Fan blade pitch is MINIMUM and Discharge damper is CLOSED

• Fan control / lub oil pressure is ADEQUATE.

• Fan bearing temperature is NOT HIGH (<60 0C.)

• CHECK if FD fan is lined up locally for starting.

• Fan lub oil system is LINED UP and oil coolers are charged.

• Lub oil tank level is ADEQUATE.

• Anyone LOP is ON and other one is on AUTO.

• Fan EPBs are in RELEASED position.

• FD fan blade pitch controller is OPERATIONAL and is REMOTE.

• Instrument air pressure is AVAILABLE.• Any or both ID fans: APHs' secondary air isolating dampers are OPEN.

• SCAPH is available

• FD fan discharge dampers are OPERATIONAL and electrical suppliesare AVAILABLE.




FD FAN OPERATION

• STARTING PROCEDURE.

• WHEN BOTH THE FANS ARE OFF• All pre-start checks are OVER.

• START the FD fan motor.

• Discharge dampers start closing

• Blade pitch comes to minimum.• As soon as discharge damper closes, "Blade pitch

minimum“ permissive comes on.

• Fan takes starting current and comes down to no load

current after a while.• Discharge damper starts opening (for the fan started).

• FD fan discharge pressure increases.

• Blade pitch for the other fan goes to minimum.




FD FAN OPERATION

• Discharge damper for the other fan closes.

• Instruct local operator to check bearing vibration andtemperature.

• ADJUST the blade pitch controller to get desired airflow.

• Fan discharge pressure increases.

• Maintain furnace draught between-5 to 10 mm wcl and

airflow 30%-40% during purging.• Fan amperage changes accordingly.

• Oxygen percentage varies accordingly.

• Wind box pressure also varies, with FD fan loading.

• MAINTAIN the Wind box to furnace DP as per boilerloading.

• Wind box to furnace DP should be maintained as shown:

• Boiler load<30% 30 to 40 mm of wcl

• Boiler load>30% 100 mm of wcl




FD FAN OPERATION• WHEN ONE FAN IS RUNNING

• All pre-start checks are OVER.

• Both ID fans are in SERVICE.

• START the FD fan

• Discharge damper of the fan starts opening

• Furnace pressure and total airflow increases slightly.

• ADJUST the blade pitch to maintain desired airflow andwind box pressure.

• Fan discharge pressure increases

• Fan amperage increases accordingly

• Furnace pressure increases slightly

• CHECK vibration and bearing temperatures.

• TRANSFER FD fans blade pitch control to AUTO.

• FD fan blades modulate maintain set oxygen percentage.

• Oxygen in flue gas varies accordingly




FURNACE PURGE PROCEDURE

• Start APHs and at least one ID and one FD fan. Maintainfurnace draft between -5 to -10 mm of WCL and maintain airflow between 30 % to 40 % of boiler full load air flow.

• CHECK ALL THE PURGE PERMISSIVE IS satisfied on theFSSS console.

• "No boiler trip" command is AVAILABLE.

• Drum lvl not high ( > 125 mm)• Drum lvl not low ( < - 125 mm)

• All ignitor valves are CLOSED.

• All HFO nozzle valves are CLOSED.

• HFO and ignitor trip valves are CLOSED.• All pulverisers and associated raw coal feeders are OFF.

• All mill hot air gates are CLOSED

• Both PA fans are OFF.





• All fire ball and oil discriminating flame scanners must besensing NO FLAME.

• AC/DC electrical power supplies to FSSS panels are AVAILABLE.

• All auxiliary air dampers of the wind box areMODULATING& furnace to wind box DP > 40 mm wcl.

• Oil elevation dampers also modulate with aux. air damperswhen no oil gun is in service

• Boiler airflow less than 30% annunciation goes off.

• Boiler airflow and wind box pressure are maintained at lessthan 40% and 40 mm wcl, respectively.

• All burners at all elevations and in all corners, come tohorizontal position "Burner tilts horizontal and Airflow lessthan 40%“ permissive comes ON.

• If all other permissive are satisfied, "Purge Ready”

indication comes ON.





• PRESS "push to purge" button on the FSSS

console

• "Purging" indication comes on the FSSS console.

• If in the meanwhile none of the permissive are lost,

"Purge complete" indication comes on FSSSconsole, with a time delay of 5 minutes.

• MFR-A & MFR-B get reset. Boiler Trip "cause" also

resets.

• "Boiler MFR Trip" annunciation clears off.




BOILER LIGHT-UP

• CHECK these conditions before the boiler light up

• Boiler "MFR TRIP" is RESET.• Pre-start checks for boiler light up have been COMPLETED.

• Fuel oil system is adequately LINED-UP.

• Super heater / Reheater air vents are OPEN.

• SH/RH start-up vents are OPEN.• Ignition air fans are LINEDUP for operation.

• Open heavy fuel oil recirculation valve

• OPEN heavy fuel oil trip valve

• Short re-circulation valve closes.

• OPEN heavy fuel oil control valve.

• HFO header pressure rises up to 10 Kg/cm2 (approx.)




BOILER LIGHT-UP

• "HFO" inlet and re-circulation flow start increasing

• "HFO header pressure very low" alarms clear off.

• HFO temperature in the HFO header increases up to 110 oC.

• OPEN Ignitor oil trip valve

• Ignitor oil trip valve opens up.

• Ignitor air fans A & B, start automatically.

• Ignitor oil and ignitor air pressure increase up to 23 Kg/cm2and 400 mm wcl, respectively.

• "Ignitor air to furnace DP low“ & "Ignitor oil/Atomising airpressure low" & "Ignitor oil/HFO trip valve closed" alarms

clear off.• CHECK these parameters are within their operation limits.

• Drum level normal (-60 mm. to 0, preferably on lower side).




BOILER LIGHT-UP

• HFO temp. 110 oC . (Min. temp. required is 95 oC).

• HFO atomising steam pressure 8.75 Kg/cm2• Light oil pressure more than 15 Kg/cm2.

• Ignitor atomising air pressure 5 to 7 Kg/cm2

• Wind box pressure between 35 to 40 mm wcl

• ADJUST HFO header pressure set point to 50%(13 Kg/cm2)and TRANSFER its control to auto.

• HFO pressure controller transfers to auto and modulates to

maintain the set HFO header pressure.

• CLOSE heavy fuel oil re-circulation valve.• HFO re-circulation flow valve closes.

• HFO re-circulation flow comes to minimum position




BOILER LIGHT-UP

• HFO header pressure goes up and is brought down to set

HFO pressure by auto controller.

• PUSH " Pair 1-3 or 2-4 Start" push button.

• In the first 10 secs of the pair start trial time; ignitors 1-3 and

2-4 are proven, in the associated oil elevation.

• "Ignitor Stop" light goes off in the associated elevation.

• If minimum 3 ignitors are proven on, command goes to

corner 1 or 2, for the gun to advance to the firing position,

provided associated ignitor is on

• Command is given to open the associated atomising steam

valve after the gun is fully advanced.

• After the atomising steam valve is fully open, command is

given to open the corresponding HFO corner nozzle valve.

BOILER LIGHT UP




BOILER LIGHT-UP

• 25 second later command goes to corner 3 or 4, as the casemay be, HFO nozzle valve open.

• Associated discriminating oil flame scanners start sensingflame.

• HFO control valve modulates to maintain set HFO headerpressure.

• ADJUST heavy oil pressure controller to desired firing• HFO header pressure changes accordingly

• Oil scanner performance improves with increasing headerpressure.

• PUSH second pair.• "Start"(Pair 1-3/2-4) push button.

• HFO guns advance and corresponding nozzle valves openup.

BOILER LIGHT UP




BOILER LIGHT-UP

• PUSH "Ignitor Stop" push button to remove ignitors if the oil

flame is stable in every corner in the elevation

• All the elevation ignitors go off.

• If any discriminating scanner flickers to show 'no flame',

corresponding oil nozzle valve is closed automatically.




PA FAN OPERATION

• CHECK that all PA fans start permissive is satisfied.

• PA fan bearing temp NOT HIGH (<60oC.).

• PA lub oil pressure is ADEQUATE.• PA fan inlet guide vanes are at MINIMUM position.

• PA fan FSSS start command is AVAILABLE (BOILER MFR:RESET & all mill cold air dampers are less than 5% OPEN).

• PA fan discharge damper is CLOSED.

• CHECK that PA fan is locally line up for starting.

• PA fan lub oil coolers are CHARGED from waterside.

• PA Fan LOP : ON and other pump is on AUTO

• PA fan lub oil tank level is ADEQUATE.

• PA fans EPBS are in RELEASED position.• PA fan guide vanes are on REMOTE. Instrument air pre. is

AVAILABLE.

• PA fan discharge damper is OPERATIONAL and powersupply is AVAILABLE.




PA FAN OPERATION

• CHECK. if air system is lined up before starting PA fan.

• APHs primary air isolation dampers are OPEN.• Seal air fans are LINEDUP and their suction dampers areOPEN.

• Mills' cold air dampers on REMOTE. Instrument air pre. is AVAILABLE.

• Furnace purging is COMPLETED and MFRs are in RESETcondition.

• All man material is removed from the pulverisers.




PA FAN STARTING PROCEDURE

• WHEN BOTH THE FANS ARE OFF

• CHECK these conditions before starting the PA fan.• All pre-start checks COMPLETED.

• Fan discharge dampers 100% OPEN.

• Regulating vanes are 100% OPEN.

• Lub. oil pressure is ADEQUATE. (>1.8 Kg)• FSSS start command (MFR - A&B reset on the FSSS

console and all mills cold air dampers are less than 5%open) is ON.

• Bearing temperature NOT HIGH. (<60 0C).

• START the PA fan motor.

• Discharge damper starts closing.

• Regulating vanes of the fan get closed.





• All mills cold air dampers go to less than 5% open and"FSSS start command" permissive comes on.

• Fan current shoots up to 700A and comes to No loadcurrent 70A.

• Discharge damper opens and for the other fan, it closes andregulating vanes of the other fan also goes to minimum

position.• ADJUST the PA fan guide vanes to get desired hot PA

header pressure of 760 mm wcl

• PA fan discharge pressure goes up.

• PA fan current go up.

• PA header pressure goes up to 760 mm wcl, gradually.

• INSTRUCT the local operator to check bearing Temperature& vibration locally. There must be no abnormal sound fromthe fan or bearings.






• All pre-start checks are COMPLETED.

• LOP: ON. Lub. Oil pressure ADEQUATE (1.8 -2.5 KSC)

• Discharge damper CLOSED.

• Regulating vanes are in MINIMUM position.

• Bearing temperature NOT HIGH (< 600C).

• FSSS start command is AVAILABLE.

• Local operator informed prior to starting of the fan.

• START the PA fan motor.

• Fan current goes up to 700A and comes down to no loadcurrent of 70A.

• Discharge damper open up.

• INSTRUCT the local operator to check bearing vibration andtemperature locally.






• ADJUST the fan guide vanes to get desired PA headerpressure and equalise fan loadings.

• Fan discharge pressure read approx. 800 mm wcl.

• PA header pressure rises to 760 mm wcl.

• ADJUST the fan biasing and header pre. set point to 50% &

80% respectively and transfer vane controllers to auto.• Header pressure and biasing set points have been provided

over the IGV controllers of PA fan A&B respectively.

• IGVs of both fans modulate to maintain set header pressure.




PA FAN SHUT DOWN PROCEDURE

• WITH BOTH THE FANS RUNNING

• TRANSFER the IGV controls to manual• STOP all the pulverisers in excess of three from the top.

• Three pulverisers only can be in service with one PA fan.

• Cut-in oil support if odd combination of mills are running.

• REDUCE IGVs of the fan to their minimum position.

• Fan discharge pressure comes down.

• Notice the other fan loading going up, to maintain the set

header pressure.

• STOP the fan motor. The fan breaker opens

• Discharge damper starts closing.

• Regulating vanes go to minimum, position.





• WITH ONE FAN IS RUNNING

• SHUTDOWN all running pulverizes one by one. Take Oilguns in service.

• Boiler total fuel flow starts decreasing.

• Oxygen percentage the flue gases starts increasing.

• Associated mills cold air dampers start closing.• Total airflow keeps on decreasing.

• ID fan vanes modulate (on auto), to maintain set furnacedraught.

• REDUCE the IGV of the PA fan to its minimum position.

• PA fan discharge pressure starts decreasing.

• PA header pressure decreases to 400 mm wcl,approximately.





• WITH ONE FAN IS RUNNING

• STOP the PA fan & Rack-out the breaker if required formaintenance.

• Breaker open indication comes on.

• Guide vanes of both PA fans will remain at minimum

position.• Discharge dampers of both PA fans go to 100% open.




Milling System• PRE START CHECKS (Typical: Raymond Bowl Mill) Local

• Ensure R.C. Bunker level satisfactory.

• R.C. feeder and mill properly boxed up and no maintenance staffworking.

• Gear box oil level normal. Lub. oil coolers charged.

• Pulveriser START PERMIT is AVAILABLE. (Boiler total airflow is< 40% and all burners are HORIZONTAL). Alternatively, if anyonecoal feeder is proven then start permit will come from the provenfeeder.

• Tramp iron gate open.

• Cold air gate 100 % open. Hot air gate closed.

• Mill outlet valve open.• Seal air valve 100 % open.

• "No unsuccessful start" permissive for pulveriser is ON.

• Mill fire fighting system ready.




Milling System

• PRE START CHECKS (Typical: Raymond Bowl Mill) UCB

• Ensure no PTW pending.• Ensure at least one P.A. fan and a seal air fan is in service.

Check the header pressure for both primary and seal air isnormal.

• Check that mill ignition energy is O.K. (Minimum 3 out of 4

gun nozzle valves in adjacent elevation are open andelevation oil flow is more than 30% OR adjacent feederspeed is more than 50% and boiler load is more than 30%.

• Check that mill start permissive as per FSSS are satisfied

• Ensure E.P. zones have been charged (for first mill).

• Get the electrical supply for the mill.• Inform the local operator to be near mill for start up.

Start the mill




Milling System

• POST START CHECKS

• Local -Check there is no abnormal sound from mill. Checkreturn oil flow from upper bearing is satisfactory. Check allthe rollers are rotating and the rate of reject is normal (afterthe mill is loaded).

• U.C.B.-Check mill starting time and current. Ensure that

they are normal. Open hot air gate. Warm up the mill.• Start the RC feeder and load the mill gradually.

• Keep the air flow through mill - 54 T/hr.

• Keep watch on mill differential to avoid mill choking.

• Maintain mill outlet temperature between 75°C to 80°C.• As the pressure, temperature of main steam shoots up

with coal firing proper check should be kept on theseparameters. (Especially for first mill).




Milling System

• MILL SHUTDOWN PROCEDURE

• TRANSFER mill feeder and fuel master controller to manual.

• Fuel master and feeder control transfer to manual.

• REDUCE feeder speed to minimum, gradually.

• Coal flow to mill starts coming down.

• Other running feeders start loading up, to maintain boiler

loading, if on auto.• STOP the mill feeder.

• Hot air gate closes with a time delay of 30 sec approx.

• Mill current and differential pressure start reducing as the millbecomes empty, gradually.

• EVACUATE the mill reject chamber locally and STOP the mill.

• Mill temperature comes down to less than 50oC.

• Mill CAD goes to <5% open

• Airflow to furnace drops slightly.




Milling System

• MILL SHUTDOWN PROCEDURE

• TRANSFER mill feeder and fuel master controller to manual.

• Fuel master and feeder control transfer to manual.

• REDUCE feeder speed to minimum, gradually.

• Coal flow to mill starts coming down.

• Other running feeders start loading up, to maintain boiler

loading, if on auto.• STOP the mill feeder.

• Hot air gate closes with a time delay of 30 sec approx.

• Mill current and differential pressure start reducing as the millbecomes empty, gradually.

• EVACUATE the mill reject chamber locally and STOP the mill.

• Mill temperature comes down to less than 500C.

• Mill CAD goes to <5% open

• Airflow to furnace drops slightly.




ELECTROST TIC PRECIPIT TORS • Electrostatic precipitators are not normally taken into service

(i.e. the zones are not changed) when firing on oil only and, ifpossible, the EP should be bypassed whilst firing on oil only.This is done to prevent oil deposition on electrodes whichcan reduce E.P. efficiency drastically.

• If EP bypasses are not fitted, the gas flow should be limited

to one of the main passes during the initial oil firing stage ofthe pressure raising.

• Anti-condensation heaters & hopper heaters, if providedmust be taken into service well before boiler light up isinitiated.

• The EP zones must be taken into service just before coalfiring is started in the boiler. The frequency of rapping shouldbe properly adjusted and their operation must be locallychecked.



TH NK YOU

boiler & aux operation pmi

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