BOILER EMERGENCIES
 Drum level low
 Drum level high
 Any FD fan trip
 Any ID fan trip
 PA fan trip
 DCF trip
Continued…
BOILER EMERGENCIES
 Bed temperature too high
 Final Steam temperature too high
 Final Steam temperature too low
 PSH O/L steam temperature high
 Economizer O/L FW temperature high
Continued…
BOILER EMERGENCIES
 High positive draught
 High negative draught
 Hot bed material leakage from PA
lines or bed ash drain
 O/L steam pressure too low
 Back fire in PA lines
Drum Level Low
 Check BFP discharge header pr. And
start another BFP if required
 Check FW control valves position in
DCS and in field
 Check position of all MOVs and operate
them accordingly.
 Check for any abnormal sound from
furnace.
Drum Level High
 Operate IBD as per requirement.
 Check FW control valves position in
DCS and in field.
 Close MOVs of Feed Water station as
per requirement.
 Observe PSH O/L steam temperatures.
 Observe Final steam temperature and if it
starts dropping, close Boiler stop valve
immediately.
Any FD fan trip
 Stop coal feeding.
 Reduce load on Turbine according to requirement
 Observe Bed temperature
 Check for reason of tripping
 If the situation diminishes further shut the Boiler
stop valve.
 Take compartments into service one by one and
load the turbine
Any ID fan trip
 Cut down air flow by operating FD dampers.
 Slump two compartments.
 Check the load on running fan.
 Reduce load on turbine according to requirement.
 Check for reason of fan tripping.
 Take compartments into service one by one and
load the turbine
PA fan trip
 Check that whether all DCF got tripped or not.
Otherwise stop them immediately.
 Reduce the load on turbine according to requirement
 See that the standby fan is started. Otherwise start it
and increase the PA header pr.
 Check PA lines for jamming and clear them
accordingly.
 Take compartments into service one by one and load
the turbine
DCF trip
 Check PA header pr. If it is less increase it.
 Increase feeding in other compartments or boiler.
 Check for reason of DCF tripping.
 In case of all DCF tripping, isolate boiler depending
on situation.
 In case of any one DCF tripping, observe final steam
pr. And temperature and if require isolate
attemparator.
 Take burner support according to requirement.
 If the problem persists for longer time and pressure
drops, reduce load on turbine.
Bed temperature too high
 Cut down coal feeding to that compartment.
 Increase air flow and PA header pr.
 Check for wind box damper position.
 Constantly observe the wind box pr.
 Charge bed material.
 Check for abnormal sound from furnace.
 Stop the boiler if temperatures still not controlled, bed
height decreases rapidly and abnormal sound is
observed.
Final Steam temperature too high
 Take attemparator by – pass into service.
 Reduce feeding in 3rd
, 4th
and 5th
compartments.
 Increase load on boiler.
 Observe the TG inlet steam temperature.
 Reduce the steam temperature in other boiler.
 Check attemparator control valve position in DCS and
in field.
 Ensure that none of drum safety valve has popped.
Final Steam temperature too low
 Isolate attemparator and check for passing/opening of
attemparator by – pass.
 Check drum level.
 Observe constantly the TG inlet steam temperature.
 Increase steam temperature in other boiler.
 Increase feeding in 3rd
, 4th
and 5th
compartments.
 Reduce load on boiler.
 If the rate of drop is higher, isolate the boiler
immediately and operate start – up accordingly.
PSH O/L steam temperature high
 Increase load on boiler.
 Minimize furnace draught.
 Check the position of overfeed secondary air dampers
and open them.
 Regulate air flow according to requirement.
 Increase bed height.
 Meanwhile confirm that the temperature indication is
correct.(Attemperator flow will increase)
Economizer O/L FW temperature
high
 Increase load on boiler.
 Reduce Economizer I/L feed water temperature.
 Minimize furnace draught.
 Check the position of overfeed secondary air dampers
and open them.
 Regulate air flow according to requirement.
 Increase bed height.
 Meanwhile confirm that the temperature indication is
correct.
High positive draught
 Confirm that the draught indication is correct.
 Check and control ID fan speed.
 Check ID dampers position.
 Check FD dampers position.
 Check for abnormal sound from furnace.
High negative draught
 Confirm that the draught indication is correct.
 Check and control ID fan speed.
 Check wind box dampers position.
 Check ID dampers position.
 Check FD dampers position.
 Check APH online and by – pass dampers position.
Hot bed material leakage from PA lines
or bed ash drain/Back fire in PA lines
 Observe bed temperatures constantly and charge bed
material if required.
 Cut down coal feeding to that compartment, let the
bed temperature be drop down and close wind box
damper.
 Check that air damper of that line is open.
 Clear that line if the leakage is from vertical portion.
 If the leakage increases further, stop the boiler.
O/L steam pressure too low
 Check bed temperatures and increase coal feeding
accordingly.
 Check for jamming of coal hopper, PA lines and clear
them accordingly.
 Take burner support if required.
 Ensure that DCF chain is rotating(no shear pin failure).
 Ensure that air flow is sufficient.
 Drain bed material slowly, if bed height is more.
Continued…
O/L steam pressure too low
 Check for passing or malfunctioning of Boiler safety
valves.
 Check for abnormal sound from furnace.
 Check for malfunctioning of Dumping control valve
and PRDS control valve.
 Check and increase the feed water temperature.
 If pressure goes down further and frequency drops,
reduce load on turbine.
TURBINE
EMERGENCIES
 Turbine trip
 Load throw off
 UAT trip
 CEP trip
 Hotwell level high
 Hotwell level low
 Vacuum drop Continued…
TURBINE
EMERGENCIES
 Fire/smoke at turbine area
 Turning gear trip
 Oil temperature high
 Bearing temperature high
 Bearing vibration high
 Steam pressure high after first stage
Turbine trip (sharing mode)
 Safeguard the running unit (Reduce load on turbine if
required and Ensure that CWP, BFP, ACWP, CT Fan,
Inst.air compressor are running)
 Cut down proportionate coal feeding in boilers.
 Observe boiler drum level and take steps accordingly.
 Control steam pressure by operating PRDS and
dumping control valves.
 Start AOP, JOP, TTG.
 Investigate the reason of tripping.
 Don’t switch on PEF until unless it is reset and load
Turbine trip (Non – sharing mode)
 Safeguard the running unit (Reduce load on turbine if
required and Ensure that CWP, BFP, ACWP, CT Fan,
Inst.air compressor are running)
 Take grid supply after ensuring Generator breaker has
opened.
 Observe boiler drum level and take steps accordingly.
 Control steam pressure by operating PRDS and
dumping control valves.
 Ensure that extraction MOV is closed.
Continued…
Turbine trip (Non – sharing mode)
 Start AOP, JOP, TTG.
 Investigate the reason of tripping.
 Don’t switch on PEF until unless it is reset and load
shedding is switched – off.
 Maintain hotwell level and ensure that CEP is running.
Load throw – off
 Check turbine speed, if it is at alarming level and is
increasing further, trip the turbine.
 Observe drum level.
 Slump compartments in boiler according to the amount
of load thrown off.
 Take PRDS into service if both extractions are out of
service.
Continued…
Load throw off
 Regulate dumping steam according to dumping header
temperature and condenser vacuum.
 Check for reason of load throw – off.
 If the load throw – off occurs because of any breaker
opening, check thoroughly before closing it.
UAT trip
 Observe the hotwell level and condenser vacuum and
if the power is not resumed within short time, trip the
turbine and isolate all steam inputs to condenser.
 Reduce load on running turbine if required.
 Observe CW and turbine oil temperatures.
 Check for reason of UAT tripping and charge all
remaining feeders/MCC keeping the faulty
feeder/MCC isolated.
CEP trip
 Ensure that standby pump has taken over.
 Check for reason of tripping.
 Check hotwell level and if it is low, take make – up
water into hotwell.
 Open hotwell re – circulation valve fully.
 Check for passing of condensate valve B or C and
isolate them accordingly.
 If the tripping is because of overload, check for
mechanical jamming of pump.
Hotwell level high
 Ensure that standby pump has taken over.
 Check running CEP(s) load.
 Close hotwell re – circulation valve.
 Check position of condensate valve B or C and
operate them accordingly.
Hotwell level low
 Take make – up water into hotwell.
 Open hotwell re – circulation valve fully.
 Check for passing of condensate valve B or C and
isolate them accordingly.
Vacuum drop
 Check gland steam pressure.
 Check CW temperatures.
 Check hotwell level.
 Check the running ejector.
 Check for air ingress from all vacuum related lines
and valves.
 Cut down dumping steam.
 Charge standby ejector if the rate of drop is more.
 If the rate of drop is more, reduce load on turbine.
Fire/smoke at turbine area
 Ensure that vapour extraction fan is running if the fire
is because of oil leakage from any bearing.
 Use CO2 fire extinguisher in case of minor oil and
electrical fires. Don’t use water or other type of fire
extinguishers.
 In case of major fire, first isolate the source (trip the
turbine and isolate generator from electrical circuit)
and then quench it.
Turning gear trip
 Ensure that jacking oil pressure is sufficient.
 Ensure that lube oil pressure is sufficient.
 Put turbine on manual barring gear.
 Check for reason of turning gear trip.
Oil temperature high
 Ensure that the CW temperatures are not on higher
side (All CT fans are running).
 Stop TOPP if it is running.
 Check oil level in Main oil tank.
 Provide external cooling arrangement.
 Ensure that oil temperature controller is working.
 If the bearing temperatures start increasing, trip the
turbine immediately and provide external cooling
arrangement for bearings.
Bearing temperature high
 Charge bleed steam.
 Check oil temperature.
 Check oil level in Main oil tank.
 Ensure proper oil flow to the bearing.
 Check axial shift.
 Provide external cooling arrangement.
 Reduce load on turbine if temperatures goes on
raising.
Bearing vibration high
 Confirm that the signal is correct and is matching with
Bently – Nevada vibration monitoring system.
 Confirm the same in field physically.
 Ensure proper oil flow to the bearing.
 Check casing temperature difference.
 Reduce load on turbine if vibration goes on raising.
Steam pressure high after first stage
 Reduce load on turbine if pressure is at alarming
level.
 Reduce bleed steam.
 Check control valve position and turbine speed.
Other emergencies
 BFP trip
 CWP trip
 Inst. Air compressor trip
BFP trip/Discharge header pr. low
 Ensure that standby pump has taken over.
 Monitor drum level (Increase dumping CV opening, if
drum level starts dropping).
 Reduce load on TG.
 Investigate the reason for tripping.
 If both the BFP tripped and standby has not taken
over because of any common problem, trip both TG
and box – up the boiler.
CWP trip/ Discharge header pr. low
 Ensure that standby pump has taken over.
 Monitor condenser vacuum.
 Reduce load on TG.
 Cut down dumping.
 Investigate the reason for tripping.
 If both the CWP tripped and standby has not taken
over because of any common problem, trip both TG
and isolate all steam inputs to the condenser.
Inst. Air compressor trip/Inst. Air pr. low
 Ensure that standby compressor has taken over.
 Check conservair O/L air pr.
 Monitor boiler drum level, furnace draft, CWP
discharge header pr., FD control dampers position
constantly.
 Ensure that running compressor is fully loaded.
 Check for choking of dryer filters.
 Ensure that both dryers power supply is ON.
 Check for leakages in the system.

Boiler -Emergency Handling

  • 1.
    BOILER EMERGENCIES  Drumlevel low  Drum level high  Any FD fan trip  Any ID fan trip  PA fan trip  DCF trip Continued…
  • 2.
    BOILER EMERGENCIES  Bedtemperature too high  Final Steam temperature too high  Final Steam temperature too low  PSH O/L steam temperature high  Economizer O/L FW temperature high Continued…
  • 3.
    BOILER EMERGENCIES  Highpositive draught  High negative draught  Hot bed material leakage from PA lines or bed ash drain  O/L steam pressure too low  Back fire in PA lines
  • 4.
    Drum Level Low Check BFP discharge header pr. And start another BFP if required  Check FW control valves position in DCS and in field  Check position of all MOVs and operate them accordingly.  Check for any abnormal sound from furnace.
  • 5.
    Drum Level High Operate IBD as per requirement.  Check FW control valves position in DCS and in field.  Close MOVs of Feed Water station as per requirement.  Observe PSH O/L steam temperatures.  Observe Final steam temperature and if it starts dropping, close Boiler stop valve immediately.
  • 6.
    Any FD fantrip  Stop coal feeding.  Reduce load on Turbine according to requirement  Observe Bed temperature  Check for reason of tripping  If the situation diminishes further shut the Boiler stop valve.  Take compartments into service one by one and load the turbine
  • 7.
    Any ID fantrip  Cut down air flow by operating FD dampers.  Slump two compartments.  Check the load on running fan.  Reduce load on turbine according to requirement.  Check for reason of fan tripping.  Take compartments into service one by one and load the turbine
  • 8.
    PA fan trip Check that whether all DCF got tripped or not. Otherwise stop them immediately.  Reduce the load on turbine according to requirement  See that the standby fan is started. Otherwise start it and increase the PA header pr.  Check PA lines for jamming and clear them accordingly.  Take compartments into service one by one and load the turbine
  • 9.
    DCF trip  CheckPA header pr. If it is less increase it.  Increase feeding in other compartments or boiler.  Check for reason of DCF tripping.  In case of all DCF tripping, isolate boiler depending on situation.  In case of any one DCF tripping, observe final steam pr. And temperature and if require isolate attemparator.  Take burner support according to requirement.  If the problem persists for longer time and pressure drops, reduce load on turbine.
  • 10.
    Bed temperature toohigh  Cut down coal feeding to that compartment.  Increase air flow and PA header pr.  Check for wind box damper position.  Constantly observe the wind box pr.  Charge bed material.  Check for abnormal sound from furnace.  Stop the boiler if temperatures still not controlled, bed height decreases rapidly and abnormal sound is observed.
  • 11.
    Final Steam temperaturetoo high  Take attemparator by – pass into service.  Reduce feeding in 3rd , 4th and 5th compartments.  Increase load on boiler.  Observe the TG inlet steam temperature.  Reduce the steam temperature in other boiler.  Check attemparator control valve position in DCS and in field.  Ensure that none of drum safety valve has popped.
  • 12.
    Final Steam temperaturetoo low  Isolate attemparator and check for passing/opening of attemparator by – pass.  Check drum level.  Observe constantly the TG inlet steam temperature.  Increase steam temperature in other boiler.  Increase feeding in 3rd , 4th and 5th compartments.  Reduce load on boiler.  If the rate of drop is higher, isolate the boiler immediately and operate start – up accordingly.
  • 13.
    PSH O/L steamtemperature high  Increase load on boiler.  Minimize furnace draught.  Check the position of overfeed secondary air dampers and open them.  Regulate air flow according to requirement.  Increase bed height.  Meanwhile confirm that the temperature indication is correct.(Attemperator flow will increase)
  • 14.
    Economizer O/L FWtemperature high  Increase load on boiler.  Reduce Economizer I/L feed water temperature.  Minimize furnace draught.  Check the position of overfeed secondary air dampers and open them.  Regulate air flow according to requirement.  Increase bed height.  Meanwhile confirm that the temperature indication is correct.
  • 15.
    High positive draught Confirm that the draught indication is correct.  Check and control ID fan speed.  Check ID dampers position.  Check FD dampers position.  Check for abnormal sound from furnace.
  • 16.
    High negative draught Confirm that the draught indication is correct.  Check and control ID fan speed.  Check wind box dampers position.  Check ID dampers position.  Check FD dampers position.  Check APH online and by – pass dampers position.
  • 17.
    Hot bed materialleakage from PA lines or bed ash drain/Back fire in PA lines  Observe bed temperatures constantly and charge bed material if required.  Cut down coal feeding to that compartment, let the bed temperature be drop down and close wind box damper.  Check that air damper of that line is open.  Clear that line if the leakage is from vertical portion.  If the leakage increases further, stop the boiler.
  • 18.
    O/L steam pressuretoo low  Check bed temperatures and increase coal feeding accordingly.  Check for jamming of coal hopper, PA lines and clear them accordingly.  Take burner support if required.  Ensure that DCF chain is rotating(no shear pin failure).  Ensure that air flow is sufficient.  Drain bed material slowly, if bed height is more. Continued…
  • 19.
    O/L steam pressuretoo low  Check for passing or malfunctioning of Boiler safety valves.  Check for abnormal sound from furnace.  Check for malfunctioning of Dumping control valve and PRDS control valve.  Check and increase the feed water temperature.  If pressure goes down further and frequency drops, reduce load on turbine.
  • 20.
    TURBINE EMERGENCIES  Turbine trip Load throw off  UAT trip  CEP trip  Hotwell level high  Hotwell level low  Vacuum drop Continued…
  • 21.
    TURBINE EMERGENCIES  Fire/smoke atturbine area  Turning gear trip  Oil temperature high  Bearing temperature high  Bearing vibration high  Steam pressure high after first stage
  • 22.
    Turbine trip (sharingmode)  Safeguard the running unit (Reduce load on turbine if required and Ensure that CWP, BFP, ACWP, CT Fan, Inst.air compressor are running)  Cut down proportionate coal feeding in boilers.  Observe boiler drum level and take steps accordingly.  Control steam pressure by operating PRDS and dumping control valves.  Start AOP, JOP, TTG.  Investigate the reason of tripping.  Don’t switch on PEF until unless it is reset and load
  • 23.
    Turbine trip (Non– sharing mode)  Safeguard the running unit (Reduce load on turbine if required and Ensure that CWP, BFP, ACWP, CT Fan, Inst.air compressor are running)  Take grid supply after ensuring Generator breaker has opened.  Observe boiler drum level and take steps accordingly.  Control steam pressure by operating PRDS and dumping control valves.  Ensure that extraction MOV is closed. Continued…
  • 24.
    Turbine trip (Non– sharing mode)  Start AOP, JOP, TTG.  Investigate the reason of tripping.  Don’t switch on PEF until unless it is reset and load shedding is switched – off.  Maintain hotwell level and ensure that CEP is running.
  • 25.
    Load throw –off  Check turbine speed, if it is at alarming level and is increasing further, trip the turbine.  Observe drum level.  Slump compartments in boiler according to the amount of load thrown off.  Take PRDS into service if both extractions are out of service. Continued…
  • 26.
    Load throw off Regulate dumping steam according to dumping header temperature and condenser vacuum.  Check for reason of load throw – off.  If the load throw – off occurs because of any breaker opening, check thoroughly before closing it.
  • 27.
    UAT trip  Observethe hotwell level and condenser vacuum and if the power is not resumed within short time, trip the turbine and isolate all steam inputs to condenser.  Reduce load on running turbine if required.  Observe CW and turbine oil temperatures.  Check for reason of UAT tripping and charge all remaining feeders/MCC keeping the faulty feeder/MCC isolated.
  • 28.
    CEP trip  Ensurethat standby pump has taken over.  Check for reason of tripping.  Check hotwell level and if it is low, take make – up water into hotwell.  Open hotwell re – circulation valve fully.  Check for passing of condensate valve B or C and isolate them accordingly.  If the tripping is because of overload, check for mechanical jamming of pump.
  • 29.
    Hotwell level high Ensure that standby pump has taken over.  Check running CEP(s) load.  Close hotwell re – circulation valve.  Check position of condensate valve B or C and operate them accordingly.
  • 30.
    Hotwell level low Take make – up water into hotwell.  Open hotwell re – circulation valve fully.  Check for passing of condensate valve B or C and isolate them accordingly.
  • 31.
    Vacuum drop  Checkgland steam pressure.  Check CW temperatures.  Check hotwell level.  Check the running ejector.  Check for air ingress from all vacuum related lines and valves.  Cut down dumping steam.  Charge standby ejector if the rate of drop is more.  If the rate of drop is more, reduce load on turbine.
  • 32.
    Fire/smoke at turbinearea  Ensure that vapour extraction fan is running if the fire is because of oil leakage from any bearing.  Use CO2 fire extinguisher in case of minor oil and electrical fires. Don’t use water or other type of fire extinguishers.  In case of major fire, first isolate the source (trip the turbine and isolate generator from electrical circuit) and then quench it.
  • 33.
    Turning gear trip Ensure that jacking oil pressure is sufficient.  Ensure that lube oil pressure is sufficient.  Put turbine on manual barring gear.  Check for reason of turning gear trip.
  • 34.
    Oil temperature high Ensure that the CW temperatures are not on higher side (All CT fans are running).  Stop TOPP if it is running.  Check oil level in Main oil tank.  Provide external cooling arrangement.  Ensure that oil temperature controller is working.  If the bearing temperatures start increasing, trip the turbine immediately and provide external cooling arrangement for bearings.
  • 35.
    Bearing temperature high Charge bleed steam.  Check oil temperature.  Check oil level in Main oil tank.  Ensure proper oil flow to the bearing.  Check axial shift.  Provide external cooling arrangement.  Reduce load on turbine if temperatures goes on raising.
  • 36.
    Bearing vibration high Confirm that the signal is correct and is matching with Bently – Nevada vibration monitoring system.  Confirm the same in field physically.  Ensure proper oil flow to the bearing.  Check casing temperature difference.  Reduce load on turbine if vibration goes on raising.
  • 37.
    Steam pressure highafter first stage  Reduce load on turbine if pressure is at alarming level.  Reduce bleed steam.  Check control valve position and turbine speed.
  • 38.
    Other emergencies  BFPtrip  CWP trip  Inst. Air compressor trip
  • 39.
    BFP trip/Discharge headerpr. low  Ensure that standby pump has taken over.  Monitor drum level (Increase dumping CV opening, if drum level starts dropping).  Reduce load on TG.  Investigate the reason for tripping.  If both the BFP tripped and standby has not taken over because of any common problem, trip both TG and box – up the boiler.
  • 40.
    CWP trip/ Dischargeheader pr. low  Ensure that standby pump has taken over.  Monitor condenser vacuum.  Reduce load on TG.  Cut down dumping.  Investigate the reason for tripping.  If both the CWP tripped and standby has not taken over because of any common problem, trip both TG and isolate all steam inputs to the condenser.
  • 41.
    Inst. Air compressortrip/Inst. Air pr. low  Ensure that standby compressor has taken over.  Check conservair O/L air pr.  Monitor boiler drum level, furnace draft, CWP discharge header pr., FD control dampers position constantly.  Ensure that running compressor is fully loaded.  Check for choking of dryer filters.  Ensure that both dryers power supply is ON.  Check for leakages in the system.