CFBC BURNER STARTUP SEQUENCE

ASHVANI SHUKLA

RELIANCE INDUSTRIES LTD.

BURNER MANAGEMENTSYSTEM• FOLLOWING STEPS TO BE CARRIED OUT FOR BURNER START-UP• Step-1: Pre-interlock satisfied • Step-2:Main interlock satisfied • Step-3: Purge interlock satisfied• Step-4: Purge required will come after all permissive satisfied and

purge Start command will be given by operator• Step-5: Purge in progress will run for 5 minutes(after purge start

command will be given by operator this indication will appear for 5 minutes) .

• Step-6 :Purge completed. After purge completed one timer will start for 15 minutes, in between this time operator has to start burner or else purge required will come and again operator will go for purging

• Step-7: MFT reset will be done by manual pushbutton. Manual open command will be given for pilot gas MFT and NG gas MFT. After open command given to both MTF(Pilot gas and NG gas) individual header vent will be closed automatically.

• Step-8: Gas firing permissive satisfied• Step-9: Burner A—F ready for start• Step-10: After start command given following step will be carried out in auto mode:• Gas gun inserted command• Ignition on command, Pilot gas up stream and down stream valve open command,

pilot gas vent valve close command.• Pilot flame on(It will be detected by a flame scanner and remain on for 5 second to

permit the opening of NG gas valve).• Gas block valve up stream and down stream valve open cmd., gas block valve vent

valve close c0mmand• Burner on.

• PRE INTERLOCK CONDITIONS: • Black furnace trip• Total airflow not very low• I.D.Fan running• S.A. Fan running• P.A. Fan running• Furnace pressure not very high• Furnace pressure not very low• Emergency stop P.B. not operated• Drum level not very low• Drum level not very high• Instrument air pressure not very low

MAIN-INTERLOCK CONDITIONS: • Pre-interlock satisfied• Fluidized bed pressure above 120MMWC• Purge finished OR any one burner in on condition OR bed

temperature greater than the minimum ignition temperature of coal

PURGE-INTERLOCK CONDITIONS:1.All fuel flow is stopped2.Flow path open (Primary and secondary air path along with flue gas path should be open for free flow of air during purging.Pre-interlock condition satisfiedPilot gas MFT in close position OR Pilot gas header vent valve in open positionORNG MFT valve in close position ORNG header vent valve in open position

No flame in furnaceAll gas block valves in close position

OR Purge finished

PURGE START COMMAND:

Ø Purge interlock is satisfiedØ Purge is not finished AND All gas block valves in close position AND No flame in furnaceØ Start command from local OR remotePURGE IN PROGRESS

Ø Purge start command is givenØ Purge timer is running for 5 minutes.Ø All air sleeve dampers in open positionØ Boiler air flow rate is above purge rate.

PURGE COMPLETED:

Purge timer completed No Burner Running

FURNACE FIRING PERMISSIVE SATISFIED:• Main interlock is satisfied

• SA air flow is not very low

• PA air flow is not very low

• Minimum bed fluidized pressure > 127MMWC

PERMISSIVE FOR PILOT GAS MFT OPEN COMMAND

• Furnace firing permissive is satisfied

• All pilot gas block valves are in close position OR Any one burner is running

• Pilot gas MFT stop push button not operated

• Pilot gas MFT stop push button is not operated

• Open command from remote/local

PERMISSIVE FOR PILOT GAS HEADER VENT CLOSE COMMAND• 1. Pilot gas MFT open command is given

• 2. Any one burner is running OR Any one pilot gas burner is started OR Pilot gas pressure is not high

• 3. Pilot gas header vent close command not given OR Pilot gas header vent closed feedback

NG GAS MFT OPEN COMMAND

• Furnace firing permissive satisfied

• All gas block valves are in close position OR Any one burner is running

• Gas MFT stop push button not operated

• Open command from remote OR local

•

NG GAS HEADER VENT CLOSE COMMAND• Gas MFT open command given

• Any one burner is running OR Any one pilot gas burner is started OR Gas pressure is not high

• Gas header vent close command is not given OR Gas header vent is in close position

GAS FIRING PERMISSIVE:

Gas PCV in start position Gas FCV in closed position

•NG pressure is not very low OR Any one burner is running•NG pressure is not very high•Furnace firing permissive is satisfied•MFT Reset bit is available•NG MFT valve open feedback

OR Any one burner is running

BURNER READY TO START FOR BURNER-A:

•Gas firing permissive satisfied•Burner A is running OR Burner-A gas block valves are in close position•Stop push button not operated from remote AND local•Burner-A ignition sparking time not over OR Burner-A flame is on•Burner-A not tripped

No ignitor running Burner –A flame not on

MFT not tripped•OR Burner-A gas firing started

BURNER-A START COMMAND GIVEN:

•Burner ready for start•Start command given from local or remoteBURNER-A GAS GUN INSERT COMMAND

Burner –A start command givenBURNER-A PILOT GAS UPSTREAM/DOWN STREAM OPEN AND VENT VALVE CLOSE COMMAND

•Burner –A gas firing permissive is satisfied AND Burner-A is not running•Burner-A pilot block valve closed feedback OR Burner-A pilot flame on•Burner-A gas gun is inserted•Furnace firing permissive is satisfied•Pilot gas pressure is not high•Pilot gas pressure isnot low OR Any one pilot burner is on•Pilot MFT valve open feedback

BURNER-A IGNITOR ON COMMAND

•Burner –A gas gun is inserted•Burner-A gas firing is startedBURNER-A GAS UPSTREAM/DOWN STREAM OPEN AND VENTVALVE CLOSE COMMAND•Burner –A air sleeve damper open feedback

•Burner-A ignition sparking time is over•Burner-A pilot flame is on OR Burner-A flame is on•Burner-A gas gun inserted•Natural gas MFT valve open feedback

Burner-A gas firing is started.