IR-CFBC BOILER BURNER STARTUP,SHUTDOWN,TRIPING INTERLOCK

1
Cfbc burner startup sequence

• Ashvani Shukla
• Reliance industries ltd.

2
BURNER MANAGEMENTSYSTEM

• FOLLOWING STEPS TO BE CARRIED OUT FOR BURNER
  START-UP
• Step-1 Pre-interlock satisfied
• Step-2Main 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

3

• 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 AF 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.

4

• 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

5

• 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

6

• PURGE-INTERLOCK CONDITIONS
• 1.All fuel flow is stopped
• 2.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 satisfied
• Pilot gas MFT in close position OR
  
• Pilot gas header vent valve in open position
• OR
• NG MFT valve in close position OR
• NG header vent valve in open position

No flame in furnace All gas block valves in close
position
OR Purge finished
7
PURGE START COMMAND Ø Purge interlock is
satisfied Ø Purge is not finished AND All gas
block valves in close position AND No flame in
furnace Ø Start command from local OR
remote PURGE IN PROGRESS Ø Purge start command
is given Ø Purge timer is running for 5
minutes. Ø All air sleeve dampers in open
position Ø Boiler air flow rate is above purge
rate. PURGE COMPLETED
Purge timer completed No Burner Running
8

• 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 gt 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

9

• 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
•  

10

• 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
OR Any one burner is running

• 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

11

• 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

• MFT not tripped
• OR Burner-A gas firing started

12

• BURNER-A START COMMAND GIVEN
• Burner ready for start
• Start command given from local or remote
• BURNER-A GAS GUN INSERT COMMAND
• Burner A start command given
• BURNER-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

13

• BURNER-A IGNITOR ON COMMAND
• Burner A gas gun is inserted
• Burner-A gas firing is started
• BURNER-A GAS UPSTREAM/DOWN STREAM OPEN AND VENT
• VALVE 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.