100268027 chapter-9-burner-management-system
2
BOILER AND AUXILIARIES BURNER MANAGEMENT SYSTEM CHAPTER 9 BURNER MANAGEMENT SYSTEM The flammable fuel air mixture admitted to a boiler furnace is immediately ignited, burnt and converted into inert. The product gases formed are evacuated by the draught system so that under normal operating conditions, the furnace pressure remains very close to atmospheric pressure. If the ignition of the flammable mixture is delayed it leads to the accumulation of the same in the furnace. When the accumulated mass in the furnace is ignited later, the rate of energy release can be tremendously high which the walls of the furnace may not be in a position to withstand that. This results in furnace explosion. Therefore to ensure safe entry of fuel in the furnace and proper combustion of the same it is essential to use a dedicated protection system, which is called as Burner Management System (BMS) or Furnace Safeguard Supervisory System (FSSS). 9.1 ROLE OF BMS IN STEAM GENERATION PROCESS When provided the BMS supervises, controls and monitors the preparation, distribution and admission of fuel and air into the furnace. Thereby it can effectively prevent the formation of an explosive mixture of fuel and air in any portion of the steam generator during any phase of operation including start up and shut down. BMS exercises authority over both operator and process controls through its safety interlocking features. The interlocking features included in the system depends upon 1) Physical characteristics of the firing system 2) Type of fuel fired It will not be the responsibility of B.M.S. to regulate the air and fuel flow quantities or to initiate start up or normal shut down of firing system components. ET – ’08 68
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Transcript of 100268027 chapter-9-burner-management-system
BOILER AND AUXILIARIES BURNER MANAGEMENT SYSTEM
CHAPTER 9
BURNER MANAGEMENT SYSTEM
The flammable fuel air mixture admitted to a boiler furnace is immediately ignited, burnt
and converted into inert. The product gases formed are evacuated by the draught system
so that under normal operating conditions, the furnace pressure remains very close to
atmospheric pressure.
If the ignition of the flammable mixture is delayed it leads to the accumulation of the
same in the furnace. When the accumulated mass in the furnace is ignited later, the rate
of energy release can be tremendously high which the walls of the furnace may not be in
a position to withstand that. This results in furnace explosion.
Therefore to ensure safe entry of fuel in the furnace and proper combustion of the same it
is essential to use a dedicated protection system, which is called as Burner Management
System (BMS) or Furnace Safeguard Supervisory System (FSSS).
9.1 ROLE OF BMS IN STEAM GENERATION PROCESS
When provided the BMS supervises, controls and monitors the preparation, distribution
and admission of fuel and air into the furnace. Thereby it can effectively prevent the
formation of an explosive mixture of fuel and air in any portion of the steam generator
during any phase of operation including start up and shut down.
BMS exercises authority over both operator and process controls through its safety
interlocking features. The interlocking features included in the system depends upon
1) Physical characteristics of the firing system
2) Type of fuel fired
It will not be the responsibility of B.M.S. to regulate the air and fuel flow quantities or to
initiate start up or normal shut down of firing system components.
ET – ’08 68
BOILER AND AUXILIARIES BURNER MANAGEMENT SYSTEM
9.2 BASIC REQUIREMENTS OF BURNER MANAGEMENT
SYSTEM
A BMS provided in a boiler must meet the following requirements:
• It should offer maximum protection.
• It should not cause any nuisance boiler trips.
• Its components should consume less power.
• The components of B.M.S. must be reliable and have long life.
9.3 OPERATION AND FUNCTIONS OF BMS
It will enforce and execute safety interlocking features on the operation of following
components and system of the boiler.
1) Boiler purging.
2) Secondary air damper modulation and on/off control and supervision in corner fired
boilers.
3) Igniters on/off control and supervision.
4) Light up (warm up oil) on/off control and supervision.
5) Heavy oil on/off control and supervision.
6) Pulverisers and feeders on/off control and supervision.
7) Flame scanners intelligence and checking.
8) Overall flame failure protection.
9) Boiler protection
ET – ’08 69
