Presentation on Commissioning of CFBC Boiler

ACTIVITIES OF COMMISSIONING

 Air Leakage Test  Hydro Test  Commissionin Commissioning g Checkpoints  Equipments Trial Run  Refractory Dry Out  Chemical Cleaning  Boiler Safety Protection Checking

ACTIVITIES OF COMMISSIONING

 Grid Air pressure Drop Study  Control Instrumentation Checking  Boiler Light up & Coal Firing  Steam Blowing  Safety Valves Floating  Steam Dumping  Synchronization

ACTIVITIES OF COMMISSIONING

 Auto loop commissioning  Reliable Test run  Performance test run

 Air Leakage Test   Pressure parts  The aim of air leak test is to ensure that erection of the pressure parts is completed and no major  leaks are there.

 Air leak test is conducted by introducing air into the boiler pressure parts at a pressure of  approximately 7 - 8ksc

 Air Leakage Test  Non Pressure parts  The purpose of air leak test of air, gas ducting & ESP is to ensure leakage proof in ducts, welding joints, flange joints to ensure efficient operation of fans, boiler 

 Hydro Test    All the pressure parts of the boiler, which are subjected

to

high

operating

pressure

during

operation, should be checked to ensure that they withstand the high pressure so hydraulic test is conducted

 Commissioning Checkpoints  Checklist have to be prepared for all equipments and all activities.

   After completion of equipments erection, check points to be made and the trial run of equipments shall commence

 Equipments Trial Run No-load trial & load trials of following equipments are completed after fulfilling the commissioning checkpoints

  ID fan

   PA fan

  SA fan

  Feed pumps

  Loop seal blower    Fuel feeders

 Refractory Dry Out  In a boiler furnace, during the phase of erection refractory is laid in many areas like furnace, second pass areas, cyclones, bed ash cooler etc,

   Refractory drying is to be carried out by utilizing either light oil or gas

 Chemical Cleaning  During the process of erection, there might be entrainment of unwanted material like rust, dirt, mill scale etc.

 The internal surfaces of a boiler where demineralized water of high purity is to be evaporated, should be maintained free of all material which come in the way of efficient heat transfer and thus effect generation.

  Chemical Cleaning  The cleaning procedures aim to removal of rust, dirt, sand and also any foreign material entrained in the contour.

The cleaning can be achieved by an alkali boil out or  alkali flushing and acid cleaning.

 Boiler Safety Protection Checking  Check

the

following

equipments

are

having

interlocks

 ID fan-I & I vs. loop seal blower   loop seal blower delivery damper open vs. loop seal blower 

 IID Fan vs. SA Fan  ID Fan vs. PA Fan

 Boiler Safety Protection Checking  Check

the

following

equipments

interlocks

 PA Fan vs. Fuel Feeders  Drum Level very LOW vs. MFT  Deaerator Level Low vs. Feed pump  Drum level Very High vs. Turbine  Furnace pressure Very high vs. MFT

are

having

 Boiler Safety Protection Checking  Check

the

following

equipments

interlocks

 Furnace pressure Very low vs. MFT

are

having

 Grid Air pressure Drop Study    Grid air pressure drop study is nothing but finding out the pressure drop across grid nozzle at different air flows

 The pressure drop values measured in grid pressure drop study are used to find out the bed height when the boiler is in running condition. i.e. at a particular  air flow

 Control Instrumentation Checking  Before boiler light-up, all control instruments have to be checked i.e. to ensure whether the remote operation of all equipments is in proper condition

 Boiler Light up & Coal Firing    Start  – up sequence

 Steam Blowing  The objective of steam blowing is to remove dirts, loose material, cutting bars etc, that

might have been

entrapped in Super Heaters, Steam piping, re-heaters during manufacture, storage, erection at site.

   Failure to remove the debris may result in damage to turbine blades, valves etc

 Safety Valves Floating  The objective of the Testing Schedule is to test the safety valves by actually floating and ensuring that safety valves lift at recommended values.

 Steam Dumping  Steam dumping is nothing but allowing steam from re-heater through MSL and by by-passing the HP turbine the steam is send to re-heater via HRH line and from re-heater it is send to condenser via CRH line by by-passing IP turbine and LP turbine.

   During initial commissioning steam dumping is done to achieve steam purity.

 Steam Dumping    Till achieving purity, the steam can be allowed to drain from CEP O/L to open drain. After achieving purity it can be taken to close circuit.

 Synchronization  After completion of all activities synchronization of  the unit shall commence

 Synchronization

is

nothing

but

matching

the

generator frequency with grid frequency using syncro-scope

 Reliable test Run  Reliability run is Seven (7) days of Continuous Power Plant operation at various loads in which 72 hrs at full load and 2 hrs at 110% MCR capacity to be demonstrated.

   During this period two tripping allowed

and

after

tripping

of the plant is plant

to

synchronization within 4 hrs to be demonstrated,

be

 Performance test Run Boiler performance test run is conducted

 For understanding the current level of performance of the boiler,

 For

any

trouble

shooting

of

the

performance deviations

 For proving the performance guarantees

boiler

for