04-01-2013, 10:57 AM
POWER PLANT EMERGENECIES
POWER PLANT.ppt (Size: 648 KB / Downloads: 56)
HIGH FURNACE PRESSURE
One I.D. Fan tripped or Mal-operation
of control vanes of I.D./F.D./P.A. Fans or closing of damper
Unstable furnace flame conditions. Sudden starting of coal mill.
Furnace water seal broken, E.P. or flue gas path manhole opened.
Water wall tube rupture/leakage.
ID FAN TRIP
Motor over-loaded.
Corresponding FD Fan has tripped.
Spurious electrical fault.
Lub. Oil pressure problem.
Bearing temperature problem.
Corresponding APH may have tripped.
FURNACE PRESSURE LOW
I.D. Fan auto control Failure.
I.D. Fan vane control mechanism Failure causing vanes to open wide.
Sudden decrease in air input or tripping of one F. D. fan.
Sudden tripping of one or more mills or choking of mill/raw coal Feeder pipe.
FD FAN TRIPPED
Motor over-loaded
Lub oil pressure trouble.
Bearing temperature trouble.
ID fan has tripped.
FD lub. Oil pressure low.
PA FAN TRIPPED
tripping is due to high bearing temp.
Boiler has tripped.
Lub. Oil pressure may be very low.
It will lead to tripping of some mills in service.
DRUM LEVEL LOW
Mal-operation of Feed Auto Control or Feed Regulator or scoop auto.
Tripping of one of working feed pump (standby pump does not start)
Sudden increase of load.
Sudden increase in firing rate, e.g.
starting of mills having sufficient coal left before previous stopping.
Tube repture/puncture of low point drain valves or Emergency drum drain Valve
Inadvertant opening of low point drain valves or Emergency drum drain valve.
WATER MILL TUBE LEAKAGE
Starved water walls due to very low drum level.
Sustained flame impingement on water wall tubes.
Blocked tube, scaling of tube, resulting in overheating of tube metal, pitting, corrosion of tubes.
Soot blower steam impingement (wet steam impingement or direct impingement of steam).
Circulation affected due to opening of low point drains.