11 April 2012

START UP IN THERMAL PLANTS

COLD START
1)           After Capital overhaul.
2)      After Annual overhaul.
3)     After any major rectification work like H2 leakage / T-G Bearing High Vibrations / Stator winding fault / Rotor earth fault.

WARM START

1)              After LTSH, SH Re heater tube leak rectifications.
2)              After H2  leakage - Rectification, After Auxiliaries like PA Fan / CW pump motor rewinding.
3)              Reserve shutdown due to High frequency, CW Sump level (River level) problem.
4)              Electrical faults like Surge Capacitor failure / Rotor earth fault / Stator Earth fault / GT Buchholzs.
5)              Coal shortage.

HOT START

1)              Economizer tube failure.
2)              Water wall tube failure.
3)              Turbine impulse line leakage.
4)              MS-Valves heavy gland leak.
5)              Generator X-r bushing oil leaks.
6)              Gland cooler gasket failure (leakages in condensate flow path) , Turbine lube oil cooler leaks.
7)              Cable flash over of Unit bushes / UAT etc.
8)              Small maintenance works on feed water line, de-Aerator etc. / small fire hazard
9)              Start up after fictions tripping (Governing System trouble / I&C trouble.
10)          Start up after trip out due to Mal-operation human error / Instrument error or relay / Protection, Momentary drum level / draft / vacuum.