Dear Gents
I have a turbine (25MW) with Mark VIe control system(upgraded from Mark II at 2013).
- Recently only, I have a problem during stopping the turbine from FSNL.
- On FSNL, The FSR is about 20.8% and FSRSD is 100%.
-Directly after stop order, the FSRSD is switched to the current FSR value then logic signal L83SDL Becomes true which makes FSRSD drop to FSRMIN by the rate of (FSKSD[2]) until intercept with value (FSKMIND[3]) of the FSRMIN shutdown curve and the speed decreases until 85.5% and the bleed valve open and the guide van closes.
-The speed freezes at this value (85.5%) and the FSR at (18.6%) and still running for long time until I trip it manually by emergency stop.
Notes: FSKMIND[3]=18.75% at FSKMINN[3]=85% TNH
FSKMIND[2]=14.1% at FSKMINN[2]= 82% TNH
FSKMIND[1]=11.8% at FSKMINN[1]= 40% TNH
FSKMIND[0]=9.5% at FSKMINN[0]= 5% TNH
FSKMINU2 [1]=17.8%
FSKSD[2]=1%/sec
FSKSD[3]=0.101%/sec
FSKSD[4]=1%/sec
- I don't know what makes the turbine speed to hold at this value?
- If I decreases the value of FSKMIND[3] slightly, Will the speed decrease below 85.5% and the turbine continue the normal shutdown sequence??
Appreciate your assistance.
I have a turbine (25MW) with Mark VIe control system(upgraded from Mark II at 2013).
- Recently only, I have a problem during stopping the turbine from FSNL.
- On FSNL, The FSR is about 20.8% and FSRSD is 100%.
-Directly after stop order, the FSRSD is switched to the current FSR value then logic signal L83SDL Becomes true which makes FSRSD drop to FSRMIN by the rate of (FSKSD[2]) until intercept with value (FSKMIND[3]) of the FSRMIN shutdown curve and the speed decreases until 85.5% and the bleed valve open and the guide van closes.
-The speed freezes at this value (85.5%) and the FSR at (18.6%) and still running for long time until I trip it manually by emergency stop.
Notes: FSKMIND[3]=18.75% at FSKMINN[3]=85% TNH
FSKMIND[2]=14.1% at FSKMINN[2]= 82% TNH
FSKMIND[1]=11.8% at FSKMINN[1]= 40% TNH
FSKMIND[0]=9.5% at FSKMINN[0]= 5% TNH
FSKMINU2 [1]=17.8%
FSKSD[2]=1%/sec
FSKSD[3]=0.101%/sec
FSKSD[4]=1%/sec
- I don't know what makes the turbine speed to hold at this value?
- If I decreases the value of FSKMIND[3] slightly, Will the speed decrease below 85.5% and the turbine continue the normal shutdown sequence??
Appreciate your assistance.