S
Hello,
Our power plant has 5 GTs, frame 6, of 30MW each. On 24th Jan 10 pm, one of the GTs which was running on 27.5 MW, CPD=8.3 bar and other parameters normal, tripped. The alarms that came were (in sequence):
1. Loss of Flame.
2. Loss of CPD bias.
3. Exhaust temperature high trip.
4. High vibration.
CPD dropped fro 8.3 to 1.37 bar suddenly.
MW changed from 27.5 to -7.3 and then to zero.
Highest TTXM was 629 and TTRX was 567 deg C.
Vibration were past trip limit on BB1, 2, 4 and 5. BB4 even got out.
When it tripped, operators say they saw the turbine air filter house shaking.
After that the GT was started twice but both time speed didn't increase beyond 2100rpm and tripped in high vibration. (a very bad decision made by the seniors present in that shift)
On inspection next morning, IGV was found badly damaged and compressor blades were found broken. Filter house was quite dirty which was cleaned. No trace of foreign particle in Inlet plenum was found except one feather on the bird mesh. The GT had returned from HGPI on September 2016, water wash was done before start up. Inlet air filter were replaced on 9 Jan 2017.
Could it be that some foreign material went inside the plenum on 9th Jan and that caused the surge on 24th Jan night?
Could there be some abnormality in Combustion chamber (Loss of flame came first)? our RLNG quality is coming quite bad these days (on going pigging (cleaning) of pipelines upstream). But the fine filter (Last filter in RLNG line) dp before trip was 0.38kg/cm2.
Please share your experiences of the possible causes.
Our power plant has 5 GTs, frame 6, of 30MW each. On 24th Jan 10 pm, one of the GTs which was running on 27.5 MW, CPD=8.3 bar and other parameters normal, tripped. The alarms that came were (in sequence):
1. Loss of Flame.
2. Loss of CPD bias.
3. Exhaust temperature high trip.
4. High vibration.
CPD dropped fro 8.3 to 1.37 bar suddenly.
MW changed from 27.5 to -7.3 and then to zero.
Highest TTXM was 629 and TTRX was 567 deg C.
Vibration were past trip limit on BB1, 2, 4 and 5. BB4 even got out.
When it tripped, operators say they saw the turbine air filter house shaking.
After that the GT was started twice but both time speed didn't increase beyond 2100rpm and tripped in high vibration. (a very bad decision made by the seniors present in that shift)
On inspection next morning, IGV was found badly damaged and compressor blades were found broken. Filter house was quite dirty which was cleaned. No trace of foreign particle in Inlet plenum was found except one feather on the bird mesh. The GT had returned from HGPI on September 2016, water wash was done before start up. Inlet air filter were replaced on 9 Jan 2017.
Could it be that some foreign material went inside the plenum on 9th Jan and that caused the surge on 24th Jan night?
Could there be some abnormality in Combustion chamber (Loss of flame came first)? our RLNG quality is coming quite bad these days (on going pigging (cleaning) of pipelines upstream). But the fine filter (Last filter in RLNG line) dp before trip was 0.38kg/cm2.
Please share your experiences of the possible causes.