Seeking opinions on a recurring issue with our 127MW GE Frame 9E gas turbine in a 1+1+1 combined cycle configuration.
We've experienced three consecutive turbine trips with the "combustion trouble, exhaust temperature high spread" alarm while the machine was on FSNL.
The most recent incident happened during start-up after outage for CI and rotor balancing activity. The turbine was on FSNL for 4 minutes, and the allowable spread limit constantly decreased, triggering the alarm and causing the trip. we also carried out BI of CI parts & no finding related to hardware was observed.
This issue also occurred consecutively during the last two shutdowns in August and September, with a possible connection to SRV/GCV hunting in August, but not in September. GCV & SRV calibration in the recent outage & no anomaly was observed.
In all cases, the trips occurred within 4 to 5 minutes of the machine being on FSNL.
Looking for insights and opinions on this
We've experienced three consecutive turbine trips with the "combustion trouble, exhaust temperature high spread" alarm while the machine was on FSNL.
The most recent incident happened during start-up after outage for CI and rotor balancing activity. The turbine was on FSNL for 4 minutes, and the allowable spread limit constantly decreased, triggering the alarm and causing the trip. we also carried out BI of CI parts & no finding related to hardware was observed.
This issue also occurred consecutively during the last two shutdowns in August and September, with a possible connection to SRV/GCV hunting in August, but not in September. GCV & SRV calibration in the recent outage & no anomaly was observed.
In all cases, the trips occurred within 4 to 5 minutes of the machine being on FSNL.
Looking for insights and opinions on this