Dear all,
We are operating two GE-9E machines with dual fuel combustion facility(non-DLN burner; standard burner).These machines have been operated for seven years.Schedule maintenance(CI,HGPI) also carried out regularly.
One of our unit recently experiencing high differential temperature alarm for third stage forward outer wheel space sensors(TTWS3FO1-TTWS3FO2>>50~120 deg C).Half months ago Offline water wash was carried for this unit. After 14 days of operation TTWS3FO1 showing deviated value from TTWS3FO2 and generate differential alarm HI. Since all other parameters were found good we shutdown the unit and replaced the TTWS3FO1 with new thermocouple and restart.During loading the the difference well within the range but after 70% load the differential alarm high again appeared.This time TTWS3FO1 value was more higher than previous value(545~580 degC) and interesting thing is that below 70MW the differential alarm disappeared and greater than 70MW it appeared again.
Can anybody explain the reasons of the alarm and its impacts of running the unit with this alarm?
We are operating two GE-9E machines with dual fuel combustion facility(non-DLN burner; standard burner).These machines have been operated for seven years.Schedule maintenance(CI,HGPI) also carried out regularly.
One of our unit recently experiencing high differential temperature alarm for third stage forward outer wheel space sensors(TTWS3FO1-TTWS3FO2>>50~120 deg C).Half months ago Offline water wash was carried for this unit. After 14 days of operation TTWS3FO1 showing deviated value from TTWS3FO2 and generate differential alarm HI. Since all other parameters were found good we shutdown the unit and replaced the TTWS3FO1 with new thermocouple and restart.During loading the the difference well within the range but after 70% load the differential alarm high again appeared.This time TTWS3FO1 value was more higher than previous value(545~580 degC) and interesting thing is that below 70MW the differential alarm disappeared and greater than 70MW it appeared again.
Can anybody explain the reasons of the alarm and its impacts of running the unit with this alarm?