GE 9FA DLN II combustion trouble
GE 9FA DLN II combustion trouble
(OP)
Good evening to all. On site we have a Gas Turbine GE 9FA DLNII. SOme time before we noticed a sudden loss of flame to one of the 4 flame detectors, after one minute we hde high exhasut spread temperatures and consequent trip of the turbine. When we put back the unit it seemed OK. Can you suggest for a possible cause?





RE: GE 9FA DLN II combustion trouble
Diagnostics of the 9FA and DLN 2.0 takes some rather substantial expertise and a host of data download of the event from the control, Mark VI is presume and a host of control tags to determine what actually happened to give you a loss of flame and subsequent HETS trip. You would need to know many conditions such as DWATT Load, DLN Mode, was the unit transfering mode at the time and lengthy list of the control tag data. Have you tried asking GE to diagnose?
Kind Regards
Romefu12
RE: GE 9FA DLN II combustion trouble
We suspect that one combustion chamber went OFF.
Does this make sense?
RE: GE 9FA DLN II combustion trouble
rmw
RE: GE 9FA DLN II combustion trouble
It is not unusual for 1 can to suffer a flame out. If you do suffer a flame out you will create a substantial High Spread. You need to download the Exhaust Thermocouple Spread data during the event (Control Tags TTXD1 thru TTXD27) and your FD_INTENS_1 thru FD_INTENS_4 to determine when you lost the flame sensor data. I suspect if you lost flame the control would interpret this event as a cold spot. If you could tell me at what Unit Load and what type of fuel was being used when this happened I could probably tell you which combustion can or cans to inspect thru a predicted swirl calculation. This could be a hardware issue, a fuel contamination issue, or other mechanical issue with the purge circuit. Many things could cause this issue.
Romefu12
RE: GE 9FA DLN II combustion trouble
Thank you in advance. Our GE support suspect also fuel contamination on the cans.
RE: GE 9FA DLN II combustion trouble
RE: GE 9FA DLN II combustion trouble
Your L28FDD alarm indicates loss of flame in Can 8. However your HIGH EXHAUST TEMPERATURE SPREAD TRIP caused by Exhaust TC 17 indicates a swirl calculation @260 MW to indicate a problem with Can 4.
I would begin by borescope inspection of cans 3,4, 5, and 8.
Romefu12
RE: GE 9FA DLN II combustion trouble
The conversation was quite informative and useful
Could u please post the Swirl chart (Load vs Swirl angle graph)for this machine. I was a startup TA in GE few years ago and now I am a freelancer
Thanks and warm regards
Samson16