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Dear Sir,
We have one 6B Gas turbine duel fuel machine which controlled by Mark V.
It tripped around 90% TNH by Loss of Flame for several times with liquid fuel during startup. What we found in trend is that liquid fuel flow FQL1 were dropped to zero within 3-4s, although servo-valve current outputs FAL was changed to negative value from -2.67, -14.10, -10.3, -49.20 then to -67.03mA in order to overcome error between Fuel flow and Command FQROUT=25.83%, but it was not successfully, then tripped by Loss by Flame, all others data are normal before tripped, such as bypass valve command FQROUT=25.83, control oil pressure A63HL_MEAN, Hydraulic oil pressure A63HQ and Liquid Fuel pressure A63HL.
We also replaced a new servo valve and checked the polarity of servo coil one by one, clean the filer of servo valve, and opened the actuator of LFCV to check. We do not found any problem for actuator.
After that, we startup serverl times, the trend and trip log are same as before. There is one things that it is diffcault to confirm what the clutch system working well or not.
In addition, we have startup successfully once or twice before replaced servo-valve, the startup phase is ok, but not stable during transfer to Gas fuel from Liquid fuel or vice versa . The main problem is that liquid fuel flow dropped more than 6% once unintelligibly during increase liquid fuel command or raise once more than 4% unreasonably during decrease liquid fuel command.
Does Servo-Valve has a problem? But we have replace a new one. Or Does clutch system has a problem? Many thanks!
We have one 6B Gas turbine duel fuel machine which controlled by Mark V.
It tripped around 90% TNH by Loss of Flame for several times with liquid fuel during startup. What we found in trend is that liquid fuel flow FQL1 were dropped to zero within 3-4s, although servo-valve current outputs FAL was changed to negative value from -2.67, -14.10, -10.3, -49.20 then to -67.03mA in order to overcome error between Fuel flow and Command FQROUT=25.83%, but it was not successfully, then tripped by Loss by Flame, all others data are normal before tripped, such as bypass valve command FQROUT=25.83, control oil pressure A63HL_MEAN, Hydraulic oil pressure A63HQ and Liquid Fuel pressure A63HL.
We also replaced a new servo valve and checked the polarity of servo coil one by one, clean the filer of servo valve, and opened the actuator of LFCV to check. We do not found any problem for actuator.
After that, we startup serverl times, the trend and trip log are same as before. There is one things that it is diffcault to confirm what the clutch system working well or not.
In addition, we have startup successfully once or twice before replaced servo-valve, the startup phase is ok, but not stable during transfer to Gas fuel from Liquid fuel or vice versa . The main problem is that liquid fuel flow dropped more than 6% once unintelligibly during increase liquid fuel command or raise once more than 4% unreasonably during decrease liquid fuel command.
Does Servo-Valve has a problem? But we have replace a new one. Or Does clutch system has a problem? Many thanks!