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Dear all,
I am facing a serious problem with GTG frame 5001PA.
When the GTG changes operation mode from Droop control (the GTG load is 20MW) to Iso. control at 14MW, we are faced with two problems:
The first problem is the turbine trip because of Low frequency trip in 17/04/2007. When I checked the trip data it is so that the flames inside combustion is unstable event. Some flames were loss, the exhaust temperature increased very high then the SFR is in temperature control after 18 seconds Turbine tripped because of low frequency.
The last trip in 10/08/2007 the turbine trip because of high exhaust temperature spread.
After I checked the historian data of GTG I found that after changing mode from Droop control to Iso. control mode about 3 seconds the exhaust temperature spread increased very quickly, and after 60 second delay Combustion trouble alarm appeared. Then the DLN I combustion mode change from premix to Extended lean - lean mode. After 9 seconds the turbine trip because of high exhaust temperature trip.
Could you please explain to me why the combustion is not stable after changing mode of GTG?
When the problem happens, can I change the combustion mode from Premix mode to Extended lean - lean mode by pressing extended lean - lean push button on the HMI of GTG in order to make the flame more stable?
Is the DLN I combuster not stable when the load changes quickly?
I am facing a serious problem with GTG frame 5001PA.
When the GTG changes operation mode from Droop control (the GTG load is 20MW) to Iso. control at 14MW, we are faced with two problems:
The first problem is the turbine trip because of Low frequency trip in 17/04/2007. When I checked the trip data it is so that the flames inside combustion is unstable event. Some flames were loss, the exhaust temperature increased very high then the SFR is in temperature control after 18 seconds Turbine tripped because of low frequency.
The last trip in 10/08/2007 the turbine trip because of high exhaust temperature spread.
After I checked the historian data of GTG I found that after changing mode from Droop control to Iso. control mode about 3 seconds the exhaust temperature spread increased very quickly, and after 60 second delay Combustion trouble alarm appeared. Then the DLN I combustion mode change from premix to Extended lean - lean mode. After 9 seconds the turbine trip because of high exhaust temperature trip.
Could you please explain to me why the combustion is not stable after changing mode of GTG?
When the problem happens, can I change the combustion mode from Premix mode to Extended lean - lean mode by pressing extended lean - lean push button on the HMI of GTG in order to make the flame more stable?
Is the DLN I combuster not stable when the load changes quickly?