A
We have GE Frame V gas turbine 5002B with 41900 running hours. during running the turbine sparks came out from exhaust at steady state. turbine was shut down normally (No trip).
Examining turbine's parameters the following was found:
1) Exhaust temperature starts normally at average 420 deg C then it rises to 480 then to 540 at the moment where sparks came out.
2) Compressor discharge pressure starts normal at 5.81 bar then it starts degrading to 5.1 bars
3) Bearing one vibration rose to about 0.48 inch/sec then degrades to 0.1 inch/sec and during sparks it rose to 0.4 inch/sec (alarm set point 0.5 inch/sec)
4) TNH remained at 100% then it showed instantaneous increase to 101.25 % then to normal
5) during TNH notch, FSR showed revers notch from 40% to 35% then back to 42%
6) Gas Nozzles were disassembled and examined as well as linears. they found to be normal
what could be the possible cause for the described problem plus what further examination shall be done?
Examining turbine's parameters the following was found:
1) Exhaust temperature starts normally at average 420 deg C then it rises to 480 then to 540 at the moment where sparks came out.
2) Compressor discharge pressure starts normal at 5.81 bar then it starts degrading to 5.1 bars
3) Bearing one vibration rose to about 0.48 inch/sec then degrades to 0.1 inch/sec and during sparks it rose to 0.4 inch/sec (alarm set point 0.5 inch/sec)
4) TNH remained at 100% then it showed instantaneous increase to 101.25 % then to normal
5) during TNH notch, FSR showed revers notch from 40% to 35% then back to 42%
6) Gas Nozzles were disassembled and examined as well as linears. they found to be normal
what could be the possible cause for the described problem plus what further examination shall be done?