In GE 9E frame gas turbine, there is repeating decrease in compressor CPD and then restores back to same level. considering GT Base load and constant (GT inlet, IGV, Frequency) conditions only
Methodology:
analysis include values of CPD and GT output, only taken for GT base-load operations at constant (GT inlet temperature, IGV angle and Frequency) and plotted for the period of two years.
Observations:
* Significant fall in CPD and hence in GT output for six months, and then CPD restores and remains unaffected for 11 months. and then again a step-fall of similar magnitude.
* Step fall in CPD is about 0.25 and 4 MW in GT output.
* Same trend is repeated at all GT inlet temperature bands (18°C, 19°C, 20°C and so on).
Analysis:
* No work has been done on the compressor or its auxiliary systems such as cooling air, sealing air during the periods of CPD fall.
* No conclusive leakage from bleed valves was observed in results of Thermographs.
* Impact of water washing is for only few following days and does not contribute to prolonged CPD trend.
* CTD increases marginally with decrease in CPD at constant GT inlet temperature.
* What can be probable reasons for this trend?
* Recommendation to avoid this loss in CPD/GT output.
Methodology:
analysis include values of CPD and GT output, only taken for GT base-load operations at constant (GT inlet temperature, IGV angle and Frequency) and plotted for the period of two years.
Observations:
* Significant fall in CPD and hence in GT output for six months, and then CPD restores and remains unaffected for 11 months. and then again a step-fall of similar magnitude.
* Step fall in CPD is about 0.25 and 4 MW in GT output.
* Same trend is repeated at all GT inlet temperature bands (18°C, 19°C, 20°C and so on).
Analysis:
* No work has been done on the compressor or its auxiliary systems such as cooling air, sealing air during the periods of CPD fall.
* No conclusive leakage from bleed valves was observed in results of Thermographs.
* Impact of water washing is for only few following days and does not contribute to prolonged CPD trend.
* CTD increases marginally with decrease in CPD at constant GT inlet temperature.
* What can be probable reasons for this trend?
* Recommendation to avoid this loss in CPD/GT output.