Waleligne M. Salilew; Zainal A. Abdul Karim; Tamiru A. Lemma
Abstract
This research work presents a gas turbine performance investigation. Researchers have put efforts into this field of study; however, the influence of the concurrence of variable inlet ...
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This research work presents a gas turbine performance investigation. Researchers have put efforts into this field of study; however, the influence of the concurrence of variable inlet guide vane (VIGV) drift, fouling, and erosion on the three-shaft gas turbine’s performance during part-load operation has remained unexplored. Therefore, this study addresses this gap. First the gas turbine design point and off-design performance model have been developed by utilizing the original engine manufacturer data provided. The accuracy of the models was validated, and the maximum mean absolute percentage error of the design point performance model is shown at exhaust temperature prediction, it is about 1.74%. The off-design performance model was also validated with the power output versus ambient temperature and efficiency versus operating curves. At each operational point, the power output versus ambient temperature error from the validation data was 0.02%, while the efficiency versus ambient temperature error was 4.5%. After the validation, the engine model was subjected to the concurrence of variable inlet guide vane drift, fouling, and erosion conditions to simulate the degradation state. The results show that the highest isentropic efficiency deviation due to component faults occurred in the upstream components, specifically in the low-pressure compressor’s (LPC) isentropic efficiency. The deviation recorded due to the concurrence of VIGV drift at -6.5° and 100% fouling severity is -11.47%, whereas 9.65% is the LPC isentropic efficiency deviation recorded when VIGV drift at -6.5° and erosion at 100% severity level simultaneously occurred. In addition, the effects of the faults above on gas path measurements were simulated, and the highest measurement deviation was observed when simultaneous LPC fouling and -6.5% VIGV drift occurred. Among the measurements, the highest deviation was observed in the exhaust temperature and thermal efficiency, about 9.23% and -7.35%, respectively.
