EVALUASI EKSERGI TURBIN GAS SEBELUM DAN SESUDAH OVERHAUL COMBUSTOR DI PT. X

Dianta Mustofa Kamal1*, Ahmad Bustomi2 1Program Studi Magister Terapan Teknologi Manufaktur, Politeknik Negeri Jakarta, Kampus UI Depok, Indonesia 2Program Studi Teknik Mesin, Jurusan Teknik Mesin, Politeknik Negeri Jakarta, Kampus UI Depok, Indonesia

Abstract

Improving the efficiency and performance of gas turbine systems in power plants is essential to ensure optimal energy conversion and operational reliability. This study evaluates the impact of combustor inspection—carried out as an overhaul procedure—on the exergy performance of a gas turbine. The analysis focuses on five key parameters: heat rate, thermal efficiency, specific fuel consumption, exergy efficiency, and exergy destruction across the compressor, combustor, and turbine. Secondary operational data from a 170 MW gas turbine unit operating between February 2022 and January 2023 were analyzed using both energy and exergy approaches. The results show that in December 2022, after the combustor overhaul, the gas turbine achieved its highest thermal efficiency of 37.48%, lowest heat rate of 2,297.86 Kcal/kWh, and lowest specific fuel consumption of 0.1804 kg/kWh. Additionally, exergy efficiency increased to 38.41%, while exergy destruction in the compressor, combustor, and turbine decreased significantly to 127,857.67 kW, 232,420.96 kW, and 134,187.11 kW, respectively. This study concludes that the overhaul of the combustor area significantly improves the thermodynamic performance of the gas turbine system. Exergy efficiency increased by 7.09%, thermal efficiency by 7.79%, while the heat rate and fuel consumption decreased by 87.07 Kcal/kWh and 0.0408 kg/kWh, respectively. These findings are consistent with the second law of thermodynamics, which states that reducing system irreversibility leads to higher energy conversion efficiency.