Thermodynamic Performance Assessment and Efficiency Evaluation of a Condensing Steam Turbine in a Geothermal Power Plant: A Case Study of Ulubelu Unit 3, Indonesia
DOI:
https://doi.org/10.64780/jeims.v2i1.19Keywords:
Condensing Steam Turbine, Geothermal Power Plant, Isentropic Efficiency, Operational Data, Thermodynamic PerformanceAbstract
The increasing demand for electricity and the transition toward sustainable energy systems have intensified the utilization of geothermal resources for power generation. Steam turbines are key components in geothermal power plants, and their performance directly influences overall plant efficiency and reliability. This study aimed to evaluate the thermodynamic performance and efficiency of a condensing steam turbine operating at Ulubelu Geothermal Power Plant Unit 3, Indonesia. Operational data were collected from the Central Control Room over a ten-day observation period and analyzed using thermodynamic property calculations based on saturated steam tables. Turbine performance was assessed through isentropic efficiency analysis, while linear regression was employed to examine the relationship between steam mass flow rate and turbine efficiency. The results showed that the turbine achieved an average efficiency of 82.49%, with values ranging from 82.14% to 83.12%. The average isentropic turbine power and plant efficiency were 63.28 MW and 80.84%, respectively. Compared with the design efficiency of 87.06%, the turbine experienced a performance reduction of approximately 4–5%. Overall, the turbine remained within the acceptable industrial efficiency range, indicating stable operation and reliable performance under actual geothermal plant conditions.
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Copyright (c) 2026 Agus Apriyanto, Hafidz Zakiyun Alrasyid, Hanifah Nurjanah Iskandar, Retno Wahyudi, Novia Utami Putri, Alexander Sembiring, Farrell Umar Rayhan
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