Title: Thermodynamic analysis of a binary geothermal power plant

Authors: Zekeriya Özcan; Özgür Ekici

Addresses: Department of Mechanical Engineering, Hacettepe University, 06800, Ankara, Turkey ' Department of Mechanical Engineering, Hacettepe University, 06800, Ankara, Turkey

Abstract: A geothermal plant located in southwestern Turkey is evaluated from thermodynamic and economic perspectives. The first and second law efficiencies of the plant are calculated to be 4.82% and 25.7% respectively. On plant level, brine re-injection process is found out to be primarily responsible for exergy losses (21.9%). Major sources of losses at ORC systems are turbines and pumps (25.44%), heat exchangers (21.78%) and condensers (10.8%). Thermal losses from heat exchangers are calculated to be around 444 kW which corresponds 0.27% of heat transfer value at heat exchangers. Applicability of water-cooled condensers instead of existing air-cooled condensers is also discussed. Results indicate that it is possible to reduce the initial capital investment around 20%. Furthermore, it may be possible to further increase the exergetic efficiency of these hypothetical water-cooled condensers by increasing the rejection temperature and subsequently decrease initial capital investment by 1.4% and reduce heat release to the environment.

Keywords: geothermal power plant; GPP; exergy analysis; plant analysis; cost estimation.

DOI: 10.1504/IJEX.2021.117605

International Journal of Exergy, 2021 Vol.36 No.1, pp.76 - 97

Received: 07 Sep 2020
Accepted: 28 Jan 2021

Published online: 07 Sep 2021 *

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