Exergoeconomic analysis of a geothermal organic Rankine cycle power plant using the SPECO method

• Published in: Environmental progress & sustainable energy Vol. 36; no. 3; pp. 936 - 942
• Main Authors: Ergun, Alper, Ozkaymak, Mehmet, Aksoy Koc, Gonca, Ozkan, Salih, Kaya, Durmuş
• Format: Journal Article
• Language: English
• Published: 01.05.2017
• Subjects: exergoeconomy; exergy analysis; organic Rankine cycle; SPECO
• ISSN: 1944-7442; 1944-7450
• DOI: 10.1002/ep.12532

In this study, exergy and exergoeconomic analyses were performed for a geothermal, Rankine cycle (Binary) power plant that generates 7.5 MW of power. The exergy analysis showed that the highest destruction of exergy, that is, about 3200 kW, occurred in the vaporizer. The losses were about 2670, 1700, 1035, 880, 421, 349, 306, and 33 kW in the turbine, recuperator, condenser, separator, organic fluid pump, production pump, preheater, and injection pump, respectively. The exergy efficiency of the system was calculated as 32.3% at the reference temperature of 25°C. The unit cost of the electricity produced in this plant is 7.96 $/Gj according to the exergoeconomic analysis that was made using the specific exergy cost (SPECO) method. It was determined that using low temperature sources is meaning significant. Thus, thermodynamic and thermoeconomic (exergoeconomic) analyses should be conducted in current plants to identify the inefficient equipment that is increasing costs. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 936–942, 2017