Thermodynamic investigation of a single flash geothermal power plant powered by carbon dioxide transcritical recovery cycle

The use of new energy sources, such as geothermal energy, is rapidly expanding world-wide, and it is a viable alternative to fossil fuels. This paper proposes a geothermal power genera-tion system (combined single flash geothermal cycle with transcritical carbon dioxide recovery cycle). To improve system performance, a recuperator is used to recover some of the heat loss. The proposed system simulation is performed in EES software and then validated by previous research. The proposed system is analyzed from the perspective of energy and exergy. The effects of the proposed system separator pressure, carbon dioxide turbine inlet pressure and carbon dioxide condenser outlet temperature on energy efficiency, exergy efficiency and system net power output have been investigated. Findings show that the proposed system in recovery mode has a net power output of 401.40 kW, energy efficiency of 53.6 percent, and exergy efficiency of 46.32 percent, which are significantly higher than the basic mode's values of 149.9 kW, 2.39 percent, and 12.12 percent, respectively.(c) 2022 THE AUTHORS. Published by Elsevier BV on behalf of Faculty of Engineering, Alexandria University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

Automated summary

This paper proposes a geothermal power generation system that combines a single flash geothermal cycle with a transcritical carbon dioxide recovery cycle, contributing to the efficient utilization of geothermal energy. The effects of different parameters on energy efficiency, exergy efficiency, and net power output are investigated. The proposed system exhibits significantly higher values in terms of net power output (401.40 kW), energy efficiency (53.6%), and exergy efficiency (46.32%) compared to the basic mode (149.9 kW, 2.39%, and 12.12%, respectively).