Energy, exergy and exergoenvironmental assessment of an enhanced single‐flash geothermal combined cycle with and without an exhaust‐steam heater

Abstract The global shift towards renewable energy has spotlighted the efficiency of geothermal power systems. Recognizing the need to harness thermal energy more effectively, this study introduces an innovative combined cycle, analyzed using EES software, which integrates a trans‐critical carbon dioxide cycle with a single flash geothermal cycle. The focus is on assessing the performance impact of incorporating a heater into the system. The study methodically evaluates the system's efficiency in both ‘with’ and ‘without’ scenarios, examining how the heater affects crucial variables like energy, exergy efficiency, and net power output. The results reveal that using a heater boosts the net power output from 201.5 to 204.7 kW, a notable increase of 1.58%. Energy efficiency, measured following the first law of thermodynamics, improves by 1.55%, escalating from 3.28% to 3.331% upon the ‘heater's inclusion. Similarly, the system's exergy efficiency, initially at 16.3%, climbs to 16.56% with the heater, marking a 1.595% enhancement. The study further delves into the system's design parameters through a comprehensive sensitivity analysis, focusing on variables like separator pressure, CO 2 turbine inlet pressure, and CO 2 condenser outlet temperature. This is complemented by a detailed examination of exergoenvironmental parameters, including the exergoenvironment factor, exergy stability factor, and the environmental damage effectiveness factor, thus providing a holistic view of the system's environmental and operational efficiency.