Examination of an ejector-enhanced geothermal plant for power generation improvement

Geothermal energy, a reliable and sustainable source, has the potential for extensive utilization in power generation. This study introduces an innovative approach to enhance the performance of geothermal-assisted power plants by integrating an ejector in place of traditional expansion valves within a flash-binary geothermal cycle. For the first time, this approach leverages the ejector to extract high-energy fluid from the cycle, significantly boosting energy recovery and system efficiency. The proposed configuration consists of a geothermal double-flash system coupled with a dual-pressure organic Rankine cycle. A comprehensive analysis is conducted from thermodynamic, economic, and environmental perspectives. Results illustrate that the innovative system achieves a power output of 6.903 MW, a total product cost rate of 204.18 $/h, and a product exergoenvironmental impact rate of 11.55 Pt/h, with energy and exergy efficiencies of 19.62 % and 70.62 %, respectively. This design reduces the payback period to 3.41 years. Besides, an optimization procedure is carried out through the use of four diverse scenarios to achieve the most ideal state for the performance of the presented system. These evaluations underscore the significant benefits of using an ejector over conventional expansion valves for enhancing geothermal power plant performance.