Economic examination and multi-objective optimization of integrating a novel geothermal-driven combined cooling and power (CCP) system using a bi-evaporator cycle with a low-temperature electrolyzer

Concerning substantial waste heat in geothermal cycles, this study suggests and investigates the feasibility of a novel framework of waste heat recovery for a double-flash binary geothermal cycle. In this manner, a novel design of an ejector-based bi-evaporator technology is configured and integrated with the geothermal cycle. For better applicability, a low-temperature electrolyzer, i.e., proton exchange membrane electrolyzer (PEME), is joined to the whole configuration producing electricity, cooling, and hydrogen simultaneously. This arrangement is analyzed from the exergy and cost viewpoints using the engineering equation solver (EES) software and is optimized coupling EES and MATLAB programming. A non-dominated sorting genetic algorithm (NSGA-II) optimization method is utilized by which the objective functions, i.e., exergy efficiency and sum unit cost of products, are computed at 40.3% and 6.9 $/GJ, respectively. Additionally, the optimum values of the produced electricity, cooling, and hydrogen are correspondingly equal to 4.29 MW, 1.90 MW, and 4.51 kg/h. In the optimum state, the major irreversibility source is ejector 1 with a 16.8% contribution to the total exergy destruction rate (= 5745.7 kW). Furthermore, turbine 1 is the expensive component among the established devices with a 22.3% contribution to the total investment cost rate (= 172.3 $/h).