Power, cooling, freshwater, and hydrogen production system from a new integrated system working with the zeotropic mixture, using a flash-binary geothermal system

Abstract

The current paper proposes a new hybrid system based on a binary-geothermal system to generate power, cooling capacity, freshwater, and hydrogen. This system includes an internal integration of the organic Rankine cycle and ejector refrigeration cycle with zeotropic working fluids, proton exchange membrane electrolyzer, and reverse osmosis desalination unit. The system is analyzed by developing a precise model in the Matlab software, and then a multi-objective grey wolf optimization is employed to optimize the proposed system performance. The net present value, payback period, and sum unit cost of products are considered the system's economic performance criteria to study the system's feasibility for investment. Results indicate that the Isobutene-R114 provides the best net output power, and the R12-R114 combination has the best cooling performance. Also, the R12-R114 reports the best overall performance as the organic Rankine cycle working fluid. Based on optimization results, the exergy and thermal efficiency reached 17.84% and 34.24%, respectively. The system could provide 856.06 kW net output power, 2410.54 kW cooling capacity, 0.743 kg/h hydrogen, and 40.22 kg/s freshwater with a sum unit cost of 25.5 $.GJ−1, and the total profit and payback period of 6.82 $M and 3.76 years.