Renewable Energy, Vol.162, 2126-2152, 2020
A new high-efficient cooling/power cogeneration system based on a double-flash geothermal power plant and a novel zeotropic bi-evaporator ejector refrigeration cycle
An innovative Bi-Evaporator Ejector Refrigeration Cycle (BE-ERC) working with different zeotropic mixtures is devised in this study. Next, the proposed BE-ERC system is used as binary cycle of a modified Double-Flash Geothermal Power Plant (DF-GPP) to simultaneously produce cooling and power from the same geothermal well. A comprehensive modeling of the proposed integrated system is carried out from thermodynamics laws viewpoints and the results are elaborated in detail. Based upon the results, the use of R142b/Pentane (0.6/0.4) is highly commendable due to achieving the maximum refrigeration load, Coefficient of Performance (COP), and total energy efficiency of 137.83 kW, 0.329, and 20.37%, respectively. Although net electricity and exergy efficiency were not maximum at this condition, their value was competitive. Accordingly, with the use of R142b/Pentane (0.6/0.4), the net electricity, exergy efficiency of the BE-ERC, and total exergy efficiency were calculated 18.61 kW, 2.16%, and 20.95%, respectively. Among all elements of the integral set-up, the first ejector (the main ejector in the BE-ERC) had the highest exergy destruction of 26.09 kW out of overall fuel exergy of 190.7 kW (13.68%), followed by the vapor generator with exergy destruction of 24.4 kW. (C) 2020 Elsevier Ltd. All rights reserved.