Parametric study and optimization of a novel geothermal-driven combined cooling, heating, and power (CCHP) system

Abstract

To reduce energy-related costs, integrating cogeneration systems is one of the most apposite avenues. Herein, a combined cooling, heating, and power (CCHP) cogeneration system grounded on geothermal (GTh) energy heat recovery is introduced. Accordingly, the cogeneration system comprises three subsystems, namely, the Kalina cycle (KC), ejector refrigeration cycle (ERC), and organic Rankine cycle (ORC). A comprehensive program is developed to address energy, exergy, and exergoeconomic analyses. Also, the TOPSIS multi-objective optimization method is used to select the optimal parameters at four different GTh heat source temperatures with the objective parameters of Net output power, Total investment cost (Ztot), and exergy efficiency. Thermal efficiency, exergy efficiency, Ztot, total exergy destruction rate, net power production capacity, and cycle cooling capacity were gauged under optimal conditions with a GTh temperature of THS = 490 K at 23.04%, 26.55%, 45944.49 $/yr, 226 kW, 75.17 kW, and 111.6 kW. In addition, the parametric study indicated that the increase in GTh heat source temperature, ammonia concentration, and KC flow rate (m˙1) reduces the thermal efficiency and increases Ztot. Finally, the effective system parameters, including ΔTcon2 and evaporator temperature were optimized for the different configurations using the Pareto multi-objective method. The optimal point of ΔTcon2 at the GTh heat source temperatures 480, 490 and 495 K are 14.58, 14.38 and 14.58 K respectively. Likewise, the optimal points based on the evaporator temperature at the GTh heat source temperatures 480, 485, 490 and 495 are 287.4, 279.3, 279.3, and 279.3 K, respectively.