Performance analysis of a heat pump coupled humidification-dehumidification desalination system with a large temperature difference using an ejector

Abstract

This study investigates whether a humidification-dehumidification desalination system can achieve enhanced performance when subjected to a large evaporation–condensation temperature difference. To this end, a heat pump coupled humidification-dehumidification desalination system using an ejector (HPE-HDH) is proposed. This configuration utilizes a heat pump system coupled with ejectors, resulting in higher heating performance of the condenser and better dehumidification of the evaporator. Thermodynamic and economic analyses were evaluated. The system’s performance uses the environmentally friendly refrigerant R1234ZE(Z) as the working fluid. The results demonstrate that the maximum MR achieved by the system with varying feed seawater mass flow rates differs and that the system exhibits enhanced performance with increasing MR. When the feed seawater mass flow rate is 900 kg/h, the maximum recovery ratio (RR) and gained output ratio (GOR) achieved are 4.882 % and 7.386, respectively. The maximum freshwater production is 43.92 kg/h and the minimum unit freshwater cost (Z_pw) is 8.09 $/m³. Furthermore, the simulation results indicate that a greater evaporation–condensation temperature difference can enhance the freshwater production performance of the HDH system. This paper provides an energy efficient fresh water production system for freshwater scarce areas and provides a novel concept for research in the field of freshwater production.