Performance assessment of a dual-operational Stirling cryocooler for ambient water harvesting and reverse osmosis desalination

Providing fresh water, especially for remote areas, is a global challenge. Ambient water harvesting and desalination are proposed as global solutions. This study proposes a novel solar-driven, dual-purpose system that integrates ambient water harvesting with water purification. When brackish water is available, the system operates in purification mode to produce clean water. In the absence of brackish water, it functions as an ambient water harvester, generating water from air moisture using a dual-operational-mode Stirling cryocooler. The system can also be utilized for electricity generation or air conditioning when water purification is not required. The mathematical model for the system components was simulated and validated using MATLAB and Engineering Equation Solver programs. A parametric analysis was conducted to evaluate the effects of beam radiation, ambient temperature, wind speed, expansion temperature, and relative humidity on the system’s performance. The results show that the system achieved a maximum power and efficiency for the solar dish Stirling engine system of 706.06 W and 20.32%, respectively, under high solar radiation, high ambient temperature, and low wind speed conditions. The maximum cooling capacity for the cryocooler, with a value of 175.21 W, occurred at high expansion temperature. Moreover, the system can achieve a purified water production rate of 4.105×103 kg/day in desalination mode and 1.413 kg/day in ambient water harvesting mode.