Techno-economic analysis and tri-objective optimization of a novel HDH desalination with PVT and vapor-compression chiller for sustainable water supply in remote areas

Abstract

Desalination is a powerful tool for addressing freshwater scarcity. This study introduces a stand-alone desalination unit based on humidification-dehumidification, photovoltaic-thermal, and vapor-compression chiller technologies for providing sustainable water supply in remote areas. The system is evaluated from both technical and economic perspectives, and three refrigerants (R22, R134a, and R407C) are tested to determine the best option for the vapor-compression chiller. The system is comprehensively modeled using an artificial neural network trained for tri-objective optimization by employing a genetic algorithm. The optimization aims to maximize the freshwater production rate and gain output ratio while minimizing the cost rate. The results indicate that the photovoltaic-thermal unit comprises about 97% of the cost rate. At the optimum point, the freshwater production rates are 43.81 m3/day for R22, 40.56 m3/day for R407C, and 36.65 m3/day for R134a. The cost rates are highest for R407C at 48.04 $/h, followed by R134a at 45.72 $/h and R22 at 43.74 $/h. Similarly, the gain output ratio follows the same order, with R407C having the highest ratio of 1.28, followed by R134a with 1.27 and R22 with 1.24. The study concludes that R407C is the best option in terms of technical, economic, and environmental factors.