Thermodynamic analysis and evaluation of a gas compression refrigeration cycle for fresh water production from atmospheric air

Abstract

In recent decades, many scientific works have been carried out to accomplish innovative solutions to achieve new resources for fresh water or improve the exploitation of current water resources. One of these new resources is the water vapor content of air. The objective of this study is to analyze the production of liquid water from atmospheric water vapor with assisted of a refrigeration cycle. The evaporator of this cycle will be as the cool surface and so the dehumidifier of the system that produces fresh water. In this study, a computer program was also developed to carry on a flexible thermodynamic model for a gas compression refrigeration cycle exclusively for fresh water production. The amount of water production and energy intensity under different climate conditions are analyzed. Despite most of previous studies, it has been tried to provide more real working conditions and some simplifying assumptions have been avoided. A case study is carried out based on ambient temperature and humidity intervals of system's best performance. The results show that a residential size of the system can produce 22–26 l/day fresh water while energy intensity is between 220 and 300 Wh/l. Since the proposed system can work without any brine discharging and environmentally friendly, a comparison of this method with other desalination technologies has been carried out, as well.