Optimization of a gas compression refrigerator for drinking water production through air dehumidification

Drinking water availability is one of the emerging challenges of the 21st century. Different approaches have been investigated as possible sources of water for arid regions. Atmospheric water vapor processing is a developing approach whose aim is to cool air to condensate the water available in the atmospheric moisture. Air dehumidification allows obtaining pure drinking water for geographical regions far from the sea, rivers or lakes, even if it is an expensive technology compared to desalinization. Gas compression refrigerators are effective and simple systems that can be used for water production through air dehumidification. Their performance are strictly related to the weather conditions of the installation location and are greatly affected by the operating parameters of the gas compression refrigerators. The object of this paper is to optimize the volumetric flow of the external humid air with the aim of maximize the quantity of the condensed water, in relation to the weather conditions (air temperature, pressure and humidity), as well to evaluate the energy consumption per liter of drinking produced water. The paper finally presents the implementation of the proposed approach to a case study of a residential user in Dubai, United Arab Emirates, evaluating and comparing three different control strategies: constant, monthly variable and hourly variable volumetric air flow.