Energy and exergy analysis of an atmospheric water generator integrated with the compound parabolic collector with storage tank in various climates

Abstract

The drinkable water storages shortage is one of the main obstacles that many societies are envisaged with. In addition, the water content of humid air is known as the main storage of drinkable water for the future. In this paper, the energy and exergy analysis of a solar driven atmospheric water generator which contains an absorption refrigeration cycle coupled to a compound parabolic collector is performed. The mathematical model of the proposed system is developed in MATLAB software. In the solar thermal system provided in this paper, the storage tank is employed for extending the working hours of the system leading to improvement of total water generation rate. Furthermore, the performance of the system is evaluated in various climates included arid, semi-arid and Mediterranean, and for this purpose three cities of Iran named Bandar Abbas, Ramsar and Tehran were selected. Moreover, by comparing the water production in various months during the year, the highest value of water production during the year is held by Bandar Abbas city leading to owning the lowest values of specific power consumption and specific collector area. The maximum rate of water production of proposed system is approximately 400 lit per month in tropical climates with specific energy consumption of 3 kWh/lit. Based on the results of exergy analysis of whole system, the most exergy destruction rate belongs to compound parabolic collector component, therefore, large amount of energy is wasted through compound parabolic collector which can be recovered for generation of chilled water. Moreover, the impacts of geographical and environmental parameters on the energy and exergy efficiencies of the atmospheric water generator are also assessed.