Experimental study and economic examination of double-glazed solar still desalination with a thermoelectric cooling system

Abstract

Low efficiency in freshwater production is one of the primary disadvantages of solar still desalination systems. Increasing the performance of solar still desalination systems has been one of the main goals of researchers in recent years. For solar still desalination systems, the double-glazing cooling technique combined with a thermoelectric module can increase the efficiency of these systems. Therefore, the main objective of this study is to investigate the impact of the double-glazing cooling technique integrated with a thermoelectric module on the performance of a solar still desalation system. The thermoelectric module generates cold air that is passed through the two glasses to provide cooling. The modified unit and a conventional one are experiemntally tested for three days under the same weather conditions in Kermanshah, Iran. A comparative analysis of results shows that cooling the double-glazed glass cover using cooled air passing through the two glasses continuously during all test hours results in a 30% increament in average freshwater production compared to the conventional system. Experimental results indicate that the solar still desalination performance can be enhanced further by increasing the linear air stream velocity. As the average air velocity increases from 1.5 to 2.5 m/s and 4 m/s, freshwater production increases by 14 % and 25 %, respectively. In addition, the results of the economic analysis represent that the cost of distilled water for the improved system is 0.1033 ($/L/ m2). Hence, cooling the double-glazed glass cover using cooled air is a cost-effective and viable method for enhancing the evaporation rate, condensation rate, and freshwater production.