Productivity Enhancement of Conventional Solar Stills Using Water Sprinklers and Cooling Fan

Abstract

Conventional solar still is a simple device uses solar energy to produce fresh water from brackish or sea water. It is regarded by many investigators as one of the important methods of utilizing solar energy to solve water scarcity problems, especially in remote areas and on a small scale production. The enhancement of solar stills performances and improving their productivity are the main goals of the investigators in recent years. The aim of the present research is to study and evaluate the effect of wind speed and the use of water sprinklers to cool down the outside surface of the inclined glass cover. Therefore, three identical conventional, single slope solar stills were designed, constructed, and tested under the actual environment of Kuwait city during the month of August. The water depth inside the stills was automatically controlled and fixed at 1 cm level and the stills' glass cover's tilted angle was fixed at 32.5º. Cooling fans have been used to vary and control wind speed.
The results of this investigation indicated that increasing the wind speed from an average natural value of 1.2 m/s to 3 m/s and 4.5 m/s has the effect of increasing the production rate by 8% and 15.5% respectively. Cooling the glass cover was carried out using water sprinklers at preset intervals of 20 min and 10 minutes respectively. It had the effect of increasing the production rate by 15.7% and 31.8% for the two situations respectively.