Enhancement of distillate output of solar still by cooling glass cover

Abstract

The difference in temperature between the temperature of the basin water and the temperature of the glass cover is the most important regulating factor for getting yield from a solar still. The higher the temperature differential, the more distillate the solar still produces. This temperature difference can be enhanced either by increasing the temperature of basin water by decreasing glass cover temperature or combining both strategies together. A strategy for lowering the temperature of a glass cover is to cool it with air or flowing water. Cooling the glass cover by water not only boosts the production of the still but also cleans it. The presence of dust particles on the glass cover reduces the amount of solar energy impacting on water in basin, which is continuously cleaned by water flowing over it. In present work a detailed review on the various methods used to cool glass cover have been discussed. The decrease in temperature of cover is up to 20oC by cover cooling and the maximum increase in efficiency of solar still by cover cooling is about 20%.