Performance Investigation on Variations of Glass Cover Thickness on Solar Still: Experimental and Theoretical Analysis

Abstract

Glass cover is very important component for the efficient design of the solar still. Sunrays are first incident on glass cover and then transfer to the solar still for the purpose of evaporation of water to get potable water. Selection of the proper glass cover is always based on transmittance and it is depends on thickness of the glass cover. Hence, to study effect of transmittance on glass cover thickness, three different thicknesses of glass cover like 4 mm, 5 mm and 6 mm were chosen for the study on three same sized solar stills and tested in composite climate conditions of Mehsana, a city of North Gujarat, India during sunshine hours of January 2011 to June 2011. Theoretical and experimental analysis of three different thicknesses of glass cover is carried out by heat and mass transfer analysis to determine the optimum thickness of glass cover for the effective distillate output from solar still and validation between them. After six months of experiments, it has found that 4 mm and 5 mm glass cover thickness increased average distillate output of 27 % and 12 % compared with 6 mm glass cover thickness. Also theoretical results found good match with experimental results.