EXPERIMENTAL INVESTIGATION AND PERFORMANCE ANALYSIS OF A POINT-FOCUS PARABOLIC SOLAR STILL

This study presents a design and performance analysis of a point-focus parabolic solar still (PPSS) during seven sunny, relative cloudy and dusty days in October. The variations of hourly and daily production rates were investigated by studying the effect of environmental and operational parameters composed of beam solar insolation, wind speed, air temperature, absorber temperature, preheating and salt concentration of raw water. The results indicated that the most effective parameter is available solar insolation and absorber temperature, as the most average daily production rate of 5.12 kg 〖day〗^(-1)was obtained on the day with the average solar insolation of 626.8 W m^(-2) and the average absorber temperature of 150.7℃. Whereas no significant effect of the air temperature and salt concentration of raw water was obtained. This means that the acceptable performance rate would be achieved by the solar still with high levels of solar insolation even in in cold and windy days. Based on the performance evaluation, the daily productivity of freshwater was increased up to 13% by preheating of raw water. The average daily efficiency of the still was calculated as 34.69% with the maximum hourly productivity of 1.5kg h^(-1). The quality of distillate from the still was analyzed to verify the ability of the still to meet the standards required for drinking water.