PERFORMANCE ANALYSIS OF MODIFIED SOLAR STILL WITH FORCED WATER CIRCULATION

This work is aimed to enhance the evaporation rate of water in the basin and the condensation rate of water vapour on the glass cover of a solar still. The evaporation rate is enhanced by supplying more solar thermal radiation and the condensation rate of water vapour is improved by removing more thermal energy from the glass cover. For enhancing the evaporation rate of water, the evacuated tubes were integrated with the stepped basin to increase the water surface area exposed to solar radiation. The internal and external reflectors reflect solar radiation on the water of the stepped still basin and inside the evacuated tubes. The forced water circulation maintains the thin film of water on the basin. Water sprinkling on the glass cover removed more thermal energy from it. As a result, the condensation rate was high. Comparisons between the moded stepped solar still with conventional solar still was carried out to evaluate the performance under the same climatic conditions. The productivity of the modified stepped solar still with reflectors and sprinkled glass cover cooling was 8660 mL per day.