Mathematical modeling and analysis of a solar still with multiple-effect cover cooling

Abstract

This paper presents a theoretical study of the thermal performance of a double-sloped basin still coupling with multiple-effect cover cooling. The still was built so that one of its cover sides (the multiple-stage) is tilted to be parallel to sun rays and, therefore, be in the shaded area. Direct solar radiation heated the saline water and evaporated it. A fraction of the resulting vapor condensed on the inner glass cover surface while the rest was condenser to the outer first partition to be condensed there. The distiller was double-slope with a double pass capillary film distiller. Is effective base area was 1m2 and its cover slope was 65° to the horizontal. The results showed that combining a capillary film distiller with basin type solar still caused an improvement in the still performance. The proposed still of two parallel cells with 50-mm gaps is theoretically predicted to produce 11.8 kgm-2 d -1 on a sunny day of daily solar radiation of 42.5 MJ m-2 d -1 on the glass cover.