Abstract
Fresh water productivity enhancement is the main goal of different improvements on solar stills. In the present work, experimental investigation of the performance parameters of two solar stills was carried out to enhance fresh water productivity. A comparison study was conducted between the pyramid solar still with natural fiber (Palmately leaf) and with the conventional solar still. Natural fibers were inserted inside the basin to enhance evaporation rate by increasing the surface area exposed to sunray, which in its turn increased water productivity. Additionally, serve as a heat sink (thermal storage material) on one hand and utilize its capillary effect property on the other hand. Thermal energy and exergy efficiencies as well as cost analysis were calculated for both systems. The results revealed that the daily accumulative freshwater productivity were reached 5160.8 gm/m2 using natural fiber with an increase of 44.5 % more than that of the conventional one. In addition, the daily thermal energy efficiency and the exergy efficiency of the solar still with natural fiber were found to be 44.9 % and 3.4 % compared with 31 % and 2.2 % for the conventional still, respectively. The cost of producing fresh water was decreased from 0.118 $/L for the conventional solar still to 0.081 $/L for the solar still with natural fiber.
•A simple design pyramid solar still with low cost of fabrication was constructed•Natural fibers (Palmately leaf) were used inside the basin of the solar still.•Natural fibers were enhanced evaporation rate by increasing the surface area exposed to sunray.•Besides its capillary effect, the natural fibers work as thermal storage material.•Maximum daily production was reached up to 5160.8 gram/m2 of fresh water.•The daily thermal energy and the exergy efficiencies values were reached 44.9% and 3.4%, respectively.