Enhancement of passive solar still yield through impregnating water jackets on side walls – A comprehensive study

Abstract

This study aims at augmenting the distillate output of passive solar still (PSS) by incrementing the surface area available for condensation by incorporating the water jacket (WJ) around the sidewalls of PSS. In the PSS incorporated with a water jacket (WJSS), the evaporated water from the basin condenses on the surface of the WJ in addition to the inner glass surface thus enhancing the dehumidification rate. The preheated water from the WJ was filled into the basin of the WJSS at an interval of 30 min depending on the distillate water output. Meanwhile, an equivalent quantity of brackish water at 30 °C was manually added to the WJ. The thermal efficiency (ηth) of the WJSS was 43.19% higher than that of the conventional passive solar still (CPSS). The overall yield of WJSS was 2.62 L/m2/day while the yield of CPSS was 1.83 L/m2/day. The presence of the water jacket in WJSS enabled an increment in its yield not only by incrementing the available surface area for condensation by 123% (1.16 m2) when compared to CPSS but also by reducing the heat loss happening in the system. Thus, leading to an increment in the exergy efficiency of WJSS (2.5%) when compared to CPSS (1.1%).