Single Slope Solar Water Still with Enhanced Solar Heating System

Abstract

This paper experimentally investigates the thermal performance of a conventional solar water still with an enhanced solar heating system in Oman. A number of variables have been considered, including the water depth inside the still and the saline water temperature inlet to the solar still from the preheater solar collector system. A single slope, single effect conventional solar still with a solar preheating unit was constructed and experimentally tested under different Omani weather conditions. The still had been modified to include a preheating solar energy system so that saline water would be preheated before entering the solar still and this preheating would enhance hourly or daily yield of pure water. Different quantities of water in the solar still basin were tested to find the effect of water quantity on the hourly yield and also to assess the thermal efficiency of the still.

It was found that 1 cm depth gives the best performance in terms of fresh water yield and thermal efficiency. The addition of the solar water preheater to the system significantly increases the inlet basin saline water temperature to almost saturated temperature. The saline water in the basin needed only a small amount of heat to be vaporized, hence increasing the production of fresh water and enhancing the solar still’s thermal efficiency.