The Effect of Partially Cooling on the Productivity of a Tubular Solar Still – A Numerical Study

Today, Solar stills have become a popular water purification facilities in desalination research areas. They use solar energy as a never ending, low cost and clean energy. They have no moving parts and without any noise. In this study, we investigate the effect of partially cooling on the productivity of a tubular solar still. For this purpose, 2-D finite volume method was used to solve velocity, momentum, energy and mass transfer equations for humid air inside the enclosure. Moreover, the effect of using glass-cover partially-cooling on the stream lines, isotherms, mass fraction and water productivity was investigated. The results showed that numerical simulation has a good agreement with experimental results. Furthermore, we concluded that increasing the Rayleigh number and using partially cooling lead to enhance water productivity. Moreover, the maximum productivity was achieved in Ra=105 when using partially cooling on top of the glass cover.