The use of a solar chimney and condensers to enhance the productivity of a solar still

Abstract

This paper analyses the effect of a solar chimney used to enhance the convective currents within a solar still. Moreover, a condenser was also installed to improve the condensation process. Condensers in solar stills typically consist of fresh seawater flowing through a bank of tubes. However, in the configuration presented, water vapour was passed through a number of ducts immersed in seawater. This solar still was constructed and tested under natural weather conditions using a typical simple solar still as a benchmark. When comparing the efficiency based on the actual evaporator (basin) area, one notes that the solar still with the solar chimney and condensers performed 8.8% better. The simple still produced 4.7 L/m2 d, while the modified still generated 5.1 L/m2 d with the majority of the yield (59%) condensing in the condensers of the still. This clearly shows that enhanced convection and condensation increases the evaporation efficiency and hence the distillation process of a solar still.