Solar Still with an Integrated Conical Condenser

A solar still requires only two processes: evaporation and condensation. In a solar still, evaporation occurs because of the pressure difference caused by the difference in the temperature of the water and that of the glass cover, while condensation occurs when the water vapour comes into contact with a surface cooler than its dew point. Condensers have been proven to effectively increase the productivity of solar stills. This study aims to compare the efficiency of two developed solar stills with integrated conical condensers to that of a conventional solar still; it also measures the effectiveness of the condenser. Three types of solar stills were used in this study: a conventional solar still (CSS), developed solar still 1 (DSS-1) and developed solar still 2 (DSS-2). All three stills were tested simultaneously. The three solar stills are all made of aluminium with a thickness of 3 mm. The software Ansys Fluent 18.2 was used to analyse the computational fluid dynamics in the stills. The results showed that the efficiency of the CSS, DSS-1 and DSS-2 were 23%, 36.5% and 46.4%, respectively. The freshwater yields of DSS-1 and DSS-2 were, respectively, 1.17 and 1.81 times greater than that of the CSS. These increases in the productivity of DSS-1 and DSS-2 are significantly influenced by the shape of the condenser integrated in these two solar stills; the effectiveness of this condenser was 85.57% and 91.25%, respectively, in DSS-1 and DSS-2. In a simulation, the condenser’s effectiveness was 99.85%.