Cavity geometry influence on mass flow rate for single and double slope solar stills

An experimental setup was built in order to evaluate the distillate yield for a double slope laboratory still under controlled conditions for basin water and collector temperatures within typical operating ranges. Additionally, experimental data previously gathered are correlated to propose a new empirical model to estimate mass flow rates in single slope solar stills. This model is compared with those from other published relations and with the double slope still experimental data. It was found that the proposed model reproduces in good agreement shallow stills experimental data and that there is not significant difference in productions between single and double slope cases subject to the same water and cover temperature. Dunkle’s model [R.V. Dunkle, Solar water distillation: the roof type still and a multiple effect diffusion still, International Development in Heat Transfer (Part 5) (1961) 895–902] is found to slightly underestimate production in shallow solar stills.