Improving the Productivity of Water by Coupling a Solar Still with Flat Plate Collector

Abstract

The last statistics show that within the next fifty years, the world population will increase by 40 to 50 %. This population growth, coupled with industrialization and urbanization will result in an increasing demand for water and will have serious consequences on the environment. To confront these problems, several techniques of desalination of brackish or waste water have been developed around the world. Among the techniques used especially for arid and deserted area, solar distillation is characterized by being simple and easy. Moreover, solar still does not require an expensive and complex installations unlike other techniques used for the desalination of water, because the solar distillation depends entirely on solar energy to raise the water temperature. Unfortunately, the solar distillation remains limited to the individual use. Where the experiments have shown that the productivity of traditional solar still estimated at about 3 liters per day this result is not satisfactory, and in order to improve the production of the solar still, our work focuses on the coupling of a still with a flat plate collector. This study was conducted various types of solar stills: single slope, double slope and spherical solar still. After having established the thermal balances of the various solar stills at instationary regime, the equations are solved by using 4th order Runge–Kutta method. The numerical results obtained show clearly the effect of coupling a solar still with a flat plate collector. The improvement of production resulting by preheating water for all types of solar stills studied was estimated