Abstract:
A computer program has been developed to simulate the effect of the orientations (east– west and south–north), on the performance of a symmetric double slope solar still compared to those of an asymmetric solar still with a double effect, in order to obtain the optimum design parameters for both types, under climatic conditions of Constantine (Eastern area of Algeria), using meteorological data of 1st August of 2005 as the hottest day selected from the
last decade (2002–2012). The obtained results show that10° is the optimum inclination angle that allows receiving a maximum solar radiation for both stills by increasing the evaporation condensation processes. A water depth of 0.02 m gives higher daily production. The stability of solar radiation seen in a south–north orientation leads to high reception of solar radiation by both stills.The coefficient of heat transfer by evaporation has contributed in major in the production of solar stills (70%), followed by the coefficient of heat transfer by radiation (23%), and the left is for the heat transfer by convection (7%). The practical limit of optimal insulation thickness that gives the maximum efficiency of the two systems of distillation is about 0.10 m. As a consequence, the daily productivity of an asymmetric still, with a double effect process is found higher than that corresponding to the symmetric one with a double slope system, and where at the south–north orientation we notice an increase of 22.57% and at the east–west orientation it is of 16.23%. It is shown also that a south–north orientation enhances the performance of the asymmetric still with a double effect by 16.76%.
