The effect of cover tilt angle of a double slope solar still on the productivity in summer and winter seasons

摘要

Algeria is interested in using solar still in order to produce distilled water from brackish water, since the climate is characterized by a high solar radiation during almost all the season. In this study, a computer program is set up in order to simulate the effect of the cover tilt angle on the performance of a double slope solar still under climatic conditions of the area of Constantine (northeast of Algeria), using meteorological data recorded during the last decade (2002-2012). 1 August 2005 and 28 February 2010 are selected as successively the hottest days for, respectively, summer and winter seasons. The obtained results show that 10 degrees and 45 degrees represent the optimum angles of inclination allowing to receive a maximum solar radiation for this type of solar still during the considered seasons, by increasing the evaporation-condensation phenomenon. However, in the summer season, a tilt of 10 degrees gives a higher daily productivity compared to that of 45 degrees with an increase of the productivity of about 24.45%. In contrast, in the winter season, a tilt of 45 degrees gives higher daily productivity compared to that of 10 degrees with an increase of the productivity of about 34.28%. Therefore, the tilt angle is an important factor to be considered for a solar still design. A water (brine) depth of 0.02m gives higher daily productivity at optimum angles of the still.