SUN TRACKING SOLAR STILL WITH EXTERNAL REFLECTOR AFFECTING PRODUCTIVITY OF DESALINATED WATER

Abstract

The main objective of the present study was to improve the productivity of a traditional single-slope solar still using an external reflector and moving the solar still to track the sunrays from sunrise to sunset. A single slope solar still was designed, installed and tested at the Agricultural Engineering Department, Faculty of Agriculture, Suez Canal University, Ismailia Governorate, Egypt (latitude angle of 30.62oN, Longitude angle of 32.27oE, and mean altitude above the sea level of 5 m). The basin of solar still is rectangular in shape, and made of galvanized iron sheet. The gross dimensions of the basin are 1.30 m long, 0.80 m wide and 0.10 m deep, with a net upper surface area of 1.04 m2. It is painted with matt black paint to absorb the maximum possible amount of solar radiation incident on it. In the sides of the basin, 70 mm of foam insulation is placed to reduce the heat losses. The solar still is covered with glass sheet 3 mm thick and inclined by a tilt angle of 31○. Three different configurations are examined; stationary non-tracking solar still without reflector, sun tracking still without reflector, and sun tracking still with external reflector. The obtained results indicated that, the productivity of tracking solar still with reflector was greater than the productivity of the other two solar stills by about 129% and 81%, respectively.