Design and Development of Salt Gradient Solar Pond to Enhance Heat Storage for Solar Still

Abstract

A salt gradient solar pond of trapezoidal shapehaving double glass cover along with reflector has been designed to increase the heat storage.A double glass cover has been kept on solar pond instead of single glass cover so that top losses of solar pond can be reduced. Further, the solar pond has been coupled with reflector to enhance the intensity of solar radiation.The position of reflector is changed manually in steps to track the sun in order to receive maximum beam radiation on the reflector. The reflector of solar pond was also used as cover on solar pond during night to reduce the heat loss from top surface during night.It was observed from the experimentation that double glass cover effect the heat storage of solar pond. Solar pond has been designed to supply heat to basin water of still during night. For this purpose, it has been proposed to minimise the bottom and side losses and maximise the volumetric storage of solar pond. Further, the experimentation was carried to find the effect of using reflector and observed that intensity of solar radiation on solar pond increased by 20% to 47%. While the temperature of solar pond increased about 10 °Cby using the double glass cover on the top surface of the solar pond.The performance of solar pond has been also experimentally for four cases, case-1: without glass cover and reflector, case 2: with glass cover but without reflector, case 3: with glass cover and reflector (fixed position) and case 4: with glass cover and reflector (changing position). The best performance of solar pond was obtained for case4 when double glass was used along with changing position of reflector.