Solar desalination system using parabolic collector

The aim of this study is to provide a modification unit to enhance the performance of the solar desalination. The modification of the conventional solar still by using the parabolic trough and simple heat exchanger which installed in the basin bottom as closed loop with the solar collector is presented in this work. Oil is used as working fluid in the heat exchanger which has high thermal properties. Black copper serpentine of the heat exchanger is immersed in basin water on the bottom of the still basin. It is extremely attached with thermally insulated pipelines through the trough. The oil is forced to flow using small pump. The parabolic trough is tracking the sun using simple mechanism to collect the highest amount of solar radiation and to increase the efficiency of the proposed solar desalination system. The saline water is heated directly by solar radiation and by the simple heat exchanger’s hot oil. Many experiments are carried out on (September, October and November 2012). The experimental setup was designed and installed at Solar Energy Laboratory, Department of Agricultural Engineering, Faculty of Agriculture, Ain Shams University, Cairo (φ=30°N). The forecast of the typical climatic conditions of the experimental Cairo site at the selected days are obtained from the Meteorological Egyptian Authority. The comparison between the performance of the conventional and the modified solar desalination still is presented. The economic study of the present system is determined. The results show that fresh water productivity is increased by an average of 41.07 %, while the total thermal efficiency of the modified system was 23% in the case of using modification still (active).