Improving the performance of a modified solar distiller with phase change material and parabolic trough collector

Abstract

The solar stills can solve the problem of freshwater shortage for the people living in remote areas. Through this work, the performance of hybrid solar desalination arrangement was investigated. The system comprised of parabolic trough solar collector, automatic solar tracking system, separation room, modified solar still, two condensation units, feed water tank, and supplementary and measuring tools. The effect of using various water flow rates on the effectiveness of parabolic trough solar collector was tested. Also, the influences of integrating condenser to the modified solar still with and without phase change material were studied. The experimental results revealed that the best flow rate for parabolic trough solar collector was obtained as 10 L/h (100 L/day), where its effectivity was 61%. Under this condition, the obtained freshwater was around 61 L/day from a total saline water of 100 L/day. In addition, integrating a condenser to the modified solar still improved its productivity. So, the total yields of conventional and modified solar stills were 2500 and 5145 mL/m².day, respectively. Therefore, the distillate of modified solar still was improved by 105.8% as compared to that of the conventional solar still due to using the hot feed water and external condenser. Moreover, using phase change material enhanced the modified solar still yield. The total yield of conventional solar still and modified solar still with hot feed water, condenser, and phase change material was 2575 and 6150 mL/m².day, respectively. Consequently, the productivity of the modified solar still with hot feed water, condenser, and phase change material was improved by around 138.83% over that of the conventional solar still. Finally, the conventional solar still had an average efficiency of 31.5%. Also, when using the hot feed water and external condenser with the modified solar still, the thermal efficiency was reported as 49.7%. Also, the modified solar still with hot water, condenser, and phase change material had a thermal efficiency of 56.5%. Finally, the water costs of 1 L from the CSS and MSS are 0.063 $ and 0.050 $, respectively.

Keywords: Collector; Condensation; Distillation; Phase change material; Separation.