Enhancing the solar still performance using nanofluids and glass cover cooling: Experimental study

The use of graphite and copper oxide micro-flakes with different concentrations, different basin water depths, and different film cooling flow rates is experimentally investigated in an attempt to improve the performance of solar still. The micro-flakes concentrations are ranged from 0.125% to 2%. While, the basin nanofluid depths are ranged from 0.25 to 5 cm. Whereas, the glass cooling flow rates are ranged between 1 and 12 kg/h. The obtained results show that the solar still productivity is enhanced by about 44.91% and 53.95% using the copper oxide and graphite micro-flakes, respectively, compared with the conventional solar still (without micro-flakes). In case of using the water over the glass cover, as a feed water, the output yield is improved by about 47.80% and 57.60% using copper oxide and graphite particles, respectively while the daily efficiency of the conventional still is 30%. Furthermore, the daily efficiencies of 38% and 40% are obtained when using copper oxide and graphite, respectively, without using glass film cooling. Finally, the stills' daily efficiencies when using copper oxide and graphite micro-flakes with glass film cooling are 46% and 49%, respectively. (C) 2016 Elsevier Ltd. All rights reserved.