Abstract
In this study, wick type solar stills with half barrel and corrugated absorbers were investigated. Three solar stills were fabricated: conventional solar still (SS), half barrel wick SS (BWSS), and corrugated wick SS (CWSS). As well known, the vertical sides of the SS have large area and high temperature due to the solar energy falling on these surfaces, and this high temperature area caused high energy losses to ambient. So, in this work, a wick material was added to the vertical sides of BWSS and CWSS from inside. The wick material helps to prevent the direct falling of solar energy on the SS vertical sides and maximizes the evaporation area of water. So, the heat losses are reduced, and the evaporation/condensation rates were increased. The results showed that the productivities of CWSS and BWSS were 43 % and 52 % greater than the conventional SS productivity, respectively. Additionally, adding vertical wick increased the productivities of CWSS and BWSS to be about 112 % and 123 % greater than that of conventional SS, respectively. For additional improvement in the performance of CWSS and BWSS, phase change material (PCM) mixed with nanoparticles (CuO) was employed beneath the absorbers. The experiments proved that the daily productivity of BWSS and CWSS was 154 % and 139 % over that of conventional SS, respectively. Also, the estimated cost per liter/thermal efficiency were 0.028 $/34 %, 0.022 $/55.5 % and 0.021 $/57 % for conventional SS, CWSS, and BWSS (with PCM and vertical wick), respectively.