Performance Evaluation of a Double-Slope Solar Still Using Various Horizontal Wick Materials Combined With a Copper Sphere Filled With Phase Change Material (CuO/ZnO)

Abstract In this present study, different wick materials and phase change materials (PCMs) were used to improve the performance of the modified double-slope solar still (DSSS) compared to the conventional DSSS. To enhance performance, various wick materials have been used, including polyester, cotton, jute, banana fabric, and black bamboo cotton (BBC). Additionally, the effects of PCM as paraffin wax as a thermal energy storage medium in conjunction with the two distinct nanoparticles with 1 wt% (CuO and ZnO powder) have been investigated. First, the experiments were carried out using a variety of wick materials without PCM to determine the efficacy of the DSSS. The freshwater productivity of the solar still with BBC, banana fabric, jute cloth, cotton, polyester, and conventional DSSS was found to be 7.7, 6.21, 4.86, 4.49, 3.67, and 2.95 L/m2 per day, respectively. The experimental results revealed that the solar still with BBC gives the productivity of fresh water 160.98% higher than the conventional one. Compared to other materials, BBC has a higher maximum still efficiency. It is because the BBC can absorb up to three times its weight in water, which enhances both absorption and evaporation rates. Second, the experiment performed using BBC and PCM along with 1 wt% CuO and ZnO nanoparticles was compared with conventional DSSS. Hence, the freshwater productivity was increased by 220% for BBC wicks with PCM (CuO) with the cumulative productivity of 9.46 kg/m2.