Improving the trays solar still performance using reflectors and phase change material with nanoparticles

The potable water shortage is a big problem facing the governments and decision-makers everywhere. Solar distiller is one of the techniques that participate in solving this problem. In this work, the impact of internal reflectors on the trays distiller performance was investigated. Besides, the influence of painting the surfaces of the solar still by the mixture of black paint and copper oxide (CuO) nanoparticles was studied. This is to enhance the heat transfer characteristics between the basin surfaces and water. Finally, the impact of using the paraffin wax mixed with CuO nanoparticles as a phase change material (PCM) on the performance of trays distiller was evaluated. Experimental results revealed that the total freshwater yield of the trays distiller was improved by 57, 14, 70.7, and 108% when using reflectors, CuO nanoparticles in paint, reflectors and nano-coating, and the collection of reflectors, nano coating, and PCM with CuO nanoparticles respectively over that of the reference still. Also, the total accumulated freshwater of the conventional and trays solar stills reached 2400 and 5000 mL/m² a day, respectively. Moreover, the thermal efficiency of the trays distiller with reflectors, nano-paint coating, and PCM-CuO nanoparticles mixture was 51.5%.