Optimization of the hemispherical solar distiller performance assisted by high thermal conductivity metal trays incorporated with reflective mirrors

The present comprehensive study aims to achieve the highest freshwater productivity of hemispherical solar distillers which are characterized by having a large condensing and receiving surface area. This was done by incorporating two effective modifications to the design of the hemispherical solar distiller, namely the use of metal trays with high thermal conductivity and reflective mirrors. In the present experimental work, three different high thermal conductivity metal trays (steel, zinc, and copper) incorporated with the reflective mirrors were tested under the same climate conditions, in order to determine the optimum selection of metal trays that are incorporated with the reflective mirrors that achieve the highest performance of the hemispherical distillers. To realize this objective, four distillers were fabricated and tested at the same climate condition namely: Hemispherical solar Distiller with Black Silicone Walls (HSD-BSW) which represent the reference case, Hemispherical Solar Distiller with Steel Trays and Reflective Mirrors (HSD-ST&RM), Hemispherical Solar Distiller with Zinc Trays and Reflective Mirrors (HSD-ZT&RM), and Hemispherical Solar Distiller with Copper Trays and Reflective Mirrors (HSD-CT&RM). The experimental results presented that the utilization of copper trays incorporated with reflective mirrors (HSD-CT&RM) represents the very effective option to achieve the highest performance of the hemispherical solar distillers. The cumulative production achieve by the reference HSD-BSW reached 4.65 l/m 2 day, while utilization of copper trays incorporated with reflective mirrors (HSD-CT&RM) increases the cumulative production to 9.5 l/m 2 day, with an improvement of 104.3%. Also, utilization of copper trays incorporated with reflective mirrors (HSD-CT&RM) improves the daily thermal and exergy efficiencies by 102.4% and 194.9%, respectively compared to HSD-BSW. Additionally, the economic feasibility showed that the use of copper trays incorporated with reflective mirrors (HSD-CT&RM) is a very effective option as it reduces the cost of distilled water by 44.1%.