Optimal concentration of El Oued sand grains as energy storage materials for enhancement of hemispherical distillers performance

Abstract

The present experimental study aims to improve the performance of the hemispherical distillers via the utilization of El Oued sand grains as sensible storage materials. The El Oued sand grains characteristic by having SiO2, large concentrations of Al2O3, and Fe2O3. These characteristics of the El Oued sand grains make them a good choice in the solar energy storage field especially in solar distillers, as they increase the absorption rate of solar radiation inside the basin in addition to improving the rate of heat transfer. To obtain the optimal concentration of El Oued sand grains that achieves the highest performance of the hemispherical distillers, eight different concentrations of El-Oued sand grains (0.5, 1, 2, 3, 4, 5, 6, and 7%) were studied. To achieve this goal, three hemispherical distillers were designed and constructed, the first and second are the modified hemispherical distillers (MHSS) which contain the sand grains with different concentrations, and the third is a traditional hemispherical distiller (THSS) which represents the reference distiller. The experimental tests of the eight concentrations were conducted on four consecutive days, on each day two concentrations were tested and compared to the reference distiller. The experimental results presented that, the concentration of 3% represents the optimal concentration of El Oued sand grains that achieves the highest performance of hemispherical distillers. The accumulative yield of the reference distiller reached 4780 mL/m2 /day, while the utilization of El Oued sand grains with a concentration of 3% improves the accumulative yield to 7270 mL/m2 /day with a 52.1% improvement in accumulative yield. Also, the daily efficiency of the reference distiller reached 39.2%, while the utilization of the El Oued sand grains with a concentration of 3% improves the daily efficiency to 59.1% with a 50.8% improvement in daily efficiency.