Enhancing the hemispherical solar distiller performance using internal reflectors and El Oued sand grains as energy storage mediums

This paper presents a comprehensive experimental study of the some effective modifications which aim to improve the cumulative productivity of solar distillers, in order to reach the best modification that achieves the highest cumulative productivity of hemispherical distillates. The experimentations were carried on the hemispherical distillers which are characterized by a large area of receiving and condensation. To obtain the best modification that achieves the highest cumulative productivity, the present comprehensive studies were conducted on two experimental scenarios. In the first scenario, the influences of internal reflective (Reflective Mirrors and Reflective Aluminum Foil) on hemispherical distillers performance was studied. In the second scenario, the influences of internal reflective with El-Oued sand grains as the energy store mediums on hemispherical distiller performances was studied. To achieve this goal, we designed and fabricated three hemispherical distillers, the first distiller represents the reference case (Conventional Hemispherical Solar Still-CHSS), the second is the Hemispherical Solar Still with Internal Reflective Mirrors (HSS-IRM), and a third is the Hemispherical Solar Still with Internal Reflective Aluminum Foil (HSS-IRAF). In the second experimental scenario, the El-Oued sand grains were added to the basin of the second and third distillers as follows; where the second distiller became a Hemispherical Solar Still with Internal Reflective Mirrors and El-Oued sand grains (HSS-IRM & SG), and a third distiller became a Hemispherical Solar Still with Internal Reflective Aluminum Foil and El-Oued sand grains (HSS-IRAF & SG). The results presented that the cumulative production of reference distiller (CHSS) up to 4750 mL/m(2), while use of internal reflective mirrors and El-Oued sand grains (HSS-IRM & SG) increases the production to 9400 mL/m(2) day. The maximum improvement in cumulative distillate production, exergy efficiency, and thermal efficiency was recorded for utilization of internal reflective mirrors and El-Oued sand grains (HSS-IRM & SG) which reached 98, 200.9, and 96%, respectively, compared to reference case (CHSS). The economic feasibility indicated that the utilization of HSS-IRM & SG represent the good modification which reduced the cost of freshwater productivity by 49.1% compared to CHSS.