Amelioration of thermal performance of an evacuated tube solar collector using a two types of reflective materials with present and absent of CuO nano-fluid.

In previous studies, an electronic curtain made of one reflective material was used, while in this study, the two electronic curtains made of two various reflective materials were utilized: acrylic mirrors and aluminum foil; this is to compare any electronic curtain of any reflective material that has the ability to reflect more solar radiation and thus increase the temperature of the fluid located inner the tube and thus improve the efficiency of the evacuated tube solar collector clearly. Copper oxide was used and adding it to distilled water as a basic working fluid with a diameter of (50nm) with three flow rates (6,12,18 L/min) and three volumetric concentrations (1%, 3 %, 5 %) to increase the heat gain and thus increasing the efficiency of the collector as well. Reflective electronic curtains were placed over the collector tubes to protect the tubes from weather conditions. The findings showed that the utilize of an electronic curtain made of acrylic mirrors had a more significant impact on the performance of the solar collector compared to the electronic curtain made of aluminum foil, Where the uttermost efficiency of the solar collector was 55% in the case of using an electronic curtain made of acrylic mirrors in the presence of nanofluid copper oxide at a flow rate of 18 L/minute and a volumetric concentration of 5%. While the maximum efficiency of an evacuated tubular solar collector in the case of using an electronic curtain made of aluminum foil was 47.68%, at the same flow rate and volumetric concentration. [ABSTRACT FROM AUTHOR]