Flat plate solar collector activated with alumina-silicon dioxide-copper oxide hybrid nanofluid: Thermal performance study

Abstract

Flat plate collectors (FPC) play a crucial role in solar-powered desalination by harnessing sunlight to purify water. They are acclaimed for their simple yet efficient design, as their dark, flat surfaces effectively transfer heat to the desalination system, making them a preferred choice for sustainable water treatment. Nevertheless, the performance of FPC systems is hindered by the working fluid, which reduces the productivity of distilled water, particularly without the use of nanotechnology to enhance the fluid’s thermal properties. This study aims to enhance the performance of FPCs in desalination processes by integrating them with conventional still systems and employing hybrid nanofluids. These nanofluids, composed of alumina (Al2O3), silicon dioxide (SiO2), and copper oxide (CuO) nanoparticles at concentrations of 0.3 % in 50:50 combinations, namely Al2O3/SiO2, SiO2/CuO, and Al2O3/CuO, are introduced into the working fluid (water). The integration of these hybrid nanofluids is evaluated in terms of thermal behaviour, including thermal conductivity, outlet temperature, energy gain, water productivity, and thermal and exergy efficiency of FPC. Among the different combinations, the Al2O3/CuO hybrid nanofluid demonstrates the highest thermal conductivity, outlet temperature, energy gain, water productivity, as well as thermal and exergy efficiencies, reaching approximately 0.631 W/mK, 87.5 °C, 568.7 W, 124.3 ml/m2, 61.4 %, and 6.7 %, respectively. The Al2O3/CuO featured flat plate solar collector system has the potential for an optimum system of addressing the pressing global issue of water scarcity.