Abstract
The hybrid nanofluid is formed when more than one type of nanoparticle is used in the nanofluid preparation process. The study of hybrid nanofluids is the most recent nanofluid trend, as they have the potential to improve greener energy production. Solar thermal energy systems still require further research before they can be widely used. As a result, the current study uses mono CuO and hybrid CuO + Cu/water nanofluids as the working fluid to explore the performance of an evacuated tube solar collector. Visual inspections and zeta potential studies showed the stability of the examined nanofluids, which were generated via ultrasonication. In the case of hybrid nanofluid, the thermal conductivity study has observed a 21% increase. The performance of the solar collector was tested at flow rates of 0.0125 L/s, 0.015 L/s, and 0.0175 L/s. With the use of a hybrid nanofluid, the collector area can be reduced by up to 38%. The heat removal factor was found to be 0.894. Hybrid CuO 2.5 g + Cu 1.5 g nanofluid exhibits a 61.7% and 14.9% greater thermal-optical efficiency than water and mono CuO, respectively.
•Different concentrations of hybrid CuO-Cu/water nanofluid were prepared.•The enhancement in thermal conductivity was 10.6% and 21% for mono CuO/water and hybrid CuO-Cu/water nanofluid, respectively.•A 38% reeducation on solar collector area was achieved with nanofluid.•Thermal-optical efficiency was increased by 61.7% with hybrid nanofluid.•Thermal energy storage raised by 26.2%.