Enhancing Thermal Performance of Evacuated Tube Solar Collector using Novel Graphene Oxide Nanofluid

Abstract

The research article investigates the thermal performance of heat pipe-based evacuated tube solar collector (ETSC) experimentally using graphene oxide (GO) and deionised (DI) water as working fluid with a mass flow rate of 0.5 lit/min, 0.75 lit/min, and 1 lit/min. The different volumetric concentrations of 0.001%, 0.002%, and 0.003% graphene oxide nanofluid samples were prepared in the deionised water. The X-ray diffraction (XRD) was used to determine the structural properties of graphene oxide and the morphology of graphene oxide was studied by scanning electron microscope (SEM). To evaluate the stability of nanofluid samples, the Zeta potential analysis was carried out which showed that prepared nanofluid samples remain stable for up to 30 days. The effect of different nanofluid concentrations on various thermo physical properties of nanofluid was studied and discussed. The thermal performance of ETSC was investigated by considering the effect of volumetric concentrations of nanofluid and mass flow rates. According to the findings, there is a significant increment in temperature difference and energy gain by using nanofluid samples, and the maximum thermal efficiency of ETSC was found to be 37.1% for a volumetric concentration of 0.003% at 1 lit/min mass flow rate as compared to water.