Experimental investigations of the performance of a flat-plate solar collector using carbon and metal oxides based nanofluids

Covalently functionalized carbon nanoplatelets and non-covalent metal oxides nanoparticles (surfactant-treated) have been used to synthesize water-based nanofluids in this paper. To prove nanofluid stability, ultraviolet–visible (UV–vis) spectroscopy is used, the results show that stable for sixty days thirty oxides. The thermophysical properties are evaluated experimentally validated with theoretical models. Thermal conductivities of f-GNPs, SiO2, ZnO enhanced by 25.68%, 11.49%, 15.42%, respectively. Lu-Li Bruggeman’s thermal conductivity models correctly matched experimental data. Similarly, viscosity, density, specific heat capacity measured compared enhancement viscosity ZnO, SiO2 0.12%, 0.22%, 0.12%; 1.54%, 0.96%, 0.73%; 12%, 9.41%, 24.05% respectively comparison distilled water. A flat-plate solar collector installed, its performance using based nanofluids, following ASHRAE standard 93–2003, at different flux intensities (597, 775, 988 W/m2), mass flow rates (0.8, 1.2 1.6 kg/min), inlet fluid temperatures (30–50 °C) weight concentrations (0.025–0.2%). efficiency water concentration (0.025–0.2%) oxide-based nanofluids. 0.1 wt% can be sequenced f-GNPs > because a percentage improvement obtained rate kg/min values 17.45% 13.05% 12.36%,