NUMERICAL SIMULATION OF THERMAL EFFICIENCY OF AN INNOVATIVE Al2O3 NANOFLUID SOLAR THERMAL COLLECTOR Influence of Nanoparticles Concentration

Investigations on the potential thermal efficiency of an innovative nanofluid solar thermal collector have been performed using a commercial software (RadTherm ThermoAnalytics rel. 10.5). The Al2O3-nanofluid has been simulated as working fluid of the solar thermal collector, varying the nanoparticles concentration from 0%vol of Al2O3 nanoparticles (pure water) up to 3%vol of Al2O3 of nanoparticles. The numerical model has been validated with experimental data, obtained with a real prototype of the simulated solar thermal collector. Real thermal properties of the nanofluids at different concentrations have been used in the simulations. The boundary conditions used for the simulations have been those of real weather conditions. An increase in thermal efficiency (up to 7.54%) has been calculated using nanofluid with a volume fraction of 3% and the influence of nanoparticles concentration on the thermal performance of the solar collector has been pointed out.