Experimental investigation of the effects of using ceryum oxide –water (CeO2-water) and zinc oxide-water (ZnO-water) nanofluids on thermal efficiency in a flat plate solar collectors

The aim of this study is to experimentally and numerically compare in terms of various parameters such as efficiency, temperature-radiation-hour and exergy loss, a system using environmentally friendly, technologically advanced flat plate solar collectors with 0.01%, 0.1%, and 1% concentrations of Cerium oxide (CeO2) and Zinc Oxide-Water (ZnO) nanofluids at different flow rates (250 liters/hour, 150 liters/hour, 50 liters/hour) and different times (07:30-17:30). In addition to the results obtained from the experimental study, numerical analysis studies were conducted using Computational Fluid Dynamics (CFD) and these numerical results were compared with the experimental data. The findings from the experimental study are consistent with the numerical analysis results obtained through CFD. According to the results obtained from the experiments, the highest increase in efficiency compared to water occurred with 1% ZnO-water nanofluid at a flow rate of 250 liters/hour, with an increase of 28%. The lowest increase in efficiency compared to water occurred with 0.01% CeO2-water nanofluid at a flow rate of 50 liters/hour, with an increase of 8%. The highest entropy production was 6.72 W/K for water at 50 lt/h flow rate, while the lowest entropy production was 5.57 W/K at 250 lt/h flow rate for 1% ZnO nanofluid. The highest exergy destruction was 1235 W for water at 50 lt/h flow rate, while the lowest exergy destruction was 1005 W for 1% ZnO nanofluid at 250 lt/h flow rate.