Exergy, economic, and environmental impact of a flat plate solar collector with Al2O3-CuO/Water hybrid nanofluid: Experimental study

Abstract

The growing demand for efficient and sustainable energy solutions has intensified research on improving the performance of solar thermal systems. The viability of a flat plate solar collector was carefully explored. Water and Al₂O₃-CuO (50:50)/Water hybrid nanofluid were used as working fluids and their results were compared. The outlet temperature, energy efficiency, exergy efficiency, and entropy generation were investigated by varying the nanoparticle concentration from 0.01 to 0.05 mass% and by changing the inlet mass flow from 0.006 to 0.015 kg/s. Experimental measurements were taken under an average solar irradiation of 912.26 W/m².Peak values of energy efficiency and exergy efficiency were seen at 72.12 % and 3.01 %, respectively at 0.03 mass% and 0.015 kg/s flow rate. The hybrid nanofluid showed lowest entropy generation of 1.45 W/K and highest exergy destruction of 425.83 W at same concentration and flow rate. The hybrid nanofluid provided better efficiency, lower entropy generation and enhanced exergy reduction compared to water. The exergetic improvement potential was lowered to 3.58 % with the application of hybrid nanofluid. Economically, using the nanofluid could reduce collector size by 30.51 %. Sustainability assessments indicated an enhancement in the exergetic sustainability index up to 1.03 and a reduced environmental impact to 0.971 at 0.03 mass%, compared to water’s highest sustainability index of 1.019 and environmental impact of 0.99. Finally, enviroeconomic analysis reveals that hybrid nanofluid utilization can reduce the CO₂ mitigation and its cost up to 44 % based on energy utilization and 50 % based on exergy utilization compared to basefluid. The study recommends the use of Al₂O₃-CuO/Water nanofluids for solar collectors, highlighting their superior thermo-economic and enviroeconomic performances, sustainability and reduced environmental impact compared to conventional water-based systems.