Z. SaidR. SaidurM. A. SabihaA. HepbasliN. A. RahimSaid, Z.Sabiha, M. A.Saidur, R.Hepbasli, A.Rahim, N. A.2025-10-0620160959-65261879-178610.1016/j.jclepro.2015.07.1152-s2.0-84959568261http://dx.doi.org/10.1016/j.jclepro.2015.07.115https://gcris.yasar.edu.tr/handle/123456789/7834https://doi.org/10.1016/j.jclepro.2015.07.115Application of nanofluid to increase the thermal efficiency of a traditional solar collector is getting tremendous attention among the scientific community. Al2O3-water nanofluid as a working fluid and its effect on the energy and exergy efficiencies of a flat plate solar collector was examined experimentally. Volume fraction used for this study was 0.1% and 0.3% while the size of the nanoparticles was similar to 13 nm. Experiments were carried out using a stable nanofluid which was obtained by controlling the pH of the solution over a period of 30 days. The mass flow rates of the nanofluid varied from 0.5 to 1.5 kg/min. Energy and exergy efficiencies of a flat plate solar collector using water and nanofluids as working fluids were matched. The results revealed that nanofluids increased the energy efficiency by 83.5% for 0.3% v/v and 1.5 kg/min whereas the exergy efficiency was enhanced by up to 20.3% for 0.1% v/v and 1 kg/min. Thermal efficiency of the system was found to be more than 50% compared to the existing system available in the literature. New findings on the stability and exergy analysis of the solar collector system operated with a pH controlled nanofluid are reported. (C) 2015 Elsevier Ltd. All rights reserved.Englishinfo:eu-repo/semantics/closedAccessNanofluid Flat plate solar collector, Energy, Exergy, Efficiency improvement, Al2O3THERMAL-CONDUCTIVITY ENHANCEMENT, ENTROPY GENERATION MINIMIZATION, IRREVERSIBLE-PROCESSES, RECIPROCAL RELATIONS, COOLING SYSTEMS, TEMPERATURE, PERFORMANCE, OPTIMIZATION, HEATEREfficiency ImprovementAl2o3ExergyNanofluidAl₂o₃Flat Plate Solar CollectorNanofluid Flat Plate Solar CollectorEnergyArticle