Performance Evaluation Of Flat Plate Solar Water Heater Using Ceo₂/Water And Al₂O₃/Water Nanofluids: Experimental And Thermophysical Analysis

Abstract

The depletion of fossil fuels and the growing demand for sustainable energy necessitate the advancement of renewable energy systems. Solar water heating systems, being cost-effective and eco-friendly, have attracted significant attention for residential and industrial applications. In this study, CeO₂/water and Al₂O₃/water nanofluids at different volume concentrations (0.01%, 0.05%, and 0.1%) were prepared using a two-step method and characterized for thermophysical properties such as thermal conductivity, viscosity, density, and specific heat. Experimental investigations were conducted on a flat plate solar water heater equipped with a ladder-type heat exchanger under the climatic conditions of Coimbatore, India, following ASHRAE standards. Results demonstrated that nanofluids exhibited superior heat transfer performance compared to conventional water, with CeO₂/water nanofluid at 0.01% concentration and 2 L/min flow rate achieving a maximum instantaneous efficiency of 78.2%. Energy and exergy analyses further confirmed the enhanced thermal performance, while economic evaluation highlighted the feasibility of nanofluid-based solar heaters for practical applications. The findings emphasize the potential of nanofluids in advancing solar thermal technologies and optimizing operating conditions for improved efficiency and sustainability.