THERMAL PERFORMANCE ANALYSIS OF FLAT-PLATE SOLAR COLLECTOR USING Al2O3/WATER NANOFLUIDS UNDER LAMINAR FLOW CONDITIONS: AN EXPERIMENTAL STUDY

In this experimental study, aluminum oxide (Al<sub>2</sub>O<sub>3</sub>)/water nanofluids were employed at mass fractions of 0.05% and 0.1% to improve the thermal efficiency of a flat-plate collector under laminar flow conditions. Two distinct volume flow rates were used, revealing a 2.73% increase in energy efficiency when the discharge was raised from 0.5 l/min to 1 l/min for water. Notably, at the lower discharge of 0.5 l/min, a maximum exit fluid temperature of 41.1°C was achieved using water alone as the fluid media, whereas an increment of 3.79% and 6.32% was reported for 0.05% and 0.1% mass fraction Al<sub>2</sub>O<sub>3</sub>/ water nanofluids, respectively. Moreover, compared to primary fluid water, the energy efficiency of the collector at 0.5 l/min was found to increase by a maximum of 5.66% and 8.20% for the corresponding mass fraction of Al<sub>2</sub>O<sub>3</sub>/water nanofluids. Additionally, energy gain and loss parameters were analyzed to comprehensively assess the flat-plate collector's performance.