Heat transfer and entropy generation analysis of alumina/water nanofluid in a flat plate PV/T collector under equal pumping power comparison criterion

Convective heat transfer of alumina/water nanofluid flow through flat plate PV/T panel in laminar flow has been investigated numerically in this study. Majority of previous studies, reported comparison in performance of nanofluid with that of basefluid, based on equal Reynolds number criterion. Hence, there is limited exploration of other comparison bases. A novel and prominent comparison basis, besides conventional equal Reynolds number, is equal pumping power and appears more practically oriented. Nanofluid, having particle dimension of 20 nm and inlet temperature of 293 K, is loaded with 1%, 4% and 6% of particle volume fraction with Reynolds number varying from 300 to 1800. Simulation results indicate average 25.2% improvement in heat transfer coefficient for nanofluid under equal Reynolds number comparison basis. While, under equal pumping power comparison criterion, the heat transfer coefficient for nanofluid is found to have average decrement up to 13.8%. Entropy generation for nanofluid reduces significantly, maximum up to 31%, under equal Reynolds number comparison criterion only. Alumina/water nanofluid in flat plate PV/T channel is found beneficial only under equal Reynolds number comparison basis.