Heat transfer, pressure drop, and exergy analyses of a shot-peened tube in the tube heat exchanger using Al2O3 nanofluids for solar thermal applications

Abstract

The effects of shot peening on the heat transfer, exergy analysis, and pressure drop in the heat exchanger were studied. Nanofluids were produced at different volume concentrations of 0.15, 0.3, and 0.45% of alumina oxide (Al2O3) nanomaterials well dispersed in solar glycol/water (80:20 by volume) as a base fluid. The outcomes point out that nanofluids (0.15, 0.3, and 0.45%) can enhance the Nusselt number by 8.098, 16.81, and 26.98%, compared with SG/H2O mixture respectively when compared with the SG-H2O blend with an impelling penalty of 1.47 folds. A higher enhancement in the CHTC of 56.32% was attained using 0.45 vol% of Al2O3 nanofluids at 0.08 kg/s. TEF of 1.118 is attained for the 0.45 vol% nanofluid inside the surface-modified (shot peening) heat exchanger. The maximal exergy efficiency was found to be 30.82% for 0.45 vol% of SG-H2O-based nanofluids and nanofluid MFR of 0.08 kg/s.