Experimental study of the thermal characteristic of a double tube heat exchanger with tapered wire coil inserts using PCM-dispersed mono/hybrid nanofluids.

An experimental study involving tapered wire coil inserts in a double-tube heat exchanger using water-based phase change material (PCM)-dispersed mono/hybrid nanofluids is conducted. The effects of the wire coils (WC) with nanofluids on the hydrothermal performance of this system are studied for different coil arrangements: converging wire coils (CWC), diverging wire coils (DWC), and converging-diverging wire coils (CDWC) and different Reynolds numbers. The experimental results indicate that among all the tested coil arrangements, the DWC presents a higher thermal performance factor (TPF) than the other arrangements. Using the DWC, the TPF of the Al2O3+PCM hybrid nanofluid is augmented by 3.98%, 9.61%, and 3.04% as compared to that for the plain wire coil (PWC), CWC, and CDWC, respectively. Besides, the DWC configuration exhibits the minimum entropy generation among all arrangements. For the Al2O3+PCM hybrid nanofluid using the DWC, the entropy generation is decreased by approximately 13.36%, 9.78%, and 5.78% as compared to that of the PWC, CWC, and CDWC at a volumetric flow rate of 15 lpm. [ABSTRACT FROM AUTHOR]