Numerical investigation on thermohydraulic and exergy performance enhancement for triplex concentric tube heat exchanger using MXene nanofluids

This study delves into heat transfer characteristics and fluid flow within a triplex tube heat exchanger (TTHX), employing water- and water-based 1% v/v. MXene and Al₂O₃ nanofluids. It scrutinizes the impact of the Reynolds number on various performance metrics such as heat transfer coefficients, performance evaluation criteria (PEC), effectiveness, exergy loss, and entropy generation. Employing a 3D RNG/k-ε model with improved wall treatment, which has been validated by empirical correlation data available in the literature, the research uncovers that the utilization of MXene nanofluid led to a 12.51% increase in heat transfer coefficients compared to the Al₂O₃ nanofluid and a 20% increase as compared to water, when deployed in a counter-flow configuration of the TTHX. Notably, the PEC and effectiveness graph indicate that MXene nanofluid exhibits a substantial increase of 21.73% and 29.71% over Al₂O₃ nanofluid at a Reynolds number of 6800 and 4400. Additionally, the exergy loss and entropy generation with Mxene nanofluid is reduced by 10.5% and 33.34% compared to Al₂O₃ nanofluid. Consequently, MXene nanofluids have the potential to significantly enhance the overall performance of a triplex tube heat exchanger compared to conventional fluids.