Heat transfer enhancement using non-equally structure in a plate-fin heat exchanger with offset fins

Abstract

In this study, a cross-flow plate-fin heat exchanger with offset fins is optimized by considering the effects of flow maldistribution for air side. For this purpose, the study is focused on an increase in the rate of heat transfer, which can be achieved by using non-equally fin structure. Numerical simulations have been carried out to investigate the thermodynamic characteristics of the non-equally full-size plate-fin heat exchanger by using the porous media approach. Based on the numerical model, flow distribution, total heat rate and pressure drop of the plate-fin heat exchanger are studied. A asymmetric structure with heat transfer enhancement is presented in this study. After comparing numerical predictions of the total heat transfer rate and the pressure drop under various Reynolds number. It is observed that, the percentages of increase in effectiveness for the final non-equally structure are in the range of 2.5-6.2% and the pressure drop remains almost constant in the cases of air inlet velocity fixed at 9.5627 m/s. The increasing asymmetric structure is numerically verified to improve the flow distribution of the plate-fin heat exchanger.