Numerical study of two-phase flow in multi-channels plate heat exchanger

Abstract

Plate heat exchangers (PHEs) have been acquired a considerable attention and have been popularly used for both single-phase and two-phase flows in the air-conditioning systems. During the study of the flow distribution of the PHEs, the two-phase flow distribution is analysed experimentally. However, since the observation of the internal flow field of the PHE is very difficult, Computational Fluid Dynamics (CFD) can be used to better predict the fluids flow field inside the plate heat exchanger. In this study, ANSYS FLUENT is used to model the flow field composed of the K050 chevron PHE to observe the two-phase flow and uneven flow distribution. Moreover, the effect of the distributor on the gas-liquid distribution in the multi-channels flow field is also evaluated. The major effort of this paper is to investigate the effect of the two-phase flow distribution in multi-channels PHE with and without an inflow distributor. For the multi-channels PHE without distributor, the simulation results show that the flow must operate at high Reynolds numbers to obtain better enhancement in the flow distribution. If the PHE operates under Reynolds number less than 1500, the vapor-liquid distribution is non-uniform. Furthermore, it is observed that when the inflow distributor is added, the two-phase flow distribution of the vapor phase improves significantly. However, the flow distribution of the liquid phase is better under low Reynolds numbers condition. In addition, it has been shown that as Reynolds number increases, the liquid flow distribution is not affected by the inflow distributor.