Optimization Analysis of Two-Phase Flow Distributor for Multichannel Heat Exchanger

Abstract

Abstract. The flow maldistribution in plate heat exchangers (PHEs) is serious, which hinders efficient operation. In this study, a multichannel two-phase flow model in porous media is established, and flow maldistribution in PHE is analyzed using numerical simulation. To improve flow uniformity, the slot-type distributor (STD) and the slot-type distributor with baffles (STDB) are proposed. The results show that the channels near the inlet exhibit higher mass flow in the baseline design, with significant nonuniformity; the standard deviation ranges from 0.31 to 0.34. Although STD exhibits good distribution performance, backflow outside the tube makes accurate flow regulation difficult. On the contrary, STDB can accurately control the flow rate of each channel by adjusting the slot angle, as the baffles prevent backflow. Compared with the baseline design, the optimized STDB achieved an 89% reduction in nonuniformity, with an average pressure drop of only 378 Pa. In addition, the influence of quality on the flow maldistribution of R410A is weak, and the nonuniformity decreases slightly with the increase of quality in all structures.