Two-dimensional numerical modeling for the air-side of minichannel evaporators accounting for partial dehumidification scenarios and tube-to-tube heat conduction

Abstract

This paper presents a comparative study between the air-side heat transfer results of a two-dimensional numerical model for minichannel evaporators (Fin2D-W), and the results of the classical ε–NTU approach. This study is carried out for different dehumidifying conditions, and for scenarios with different degree of temperature difference between tubes due to the refrigerant superheat. The Fin2D-W model solves the two-dimensional heat conduction in the fin wall considering also a 2D discretization for the air flow in contact with it. Thus, the presented model is able to capture the partial dehumidification scenarios and the effect of the heat conduction between tubes. The results analyze the differences, due to these phenomena, between the proposed model and the classical approach. Significant deviations between the two models are reported, especially in the cases of partially wet fin and high values of superheat, resulting in being up to ≈ 52% in total heat transfer.