Simulation of air-to-refrigerant fin-and-tube heat exchanger with CFD-based air propagation

A new model for simulating air-to-refrigerant fin-and-tube heat exchangers with computational fluid dynamics (CFD)-based air propagation is introduced. This model is based on a segment-by-segment approach and is developed to be a general purpose and flexible simulation tool. The model superimposes a CFD mesh on the heat exchanger model’s geometric grid, interprets the CFD results, and processes them to generate the air propagation path through the heat exchanger. The model is capable of accounting for air flow maldistribution and other complex flow patterns including recirculation zones within the heat exchanger, as well as, entrainment of exit flow into the heat exchanger, using both two-dimensional (2D) and three-dimensional (3D) CFD results. The modeling results show that the overall predicted heat load using 3D-CFD simulation results agrees within ±4% of the experimental data, without employing any multipliers on air side correlations.

► We model an air-to-refrigerant heat exchanger with airflow being simulated using CFD.
► The CFD results are interpolated and used to generate a computational sequence of airflow through the heat exchanger.
► The interpolated airflow is used in a segmented heat exchanger model.
► This results in an accuracy of ±4% in heat load prediction without any correction factors.
► The technique can be used to optimize heat exchanger circuits and angles of inclination of air to refrigerant heat exchangers.