A flexible hybrid CFD model for refrigerant mal-distribution among minichannels in parallel flow condensers

In the present work, a flexible hybrid CFD model is constructed for parallel flow condensers to compute their refrigerant mal-distributions, where the DEFINED Macros of ANSYS Fluent are utilized to embed the one-dimensional finite element analysis of the heat transfer and flow resistance of refrigerant flowing through flat tubes. The parallel flow condenser in the literature is simulated with current hybrid model, and the comparison between the numerical and experimental performances is conducted for validation. Besides, the refrigerant flowrates in different flat tubes and minichannels are predicted, and the physical mechanism of fluid mal-distribution is discussed based on contours and vectors. The current investigation demonstrates that the proposed hybrid model could simulate the refrigerant flow in parallel flow condensers efficiently and its prediction has a reasonable precision. Besides, notable mal-distributions among different flat tubes and different minichannels of same flat tube are observed in the 1st tube pass. The tube flowrates in the rest passes are relatively uniform, while the mal-distribution among different minichannels of same tube could be more notable, with the maximal relative deviation about 15.6%. The current numerical model could be referred for the optimal design of heat exchangers. (C) 2018 Elsevier Ltd and IIR. All rights reserved.