Numerical study on hydrodynamic characteristics of plate-fin heat exchanger using porous media approach

• Hydrodynamic features of full-size PFHE were studied based on porous media method.
• Flow distribution of PFHE is improved by increasing its fins and fluid viscosity.
• A dynamic flow redistribution process was proposed to explain observed tendency.
• Correlation among flow distribution, pressure drop, and Re in PFHE was analyzed.
• Two strategies for improving flow distribution of PFHE were proposed and verified.

A numerical plate-fin heat exchanger (PFHE) model was proposed to investigate the hydrodynamic characteristics of a full-size PFHE by using the porous media approach. Based on the model, effects of the fluid dynamic viscosity and perforated fins on flow distribution and pressure drop of the PFHE were studied. The results showed that flow distribution of the PFHE was improved by increasing the fluid dynamic viscosity or adding perforated fins in each fin channel, but at the cost of an increased pressure drop. Therefore, the relationship between flow distribution and pressure drop was further analyzed under various Reynolds numbers. Based on the results, a correlation among flow distribution, pressure drop, and Reynolds number was derived. Finally, two strategies, the fin channel-based strategy and the header-based strategy were proposed and numerically verified to improve flow distribution of the PFHE. Our results indicate that the first strategy is better than the latter one.