A dynamic 2D model for thermal performance of plate heat exchangers

A 2D dynamic model was developed to interpret the transient thermal performance of plate heat exchangers (PHEs) as a stepping stone toward better understanding of localized milk fouling phenomena. The conventional ID model, which is used as a basis of most fouling models, was compared with the 2D model in two different types of multichannel PHEs. To measure the local temperatures of the fluid, T-type thermocouples, placed at 15 different locations on a plate, were inserted between the channels of interest. The ID model, which is based on unidirectional, constant velocity flow, showed limited predictive accuracy for the experimental data and was dependent on the flow characteristics (i.e., an average 3.9% deviation for a fully developed flow scheme, and 36.1% deviation for a potential eddy flow scheme). On the other hand, the 2D model, which takes into account the hydrodynamics of the flow stream, was capable of predicting the temperature distribution of the fluid flow with an average 62% deviation, irrespective of the flow pattern. The validated 2D model is expected to enable better identification of potential regions of milk deposits when compared with the conventional ID model.