Development of a numerical analysis model using a flow network for a plate heat exchanger with consideration of the flow distribution

A numerical analysis model using a flow network approach is developed to evaluate the performance of a plate heat exchanger (PHE). In order to consider complex flows in PHEs in the model, the flow paths in the channels are represented by a flow network consisting of nodes and branches. This model is able to evaluate the node-average local properties of the working fluids of each channel in a PHE. Several empirical correlations for the pressure drop and the heat transfer are evaluated against various experimental data to implement the selected correlations into the numerical analysis model according to the flow conditions and geometry of the heat transfer plates used. The pressure drop and heat transfer capacity of a PHE were experimentally measured with a range of operating parameters and the measured values were then compared with the prediction by the numerical analysis model. The predictions of the heat transfer capacity are in good agreement with the experimental data within a discrepancy of 10%, whereas the prediction of the pressure drop significantly deviated from the experimental data. The analysis also demonstrates that the total heat transfer rate varies little whereas the pressure drop increases sharply as the maldistribution of the flow is intensified.