Effect of flow distribution to the channels on the thermal performance of a plate heat exchanger

Abstract

Plate heat exchangers are making their presence felt in the power and process industry in the recent past. Hence, it has become necessary to model their temperature response accurately. The traditional way of modelling a plate heat exchanger with equal flow in all the channels is unrealistic, and previous studies indicate that considerable differences remain in the flow rates in different channels. The present work brings out the effect of flow maldistribution from channel to channel comprehensively. This poses a serious question about the usual method of analysis of the experimental heat-transfer data of the plate heat exchanger. Unlike previous studies, the present study indicates the importance of considering the heat-transfer coefficient inside the channels as a function of flow rate through that particular channel. This eliminates the contradictory proposition of unequal flow rates but an equal heat-transfer coefficient. A wide range of parametric study have been presented, which brings out effects such as those of the heat-capacity rate ratio, flow configuration, number of channels and correlation of heat transfer. The analysis presented here suggests a better method of heat-transfer data analysis for plate heat exchangers.