An analytical model to study the dynamic response of heat exchanger network

Abstract

An analytical model for the heat exchanger network (HEN) has been proposed in this work to study the dynamic performance of HEN in the design stage. The model relies on the Laplace transform to obtain the system outlet temperature function when facing operational changeover. Equipped with the decomposition strategy and pathway analysis, the model can reach the system outlet temperature function in the time domain in an easy way and free of the numerical difficulty concern caused by the inverse Laplace transform process that may occur toward complicated expressions. The potential bias of the model has been illustrated both in static and dynamic aspects by changing the operational conditions of a heat exchanger. The analytical model has been applied in a four streams HEN synthesis problem to investigate the trade-off result between the economic cost and the response time. Moreover, the comparison with the simulation result toward selected HENs has shown that the proposed model may act as a pre-selection tool to predict the dynamic performance of various HENs during the design stage.