Performance simulation of condensing heat exchanger in different work conditions

This article aims to provide a more accurate calculation method for design of condensing heat exchanger (CHX) through an in-depth discussion about work conditions of the CHX commonly used in temperature and humidity control system. With difference of the simplified configuration of CHX, a mathematical model is given. Specifically, the Log-mean temperature difference (LMTD) method is used in dry conditions, while in wet conditions mass and energy conservation equations are used. The set of equations of the model are solved by using the shooting method provided by Matlab/Simulink program. The results of work conditions and the performances of heat transfer and dehumidification of CHX are determined. Analysis shows that the simulation model can evaluate performances of the CHX in different work conditions reasonably and the results are close to the physical phenomenon. The method raised in this paper is valuable for design and optimization of CHX.