A fast and efficient dynamic simulation model of heat exchangers is urgently needed to meet the requirements of the advanced control system design for the integrated environmental control and thermal management system of aircraft. In this paper, a dynamic model by transfer function matrix, composed of two delay links and four first-order inertia links, is proposed for plate-fin heat exchangers. The identification method for the calculation formulas of thermal resistance based on the efficiency of the heat exchanger is given, which solves the issue of setting two key parameters in the model. The calculation formulas of four-time constants in the simplified model are derived according to the mechanism of the heat exchanger by using the Laplace transform. Taking an air-liquid plate-fin heat exchanger as the research object, the new dynamic simulation model is built in Simulink software, and compared with the mechanism model built in AMESim software. The results show that both models have similar dynamic responses of the outlet temperature at both flow sides with step change of inlet temperature or flow rate. Under four working conditions, the highest steady-state variations of the air and cooling water outlet temperatures are 0.034 ℃ and 0.029 ℃, respectively. The maximum dynamic relative deviation of airflow outlet temperature is 9.27% with a step change of the cooling water flow rate. The maximum dynamic relative deviation of cooling water flow outlet temperature is 7.03% with a step change of the airflow rate. © 2024 Beijing University of Aeronautics and Astronautics (BUAA). All rights reserved.
