Dynamic modeling and control of a plate heat exchanger

Heat exchangers have a predominant role in heat transfer and constitute a key component of integrated energy systems. For instance, heating and cooling of fluids are the cornerstone of district heating systems. Thus, it is fundamental to understand the heat exchanger's dynamic behavior to design controllers which are robust to temperature variations. Following this line, this paper presents a dynamic model of a plate type heat exchanger. The model is obtained from first principles of energy transfer and fluid mechanics and describes the thermal behavior of fluids involved in the heat transfer process. Although the system is non-linear, system linearization is performed to obtain a frequency domain model suitable for control system design. The linear model is implemented in MATLAB to design a controller that regulates the cold stream outlet temperature. To assess its effectiveness, the controller is discretized, programmed in Python and implemented in Apros — an advanced process commercial simulation software. Simulation results show that the controller is capable of tracking reference temperatures while ensuring a good performance of the heat exchanger system.