Error Performance Index Based PID Tuning Methods for Temperature Control of Heat Exchanger System

Heat exchangers are commonly used in industries for the transfer of heat from one fluid to another fluid or from one form to another form. In this process of heat transfer, there is a need for continuous monitoring and control of the system to achieve desired heat levels. Normally, a robust PID controller is used for this purpose. To tune these PID controllers, many conventional methods are available. Of these methods, the OLTR (Open Loop Transient Response) methods are frequently used to obtain the gain parameters of the controllers. However, these methods are limited with respect to adjustment of steady-state error. As the heat exchanger systems are so sensitive to transients, any minor error can deviate the system behavior. In such systems, EPI (Error performance Index) methods provide a better system response by effectively nullifying the steady-state errors. Hence, this paper presents the design of PID controller gain parameters using various EPI methods. MATLAB/Simulink software is used to model the entire heat exchanger system and various control methods. The results justify that a better response is achieved with the use of ITAE based EPI method.