Comparative study of Fuzzy and IMC based controllers for heat exchanger system

Abstract

This paper presents the comparative study of PID, Fuzzy logic and Internal model based controller for heat exchanger system. The H.E. system plays a dynamic role in process industry. The performance of heat exchanger is largely depending upon the outlet fluid temperature. The selected heat exchanger system is intended to control the temperature of outlet fluid to a desired set point despite of different disturbances like fluid flow variations and fluctuations in input fluid temperature. The input fluid and inlet steam are the input parameters and outlet temperature of the fluid is the output parameter. Outlet fluid temperature is the controlled by manipulating the inlet steam flow. Whereas the deviation produced in input fluid flow is considered as one of the effective and dominant disturbance. Conventional PID controller is commonly used to control the output temperature. It has its own drawbacks and cannot handle the disturbance properly overall performance of PID is not satisfactory. This report is an attempt to design advanced controller like FLC and IMC for heat exchanger system. To design this controller, the mathematical modeling of H.E. is studied theoretically. Its component wise model is developed in MATLAB Simulink for this developed model, FLC has designed with different membership functions and Mamdani and Takagi-Sugeno (TS) method, and its performance is compared with PID. Further for the same model IMC controller is designed. The performance of PID, FLC and IMC is compared in MATLAB Simulink environment. The performance of IMC controller is superior to PID and FLC. It successfully tracks the set point and handles the disturbances.