Robust controller design for a heat exchanger using H-2, H-8, H-2/H-8, and mu-synthesis approaches

Possibilities of using robust controllers for a shell-and-tube heat exchanger control were studied, tested and compared by simulations and obtained results are presented in this paper. The heat exchanger was used to pre-heat petroleum by hot water; the controlled output was the measured output temperature of the heated fluid - petroleum, and the control input was the volumetric flow rate of the heating fluid - water. Robust controllers were designed using H-2, H-infinity, H-2/H-infinity strategies and mu-synthesis. A comparison with the classical PID control demonstrated the superiority of the proposed robust control especially in case when the controlled process is affected by disturbances.