Optimal tracking control of a heat exchanger with change in load condition

An optimal tracking control of a heat exchanger with load change is considered. It is assumed that the plant is described by a discrete-time state-space model with time-delay, and a direct link between input and output. First, based on the linear quadratic inverse technique, the authors derive an optimal tracking controller having integral, state feedback plus preview actions. To derive a state-space model of a heat exchanger, an ARX model was fitted to the open-loop data obtained from the plant. The properties of the tracking control algorithm are analyzed by simulation studies using the identified model. The optimal control algorithm with an observer was installed on a process computer to provide the set points for the analog PID (proportional plus integral plus derivative) regulators of a heat exchanger plant. Experimental studies show that the control performance of water outlet temperature in the presence of load change is greatly improved