Evaporator and Gradient Control

A Simulink model of an evaporator with gradient control

This package includes a Simulink model of the evaportaor described by Newell and Lee (1989) together with a gradient control system which achieves self-optimizing operation in terms of minimizing the operation cost. The work has been published in International Journal of Automation and Computing, Vol. 2, No. 1, pp. 13—19, 2005. A preprint version of the paper is enclosed in the zip file.

Gradient control is an approach to achieve optimal operation. The basic idea is that if the gradient of the cost function can be controlled at zero, then the overall system will operate at optimal condition. Another
novalty of the work is to propose a cascade structure to deal with conditionally active constraints in optimizing control. To work with constraints, anti-windup PID controllers are used in the model.

The evaporator of Newell and Lee is a popular example used in process control. Theerfore, the Simulink model of the evaporator can also be used for other control studies, for example, linear or nonlinear MPC.