Modelling, identification and control of sugar evaporation - theoretical design and experimental evaluation

This paper discusses the problem of controlling a multiple-stage industrial evaporator in a sugar factory. The control objectives are: syrup should ha ve a sucrose concentration of 72%, the evaporator should produce the requir ed amount of steam, and the steam consumption should be as low as possible. Achieving these objectives is difficult, due to the following plant featur es: strong disturbances, large time delays and many constraints. The contro l problem is solved by developing a physical model which is used as benchma rk; then, a parametric identification is performed to obtain a control mode l. Finally, a successful real-time application of a multivariable GPC contr oller is presented. (C) 1999 Elsevier Science Ltd. All rights reserved.