Classical and Dynamic Matrix Control of Kamyr Digesters-A Comparative Study

详细信息    查看全文

• 作者：Luay Al-Awami ; Yousry Sidrak ; and Maamar Bettayeb
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：1999
• 出版时间：October 1999
• 年：1999
• 卷：38
• 期：10
• 页码：3950 - 3956
• 全文大小：94K
• 年卷期：v.38,no.10(October 1999)
• ISSN：1520-5045

文摘

In Kamyr digesters, used for the production of paper pulp from wood chips, there are stronginteractions between the many process variables, long time delays, and frequent disturbances.As a result, steady-state operation is difficult to attain and process control is a challengingproblem. There are, however, major economic incentives to stabilize the operation of the digester.This paper investigates and compares, via extensive simulation using MATLAB, the performancesof both classical and dynamic matrix controllers on Kamyr digesters, using the actual Purduemodel as well as a transfer function matrix that is generated from the Purdue model and reportedearlier. In classical control, the performances of both single-input-single-output (SISO) andmultiple-input-multiple-output (MIMO) controllers were tested. A dynamic matrix controllerthat is built from four controlled variables, five manipulated variables, and two measureddisturbances was designed and simulated using a discrete step-response model. Both constrainedand unconstrained cases were addressed. It has been shown that a SISO feedback controllerpairing the blowline Kappa number with the lower-heater outlet temperature, while treatingall other major inputs as disturbances, performs much better than a decentralized MIMOcontroller based on a 4 × 4 transfer function matrix. The dynamic matrix controller (constrainedand unconstrained) was remarkably superior over all conventional control structures.