The Design And Theoretical Analysis Of Advance Control For Distillation Column

Distillation column is a multi-input and multi-output process. It is complex in internal mechanism, slowly on dynamic response, correlative between variables, difficult to measure online and proposed highly on process control requirements. So, it is a very important issue on how to determine the control program for distillation column. For this reason, the design and theoretical analysis of advance control for distillation column is studied in this paper. Its main content is divided into the following three parts.1. In this paper, a novel decoupling control based on the dynamic input for multi-variable processes is designed to improve the quality of dual composition control, which according to the characteristics of strong coupling and long dead-time. Firstly, a dynamical decoupling is applied to eliminate the interactions of variables. Secondly, the generalized process (decoupling and process) is simplified to several independent single variable first order plus time delay processes. Lastly, the predictive PI controller is designed based on these single variable processes. The main advantage of this controller is that it combines dynamical decoupling with predictive PI algorithm reasonably.2. The dual control is designed for stripper of distillation column due to the single-loop control of temperature was not effectiveness. It is also means that the dual control of steam flow control and reflux control. The basic idea of dual control is made up by the steam flow control as the main loop to achieve rapidity and to ensure its good dynamic response, and the reflux control as the secondary loop to play a slow regulating effect and maintain its static performance. The control algorithm solved the contradiction between dynamic and static, and achieved the purpose of the operation optimization.3. To industrialize the theory of the novel decoupmailing control system, a real-time simulation is built through the OPC connection between Simulink and the Opto22PAC Project software suite. This simulation system will imitate the practical industrial process, and will use the novel decoupling control system based on the dynamic input. At last, the output of the system is used to prove the superiority of this control strategy.