Design Of The Batch Reactor Propylene Polymerization Process Control System

Based on the CIMS three-tier structures of "Liaoning Key Lab of Advanced Control Systems for Industry Equipments" and the requirement of practical production using batch reactor as the containers of chemical reaction, we design process control system and study the advanced control algorithms of polypropylene production.According to the process flow of batch reactor and the control requirements of PP production process, this paper analyzes the temperature characteristics and control difficult in propylene polymerization process. Different control strategies have been proposed to solve the different stages of batch charging, rise of temperature and pressure, constant temperature and pressure, alarming system, where the process of casting material using the sequential control while the pressure using fuzzy control. Because establishing the model of reactor's temperature is difficult, and the system exists serious non-linear, time-delay, the reactor temperature control takes the variable universe fuzzy control strategy, uses the advantages of fuzzy controller and the characteristics of high accuracy to tracking input. At the same time, establishing the WinCC monitoring platform achieves the monitoring of control process and the function of data acquisition. After accomplishing the control algorithm by VBScript and parameters adjustment, actual operation proves that the system is reliable and stable. It could ensure reactor temperature track to set temperature changes.The establishment of the entire control strategy by combination of laboratory equipments enriches the process control layer of the CIMS structures and increases the variable universe fuzzy controller-expansion factor study. A new method is provided to select the contraction-expansion factor of universe fuzzy controller, and also given the principle of select new contraction-expansion factor parameters by simulation. Not only a useful way to solve the problem of variable universe fuzzy controller practical application is obtained, but also the foundation of control strategy for batch reactor actual production is established.