Study Of Advanced Control On Polymerization Temperature Of Chlorinated Polyethylene

In recent years, with the vigorous development of petrochemical industry, all kinds of petrochemical products have been widely used in many areas. As one of impact modifiers for polyvinyl chloride (PVC), chlorinated polyethylene (CPE) has advantages of simple raw materials and lower production costs, and plays an important role in the plastic and rubber, so there is a rising trend in international and domestic demand. The production process of chlorinated polyethylene is mainly a chloride polymerization reaction in batch reactor. The reactor temperature, which is directly related to the quality of products, is an important parameter. Because the polymerization reaction is a strong exothermic reaction, so the temperature has characteristics of large delay, time-varying and non-linear. Conventional PID control is unable to meet the control requirements, so we propose the use of the advanced control algorithm to give the transformation an effective attempt.The thesis is based on the chlorinated polyethylene production process of a chemical plant in Qingdao. According to the in-depth analyses of temperature characteristics in chlorinated polyethylene chloride polymerization reaction and the control difficulties, an advanced control method of IMC-PID, based on neural network, is proposed to use. By self-learning adjustment, the neural network has a highly adaptive ability on non-linear and time-varying. Internal model control has characteristics of simple parameter adjustment and good tracking performance. The IMC-PID control method, which designs the PID controller in the internal model control framework, has the better control effect on time-delay and disturbance of the system. The combination of neural network and IMC-PID can give full play to the advantages of the two, and the temperature of chlorinated polyethylene polymerization reaction can be controlled accurately and stably. The experimental results show that,the neural network IMC-PID control can achieve good adaptability, robustness and anti-disturbance. The stability of control system can be improved effectively.In order to display and control the chlorinated polyethylene polymerization reaction production process vividly and directly, the monitoring software is designed based on Kingview in the thesis. Kingview has excellent functions of real-time monitoring and dynamic displaying. Matlab, with the strong mathematical calculation ability, can realize the complex advanced control algorithm. By using the dynamic data exchange (DDE) technology, the data communication of Kingview and Matlab can be realized. The software provides an effective way, for reference, to apply the advanced control method in industrial practice.