The Modeling And Application Research Of Typical Industrial Polymerization Process

Polymerization is a kind of complex production process, during the polymerization process there are always some process with high-pressure and rapid-radiative, which can be dangerous. As a result, there are numerous variables should be controlled as real-time control and optimized control.Polyethylene production is a typical kind of polymerization process, as other polymerization process, polyethylene production is also a process which can be influenced by numerous variables and which is large-lag and non-linear. Among these numerous variables, there are 3 parameters that can be the most important. As the dew point is related to the safety, the production rate is related to the profit, and the melt index and density is related to the resin quality, the enterprise always pay the most attention to the 3 parameters. Contents in this paper are as following:1. The paper summarizes the development of the modeling on polymerization and the application of the modeling. As to polyethylene production, the paper analyses the article flow, analyses the influence factors of the three important parameters. According to these influence factors and the author's experience, the paper gives the control methods to the three parameters.2. Introduces the calculation process of the dew point, and ratiocinates the production rate calculation method from the conservation of mass and the law of conservation of energy. As to the resin property model, based on the reactivity kinetics and the influence factors, deduces the basic model form, then uses the SQP arithmetic which is already in Matlab software to optimize the unknown parameters. After that, the paper improved the model, and uses the online-emendation to optimize the model in order to make it used better.3. Synthesizes the technical characteristics and request of the polyethylene production, use the model to the manufacture place with the InfoPlus.21 support. By searching the data stream of InfoPlus.21 database, the paper proves that the online-emendation of the polyethylene production resin property model is feasible.4. Tests the dew point model and production rate model with the data from the manufacture place, and the result indicates that the calculation result is believable. The result of the resin property model indicates that the model with online-emendation is useful but the model without is useless because the situation is changed. At last, the paper summarizes the solved problem and the harvest, points out the shortage of the model and some future research areas are highlighted.