The Application Of Advanced Control Technology In The Production Of Vinyl Chloride Monomer

Vinyl chloride is commonly used in chemical engineering.Reaction mechanism of vinyl chloride monomer production process is very complex,and the reaction process is nonlinear,uncertain and time-varying.The production process has the typical characteristics of a series of complex chemical reaction process.Production of vinyl chloride monomer technology level and the control technology in the process of production will affect the quality of the production of vinyl chloride monomer.In vinyl chloride production,therefore,research on production technology and advanced process control technology is now the focus of many chemical enterprises and self-control study.In the vinyl chloride production process,vinyl chloride rectification process influences the quality of vinyl chloride.A chemical enterprise used secondary distillation process in the process of vinyl chloride rectification,while low boiling tower and high boiling tower are in parallel operation.This is a typical vinyl chloride rectification production process.But the heat transfer and mass transfer in this process is very complex,with large delay,serious nonlinear problem,many control parameters and strong affinity,difficult online measurement.There are so many interference factors in the whole process with large fluctuations.It is hard to use conventional PID control system and the control effect is poor.The rectification of vinyl chloride monomer purity is low,and the quality is poorer.It may cause large energy consumption,emissions levels and severe consequences,such as environmental pollution.As a result,the chemical enterprises are seeking better control system to improve the quality of vinyl chloride monomer.In this paper,the present situation of the vinyl chloride production control is firstly studied,and also the vinyl chloride production control and existing problems.Based on current situation of enterprise production status and control and the vinyl chloride production process flow and control requirement of one chemical enterprise,I chose the vinyl chloride rectification device,with advanced control technology and advanced control system design to optimize the process control and improve the control quality to guarantee the quality of vinyl chloride monomer can satisfy the demands of subsequent polyvinyl chloride production.The purpose of this study is to provide control case for vinyl chloride chemical production enterprises,and help enterprises to improve the level of automation,save the cost of chemical enterprise,reduce labor intensity,improve the quality of production,and maximize production efficiency.In this paper,we studied the vinyl chloride distillation process,analyzed the dynamic mathematical model of the process,and reduced the order of the model.We also studied the two-variable-system and the decoupling of PID and fuzzy control algorithm.Comparing the two algorithms by Matlab simulation software,we discovered that fuzzy control algorithm is much better than PID.At the same time,we studied predictive control algorithm,a new advanced control algorithm.that mainly studies.By using the JX-300 x control system and multivariable predictive control software package APC-Hiecon discovered by Zhejiang university central research,we developed advanced software package designing controller,advanced control solutions are optimized process.Our research showed that fuzzy control system had nice control quality,which could successfully solve the main problems existing in the vinyl chloride production.The purity of vinyl chloride monomer could be increased,and the consumption of raw material and power be reduced.Finally the purpose of high quality,high yield,low consumption,the maximum economic benefit for the enterprise could be achieved.