Research On Extractive Distillation Control System Based On PCS7

The extractive distillation increases the relative volatility between the components areseparated, so it can be carried out smoothly when it is difficult to isolate theseparation(separation of close boiling substances and azeotrope),and thus it is widely used in theproduction of petrochemical products. The topic for the automatic control of teaching extractivedistillation plant production line designs a control system based on PCS7extractive distillation,the production line is mainly used for the production of ethanol and other chemical reagents ororganic solvents.Industrial automation and process control theory continues to mature and the rapiddevelopment of computer technology are rising demands on all aspects of industrial automationand process control systems. As the typical representative of the fourth generation of DCSSIMATIC PCS7process control system is the German company Siemens using most advancedcomputer hardware and software, network technology development of a process-orientedcomputer network control system, and PCS7is widely used in the industrial production process.The article describes the production process in distillation columns and extractivedistillation process control system based on PCS7.In order to improve ethanol quality andreduce energy consumption as the goal and Siemens S7-400in the system as the site controller,the process control system configurates the hardware and network under PCS7integratedenvironment, and uses PCS7programming language CFC to finish distillation column (overheadand bottom) temperature control, stirring motor start and stop control, level monitoring and acouple of pumps start and stop control, automatic teaching factory production line automaticcontrol and real-time monitoring the distillation process temperature, liquid level, pressure, flow,and other variables. The system uses a hierarchical structure, and various process parameterscollected by the S7-400controller are sent to the host computer (operation station andengineering station) to monitor the implementation of the factory production of the entireteaching process by monitoring interface based on WinCC, and displays process parameterscurve, and forms the process variable settings, a variety of production equipmentmanual/automatic switching,equipment operating status and fault alarm state history.The extractive distillation production process is more complicated, and it is difficult toestablish a precise mathematical model, and has many control parameters, strong coupling, sothe effect of traditional PID regulator control is difficult to achieve both improving productquality and reducing energy consumption. Based on artificial intelligence control theory thispaper puts forward a fuzzy decoupling control algorithm, and in the algorithm the distillation temperature control is divided into two steps, in the first, the fuzzy decoupling control todecouple the controlled object model, and then for single variable after decoupling to implementfuzzy control.This paper describes the structure of fuzzy decoupling controller, and the specificimplementation method of fuzzy control various aspects, also elaborates on the specificimplementation process of the fuzzy decoupling control algorithm on the PCS7,finally,introduces the simulation process of fuzzy decoupling control system in Matlab environment.The results show that the fuzzy decoupling control algorithm can significantly improve thedistillation temperature control effect. Finally, the article focuses on the problems encountered inthe course of the study and summarizes the insurviving defective in control algorithm,andfollow-up research is proposed...