Design And Implementation Of PVA Process Control System Based On PCS7

PVA is a fairly wide used water-soluble polymers; its consumption is very large in the world. China is the leader of PVA producing countries in the world. But, because the PVA productive technology has a long process, the production complex, large investment, technology and management are not easy to grasp, and there are still uncertainties, time-varying, nonlinear, and security factors in the production process, so it has high requirements of the control. As a new generation of advanced process control system, Siemens SIMATIC PCS7 is simple, easy to maintain with stable operation, nice scalability and security features, and the system can be seamlessly embedded into the Siemens Totally Integrated system, providing an excellent solution for users.The paper is in a setting of a company of Ningxia 100 thousand tons/year PVA production DCS project, with PVA production line for research and design object, on the basis of detailed analysis of PVA production process and its control requirements, and a PVA production line DCS control system is designed based on Siemens SIMATIC PCS7, realizing the control and management of the entire system with the application of Siemens SIMATIC PCS7 software. The whole control system adopts client/server distributed architecture, dividing into process control layer, system network layer and terminal network layer. Siemens 100M Ethernet is used for constituting the fiber redundant ring network in DCS system network and Profibus DP fieldbus technology is brought to realize communication among remote I/O local control equipments. The paper expounds the system architecture, hardware design, software design configuration process and its operation results. Meanwhile, based on PCS7 software platform, ELEC electrical control module is designed and developed for satisfying the requirements of monitoring and control, including Function Block (FB), Block Icon and Faceplate, according to the technological and customer's requirements for electrical control points.At present the whole control system has been put into operation. The results of its operation show that the PVA production efficiency has been greatly improved and better economic benefits have been achieved, which has obtained the desired goal of design. Meanwhile, the paper work shows that it has practical application value to apply PCS7 to PVA process control.