Designed And Advanced Control Strategy Implement Of DCS Base On PCS7 PVA Production Process

This paper is based on a PVA project with an annual output of 100,000 tons. According to the project's function requirement, distributed control, centralized display and other control methods must be applied, in order to reduce energy consumption and reduce labor intensity. For this reason, the paper proposes and implements a fully automated control system, which is based on Siemens PCS7. Mean while, the paper raises a control solution for typical production process in the PVA plant, in which different control strategies and algorithms are adopted to achieve different control requirements.First, the paper presents a comprehensive study on the principles and technics of calcium carbide PVA production; Secondly, it complete the design of the polyvinyl alcohol DCS control system, including hardware selection and integration, system redundancy, hardware configuration & software development, host computer WINCC monitoring HMI design; again, in concern with special feature of the distillation and combination process of PVA(nonlinear, time-varying, large time delay, strong coupling), we proposed a model-based advanced control method of predictive control and fuzzy adaptive PID control, to obtain far-beyond-PID effect. Finally, customer demand-focused electronic block icon and faceplate with analog display and alarm makes the operation more simple and convenient. All of the system network debug, loop test and interlocking check are successfully finished.Currently, this PCS7 system has been put into operation, the application of the system reduces the labor intensity, and improves product quality and production level of automation, finally achieves the target of energy saving and efficiency improvement.