The Research And Application Of The Advanced Process Control Based On Soft Sensor

From the engineering application aspect, aiming at the nonlinear, time-varying and strong coupling characteristic of butadiene distillation column, in this paper, the soft-sensor and the advanced process control (in short, APC) theory are studied. An advanced inferential control system based on soft-sensor are designed, which has solved the problem of the important process variables measured and controlled. The paper includes six chapters, which is classed to two parts. In the one part, soft sensor technology and engineering design are studied. In the other part, APC theory and application to the distillation operation are researched. The every part is discussed from the theory study to simulation analysis and engineering application. The main content of the paper is as follows:1. Summarize Soft sensor technology and the development of APC.2. Study the theory of soft sensor. Build the reliable soft sensor model of the industry object by many techniques, such as mechanism analysis, multivariate regress and neural network. At the same time, the soft-sensor engineering designed processes are given.3. The assistant variables of soft sensor model are selected with mechanism analysis and simulation; data acquisition system is designed correctly; the model sample sets are built.4. Build the soft sensor models by mechanism analysis, multivariate regress and neural network, and compare the smoothness and extrapolation of the models through simulation, and confirm four industrial models.5. Realize four industrial models on the DCS through CL programming; get the on-line estimation and real-time display of soft instruments.6. The correcting module is designed and simulated. After the model is corrected on-line, the models get the reliable estimation precision.7. The correlative theories of APC are studied, such as inferential control, decoupling control, expert control, saving energy control.8. An advanced control scheme including four subsystems is designed, aiming at the real control problems of butadiene distillation column. The two important subsystems are mainly discussed here, which included control object selecting, strategy analyzing, simulating and running. It realizes the component close-loop control, and gains the economic benefit.9. Logic control module and expert control module are added in the scheme. Which formed the hybrid control based on the inferential control. Thescheme strengthens the robustness of the control system, and improves the engineering application of the inferential control system.