Research And Application Of Advanced Control Strategy For Regenerative Reheating Furance

China is the world’s largest steel producer and consumer,steel provides a strong material basis for the national economic development.As an important equipment in the steel production process,reheating furnace’s stable,efficient and economical operation can not only improve the economic efficiency of the steel industry,but also reduce the emission of industrial pollutants,which will have good economic value and environmental value.Reheating furnace is an object with the characteristics of great inertia,large delay and multi disturbance.It is difficult to obtain satisfactory control effect by using conventional control strategy.In order to improve the control quality of reheating furnace,a set of advanced control system is designed in this dissertation,which has been successfully applied in industrial field.The main research work of this dissertation is as follows:(1)According to the characteristics of furnace temperature and gas flow,a cascade control scheme of furnace temperature-gas flow has been designed,SGPC and PID are chosen to be the primary controller and secondary controller.A kind of exhaust gas temperature-furnace pressure selection control scheme has been designed,integral separation PID and PID are chosen to be the corresponding controllers.The bumpless switch and controller anti-saturation problem of each loop are solved.The advanced control system of reheating furnace is composed of control algorithm,data communication,graphical user interface and configuration file four parts,the concrete realization of each part is given.(2)The hardware platfom for advanced control system of reheating furnace is built on the basis of the original hardware equipment,and the connection between advanced control system and SIMATIC WinCC is tested,controller parameters of each loop are tuned.The advanced control system of reheating furnace is carried out in practical,which has reduced gas consumption and improved steel heating quality.Data analysis shows that the application of advanced control system has achieved good economic benefits.(3)Aiming at the coupling of reheating furnace’s furnace temperature,a decoupling controller is proposed.By using this proposed method,the coupling among each loop is eliminated and the robust stability is improved.In the process of the controller design,the poles of the closed-loop transfer function matrix are reconfigured,which has improved the system’s ability to track the input signal and to suppress the disturbance signal.