Control System For Horizontal Continuous Furnace And Optimization Of Heating Zone Temperature

The dissertation focuses on the control system of one new built hot rolled stainless steel annealing line. The deep research is for the further engineering application of horizontal continuous furnace.1. The developments of the continuous annealing control system and engineering applications are reviewed. The keys and difficulties of control system for continuous furnace are pointed out. The research directions are proposed for the engineering application of the continuous stainless steel line.2. The requirements of stainless steel annealing process are summarized. The thesis gives introduction of outline of the horizontal continuous annealing line.3. The control system is designed based on the characteristics of continuous annealing line. The hardware and software used to the project is based on SIMATIC PCS7 for DCS control. The process control and communication are analyzed in detail.4. The corresponding functions are studied for furnace's temperature control, pressure control, safety lock control, cooling control and dry control. The control techniques of double-cross amplitude limited, oxygen correction, and pyrometer correction are used in temperature control loop.5. The combustion control system is designed for heating zone. The design of double-cross amplitude limited is compared with normal serial combustion control in operation principle. The simulation model of combustion control loop is built to avoid the filed tuning of PID. Comparisions are made among the PID control and self-tuning fuzzy control. A fuzzy PID controller is used to realize self adapting accommodation in the control systerm.6. Considering the variabilities with variable products in the operation process, the dynamic model and set value optimization is studied in strip temperature control. The temperature model is built on the basis of MRAN-RBF neutral network.With the help of GA arithmetic the model can give the optimized furnace temperature to guarantee small strip temperature tolerance.The DCS control system is designed for engineering conditions with the precondition of operation safety and stability. From these points of view, the heating zone combustion, temperature control math-model and set value optimization are the main issues in the thesis. The scheme for complex system on-line control and simulation model may have some values for relative engineering application.