Design And Research Of Temperature System For Silicon Steel Annealing Furnace

With the rapid development of China's industry,many manufacturing industries have a growing demand for high-quality plates.Annealing furnace is an important equipment in steel plate production.Because of its short production cycle and low cost,it is widely used in plate production.Continuous annealing furnace is the core equipment of annealing treatment for strip steel.It will heat the strip entering the furnace at a certain speed to the pre-set process production temperature,and then gradually reduce the strip temperature according to the production process requirements to achieve the final heat treatment of strip steel.Based on the continuous annealing furnace of silicon steel production line in Baotou steel sheet plant,this paper designs the control system of continuous horizontal annealing furnace,studies the temperature control strategy for its large lag and time-varying,analyzes the furnace temperature control loop,air and gas flow loop in the control system,and studies the double cross limiting control adopted in the system.Through the analysis of the actual production of the furnace temperature control,PID furnace temperature control is stable when the production line runs smoothly,but the temperature fluctuates greatly when the external conditions change.Compared with PID control and fuzzy PID control,it is found that the latter control method has good tracking performance for furnace temperature change,small overshoot,short regulating time and strong stability.The control system of annealing furnace adopts PCS7 control system,including three layers of network structure,namely computer monitoring layer,executive control layer and field control layer.The PCS7 control system adopts the excellent upper computer software WinCC as the human-machine interface for operation and monitoring,which can view the real-time and historical data curves;uses the open field bus and industrial Ethernet to realize the field information collection and system communication;uses Siemens S7-400 PLC to realize all the control functions,mainly carries out the design of software and hardware.In the aspect of hardware design,variable statistics is carried out.According to the results of variable statistics,equipment selection is carried out,including sensors,functional modules,etc.,and the electrical schematic diagram is drawn.In the aspect of software,we use step 7 software of Siemens company to realize the specific functions.At last,we use Simulink function of MATLAB to simulate and compare the traditional PID control and fuzzy PID control.According to the simulation curve,we can see that the effect of fuzzy PID control on furnace temperature is better.