Dynamic Secondary Cooling Soft Reduction Model For Continuous Casting Based On Continuous Temperature Measurement In Tundish And Its Application

With the development of automatic control technology of continuous caster athome and abroad,it has experienced the initial traditional basic control,and later the modern process control.High-efficiency intelligent continuous caster characterized by model control emerged in recent years and is becoming the future development direction of continuous casting automation control.With the continuous increase of the competitive pressure in the steel market,customers have put forward more severe requirements on the Inspection rate in slabs.The mathematical model for the quality control of slabs has been excavated in depth and has achieved good results in production practice.The process of molten steel from liquid to solidification is the key node for the internal quality control of the slab.Researchers at home and abroad aim at this process from temperature control,water distribution control,roller reduction,depressing interval and liquid core length calculations as the entry points.Mathematical algorithms are used for modeling studies to form typical quality control models such as solidification heat transfer model,dynamic secondary cooling water distribution model,and dynamic soft reduction model.It plays an important theoretical guiding role in actual production and has far-reaching significance for continuous casting automation control.This paper takes the 1#slab continuous casting machine of the Shandong Iron as the background and,positions the high alloy content products,focuses on the optimization of slab quality and the improvement of the qualified rate of flaw detection,and summarizes the development status of dynamic secondary cooling soft reduction technology at home and abroad.Through reading a large number of domestic and foreign journals and literature,the following three aspects of work are mainly completed:1.The solidification heat transfer model is established,the boundary conditions are analyzed,the conduction equation is derived,the theoretical scope of the model research and analysis is defined,and the accuracy of the model is verified by the pin shooting method.The influence of casting speed and temperature on the solidification end position of slab liquid core is analyzed,and the empirical formulas of liquid core length and casting speed are obtained.2.The dynamic soft reduction model and its control strategy are analyzed.The ASTC soft reduction system of No.1 Continuous Caster in Shandong Iron is built.The cause of segments out of tolerance alarm and its response strategy are studied and analyzed.The roll gap calibration calculation formula and driving roll positioning and tracking technology are developed.3.The dynamic secondary cooling water distribution model and its control strategyare analyzed,the secondary cooling water distribution system of No.1 Continuous Caster in Shandong Iron is designed,the control principle of the continuous tundish temperature detector based on the blackbody cavity theory is studied and analyzed,the parallel mode of continuous tundish temperature measurement are developed,and the accuracy of the continuous temperature measurement mode is verified.