Simulation Of Blast Furnace Temperature Control System Based On The Combination Of Material Flow And Energy Flow

China’s iron and steel industry is a "pillar" basic industry in China’s national economy and plays an important role in national industrialization and national defense modernization.The "Peak carbon dioxide emissions" and "carbon neutrality" require industrial upgrading and technological reform of traditional industries such as iron and steel.Blast furnace ironmaking is the most important way of ironmaking in the world.Its technical reform needs the premise of stable and smooth behavior of blast furnace,that is,the stability of blast furnace temperature.However,blast furnace smelting is a complex process with the characteristics of multivariable,nonlinear,strong coupling and large lag,which brings great difficulties to the modeling and control of blast furnace smelting process.In addition,molten iron temperature and silicon content are often used to represent the blast furnace temperature in the blast furnace smelting process,but the parameters can not be obtained in real time and the detection time is long.These parameters cannot be obtained in real time,it is impossible to accurately judge the furnace temperature and it is difficult to adjust the furnace condition in time and effectively.Therefore,it is necessary to study the modeling and control of blast furnace temperature so that the furnace temperature can be adjusted timely and effectively.Especially for the simulation of blast furnace temperature control system with the combination of material flow and energy flow.The interior of blast furnace is extremely complex,but it still needs to follow the material balance and energy balance.Based on this,this thesis analyzes the mechanism of blast furnace through the relationship between material flow and energy flow.By simplifying the variables of the blast furnace and making certain assumptions,the blast furnace model is simplified into a container with upper feeding,lower discharging and internal heating,and it is similar to the box water heater model.Therefore,the parameters of the box water heater are used to simulate the control of furnace temperature.The model is a dual input single output system.In order to achieve better control effect,the performance index function about temperature error is constructed.The gradient descent algorithm is used to solve the minimum value of the index function to achieve control.When the index function is the smallest,the temperature error is the smallest.The simulation results show that the gradient descent algorithm has high control accuracy.According to the analysis of material flow and energy flow,it is obtained that many batches of ore,coke,coal injection,air volume and other variables in the blast furnace will affect the current furnace temperature,not only the current input variables.Based on this,this paper establishes a data-driven model of blast furnace temperature with the accumulation of blast furnace variables as the input.Firstly,by knowing the lag time of blast furnace through expert experience and knowledge,the accumulation of variables in blast furnace can be determined.However,the lag time range provided by expert experience and knowledge is not accurate.In order to clarify the lag time of blast furnace,multiple times points are selected within the range for analysis and comparison.Secondly,the results of conventional correlation analysis are often inconsistent with the knowledge of blast furnace.In order to select variables more accurately,the cumulant of variables is used for correlation analysis.Finally,the furnace temperature model of blast furnace is established with the accumulations as input,and the furnace temperature is controlled by PSO algorithm.Through simulation experiments,it is verified that the furnace temperature model based on the combination of material flow and energy flow based on empirical knowledge and data has high accuracy,and PSO algorithm has a good control effect on the model,making the furnace temperature stable near the set value,reducing fluctuations,and contributing to the stable and smooth operation of the blast furnace.