A Mathematical Model of Blast Furnace for Control of Hot Metal Temperature

Abstract

For the automatic control of hot metal temperature, a new simplified mathematical model of blast furnace has been developed on the following assumptions : (1) The working volume in the furnace is divided into five horizontal zones. Only the specified materials and reactions are considered in each zone. (2) By taking material balance, the flow rates of solid and gas at each zone are determined so that the amount of the material existed in each zone remains constant. (3) Heat balance is applied to solid and gas in each zone, respectively, taking account of their average temperature. (4) The reaction rates are formulated as the functions of operational variables on the basis of their step response characteristics. The temperature of solid and gas at each zone can be predicted by the adjustment of parameters in the model using actual operational data. Since the predicted solid temperature at the fifth zone (tuyere level) agrees well with the actual hot metal temperature, the validity of the model has been proved. At Kokura No. 2 BF, Sumitomo Metal Industries, Ltd., the model is being used for the automatic control and contributes to the stable blast furnace operation.

Numerical modelling of blast furnace – Evolution and recent trends

“…A few such models will be reviewed here. Hatano et al (1982) developed an approach for describing the dynamic state of the blast furnace under less extreme conditions than those in the blow-in or blow-out analysis described above. This one-dimensional model discretized the furnace volume into five zones, considering preheating, initial ore reduction, indirect reduction and solution loss, direct reduction, as well as combustion of coke and auxiliary reductants.…”

Practical Operation Guidance on Thermal Control of Blast Furnace

“…This section presents the 2D transient model and its validation using real plant data. Various blast furnace models have been proposed so far: for example, 1D steadystate model, 17) 1D transient model, [18][19][20][21] 2D steady-state model, [22][23][24][25] 2D transient model, 26,27) and 3D transient model. 28) The 1D transient models have been adopted in the model predictive control of HMT.…”

Online Prediction of Hot Metal Temperature Using Transient Model and Moving Horizon Estimation

“…Hence, the one-dimensional (1D) transient model was developed to predict the future HMT in the previous work. 1) Various blast furnace models have been developed: for example, 1D steady-state model, 2) 1D transient model, 3) 2D steady-state model, [4][5][6][7] and 3D transient model. 8) When these models are used for process control, estimation errors are caused by changes in the iron content of iron ore and the carbon content of pulverized coal.…”