Numerical Study Of Blast Furnace Burden Distribution Effect On The Heat And Mass Transfer Process Based On CFD-DEM Method

In the context of China’s “carbon peaking and carbon neutrality” goal in the iron and steel industry,seeking green,low-carbon and efficient smelting of ironmaking blast furnaces is one of the important breakthroughs.Conventional physical experiments on blast furnaces are characterized by high cost and limited access to detailed information on internal flow and thermochemical behavior due to experimental conditions and equipment constraints.Therefore,an increasing number of researchers are adopting numerical simulation techniques to obtain detailed information on the flow field,temperature field,and transfer of reactants inside the blast furnace,in order to further understand and comprehend the smelting process of the blast furnace and guide actual blast furnace operations.Study on the evolution of thermal-chemical behavior during the batch conversion process in a blast furnace.A particle-scale blast furnace process model was constructed with a verified CFDDEM coupling approach to analyse the effect of dynamic changes in the burden batch weight on the temperature field,pressure field,position and height of the cohesive zone,and distribution of iron ore reduction degree inside the blast furnace.The results show that changes in burden batch weight have a significant impact on the temperature of the furnace burden,the shape of the cohesive zone,and the distribution of iron ore reduction degree.For example,when the ore batch weight changes from 207 kg to 163 kg and the coke batch weight changes from 64 kg to 50 kg,the furnace burden temperature decreases by approximately 5.81%,the height of the cohesive zone decreases by approximately 7.18%,and the average reduction degree of iron ore inside the furnace decreases by approximately 3.08%.In addition,the time required for the blast furnace to transition from one stable state to another during the adjustment of the burden batch weight gradually shortens.Study on the influence of iron ore particle size variation on thermal-chemical behavior in blast furnace.The particle size of iron ore has an important effect on the structure of the burden,which in turn affects the upward flow of the gas inside the furnace,thus affecting the smooth and efficient operation of the blast furnace.Therefore,based on the particle-scale blast furnace process model,this article extends the study to investigate the effects of different iron ore particle sizes on the key indicators of the blast furnace and explore the corresponding relationship.The results showed that under the conditions of the blast furnace numerical model used in this study,as the particle size of iron ore decreased from 40 mm to 30 mm,the distribution of the upper burden tended to be uniform,the larger contact force area of particles in the lower part of the blast furnace gradually increased,the pressure inside the furnace increased,and the pressure drop increased from 9580 Pa to 12900 Pa,an increase of about 34.65%.The height of the cohesive zone decreased,and compared with the conditions of the 40 mm particle size of iron ore,the average height of the cohesive zone decreased by 12.50% when the particle size of iron ore was 35 mm,and by about 22.92% when the particle size of iron ore was 30 mm.Study on the movement law of materials in blast furnace based on 3D model.Based on the design parameters of an actual blast furnace in a steel company,this article developed a 3D sector blast furnace numerical model and explored the formation and evolution of the burden structure under the action of the charging system.The results showed that under the condition of 30 mm particle size of iron ore,the center thickness of the ore layer initially formed was about 0.9 m,and as the material moved downward,the center thickness.