Numerical Simulation Of Physicochemical Processes In Tuyere And Raceway Of Blast Furnace

Tuyere cyclotron zone is the energy and heat source of blast furnace,and it is an indispensable reaction zone for stable operation of blast furnace.The formation and reaction of tuyere raceway will directly affect the distribution of gas in the lower part of blast furnace,the uniform decline of burden in the upper part of blast furnace,and the heat and mass transfer process in the whole blast furnace.It is very important to study and analyze the characteristics of tuyere and raceway of blast furnace,to create the best blast furnace smelting conditions,to realize the accurate control of the production process and to give full play to the advantages of large blast furnace production.Based on the actual production data of a steel plant,this paper established a tuyere cyclotron model with CFD simulation method,studied the characteristics of tuyere cyclotron under pulverized coal injection,and applied the model to hydrogen-rich injection conditions,analyzed the characteristics of two hydrogen-rich injection processes,and obtained the following results:(1)using CFD software,the gas-solid two-phase model is adopted to describe the movement of pulverized coal particles and fluids,and the combustion process of pulverized coal in the cyclotron region is described by using vortex dissipation model,dual-competition model,k-volatility turbulence model and dynamic/diffusion-limited rate model,and the CFD model of tuyere cyclotron region is established.(2)the characteristics of tuyere cyclotron zone of coal injection process under standard working conditions were studied by using the model.It was found that with the increase of blast volume,the location of combustion reaction moved backward,the content of CO2 increased,pulverized coal burnout rate decreased,and the average temperature of cyclotron zone decreased.If the blast temperature increases,the combustion reaction will advance,the CO and CO2 content will increase,the pulverized coal burnout rate will rise,and the average temperature in the raceway will rise.With the increase of oxygen enrichment rate,combustion reaction rate increases,CO2 and CO content increases,pulverized coal burnout rate increases,and the average temperature in the raceway increases.(3)using the model of coke oven gas injection and compound injection two pure hydrogen rich hydrogen injection mode tuyere raceway under standard conditions of characteristics are studied,and discusses the before and after thermal compensation,different amount of hydrogen rich gas blowing on the cyclotron district characteristics,the influence of found after thermal compensation,rich hydrogen compound injection conditions,cyclotron in reducing gas concentration increases,the blast oxygen enrichment rate increase,at the same time,the combustion characteristics of pulverized coal is improved.