Numerical Simulation Study of Co-injection of Pulverized Coal and Hydrogen in the Tuyere-Raceway

Hydrogen can replace partially pulverized coal in the blast furnace injection as the clean and high-calorific energy, which can reduce energy consumption and carbon emission in molten iron production. In this study, a discrete phase model is used to describe the complex flow and thermochemical behavior associated with the co-injection of hydrogen and pulverized coal in the raceway. The effect of hydrogen injection rate on the raceway is studied from the aspects of gas velocity, temperature, concentration distribution and coal burnout rate. It can be concluded that with the hydrogen injection rate increases, the gas velocity slightly increases and the gas temperature decreases significantly at the deeper location of the coke bed. With the hydrogen injection rate increase every 10 m³·t⁻¹, the theoretical combustion temperature decreases about 14 K and the amount of gas in the bosh increases about 46.91 m³. When the hydrogen injection rate increased to 50 m³·t⁻¹, the coke ratio is reduced by 8.66%, and the concentration of CO and hydrogen along the axis of tuyere increases by 0.5% and 7.79%, respectively. However, when the hydrogen injection rate exceeds 30 m³·t⁻¹, the pulverized coal burnout rate decreases.