Research on the impact of tuyere parameters on the states of hydrogen-rich blast furnace.

It is critical to reveal the change in tuyere parameters for the efficient consumption of coal particles and natural gas in the lower zone of the blast furnace. Combined with the actual size and injection conditions of the blast furnace for natural gas utilization, the three-dimensional simulation model involving the tuyere, two lances, raceway and blowpipe is built to explore the influence of the tuyere diameter, tuyere length and inclination angle of tuyere on the difference of flow, temperature, gas concentration and fuel reaction in the tuyere and raceway. The research outcomes show that the change of tuyere diameter has the most significant influence on the gas velocity in the three conditions. The high-temperature district in the computational domain increases gradually with the diameter of the tuyere. However, the result is contrary to the increase of the length and inclination angle of the tuyere. Besides, when the diameter, length and inclination angle increase, the burnout of pulverized coal has a trend of decreasing, increasing and increasing, respectively. To obtain a better fuel combustion effect, it is recommended that the diameter of the tuyere should not exceed 160 mm, the length of the tuyere should not exceed 530 mm, and the inclination angle of the tuyere should not exceed 7° under the current operating conditions. • A 3D model of actual size of blast furnace injection natural gas and coal is used. • Effect of tuyere conditions on the combustion of natural gas and coal is studied. • The size of the raceway is considered after the tuyere diameter changes. • Suggestions are provided for efficient combustion of coal and natural gas. [ABSTRACT FROM AUTHOR]