Study on the effects of oxygen enrichment modes on the tuyere raceway states of blast furnace
In this paper,based on the actual dimension of the vanadium titanomagnetite blast furnace of a domestic enterprise,a three-dimensional physical model is established.The numerical simulation method is used to compare and study the flow and combustion behavior of pulverized coal in the tuyere gyration area under different oxygen enrichment methods.The results show that the overall trend of the tuyere velocity change with the oxygen enrichment rates is consistent with that of the constant air en-richment mode,but the difference in the change amplitude is significant.That is,when the oxygen en-richment rate is increased by 1%,the cross-sectional velocity of the tuyere is increased by 4.25 m/s(fixed air)and 0.41 m/s(reduced air),respectively.Under the two oxygen enrichment modes,the tem-perature,reducing gas content and burnout rate of the pulverized coal in the gyratory area have the same trend with the oxygen enrichment rates.As temperature increases,the high temperature area expands with the increase in the reducing gas content,and the burnout rate of pulverized coal increases.Among them,the amount of N2 brought into the blast furnace decreases due to the decrease in hot air flow rate,and the content of CO and H2 in the coal gas changes greatly,preventing the formation of carbon ni-trides and titanium carbides,and improving the reduction effect of iron ore in the blast furnace.It is cal-culated that the average temperature of the gyratory zone is increased by 34.22 K(fixed air)and 32.88 K(reduced air)for every 1%increase in the oxygen enrichment rate.Under the condition of reduced air and oxygen enrichment,the N2 content brought into the blast furnace is reduced by 10 m3/min and the CO concentration in the gas is increased by 8.61%.
NETL
NSTL
万方数据
