Research on main technical parameters of blast furnace with natural gas injection

With the application and popularization of blowing natural gas in blast furnace, it is necessary to study the thermodynamic behavior of natural gas and the variation of operating parameters in blast furnace. By the second law of thermodynamics, the reduction behavior of blowing natural gas in blast furnaces was analyzed. Based on the material balance and heat balance model, the influence of oxygen enrichment, blast temperature and humidity on the blast furnace bosh gas volume and the theoretical combustion temperature in the front of tuyere raceway after natural gas injection were discussed. The quantitative analysis of dynamic coupling effect was realized by linear regression on the effect of key parameters. The results show that natural gas first absorbs heat at high temperature and cracks into CO and H2, which helps to improve the volume fraction and reduction potential of CO and H2 in the gas and promote the indirect reduction reaction. Natural gas injection into blast furnace leads to the rapid increase in the bosh gas volume and the rapid decrease in the theoretical combustion temperature. The change of humidity has a great influence on the bosh gas volume and the theoretical combustion temperature, followed by the oxygen enrichment. However, the blast temperature has a mild influence due to the limited potential to change relatively.