Numerical Simulation of the Inner Characteristics in a Hydrogen-Rich Low-Carbon Reduction Smelting Furnace

A full-oxygen hydrogen-rich low-carbon reduction smelting ironmaking system and method have been proposed. This concept integrates the direct reduction shaft furnace with the carbon thermal smelting furnace, aiming to significantly reduce CO2 emissions and efficiently utilize low-grade mineral resources. In this work, the reduction section of the reduction smelting furnace was simulated by CFD, and the influence of hydrogen-rich gas injection velocity on the inner characteristics was investigated. The findings suggest that an increase in the injection velocity of the hydrogen-rich gas enhances the penetration depth of the peripheral flow and the thermal state in the furnace, thereby increasing the average metallic iron content and improving reduction uniformity along the furnace radial direction. However, the effect of increasing the injection velocity becomes limited when the velocity exceeds 17 m/s. The gas volume per ton of solid burden increases with the increase of the injection velocity of hydrogen-rich gas, leading to a decrease in the overall gas utilization ratio. After separate analysis of bottom CO gas and hydrogen-rich gas injected from the wall, it was found that the utilization of the bottom CO gas first increases and then decreases, peaking when the hydrogen-rich gas injection speed reaches 17 m/s.