熔融气化炉填充床冶炼特征的数值模拟

Numerical simulation of smelting characteristics in moving-bed of melter gasifier

  • 摘要: 熔融气化炉填充床是将预还原炉料熔炼为液态铁水,并利用块煤裂解生成大量还原煤气供预还原竖炉使用的主要冶炼场所.文章建立了熔融气化炉填充床一维稳态数学模型,数值模拟分析了填充床内还原煤气与固体炉料的温度及组分分布特征.结果表明:由于海绵铁与块煤及熔剂的温差较大,固相间辐射热传递使得海绵铁温度呈先降低后升高的变化趋势,随着固体炉料的下降,海绵铁逐渐熔炼为液态铁水,至填充床底部,铁水温度可达1 774 K.另一方面,随着煤气流的上升,块煤热解使得H2体积浓度大幅提高,熔剂分解及海绵铁还原亦导致CO2体积浓度逐渐增大,至填充床上部,CO体积浓度稳定于71.8 %.

     

    Abstract: The melted gasifier packed bed is the main smelting place for smelting prereduced charge into liquid hot metal and using lump coal to generate large amount of reduced gas for prereduction shaft furnace. In this paper, a one-dimensional steady-state mathematical model of a melted gasifier packed bed was established. The temperature and composition distribution of the reduced gas and solid charge in the packed bed were numerically simulated. The results show that sponge iron gradually melts into liquid molten iron as the solid charge decreases when the temperature difference between sponge iron and lump coal and flux is relatively large, To the bottom of the packed bed, hot metal temperature is up to 1 774 K. On the other hand, with the increase of gas flow, the pyrolysis of lump coal increased the volume concentration of H2 significantly, and the volumetric concentration of CO2 gradually increased with flux decomposition and sponge iron reduction. At the upper part of the packed bed, the volume concentration of CO stabilized at 71.8 %.

     

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