氧气高炉回旋区内煤粉燃烧行为的三维数值模拟研究

Three dimensional numerical simulation of pulverized coal combustion behavior in the raceway of an oxygen blast furnace

  • 摘要: 炉顶煤气循环氧气高炉是一种全新的炼铁新工艺,它可以有效提高煤比、减少CO2的排放.但是其复杂的燃烧条件将使煤粉在回旋区内的燃烧及高炉下部的行为发生很大变化.为了了解氧气高炉炼铁新工艺条件下喷吹煤粉的复杂现象,建立了一个氧气高炉条件下的氧煤枪-直吹管-风口-回旋区-焦炭床的三维数学模型,研究了氧气高炉下部的温度场、浓度场及煤粉的流动和燃烧特性.模拟结果表明,氧气高炉条件下的回旋区温度显著升高、高温区面积扩大,CO2含量提高,焦炭床内CO含量显著增加.此外,与传统高炉相比,氧气高炉回旋区表面的煤粉燃尽率增加了10.24%.

     

    Abstract: The top gas recycling oxygen blast furnace is a new iron making process that can effectively increase the coal ratio and reduce carbon dioxide emissions. However, the complex combustion conditions will make the combustion of coal in the raceway and the behavior of the lower part of the blast furnace change greatly. In order to understand the complicated phenomenon of pulverized coal injection under the new oxygen blast furnace process, a three-dimensional CFD model has been developed to simulate oxygen coal lance-blowpipe-tuyere-raceway-coke bed of oxygen blast furnace. The temperature field, the concentration field and the flow and combustion characteristics of pulverized coal were investigated. The results indicate that the temperature is significantly increased, the high temperature area is enlarged, and the carbon dioxide content is increased of the raceway under the oxygen blast furnace. And the carbon monoxide content in the coke bed increased significantly. In addition, the coal burnout increased by 10.24% compared to that of the TBF.

     

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