有限空间内煤粉燃烧特性的研究

Study on combustion characteristics of pulverized coal in confined space

为了提高高炉煤粉燃尽率,增强高炉的喷煤效果,研究了直吹管-回旋区内气固两相湍流、传热和煤粉燃烧的数学模型,同时基于实际高炉工艺参数,通过数值模拟研究了鼓风温度、煤粉粒径分布、混合煤粉等对煤粉燃烧的影响,采用煤粉燃尽率衡量高炉内煤粉燃烧的程度。研究结果表明:减小煤粉粒径、提高鼓风温度、增大混合煤粉中挥发分比例均可使煤粉的燃尽率升高;在燃烧过程中,挥发分燃烧量达到100%,影响燃尽率大小因素主要是固定碳的燃烧量。

To improve the burnout rate of coal in blast furnace and enhance the effect of pulverized coal injection in blast furnace,the mathematical models of gas-solid two-phase turbulence flow,heat exchange and pulverized coal combustion in blowpipe and raceway were studied. At the same time,based on the technological parameters of practical blast furnace,the effects of blast temperature,the distribution of particle size of pulverized coal and mixed pulverized coal on the combustion of pulverized coal were studied by numerical simulation. The burnout rate of coal was used as the measure of the combustion extent of pulverized coal in blast furnace. The results showed that decreasing the particle size of pulverized coal and increasing the blast temperature and the ratio of the volatile in mixed coal could raise the burnout rate of coal. In the combustion process,the combustion amount of volatile reached 100 %. The factor which influenced the burnout rate was mainly the combustion amount of the fixed carbon.