煤粉预热对高炉喷吹中煤粉燃烧行为的影响

Impact of Pulverized Coal Preheating on Coal Combustion Behavior in Pulverized Coal Injection of Blast Furnace

通过建立数学模型,在Fluent软件的基础上结合自编程序,对不同预热温度下高炉喷吹煤粉的燃烧进行了模拟,得到了预热温度对煤粉燃烧的影响规律.模型中包含了煤粉与O2,CO2及水蒸汽的异相反应,且考虑了焦炭的燃烧反应.确定了回旋区的大小与形状,将煤粉燃烧空间划分为4个区域,对不同区域分别提出不同假设进行处理.计算结果表明,煤粉预热后进行喷吹可促进煤粉在风口前提前气化,使煤粉的燃烧区域前移,提高了煤粉在回旋区的燃尽率;预热温度每提高50℃,煤粉在回旋区的燃尽率平均提高2%.

By establishing the mathematical model and using own program based on Fluent software, the combustion of pulverized coal injected at different preheated temperatures was simulated, and the impact of different preheated temperatures on coal burning was examined. The model contained the heterogeneous reactions of coal with oxygen, carbon dioxide and steam, and the burning reaction of coke was also considered. The size and shape of raceway were determined, and the coal combustion space was divided into four zones which were treated with different assumptions respectively. The computational results show that when preheated pulverized coal is used in pulverized coal injection, the coal gasification is promoted in advance, the combustion region is moved forward, and the burnout rate of coal in the raceway is improved, When coal preheated temperature is increased 50 ℃, the coal burnout rate is raised 2% on average.