深度空气分级条件下配风方式对炉内燃烧特性影响的数值模拟研究

Numerical Simulation of Air Distribution Influence on Combustion Characteristics in Furnace Under Deep Air Staging Condition

借助数值模拟方法对四角切圆煤粉锅炉进行三维稳态数值模拟,观察其炉内燃烧过程,重点对比了在空气分级下不同配风方式对炉内空气流动和燃烧特性的影响。结果表明:底部配风量较多的正宝塔型、均等、缩腰型配风在炉膛底部形成较高切圆且温度较高,主燃区上部风量较小的正宝塔型和鼓腰型配风速度分布均匀,温度偏差较小,倒宝塔型和鼓腰型配风时出口NO x较其他3种配风方式要小。

A three-dimensional steady-state numerical simulation of a four-cornered round pulverized coal boiler with a numerical simulation method was performed to observe the combustion process in the furnace.The effects of different secondary air distribution methods on air flow and combustion characteristics in the furnace under air classification were compared.The results show that:the positive pagoda with a large air volume distribution at the bottom,the equal and reduced waist air distribution form a higher tangent circle at the bottom of the furnace and the temperature is higher,and the positive pagoda with a smaller air volume at the upper part of the main combustion zone has a uniform air velocity distribution.The temperature deviation is small,and the NO x at the outlet of the pagoda and drum waist is smaller than the other three.