孤立碳颗粒聚团燃烧过程的研究

数值模拟气体流过孤立碳颗粒聚团的燃烧反应过程。计算表明穿过颗粒聚团的气体流量主要与颗粒聚团空隙率有关。当颗粒聚团空隙率小于0．8时,穿过颗粒聚团的气体流量可忽略不计。碳颗粒聚团内温度呈现迎来流面低、背流面高,两侧低中间高; CO和CO2含量呈现迎来流面低、背流面高,两侧低中间高的变化趋势;而O2含量迎来流面高、背流面低,两侧高中间低。颗粒聚团内不同位置的颗粒消耗的碳量不同。颗粒的相互团聚将降低碳的消耗量,同时也抑制碳颗粒燃烧过程NO和N2O的生成。

STUDY OF COMBUSTION PROPERTIES OF AN ISOLATED CHAR PARTICLE CLUSTER

The burning properties of an isolated char particle cluster were numerically studied in the stream. It is found that the gas flux passing through a cluster is mainly related with the porosity of cluster. The gas flux can be neglected as the porosity is less than 0.8 in present simulations. The results indicated that gas temperature is lower at the foreside than that at the backside of cluster, and in the radical direction it is higher at center than at sides of cluster. The CO and CO2 concentration distributions are increased along axial direction, while the O2 concentration distribution has a contrast tendency. Numerical results show that the carbon consumption of each particle is difference in the cluster more consumption at the foreside than the backside and less at the inside than the outside of cluster. Comparing to an isolated single particle in gas stream, the carbon consumption of each particle is varied along its periphery. Simulated results indicated that particle clustering will decrease carbon consumption. However, the products of NO and N2O will be restrained by particle clustering.