燃煤碳烟生成的实验研究

Experimental Study of Soot Formation in Coal Combustion Process

本文利用Hencken型的平面燃烧器,以激光诱导白炽光(LII)和平面激光诱导荧光(PLIF)系统对燃煤碳烟的生成进行在线测量。对直径4～12 mm的煤柱颗粒开放式燃烧的OH和碳烟颗粒进行PLIF和LII的实验结果表明,燃煤形成碳烟和挥发分火焰几乎同时出现和消失,煤柱产生碳烟的持续时间约和煤柱颗粒的粒径的1.8次方呈正比。碳烟多在煤柱上方两翼产生,但是雷诺数大于100时会出现脱体造成分布的变化。燃煤产生的碳烟主要是在挥发分火焰的内部产生的,有时会出现集中喷射生成的现象。

A Hencken burner was built up to study the formation of soot particles during open fire of coal combustion. Laser diagnostic techniques, including laser induce incandescence （LII） and planar laser induced fluorescence （PLIF）, were used to investigate soot formation in the combustion of bulk coal cylinder. Experiment results indicate that the soot formation is strongly dependent on the devolatilization process. The existence lifetime of soot around coal cylinder is in proportion to the coal diameter. Soot is concentrated in the two wings most time, but when the Reynolds number is larger than 100, separation occurs and the distribution changes. Soot around the coal particle is in the diffusion flame of the volatile matter, and there is volatiles ejection sometimes.