摘要
在一维携带流实验台上研究了烟煤煤粉着火模式,包括均相着火和非均相着火,对煤粉再燃还原NO的影响。实验结果表明,温度一定时,随着再燃区氧体积分数的增加,煤粉挥发分首先着火,脱硝效率明显下降;而非均相着火初期造成的颗粒高温有利于异相还原NO,脱硝效率得以回升;氧体积分数进一步提升,再燃区呈现富氧状态,脱硝效率再次下降。提高再燃区温度促进煤粉还原NO,脱硝效率更高,但是也促使挥发分在更低的氧体积分数下着火,着火后脱硝效率下降更多;粒径对煤粉着火以及还原NO的影响较为复杂,粒径在40μm以上,不同氧体积分数下脱硝效率基本上随粒径增大而下降。
NO reduction through coal reburning can be conducted in two ways： homogeneous reduction by volatile matters and heterogeneous reduction by char. Experiments were undertaken in a 1-D entrained flow reactor （EFR）. The effects of the ignition including volatile homogeneous ignition （GI） and carbon heterogeneous ignition （HI） on the reburning process were studied. The results indicate that with increasing the concentration of 02 , GI occurs and NO reduction efficiency decreases sharply. At the beginning of HI, the reduction efficiency increases in a narrow span of lower O2 concentration, and with the O2 concentration increasing the reduction efficiency will fall due to the overmuch oxygen. Higher reburning zone temperature can promote NO reduction reactions but also improve the ignition reaction under lower O2 condition. The effect of particle sizes on coal ignition and NO reduction process is more complicated. When the coal size is greater than 40 μm, the reduction efficiency will decrease with the particle size increasing.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2008年第5期551-556,共6页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(50476018)
国家重点基础研究发展规划(973计划
2006CB200303)
关键词
煤粉再燃
着火
脱硝效率
氧体积分数
粒径
再燃温度
coal reburning
ignition
reduction efficiency
O2 concentration
particle size
denitrification temperature
