燃料燃烧特性及其对烧结烟气CO排放的影响

Fuel combustion property and their influence on CO emissions from sintering exhaust gas

本文采用热重分析试验开展焦粉和洗精末的燃烧特性分析,随后通过烧结杯试验探究不同燃料结构和粒度分布下燃料的燃烧行为对烧结烟气中CO排放的影响,从烧结CO生成机理分析出发,深入解析了固体燃料在热解和燃烧过程中固体碳的反应机制,阐述了烧结燃料结构与粒度分布变化导致料层内部温度及氧势变化对燃料燃烧产生CO的不同影响。结果表明,随着洗精末比例的逐渐提高,烟气中CO体积分数逐渐上升,尤其在洗精末配比超过50%后,CO体积分数由2.12%显著上升到2.60%,燃料粒级分布改善后烟气中的CO体积分数有较明显的下降,降幅约为39.5%。因此,适当的增加烧结燃料中洗精末的配比再配合燃料粒度的提高可以有效降低烧结烟气中CO的排放。

The combustion property of coke and washed powder are analyzed by a thermogravimetric analysis test,and then the influence of fuel combustion behavior on CO emissions in sintering exhaust gas under different fuel structures and particle size distributions is explored through a sintering cup test,and the formation mechanism of solid carbon in the pyrolysis and combustion process of solid fuels is deeply analyzed from the analysis of sintered CO generation mechanism,and the different effects on the change of internal temperature and oxygen potential of the material layer on the CO produced by fuel combustion caused by the change of sintering fuel structure and particle size distribution are described.The results show that,with the gradual increase of the proportion of washed powder,the CO volume fraction in the exhaust gas is increased gradually,especially after the proportion of washed powder exceeds 50%,the CO volume fraction is increased significantly from 2.12%to 2.60%,and the CO volume fraction in the exhaust gas is decreased significantly after the improvement of fuel particle size distribution,with a decrease of about 39.5%.Therefore,an appropriate increase in the proportion of washed powder in the sintering fuel and the increase of fuel particle size can effectively reduce the CO emission in the sintering exhaust gas.