无烟煤代替焦粉燃烧行为及对烧结NO_x排放的影响

Combustion behavior of anthracite substituting for coke and its effects on NO_x emission in sintering process

为了明确固体燃料燃烧行为对烧结过程NOx排放及其产质量的影响规律,采用微型燃烧装置考察了无烟煤代替不同比例焦粉时其燃烧速率、CO生成等燃烧行为对NOx排放浓度和总量、氮元素转化率的影响规律,并在此基础上进行工业性试验,研究不同替代比例下NOx排放和烧结产质量指标的变化规律。结果表明,随着无烟煤代替焦粉比例的升高,其燃烧速率逐渐减小,且其与NOx排放浓度整体呈线性正相关关系,同时其CO生成量则先增大后减小,且与NOx排放总量和氮元素转化率均呈线性负相关关系。此外,固体燃料的燃烧热值会对烧结产质量指标产生影响,而在兼顾NOx排放指标及烧结产质量指标下,低氮无烟煤代替焦粉的适宜比例为70%。

In order to clarify the effect of the combustion behavior of solid fuels on the NOx emission and sintering indexes during the iron ore sintering.When the low-nitrogen anthracite substituted coke breeze with different proportions,the influence of the combustion rate and the CO formation of solid fuels on the NOx concentration,the emission total and the conversion rate of N elements during the combustion process were investigated by the micro-combustion equipment.Then,industrial experiments were conducted to study the influences of different substitution ratios of low-nitrogen anthracite for coke breeze on the NOx emission and sintering indexes.The results indicated that the combustion rate of solid fuels decreased with the increase of the proportion of anthracite substituting of coke breeze,and it had a positive linear correlation with the NOx concentration.While the CO formation firstly increased and then decreased,which had a negative linear correlation with the emission total of NO and the conversion rate of N element,respectively.Moreover,the sinter indexes were affected by the low calorific value of solid fuels.Hence,considering the NOx emission and sintering indexes,the appropriate substituting proportion of low-nitrogen anthracite for coke breeze was 70%.