微富氧条件下煤粉燃烧及NO生成特性的研究

利用热重分析技术对微富氧条件下煤粉的燃烧特性进行了研究，并与富氧条件下煤粉的燃烧特性进行了对比，利用固定床测定了燃煤NO的生成规律，分析了反应气氛和煤种的影响．结果表明：随着氧体积分数增加，微富氧条件下煤粉的燃烧向低温区移动，综合燃烧特性指数S逐渐增大；在相同的氧体积分数下，由于N2和CO2的物性差异，煤粉的微富氧燃烧特性优于富氧燃烧特性，但当氧体积分数升高到40％时，两种气氛的燃烧特性差别不大；反应气氛和煤种均对燃料氮的转化率影响显著；氧体积分数升高或N2的参与会使反应温度上升，影响燃料氮的转化率；煤的挥发分和元素氮的质量分数也会影响燃料氮的转化率．

Characteristic Study on Pulverized Coal Combustion and NO Formation Under Air Enrichment Conditions

Combustion characteristics of pulverized coal under air enrichment conditions were studied and compared with that under oxy-fuel conditions by thermo-gravimetric analysis, while the NO formation rate measured using fixed-bed reactor, so as to analyze the influence of reaction atmosphere and coal category on the NO formation. Results show that with the rise of oxygen concentration, the combustion characte- ristic curves of pulverized coal move to lower temperature regions, and the comprehensive combustion characteristic index S increases; at same low oxygen concentrations, the characteristics of air enrichment combustion are better than oxy-fuel combustion due to different physical properties of N2 and CO2, however, when the oxygen concentration gets up to 40%, the advantage of air enrichment combustion becomes not obvious; both the reaction atmosphere and coal category play a role in influencing the NO conversion rate; the reaction temperature increases with rising oxygen concentration or with participation of N2, and hence affecting the NO conversion rate; the volatile content and the mass fraction of element N also affect the NO conversion rate.