O2/CO2气氛下煤粉燃烧NO的排放特性

以徐州烟煤和娄底无烟煤为研究对象，在水平管式炉上对比了O2/N2和O2/CO2两种气氛下NO的析出释放规律，获得了O2/CO2气氛下，温度、氧气体积分数、石灰石添加剂与煤种对NO排放量的影响规律。实验结果表明：高体积分数CO形成的还原性气氛是导致富氧燃烧条件下NO排放总量低于空气气氛的主要原因；700～900 ℃时，升高温度对两种气氛下NO的释放均有促进作用，O2/CO2中两种煤对温度的变化更为敏感；O2体积分数增加能够促进两种煤NO的释放；CaCO3的加入在两种气氛下都能对NO起减排作用，在O2/CO2气氛中的减排效果要优于O2/N2气氛；高含氮量煤种的NO排放总量更大，但转化率低。

Characteristics of NO emission during pulverized coal combustion under O2/CO2 atmosphere

In order to understand the characteristics of NO emission during pulverized coal combustion under O2/N2 and O2/CO2 atmosphere，a series of experiments were conducted at horizontal tube furnace using both Xuzhou bituminous and Loudi anthracite as samples respectively.The effects of temperature，O2 concentration，limestone additive and coal rank on the characteristics of NO emission under O2/CO2 atmosphere were obtained.The results show that comparing with combustion under O2/N2 atmosphere，the presence of carbon oxide with higher concentration is observed during the combustion under O2/CO2 atmosphere，which is deduced to be the main factor for the NO reduction.In the temperature ranges from 700 ℃ to 900 ℃，the NO emission increases with the temperature rises，and the NO emission is more sensitive to the temperature under O2/CO2.The NO emission is enhanced with the increase of O2 concentration.The addition of limestone results in the NO emission reduction in both atmospheres and is more effective in O2/CO2 atmosphere.The sample whose nitrogen content is higher emits more NO，while its conversion rate is low.