Abstract:

NO_x emission characteristics during pulverized coal combustion in O₂/CO₂，O₂/N₂ and O₂/CO₂/NO atmospheres were studied by using a drop tube furnace.The results showed that in the O₂/N₂，atmosphere NO emission increased with the increase of O₂ concentration or temperature.The same tendency of NO_x emission was also found in the O₂/CO₂ atmosphere.However，the NO_x emission in the O₂/CO₂ atmosphere was 30%—40% lower than that in the O₂/N₂ atmosphere.In the O₂/CO₂/NO atmosphere，the effects of O₂ concentration on NO_x emission as well as on recycled-NO reduction were different at different temperatures.High temperature did not favor recycled-NO reduction.There were two peak values of NO_x emission with the increase of residence time.

Key words:

O₂/CO₂气氛, 煤粉燃烧, NO_x排放, 循环NO

摘要：

利用滴管炉研究了O₂/N₂、O₂/CO₂和O₂/CO₂/NO气氛下煤燃烧过程中NO_x的排放特性。实验结果表明，在O₂/N₂和O₂/CO₂气氛下，高温或高O₂浓度均使NO排放量增加。O₂/CO₂气氛下NO排放量比O₂/N₂气氛下NO排放量低大约30%～40%。在O₂/CO₂/NO气氛下，温度不同时，O₂浓度变化对NO排放量的影响规律不同，对循环NO降解的影响规律也不同。高温不利于循环NO降解。随停留时间的延长NO排放量出现两个峰值。

关键词:

O₂/CO₂气氛, 煤粉燃烧, NO_x排放, 循环NO