Abstract Experimental researches on combustion characteristics of pulverized Ningdong bitumite preheated by a preheating burner were carried out in a 0.2 MW coal preheating combustion test rig, and the effects of preheating temperature, secondary air equivalence ratio and the positions of tertiary air nozzles on combustion, flame and NOX emissions of preheated fuels were studied. The results showed that the 0.2 MW coal preheating combustion test rig can operate stably and the combustion efficiency can be higher than 97% while the NOX emissions are lower than 100 mg/Nm3. With the increase of preheating temperature, NOX emissions increase, and the combustion efficiency does not change obviously. With the increase of secondary air equivalence ratio, the combustion efficiency increases, and NOX emissions increase as well. With the increase of the distance between the tertiary air nozzle and the preheated fuel nozzle, NOX emissions decrease, and the combustion efficiency decreases as well. The flame characteristic is not sensitive to preheating temperature, but closely related to the air distribution of down-fired combustor. With reasonable air supply positions, flameless combustion can be realized.

中文翻译：

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预热燃烧器预热煤粉燃烧、火焰及NOx排放的实验研究

摘要 在 0.2 MW 煤预热燃烧试验台上对预热燃烧器预热的宁东烟煤粉燃烧特性进行了试验研究，研究了预热温度、二次风当量比和三次风喷嘴位置对燃烧、火焰的影响。并研究了预热燃料的 NOX 排放。结果表明，0.2 MW煤预热燃烧试验台运行稳定，燃烧效率高于97%，NOX排放低于100 mg/Nm3。随着预热温度的升高，NOX排放量增加，燃烧效率变化不明显。随着二次空气当量比的增加，燃烧效率提高，NOX排放量也增加。随着三次风喷嘴与预热燃料喷嘴之间距离的增加，NOX排放量减少，燃烧效率也随之降低。火焰特性对预热温度不敏感，但与下燃燃烧室的气流分布密切相关。合理的送风位置，可实现无焰燃烧。