Pilot-scale study on NO emissions from coarse coal combustion preheated by circulating fluidized bed

FUEL

卷:280

Article

Zhu, Shujun^1,2  Zhu, Jianguo^1,3  Lyu, Qinggang^1,3  Liu, Jingzhang¹  Ouyang, Ziqu¹ 

[1] Chinese Acad Sci, Inst Engn Thermophys, Beijing 100190, Peoples R China

[2] Chinese Acad Sci, Inst Mech, State Key Lab High Temp Gas Dynam, Beijing 100190, Peoples R China

[3] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

关键词: Pilot-scale;    Coarse coal combustion;    NO emissions;    Preheating;    Circulating fluidized bed;   

DOI  :  10.1016/j.fuel.2020.118563

来源: Elsevier

【 摘 要 】

Achieving stable low-NOx combustion of coarse pulverized coal could improve the energy efficiency of the combustion system. In this study, a pilot-scale experiment on coarse coal (0-1 mm) combustion preheated by circulating fluidized bed is conducted. The coarse coal could achieve a long-term stable preheating, and the assisted combustion by the high-calorific preheated coal gas (3.06 MJ/Nm(3)) and the higher physical sensible heat (754 degrees C) greatly improved the ignition performance and the combustion stability of the preheated fuel. Meanwhile, the release ratio of fuel-nitrogen during the preheating was 36.56%, while the concentrations of NOx in the preheated coal gas were all 0 ppm. During the stable combustion, the volume-based average temperature and the volume-based temperature fluctuation coefficient in the main combustion zone was approximately 1112 degrees C and 8.89%, and the combustion efficiency was approximately 95%. The NOx concentrations in the strong reductive zone were almost 0 ppm. As the reaction atmosphere along the combustion path gradually varied from reducing to oxidizing, fuel-nitrogen was mainly oxidized to NO, and the NO emissions was approximately 68 ppm (114 mg/m(3) @6%O-2). In addition, the effects of burnout air positions in strong reductive zone on NO emissions could be ignored.

【 授权许可】

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