甲烷在不同空气温度下MILD燃烧的数值模拟  

Numerical Simulation of Methane MILD Combustion at Different Preheating Air Temperatures

作　　者：李国元 陈兵兵 邹春[2] LI Guoyuan;CHEN Bingbing;ZOU Chun(POWER CHINA Henan Electric Power Survey & Design Institute Co., Ltd, Zhengzhou 450007, China;Stated, Key Laboratory of Coal Combustion, Huazhong University of Science &Technology, Wuhan 430074, China)

机构地区：[1]中国电建河南省电力勘测设计院有限公司,河南郑州450007 [2]华中科技大学煤燃烧国家重点实验室,湖北武汉430074

出　　处：《工业炉》2019年第2期9-14,共6页Industrial Furnace

基　　金：国家自然科学基金资助项目(51176055)

摘　　要：采用Realizable k-ε湍流模型和EDC燃烧模型对甲烷进行了不同预热空气(303 K和673 K)下的MILD燃烧数值模拟。模拟结果显示:预热空气下炉内温度明显高于常温空气下,而氧气含量则低于常温工况;模拟的CO峰值随着预热空气温度的升高向炉膛中心发生了迁移;对NO的预测,预热空气下的模拟值高于常温工况下,但是总体来讲,模拟炉内的NO含量很低。模拟炉内的近燃烧器区域出现了低温高氧区,表明以燃烧化学反应速率低为显著特征的MILD燃烧,在炉膛进出口处,存在强烈的烟气卷吸混合稀释,针对此区域的燃烧,湍流混合影响可能大于化学反应的影响。Realizable k-ε turbulence model and EDC combustion model are adopted in CH4 MILD combustion simulation at different preheating temperature(303 K and 673 K). The results show that, the temperature in furnace in preheating condition is obviously higher than that in normal condition and the contrary condition appears in the concentration of oxygen. The peak value of CO shifted toward to the center of furnace when compared to the normal condition. The simulation data of NO is much higher in preheating condition than in the normal temperature. The concentration of NO is low in the whole range. It appears low temperature enriched oxygen near burner region. It is indicated that the characteristic of MILD combustion is the low chemical reaction rate. It exists intensity flue gas entrainment in the inlet and exit of furnace. The effect of turbulence is much more than the one of chemical reaction in that area.

关 键 词：预热空气 MILD燃烧 EDC模型 化学反应机理 

分 类 号：TK16[动力工程及工程热物理—热能工程]