The flame structure and combustion dynamics in a steam diluted H2/Air micromix flame
The flame structure and combustion dynamics in a steam diluted H2/Air micromix flame
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DOI：
10.1016/j.fuel.2023.129903
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发表时间：
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期刊：
影响因子：
7.4
通讯作者：
Cheng Lu;Linyao Zhang;Xiaopeng Jiang;Chang Xing;Li Liu;Penghua Qiu
中科院分区：
文献类型：
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作者：
Cheng Lu;Linyao Zhang;Xiaopeng Jiang;Chang Xing;Li Liu;Penghua Qiu
OH* 化学发光用于实验研究喷嘴直径 (d)、蒸汽稀释比 (D) 和当量比 (φ) 对蒸汽稀释氢气/空气微混合燃烧器中火焰结构和燃烧动力学的影响。发现了两种火焰类型：锚定火焰和升起火焰。锚定火焰的 OH* 信号主要出现在火焰剪切层区（SLZ），而升起火焰的 OH* 信号主要出现在火焰中心再循环区（CRZ）和火焰尾区（FTZ）。氢气速度的增加（随着D的减少或增加）会将锚定火焰变为升起火焰。功率谱密度（PSD）分析表明，从锚定火焰变为升起火焰会导致较高的OH*波动频率，这与d的下降趋势相同。动态模态分解（DMD）分析表明，主模的分布与OH*信号的分布相似。 SLZ 是锚定火焰的主要振荡区域，CRZ 是提升火焰的主要振荡区域。锚定火焰比升起火焰更稳定，在实际燃烧器中应避免升起火焰。此外，燃料与氧化剂的高混合强度有利于微混合火焰的稳定性。
The OH* chemiluminescence is used to investigate experimentally the effects of nozzle diameter (d), steam dilution ratio (D) and equivalence ratio (φ) on flame structure and combustion dynamics in a steam diluted H2/air micromix burner. Two flame types, anchored and lifted, are found. The OH* signal for the anchored flame primarily presents in flame shear layer zone (SLZ), while that for the lifted flame mainly appears in the flame central recirculation zone (CRZ) and flame tail zone (FTZ). The increase of the velocity of hydrogen (as theDdecreasing or theφincreasing) would change anchored flame to lifted flame. The Power Spectral Density (PSD) analysis shows that changing from anchored to lifted flame would result a high OH* fluctuation frequency, which shows the same trend as the decrease ofd. The Dynamic Mode Decomposition (DMD) analysis shows that the distribution of dominant mode is similar to the distribution of OH* signal. The SLZ is the primary oscillation zone for anchored flame and the CRZ for lifted flame. The anchored flame is more stabler comparing to the lifted one, and the lifted flame should be avoided in practical burners. Besides, the high mixing intensity of fuel and oxidizer is beneficial to the stability of micromix flame.