摘要
氢是非常有潜力的清洁能源载体,富氢燃料燃烧是降低碳排放的可行方式。燃料掺氢会使火焰结构发生明显改变,进而会影响燃烧过程的排放特性与稳定性。然而,氢气掺混对旋流钝体火焰结构影响机理还不甚明确,高掺氢比下火焰结构特征的研究尚且不足。本文基于预混CH_(4)/H_(2)旋流钝体火焰,对宽广掺氢比范围内(0%~80%)的火焰多场信息进行了表征。实验中采用OH-PLIF和PIV测量技术获取不同掺氢比下火焰的结构信息与流场信息。结果表明,掺氢后旋流钝体火焰结构逐渐从V型转变为M型,当掺氢比达到80%时,外剪切层火焰根部可以驻定在钝体平面上,而外回流区向外剪切层根部能量与自由基的输运是火焰在外剪切层稳定燃烧的重要原因。
Hydrogen is a promising clean energy, and hydrogen-enriched fuel is a feasible approach to reduce carbon emissions. The hydrogen enrichment affects the flame structures, and further affects the pollutant emissions and the flame instability. However, the mechanism of the H_(2)-induced transition of confined swirl flames is not fully addressed, especially when a high H_(2) fraction is enriched. The present study was focused on the lean premixed CH_(4)/H_(2)/air flames with H_(2) fractions up to 80%. The flame structure was obtained with Planar Laser-Induced Fluorescence(PLIF) of the OH radical. Flow fields were measured with particle image velocimetry(PIV). It was observed that the flame tip in the outer shear layer(OSL) gradually propagated upstream and finally anchored to the injector with the hydrogen fractions increase, yielding the transition from the “V” to “M” flame.The enlarged outer recirculation zone was expected to be crucial for forming the “M” flame since the burned gases could reside within and helped ignite unburned gases around the root of the OSL flame.
作者
毛润泽
林文隽
安振华
张玮杰
张猛
王金华
黄佐华
MAO Run-Ze;LIN Wen-Jun;AN Zhen-Hua;ZHANG Wei-Jie;ZHANG Meng;WANG Jin-Hua;HUANG Zuo-Hua(State Key Laboratory of Multiphase Flow in Power Engineering,Xi'an Jiaotong University,Xi'an 710049,China)
出处
《工程热物理学报》
EI
CAS
CSCD
北大核心
2022年第3期824-829,共6页
Journal of Engineering Thermophysics
基金
国家自然科学基金项目(No.51888103)。
关键词
富氢燃烧
旋流钝体结构
预混稀燃
PLIF
PIV
受限空间火焰
lean premixed combustion
strongly confined flames
highly hydrogen-enriched flames
swirl flames
flame-flow dynamics
