Study of turbulent flame characteristics of water vapor diluted hydrogen-air micro-mixing combustion
Study of turbulent flame characteristics of water vapor diluted hydrogen-air micro-mixing combustion
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DOI：
10.1016/j.renene.2022.03.093
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发表时间：
2022-03
期刊：
影响因子：
8.7
通讯作者：
Yajin Lyu;Chang Xing;Li Liu;Jiangbo Peng;Wenkai Shen;Xinzhu Yu;Penghua Qiu
中科院分区：
文献类型：
--
作者：
Yajin Lyu;Chang Xing;Li Liu;Jiangbo Peng;Wenkai Shen;Xinzhu Yu;Penghua Qiu
氢气被认为是一种重要的替代燃料，特别是在燃气轮机应用中。但纯氢预混燃烧存在易回火、NOx排放高等问题。更合理的燃烧方法是采用微混合技术与水蒸气稀释相结合。实验研究了稀释率（D）和当量比（φ）对水蒸气稀释的氢气-空气微混合燃烧火焰特性的影响。结果表明，增加通过减少下游OH自由基信号来减少火焰面积，这与CO2稀释的效果相反。火焰局部曲率半径表明微混合燃烧属于高湍流强度燃烧，且凸结构较为频繁。此外，增大φ或减小D会导致瞬时平均曲率半径（Rave）减小，表明产生了更多的小尺度皱纹结构。D和φ对Rave和火焰面积在时域上的波动有类似的影响，而火焰面积的波动在稀薄燃烧极限附近更为明显。当D=25%时，火焰结构和化学反应的频率特性是同步的。
Hydrogen has been regarded as an important alternative fuel, especially in gas turbine applications. However, the premixed combustion of pure hydrogen has problems such as easily flashback and high NOxemissions. A more reasonable method of combustion is to use micro-mixing technology combined with water vapor dilution. This work experimentally investigated the influences of dilution rate (D) and equivalence ratio (φ) on the flame characteristics of hydrogen-air micro-mixing combustion diluted with water vapor. Results show that increasingDreduces the flame area by reducing the downstream OH radical signal, which is contrary to the effect of CO2dilution. The flame local curvature radius shows that the micro-mixing combustion is a high turbulence intensity combustion, and the convex structure is more frequent. Moreover, increasingφor decreasingDleads to a decrease in the instantaneous average curvature radius (Rave), indicating more small-scale wrinkle structures are generated.Dandφhave a similar influence on the fluctuations ofRaveand flame area in the time domain, while the fluctuation of the flame area is more evident near the lean-burn limit. WhenD= 25%, the frequency characteristics of the flame structure and chemical reactions are synchronized.