Ignition and extinction characteristics of n-alkane cool flames on a heated wall with different surface reactivity
Ignition and extinction characteristics of n-alkane cool flames on a heated wall with different surface reactivity
复制标题
正构烷烃冷焰在不同表面反应性受热壁上的着火和熄灭特性
DOI：
10.1016/j.fuel.2023.128587
复制
发表时间：
2023
期刊：
影响因子：
7.4
通讯作者：
Suzuki Yuji，Lee Minhyeok
中科院分区：
文献类型：
--
作者：
Tomotaka Mizuno;Suzuki Yuji，Lee Minhyeok
冷火焰在碳氢燃料的点火过程中起着至关重要的作用，因此了解其动力学对于开发具有高热效率的先进发动机至关重要。人们进行了大量的研究来阐明冷火焰的燃烧特性以及控制其动力学的低温化学。然而，尽管我们最近的相关工作已经表明壁化学对冷焰点火和熄灭的影响仍然没有完全阐明，但其对DME冷焰点火温度的显着影响在本研究中系统地研究了碳数为7至10的正构烷烃的点火和熄灭特性，特别关注燃料碳数、氧浓度和表面反应性的影响。新建了一个实验装置，可以在墙壁附近点燃和熄灭冷火焰。表面反应性是通过在壁表面沉积特定材料（即 SiO2、Fe 和 Ru）的薄膜来控制的。通过使用激光诱导荧光 (LIF) 测量 HCHO 分子，可以识别每面壁上每种燃料的冷焰点火和熄灭行为。此外，还进行了假设一维轴对称冲击流和详细气相反应的数值模拟，以进一步研究燃料碳数对冷焰点火和熄灭的影响。结果表明，冷焰点火和熄灭行为高度依赖于表面反应性，根据燃料的不同表现出完全不同的方面。
Cool flames play essential roles in the ignition process of hydrocarbon fuels, so that understanding their dynamics is highly crucial to develop advanced engines with high thermal efficiency. There have been extensive studies to elucidate the combustion characteristics of cool flame and the low-temperature chemistry governing its kinetics. However, wall chemical effects on the cool flame ignition and extinction are still not fully clarified, although our recent related works have shown their significant impact on the cool flame ignition temperatures of DME.In this study, ignition and extinction characteristics ofn-alkanes with carbon numbers from 7 to 10 are examined systematically, with particular attention paid to the effects of fuel carbon number, oxygen concentration, and surface reactivity. An experimental setup enabling the ignition and extinction of cool flames in the vicinity of a wall is newly built. The surface reactivity is controlled by depositing thin films of specific materials, namely SiO2, Fe, and Ru, on the wall surface. The cool flame ignition and extinction behaviors of each fuel on each wall are identified by measuring HCHO molecules with laser-induced fluorescence (LIF). In addition, numerical simulations assuming one-dimensional axisymmetric impinging flows with detailed gas-phase reactions are performed in order to further investigate the effect of fuel carbon number on the cool flame ignition and extinction. The results indicate that the cool flame ignition and extinction behaviors are highly dependent on the surface reactivity, showing completely different aspects according to the fuel.