NCN concentration and interfering absorption by CH2O, NH and OH in low pressure methane/air flames with and without N2O
NCN concentration and interfering absorption by CH2O, NH and OH in low pressure methane/air flames with and without N2O
复制标题
在有或没有 N2O 的低压甲烷/空气火焰中 NCN 浓度和 CH2O、NH 和 OH 的干扰吸收
DOI：
10.1016/j.combustflame.2011.04.009
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发表时间：
2011
影响因子：
4.4
通讯作者：
Ter Meulen
中科院分区：
文献类型：
--
作者：
Rjh Robert Klein;A. Konnov;N. Dam;Ter Meulen
在各种低压 (200hPa) CH4/空气火焰中，使用腔衰荡技术记录了 329nm 左右波长区域的吸收光谱，其中两种火焰添加了 N2O（一氧化二氮）。 NCN（氰基氮烯）吸收似乎仅在富含 N2O 的火焰中才显着，这也揭示了 NH 的光谱附近吸收。在φ=1.14、N2O氧化剂体积分数=57.0%的火焰中，NCN摩尔分数的上限为4.0×10−6。吸收光谱已被记录为高度的函数，这些也清楚地表明了 CH2O（甲醛）和 OH 的存在。在 CH4/空气火焰中，CH2O 在火焰锋面及其附近的吸收足够强，足以掩盖 NCN 引起的任何可能的吸收信号。还观察到 OH 吸收光谱与最大 NCN 吸收一致。 CH2O 吸收存在于整个 327-331 nm 范围内，如果测量体积中同时存在这两种物质，则会严重影响 NCN 浓度测量的准确性。这就需要采集连续光谱，而不是在几个特定波长下进行吸收测量。将 NCN、CH2O、NH 和 OH 特征波长处的吸收信号作为火焰高度的函数进行分析。讨论了这些信号可以明确分配给单个物种的概率。
Absorption spectra in the wavelength region around 329nm have been recorded with the cavity ring-down technique in various low pressure (200hPa) CH4/air flames, two of which with N2O (nitrous oxide) addition. NCN (cyanonitrene) absorption appears to be significant only in N2O-enriched flames, which also reveal spectrally nearby absorption by NH. In a φ=1.14, N2O oxidizer volume fraction=57.0% flame, an upper limit for the NCN mole fraction of 4.0×10−6has been found. Absorption spectra have been recorded as a function of height and these clearly show the presence of CH2O (formaldehyde) and OH as well. In CH4/air flames, absorption by CH2O at and near the flame front is strong enough to mask any possible absorption signal due to NCN. OH absorption spectrally coincident with the maximum NCN absorption has been observed as well. CH2O absorption is present throughout the whole 327–331nm range, which can severely affect the accuracy of NCN concentration measurements if both species are present in the measurement volume. This necessitates the acquisition of continuous spectra instead of absorption measurements at a few specific wavelengths. Absorption signals at wavelengths characteristic for NCN, CH2O, NH and OH are analysed as function of height in the flame. Probabilities that these signals may be assigned unambiguously to a single species are discussed.
NCN(3)作为高温NCN自由基源的热分解：NCN((3)Σ)的单重态-三重态弛豫和吸收截面
DOI：
10.1021/jp1043046
发表时间：
2010
期刊：
The journal of physical chemistry. A
影响因子：
--
作者：
J. Dammeier;G. Friedrichs
通讯作者：
G. Friedrichs