Laminar flame speeds of moist syngas mixtures
Laminar flame speeds of moist syngas mixtures
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DOI：
10.1016/j.combustflame.2010.09.004
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发表时间：
2011-02-01
影响因子：
4.4
通讯作者：
Sung, Chih-Jen
中科院分区：
文献类型：
--
作者：
Das, Apurba K.;Kumar, Kamal;Sung, Chih-Jen
这项工作使用逆流双火焰配置，通过实验研究了水蒸气的存在对潮湿合成气/空气混合物的层流火焰速度的影响。这里给出的实验结果针对贫燃料合成气混合物，其中氢气在氢气和一氧化碳混合物中的摩尔百分比从5%变化到100%，未燃烧混合物温度为323K并且在大气压下。在给定的当量比下，证明了改变水蒸气添加量对测量的层流火焰速度的影响。实验层流火焰速度也与文献中报道的化学动力学机制的计算值进行了比较。发现对于富含一氧化碳的混合物，层流火焰速度随着水的添加而非单调变化。它首先随着加水量的增加而增加，达到最大值，然后减少。进一步进行综合反应路径分析，以了解由于加水导致层流火焰速度非单调变化的控制机制。另一方面，对于较高的 H-2/CO 比率值，层流火焰速度随着水添加量的增加而单调降低。结果表明，加水的化学效应和热效应之间的竞争导致了观察到的响应。此外，还进行了反应速率敏感性分析以及二元扩散系数敏感性分析，以确定实验值和预测值之间差异的可能来源。灵敏度结果表明，H-2 + OH = H2O + H 的反应速率常数值得重新审视，并且可以考虑对 N-2-H2O、N-2-H-2 和 H-2-H2O 对的二元扩散系数数据进行细化。 (C) 2010 年燃烧研究所。由爱思唯尔公司出版。保留所有权利。
This work experimentally investigates the effect of the presence of water vapor on the laminar flame speeds of moist syngas/air mixtures using the counterflow twin-flame configuration. The experimental results presented here are for fuel lean syngas mixtures with molar percentage of hydrogen in the hydrogen and carbon monoxide mixture varying from 5% to 100%, for an unburned mixture temperature of 323 K. and under atmospheric pressure. At a given equivalence ratio, the effect of varying amount of water vapor addition on the measured laminar flame speed is demonstrated. The experimental laminar flame speeds are also compared with computed values using chemical kinetic mechanisms reported in the literature. It is found that laminar flame speed varies non-monotonically with addition of water for the carbon monoxide rich mixtures. It first increases with increasing amount of water addition, reaches a maximum value, and then decreases. An integrated reaction path analysis is further conducted to understand the controlling mechanism responsible for the non-monotonic variation in laminar flame speed due to water addition. On the other hand, for higher values of H-2/CO ratio the laminar flame speed monotonically decreases with increasing water addition. It is shown that the competition between the chemical and thermal effects of water addition leads to the observed response. Furthermore, reaction rate sensitivity analysis as well as binary diffusion coefficient sensitivity analysis are conducted to identify the possible sources of discrepancy between the experimental and predicted values. The sensitivity results indicate that the reaction rate constant of H-2 + OH = H2O + H is worth revisiting and refinement of binary diffusion coefficient data of N-2-H2O, N-2-H-2, and H-2-H2O pairs can be considered. (C) 2010 The Combustion Institute. Published by Elsevier Inc. All rights reserved.