Shock tube ignition delay times and methane time-histories measurements during excess CO2 diluted oxy-methane combustion
Shock tube ignition delay times and methane time-histories measurements during excess CO2 diluted oxy-methane combustion
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DOI：
10.1016/j.combustflame.2015.11.011
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发表时间：
2016-02
影响因子：
4.4
通讯作者：
B. Koroglu;Owen M. Pryor;Joseph G. Lopez;L. Nash;Subith S. Vasu
中科院分区：
文献类型：
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作者：
B. Koroglu;Owen M. Pryor;Joseph G. Lopez;L. Nash;Subith S. Vasu
甲烷在空气中的燃烧会产生大量的二氧化碳和氮氧化物排放。为了减少NOX的排放，一种可能的解决方案是甲烷氧燃烧，同时增加CO2的稀释度，使燃烧产物主要还原为CO2和H2O。然而，关于二氧化碳稀释环境下甲烷氧燃烧的化学动力学研究很少。在这项研究中，在反射激波后进行了甲烷时间历程、CH*排放分布和压力时间历程测量，以深入了解混合气体中CO2稀释对甲烷着火的影响。测量温度为1577-2144K，压力为0.53-4.4atm，当量比(Φ)为0.5、1和2，CO2摩尔分数(XCO_2)为0、30和60%。激光吸收测量采用中心波长为3403.4 nm的连续波分布反馈带间级联激光器(DFB ICL)。结果表明，随着CO2稀释量的增加，着火活化能减小，着火延迟时间延长。然而，这些变化很小，在测量的实验不确定度范围内。此外，还将结果与两种不同的天然气机制：GRI 3.0和AramcoMech 1.3机制的预测进行了比较。总体而言，与实验数据相比，预测是合理的；但在某些情况下，存在差异。考察了在氩浴气体中添加二氧化碳对化学成分、碰撞效率和热容的三种不同影响。此外，本研究还包括在有二氧化碳稀释和不有二氧化碳稀释的情况下，在温度1200<；T<；-2000℃和压力0.7-lt；P<；-1.2atm之间的情况下，实验获得的甲烷在v3波段的P(8)线的吸收截面关联式。
The combustion of methane in air results in large amounts of CO2and NOXemissions. In order to reduce the NOXemissions, one possible solution is the oxy-methane combustion with large CO2dilution so that the combustion products can be reduced mainly to CO2and H2O. However, there are very few studies on the chemical kinetics of oxy-methane combustion in a CO2diluted environment. In this study, methane time-histories, CH*emission profiles, and pressure time-histories measurements were conducted behind reflected shock waves to gain insight into the effects of CO2dilution of the gas mixtures on the ignition of methane. The measurements were carried out for mixtures of CH4, CO2and O2in argon bath gas at temperatures of 1577–2144 K, pressures of 0.53–4.4 atm, equivalence ratios (Φ) of 0.5, 1, and 2, and CO2mole fractions (XCO2) of 0, 30, and 60%. The laser absorption measurements were conducted using a continuous wave distributed feedback interband cascade laser (DFB ICL) centered at 3403.4 nm. The results showed the decrease of activation energy and the increase of ignition delay time as the amount of CO2dilution was increased. However, the changes were minor and within the experimental uncertainties of the measurements. Also, the results were compared to the predictions of two different natural gas mechanisms: GRI 3.0 and AramcoMech 1.3 mechanisms. In general the predictions were reasonable when compared to the experimental data; however, there were discrepancies at some conditions. Three different influences of CO2addition to the argon bath gas in regards to chemistry, collision efficiencies, and heat capacities were examined. In addition, the present study included experimentally obtained correlations for absorption cross sections of methane for its P(8) line in the v3band in argon bath gas with and without carbon-dioxide dilutions at temperatures between 1200 < T < 2000 K and pressures between 0.7 < P < 1.2 atm.