Ignition characteristics of methane/ethane and methane/propane mixed fuels

doi:10.11949/j.issn.0438-1157.20170960

Abstract

Abstract:

The effects of the mixing of ethane and propane on the ignition delay time of methane were studied through the shock tube and CHEMKIN software.The cause of these effects was analyzed from the perspective of chemical kinetics. The results show that the addition of ethane and propane can shorten the delay time of methane ignition, but this influence becomes smaller along with the increase of temperature. The sensitivity analysis suggests that H + O₂=O + OH (R1) promotes ignition most both for the mixture fuels of methane/ethane and methane/propane, and the two elementary reactions of CH₄ + H=CH₃ + H₂ (R128) and CH₄ + OH=CH₃ + H₂O (R129) exert maximum inhibition for the ignition of methane/ethane and methane/propane blends. It is found that the increase of the ratio of ethane and propane in the mixed fuels of methane/ethane and methane/propane has little influence on the main reaction path of methane, but mainly affects the consumption rate of CH₃.

Key words: methane, blend, shock tube, ignition delay time, chemical kinetics

摘要：

利用激波管与CHEMKIN软件研究了不同初始条件下乙烷和丙烷的掺混对甲烷着火延迟时间的影响规律，并从化学动力学角度分析了掺混乙烷和丙烷对甲烷着火延迟时间造成影响的原因。实验与模拟研究表明乙烷和丙烷的掺混会造成甲烷着火延迟时间的大幅度缩短，但随着温度的升高，其对甲烷着火延迟时间的影响逐渐变小。通过敏感性分析发现无论是甲烷/乙烷混合燃料还是甲烷/丙烷混合燃料，对着火促进最大的基元反应都是H+O₂=O+OH（R1），在甲烷/乙烷和甲烷/丙烷混合燃料的着火反应中对着火抑制最大的两个基元反应是CH₄+H=CH₃+H₂（R128）和CH₄+OH=CH₃+H₂O（R129）。通过路径分析发现在甲烷/乙烷与甲烷/丙烷混合燃料中，随着混合燃料中乙烷与丙烷比例的增加，甲烷的主要反应路径基本不发生变化，主要影响了CH₃的消耗速率。

关键词: 甲烷, 混合, 激波管, 着火延迟时间, 化学动力学

CLC Number:

TK16

ZHANG Zunhua, XU Li, LIANG Junjie, LI Jingrui, LI Gesheng. Ignition characteristics of methane/ethane and methane/propane mixed fuels[J]. CIESC Journal, 2018, 69(5): 2199-2207.

张尊华, 徐力, 梁俊杰, 李敬瑞, 李格升. 甲烷/乙烷与甲烷/丙烷混合燃料着火特性[J]. 化工学报, 2018, 69(5): 2199-2207.

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