Abstract Liquefied Natural Gas (LNG) has become an increasingly important world energy resource and is a part of the European Union clean fuel strategy launched in 2013. Therefore, there are currently several ongoing measurement strategies considering quality specification of LNG. In this context, for application in gas engines, it is essential to understand the combustion behavior of these natural gas mixtures. The methane number (MN) which represents a scale for the knocking propensity, is one of the main indicators for this combustion behavior. In this study, we investigated the influence of the LNG composition on the ignition delay time and thus the knocking behavior of prototypical LNG Mixtures. Several LNG typical mixtures containing CH4/C2H6/C3H8/n-C4H10/i-C4H10/n-C5H12/i-C5H12/N2 were studied in the temperature range 850–1450 K, with pressures of 20 and 40 bar and at equivalence ratios of 0.4 and 1.2. The use of a shock tube and a rapid compression machine facility allowed us to study the ignition behavior over a wide range of operating conditions relevant to gas engines. We report a detailed investigation of LNG autoignition with respect to temperature, pressure and equivalence ratio thereby providing crucial validation data for chemical kinetic models for real applications.

中文翻译：

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激波管和快速压缩机中液化天然气 (LNG) 的自燃研究

摘要 液化天然气 (LNG) 已成为越来越重要的世界能源，是 2013 年启动的欧盟清洁燃料战略的一部分。因此，目前有几种正在考虑 LNG 质量规范的测量策略。在这种情况下，对于在燃气发动机中的应用，必须了解这些天然气混合物的燃烧行为。代表爆震倾向量表的甲烷值 (MN) 是这种燃烧行为的主要指标之一。在这项研究中，我们研究了 LNG 成分对点火延迟时间的影响，从而影响了原型 LNG 混合物的爆震行为。在 850–1450 K 的温度范围内研究了几种含有 CH4/C2H6/C3H8/n-C4H10/i-C4H10/n-C5H12/i-C5H12/N2 的 LNG 典型混合物，压力为 20 和 40 巴，当量比为 0.4 和 1.2。使用冲击管和快速压缩机设备使我们能够研究与燃气发动机相关的各种操作条件下的点火行为。我们报告了 LNG 自燃在温度、压力和当量比方面的详细研究，从而为实际应用的化学动力学模型提供了重要的验证数据。