The ignition delay times (IDTs) of iso-octane with or without exhaust gas recirculation (EGR) in the 600–950 K temperature range and at pressures of 20 and 30 bar were measured under various equivalence ratios (Φ = 0.6–1.4) with the aid of a rapid compression machine. As for neat iso-octane IDTs measurements at 20 bar, it was found that the IDTs obtained in this work were consistent with the ones measured by other groups. Notable prolonging effects can be seen at the negative temperature coefficient region with EGR, which is independent of equivalence ratios. Moreover, the IDTs with EGR under fuel-rich and stoichiometric conditions showed a similar trend at both 20 and 30 bar. In the presence of NO in EGR, at a temperature of 632 K and temperatures above 732 K, the promoting effect of NO was observed, resulting in reductions of the IDTs. In parallel, the influence of NO was negligible in the 667–732 K temperature range. A comprehensive detailed kinetic model was employed to interpret the experimental data. The model performance was improved by adopting a high-level theoretical calculation of the 2HO₂ = H₂O₂ + O₂ reaction. Merging the N submechanism into the core model by considering the interactions between NO_x and C₀–C₂ species can generally capture the influence of NO on the IDTs. Reaction path analysis indicated that the NO + HO₂ = NO₂ + OH reaction dominated in the presence of NO and its reaction rate increased as a function of temperature, which can explain the different IDTs behaviors with NO addition.

中文翻译：

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快速压缩机中废气再循环和NO对异辛烷点火延迟时间的影响

在600-950 K的温度范围内以及20和30 bar的压力下，在不同的当量比（Φ= 0.6-1.4）下，测量有或没有排气再循环（EGR）的异辛烷的点火延迟时间（IDTs）。借助快速压缩机。至于在20 bar下纯净的异辛烷IDT的测量结果，发现在这项工作中获得的IDT与其他小组测量的IDT一致。在带有EGR的负温度系数区域可以看到显着的延长效应，这与当量比无关。此外，在富燃料和化学计量条件下，带EGR的IDT在20和30 bar压力下都显示出相似的趋势。在EGR中存在NO的情况下，在632 K的温度和732 K以上的温度下，观察到NO的促进作用，导致IDT降低。同时，在667–732 K温度范围内，NO的影响可忽略不计。使用全面详细的动力学模型来解释实验数据。通过对2HO进行高级理论计算，提高了模型性能₂ = H ₂ O ₂ + O ₂反应。通过考虑NO _x和C ₀ –C ₂物种之间的相互作用，将N次机制合并到核心模型中，通常可以捕获NO对IDT的影响。反应路径分析表明，在NO存在下，NO + HO ₂ = NO ₂ + OH反应占主导地位，其反应速率随温度的升高而增加，这可以解释添加NO的不同IDT行为。