Abstract Modern societies require cleaner and more efficient internal combustion engines. Low-temperature combustion (LTC) has been proved to be a good step toward this goal. This study aims at investigating the promoting effect of a cetane booster additive named 2-ethylhexyl nitrate (EHN) on the reactivity of a low-octane gasoline at LTC-relevant conditions. Rapid compression machine experiments were conducted at 10 bar, from 675 to 960 K for stoichiometric mixtures. The neat fuel was a mixture of toluene and n-heptane whose research octane number is 84. The doping levels of the additive were set at 0.1 and 1% molar basis. At the experimental conditions, it is found that EHN provides a promoting effect on the surrogate reactivity over all the whole temperature range. This effect increases with EHN doping levels. The negative temperature coefficient (NTC) behavior of the surrogate fuel is mitigated by the presence of the additive. The EHN reactivity promoting effect is lowest around 710 K and then increases with temperature. Under some conditions, heat releases are observed during the compression process. The chemical reactivity of the fuel gas mixture during the piston movement has to be considered to get reliable simulations. Kinetic modeling works show a good agreement with experiments. The model of this study reproduces properly the EHN promoting effect over the whole range of investigated temperatures and doping levels. Numerical analyses were conducted. EHN can totally decompose during the compression process resulting in heat releases. EHN is less effective at low Tc ( NO loop. The reactions between NO and n-heptyl peroxy radicals are found to be the main reason for the EHN effect in NTC region of the surrogate fuel oxidation.

中文翻译：

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十六烷值促进剂在快速压缩机中低辛烷值汽油燃料中促进作用的实验和数值研究：硝酸2-乙基己酯的研究

摘要 现代社会需要更清洁、更高效的内燃机。低温燃烧 (LTC) 已被证明是朝着这一目标迈出的重要一步。本研究旨在研究一种名为 2-乙基己基硝酸酯 (EHN) 的十六烷值促进添加剂在 LTC 相关条件下对低辛烷值汽油反应性的促进作用。快速压缩机实验在 10 bar 下进行，化学计量混合物的压力从 675 到 960 K。纯燃料是甲苯和正庚烷的混合物，其研究辛烷值为 84。添加剂的掺杂水平设置为 0.1% 和 1% 摩尔基础。在实验条件下，发现 EHN 在整个温度范围内对替代反应性提供促进作用。这种影响随着 EHN 掺杂水平的增加而增加。添加剂的存在减轻了替代燃料的负温度系数 (NTC) 行为。EHN 反应性促进作用在 710 K 附近最低，然后随温度升高。在某些条件下，会在压缩过程中观察到热量释放。必须考虑活塞运动期间燃料气体混合物的化学反应性，以获得可靠的模拟。动力学建模工作与实验显示出良好的一致性。本研究的模型在整个研究温度和掺杂水平范围内正确再现了 EHN 促进作用。进行了数值分析。EHN 在压缩过程中会完全分解，从而导致放热。EHN 在低 Tc 时效果较差（NO 回路。