Abstract A numerical study is performed by KIVA-CHEMKIN code to compare the combustion, performance and emission characteristics of neat biodiesel (B100) and biodiesel blend including a mixture of 20% biodiesel and 80% diesel (B20) resulting from the PCCI combustion mode in a light-duty diesel engine. For the biodiesel reaction mechanism, multi-chemistry surrogate mechanism using methyl decanoate (MD) and methyl-9-decenoate (MD9D) is used in this study. The results show that PCCI combustion like high temperature conventional combustion cannot cover the lower ISFC of the biodiesel blend fuel compared to the diesel fuel. A detailed analysis of combustion and emissions, involving the role of formaldehyde (CH2O) and hydroxyl (OH) radicals as well as O and H radicals, was performed in the PCCI combustion stages and emissions formation for the B100 and B20 fuels. The results indicate that higher concentration of formaldehyde as well as lower concentration of hydroxyl radicals for the B20 case advances low temperature heat release (LTHR) and retards high temperature heat release (HTHR) respectively compared to the B100 case. In addition, O and OH radicals as well as cylinder temperature are effective parameters regarding higher NO and CO concentrations for the B20 case compared to the B100 case.

中文翻译：

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KIVA-CHEMKIN联轴器对B20和B100燃料柴油机PCCI后期燃烧、性能和排放的比较

摘要 通过 KIVA-CHEMKIN 代码进行了一项数值研究，以比较纯生物柴油 (B100) 和包含 20% 生物柴油和 80% 柴油 (B20) 混合物的生物柴油混合物的燃烧、性能和排放特性，这些混合物由 PCCI 燃烧模式产生。轻型柴油机。对于生物柴油反应机理，本研究使用了使用癸酸甲酯 (MD) 和 9-癸烯酸甲酯 (MD9D) 的多化学替代机制。结果表明，与柴油燃料相比，PCCI 燃烧与高温常规燃烧一样无法覆盖生物柴油混合燃料的较低 ISFC。燃烧和排放的详细分析，涉及甲醛 (CH2O) 和羟基 (OH) 自由基以及 O 和 H 自由基的作用，在 PCCI 燃烧阶段和 B100 和 B20 燃料的排放形成中进行了测试。结果表明，与 B100 情况相比，B20 情况下较高浓度的甲醛和较低浓度的羟基自由基分别促进低温放热 (LTHR) 和延迟高温放热 (HTHR)。此外，与 B100 情况相比，B20 情况下 O 和 OH 自由基以及气缸温度是有关更高 NO 和 CO 浓度的有效参数。