Abstract The combination of distinctive physicochemical properties of biofuels and recent engine technologies offer benefits in terms of efficiency improvement and emissions reduction. The recent development in butanol bio-based production pathways encourage researchers to study their combustion characteristics. This paper experimentally evaluates the combustion and emissions of a gasoline direct injection (GDI) engine fueled with the butanol isomer/gasoline surrogate blends, in which primary reference fuel (PRF) and toluene primary reference fuel (TPRF) are selected as the gasoline surrogates, respectively. The flame propagation behaviors, in-cylinder pressure, apparent heat release rate, along with PN emissions from this optical GDI engine are discussed. First, butanol addition to the gasoline surrogates is found to slow down flame propagation, reduce peak cylinder pressure and heat release rate, and extend ignition delay and combustion duration. Further, among the four butanol isomers, n-butanol and tert-butanol are the most and least reactive fuels, respectively, whereas iso-butanol and sec-butanol show reactivities in between, as supported by the measured flame propagation and pressure traces, calculated heat release rates, as well as time scales describing the combustion progress, e.g. ignition delay and combustion duration. Finally, butanol addition reduces the PN emissions from the GDI engine, and the PN emissions reduction capacity of the four butanol isomers ranks as sec-butanol > iso-butanol > n-butanol > tert-butanol. Also, compared to the PRF/butanol blends, the PN emissions are reduced to a less extent when butanol is blended with TPRF.

中文翻译：

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光学 GDI 发动机上异构丁醇/汽油替代品混合物的燃烧和排放

摘要 生物燃料独特的物理化学特性与最近的发动机技术相结合，在提高效率和减少排放方面提供了好处。丁醇生物基生产途径的最新发展鼓励研究人员研究其燃烧特性。本文通过实验评估了以丁醇异构体/汽油替代品混合物为燃料的汽油直喷 (GDI) 发动机的燃烧和排放，其中选择主要参考燃料 (PRF) 和甲苯主要参考燃料 (TPRF) 作为汽油替代品，分别。讨论了该光学 GDI 发动机的火焰传播行为、缸内压力、表观热释放率以及 PN 排放。首先，发现向汽油替代品中添加丁醇会减缓火焰传播，降低峰值气缸压力和放热率，延长点火延迟和燃烧持续时间。此外，在四种丁醇异构体中，正丁醇和叔丁醇分别是反应性最高和最低的燃料，而异丁醇和仲丁醇显示出介于两者之间的反应性，这得到了测量的火焰传播和压力轨迹的支持，计算得出热释放率，以及描述燃烧过程的时间尺度，例如点火延迟和燃烧持续时间。最后，加入丁醇降低了GDI发动机的PN排放，四种丁醇异构体的PN减排能力依次为仲丁醇>异丁醇>正丁醇>叔丁醇。此外，与 PRF/丁醇混合物相比，当丁醇与 TPRF 混合时，PN 排放量减少的程度较小。