Effects of center of heat release on combustion and emissions in a PCCI diesel engine fuelled by DMC-diesel blend
Effects of center of heat release on combustion and emissions in a PCCI diesel engine fuelled by DMC-diesel blend
复制标题
放热中心对 DMC-柴油混合燃料 PCCI 柴油机燃烧和排放的影响
DOI：
10.1016/j.applthermaleng.2016.12.064
复制
发表时间：
2017-03-05
影响因子：
6.4
通讯作者：
Baar, Roland
中科院分区：
文献类型：
--
作者：
Mei, Deqing;Yue, Shan;Baar, Roland
实验在改造后的单缸共轨柴油机上进行，该柴油机采用低温预混增压喷射（PCCI）模式，采用先导-先导-主喷射策略，并结合重EGR。本研究的目的是研究纯柴油和D10（含10%体积碳酸二甲酯（DMC）的柴油）在五种热释放中心（COHR）模式下的燃烧、性能和排放特性，因为很少有研究将这些参数放在一起考虑。结果表明，COHR对缸内压力、平均体气温度和放热主峰有显著影响。采用推迟喷油和重质EGR相结合的方法，可以提高预混燃烧的比例，同时对燃烧的稳定性没有明显影响。随着COHR的减慢，由于燃烧过程中温度的降低，HC和CO的排放量都略有增加，这不利于充分的后期氧化。与纯柴油相比，DMC的加入可使PM降低40%以上，而D10燃料产生的氮氧化物比柴油多。由于COHR的延迟，氮氧化物和PM排放之间的权衡可以很好地调整，这要归功于更高比例的预混燃烧。(C) 2016 Elsevier Ltd.版权所有。
The experiments were performed in a reformed single cylinder common-rail diesel engine which adopts a low temperature premixed charge compression injection (PCCI) mode by a pilot-pilot-main injection strategy coupled with heavy EGR. The objective of this study was to examine the combustion, performance and emission characteristics of neat diesel and D10 (diesel fuel with 10% dimethyl carbonate (DMC) by volume) in five center of heat release (COHR) modes, since there is rare research considered these parameters together. The results show that the COHR has significant influence on the in-cylinder pressure, average bulk gas temperature and the major peak of heat release. By means of postponing fuel injection coupled with heavy EGR, a larger fraction of premixed combustion is achieved, while the stability of the combustion is not evidently affected. Both HC and CO emissions increase slightly with retarding COHR due to the decreased temperature during combustion, which does not favor a sufficient late oxidation. The additions of DMC can reduce PM more than 40% compared to neat diesel, while D10 fuel generates more NOx than the diesel fuel. With retardation of COHR, a tradeoff between NOx and PM emissions can be well tuned, thanks to a higher fraction of premixed combustion. (C) 2016 Elsevier Ltd. All rights reserved.