Effects of different aromatics blended with diesel on combustion and emission characteristics with a common rail diesel engine
Effects of different aromatics blended with diesel on combustion and emission characteristics with a common rail diesel engine
复制标题
DOI：
10.1016/j.applthermaleng.2017.07.145
复制
发表时间：
2017-10
影响因子：
6.4
通讯作者：
Yong Qian;Y. Qiu;Yahui Zhang;Xingcai Lu
中科院分区：
文献类型：
--
作者：
Yong Qian;Y. Qiu;Yahui Zhang;Xingcai Lu
芳烃被认为是柴油代用燃料的重要组成部分。研究不同芳烃对柴油燃烧过程的影响具有重要意义。在一台改装后的单缸柴油机上进行了试验研究，分析了柴油中掺烧不同芳烃对燃烧和排放特性的影响。选择四种典型的芳烃（甲苯、正丁苯、四氢萘和1-甲基萘），分别以30%的体积分数与柴油混合，制成试验燃料。研究表明，与传统柴油相比，芳烃的掺混使柴油具有更高的密度和更低的粘度。甲苯在很大程度上降低了混合燃料的蒸馏温度。实验发现，着火延迟期和放热速率峰值均有所增加。燃烧持续期缩短，尤其是多环芳烃。在中、高负荷时，最大压力上升率也有明显提高。在污染物排放方面，芳烃/柴油混合燃料在低负荷时CO排放较高。多环芳烃的CO排放高于单环芳烃和商品柴油。多环芳烃的HC排放高于柴油，而单环芳烃的HC排放与柴油相近。在中高负荷时，掺混芳烃会导致NOx排放增加。由于点火延迟较长，烟度排放得到改善。芳烃掺混后，颗粒数/粒径分布曲线峰值向小粒径侧移动，其中单环芳烃的颗粒排放量高于多环芳烃。
Aromatic hydrocarbons are thought to be the important components of diesel surrogate fuel. The studies on the effects of different aromatic hydrocarbons on diesel combustion process are of great significance. In this paper, experimental study was carried out on a modified single cylinder diesel engine to analyze the influences of different aromatics blended with diesel on the combustion and emission characteristics. Four typical aromatics (toluene, n-butylbenzene, tetralin and 1-methylnaphthalene) were selected and blended with commercial diesel fuel in 30% volume fraction to form the test fuels, respectively. Studies showed that the blending of aromatics resulted in the higher density and lower viscosity compared with traditional diesel fuel. Toluene lowered the distillation temperature of the mixed fuel to a large extent. The increases in both the ignition delay and the peak values of heat release rate were found in the experiments. The combustion duration was shortened especially for the multi-ring aromatics. It also increased maximum pressure rise rate remarkably at medium and high loads. As for the pollutant emissions, the higher CO emissions were detected at low loads for aromatics/diesel blends. The CO emissions of the multi-ring aromatics were higher than those of the single-ring aromatics and commercial diesel. HC emissions of the multi-ring aromatics were higher than those of diesel, while the single-ring aromatics had similar HC emissions to those of diesel. Blending aromatics leaded to the higher NOx emissions at medium-high loads. Smoke emissions were improved due to the longer ignition delay. The peak value of particle number/size distribution curve was shifted to the small-size sides after blending aromatics, in which the single-ring aromatics showed higher particle emissions than multi-ring aromatics.