喷油参数对汽油类燃料压燃模式颗粒物及气态污染物影响的试验研究

发布时间：2018-01-31 20:44

本文关键词： 喷射压力 EGR率喷射时刻汽油压燃粒径分布　出处：《烟台大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着汽车行业的飞速发展,给人们带来方便的同时,也带来了严重的能源和环境危机。因此高效环保的发动机成为了现在发展的趋势,汽油压燃发动机便是其中的一种。汽油压燃能够将传统柴油机和汽油机的优点结合到一块,既能实现柴油机的高效,又能保留汽油机的清洁。目前汽油压燃主要有HCCI(均质充量压燃)、PPCI(部分预混压燃)、MPCI(多段预混压燃)三种模式,但三者各有其优点和不足,仍需进一步优化和研究。本课题针对燃油喷射参数对颗粒物及气态污染物排放的影响进行了试验研究,分析了燃油喷射时刻、喷射压力及EGR对颗粒物及其气态污染物排放的影响规律。实验在一台四缸柴油机上进行,采用了80%汽油与20%柴油的混合燃料,记为G80。实验结果表明,在其它喷油参数不变的情况下,提高喷射压力,各模态微粒数量浓度峰值向小粒径方向偏移,数量均呈下降趋势,NO_x排放有大幅度提升,而HC、CO呈下降趋势;当EGR率从10%增加到30%时,各模态微粒数量浓度峰值均向大粒径方向偏移,数量均呈上升趋势,尤其EGR率从25%增加到30%时,微粒数量大幅度增加,而EGR率的增大同样抑制了NO_x的生成,HC变化不大,CO增长较大;提前第一次喷射时刻,实验结果表明对微粒排放影响不大,NO_x排放降低,HC和CO均减少;提前第二次喷射时刻,各模态微粒数量浓度峰值均向小粒径方向偏移,且微粒数均呈下降趋势,而NO_x呈现明显的上升趋势,HC降低,CO升高。
[Abstract]:With the rapid development of automobile industry, it brings convenience to people, but also brings serious energy and environmental crisis. Therefore, efficient and environmentally friendly engine has become the trend of development. Gasoline Compression Ignition engine is one of them. Gasoline Compression Ignition can combine the advantages of traditional diesel engine and gasoline engine to realize the high efficiency of diesel engine. At present, HCCI (homogeneous charge Compression Compression Ignition) PPCI (partial premixed Compression Ignition) MPCI (multistage premixed Compression Ignition) mode is available. However, each of them has its own advantages and disadvantages, which still need to be further optimized and studied. In this paper, the influence of fuel injection parameters on the emission of particulate matter and gaseous pollutants is studied experimentally, and the fuel injection time is analyzed. The effect of injection pressure and EGR on the emission of particulate matter and gaseous pollutants. The experiment was carried out on a four-cylinder diesel engine with a mixture of 80% gasoline and 20% diesel. The experimental results show that when the injection pressure is increased, the peak concentration of particles in each mode deviates to the direction of small particle size, and the number of particles decreases with the other injection parameters unchanged. The emission of NO_x increased significantly, but the emission of NO_x decreased. When the EGR ratio increased from 10% to 30, the peak value of the particle concentration in each mode shifted to the direction of large particle size, and the number of particles increased, especially when the EGR rate increased from 25% to 30. The number of particles increased greatly, but the increase of EGR rate also inhibited the formation of NO_x. In advance of the first injection time, the experimental results show that there is little effect on particulate emission. In advance of the second injection time, the peak concentration of particles in each mode shifted to the direction of small particle size, and the number of particles decreased, while the NO_x showed an obvious upward trend that HC decreased the increase of CO.
【学位授予单位】：烟台大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X734.2;U467.2

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