为了探讨甲醇对柴油机排气颗粒的影响，通过加装进气道喷射甲醇系统，在一台四缸增压中冷柴油机上采集了柴油机在2 400 r/min转速，100%负荷工况下的颗粒，分析了进气道喷射甲醇对柴油机缸内可燃混合气的形成以及F-T柴油颗粒物微观结构影响。通过建立甲醇氛围柴油机燃烧过程模型，分析了甲醇氛围对碳烟前驱体生成的影响。结果表明，缸内甲醇氛围显著改善了碳烟颗粒的氧化程度与微观结构，当甲醇浓度达到30%时，与不掺烧甲醇相比，颗粒平均层面间距增大13.2%，微晶长度减小29.6%，曲率升高28.9%。随着甲醇浓度的增加，所有PAHs的峰值浓度显著降低，且峰值出现时间整体提前，甲醇的添加对高环PAHs的抑制效果更显著，且在M30下显著降低了碳烟浓度。
To investigate the influence of methanol on exhaust
particulates of diesel engines, a port
methanol injection system was installed on a four-cylinder
turbocharged intercooled common rail diesel engine. The particulate matter
emissions were measured at 2 400 r/min and 100% load, and the effects of
methanol introduction into the intake port on combustible mixture formation in
the cylinders and the microstructure of particulate matter from F-T diesel were analyzed. A computational model of the diesel
combustion process under a methanol atmosphere was developed to examine the
impact of in-cylinder methanol atmosphere on soot
precursor formation. The results show that the presence of methanol in the
cylinder significantly improves the oxidation degree and microstructure of soot
particles. At a methanol concentration of 30%, the average interlayer spacing
of the particles increases by 13.2%, the microcrystalline length shortens by
29.6%, and the curvature increases by 28.9%. With the increase of methanol
concentration, the peak concentrations of all PAHs decrease significantly, and
their peak occurrence times generally advance. Methanol exerts a more
pronounced inhibitory effect on high ring number PAHs and significantly reduces the soot concentration at M30.
