乙醇/柴油燃烧颗粒状态特征试验研究

Particulate Status of Diesel Engine Fueled with Ethanol/Diesel Blends

摘要:

针对柴油机燃用乙醇/柴油的燃烧颗粒，采用热重分析、扫描/透射电镜和颗粒分级采样的方法，研究乙醇/柴油燃烧颗粒的状态特征，探讨颗粒组分、粒径分布和微观结构随乙醇掺混比例的变化规律。热重分析结果表明，碳烟约占乙醇/柴油燃烧颗粒总质量的75%；随着乙醇掺混比例的增加，颗粒组分中的可溶性有机物比例升高，硫酸盐比例下降。颗粒分级采样结果表明，掺混乙醇后，粒径在0.78～1.4μm范围内的颗粒减少，粒径为0.25μm的颗粒增加，颗粒粒径向小粒径方向移动。扫描/透射电镜结果表明，随着乙醇掺混比例的增加，颗粒的团聚程度提高；颗粒微观结构呈聚合、内核-外壳和无序结构。

关键词:乙醇;柴油;排放颗粒物;特性分析

Abstract:

The particulate status characteristics of diesel engine particulate were studied by using thermo gravimetric analysis, scanning/transmission electron microscopy (SEM/TEM) and staged sampling particulate system methods. The variation of the composition, size distribution and microstructure of particulate with different ethanol ratios were studied. Results showed that soot accounted for about 75% of the total particulate mass. With the increase of ethanol ratios, the proportion of soluble organic fraction (SOF) increased and sulfate decreased. With the increase of ethanol ratios, the particulate of size range 0.78～1.4μm decreased and the proportion of 0.25μm increased. The distribution of particulate moved to small size. The particulate size decreased and agglomeration improved with the increase in the proportion of ethanol ratios. The microstructure of the particulate was polymerization, core-shell and disordered.

Key words:Ethanol;Diesel;Particulate emission;Characteristic analysis