废气冷却对柴油机微粒组分的影响

采用自行设计的微粒取样装置，在某一柴油机排气管不同温度处进行了排气微粒的取样。对采集的微粒样品进行了不可溶性有机组分(IOF)和可溶性有机组分(SOF)的分离，利用色谱一质谱联用技术对SOF进行了色谱分析。试验结果表明，标定转速及最大转矩转速的中小负荷工况下，柴油机排气微粒中绝大部分为IOF；同一工况下，取样温度降低，SOF的质量分数增大，组分种类增多，且烷烃质量分数增加，芳香烃质量分数减少。

Effect of Diesel Exhaust Temperature on Particulate Fractions of Emission

A particulate sampling device was developed and the sampling experiments were carried out in different positions, corresponding to different exhaust temperatures, inside the exhaust pipe of a diesel engine. The insoluble organic fraction (IOF) and the soluble organic fraction (SOF) were separated for each particulate sample and the SOF was analyzed through the GC/MS technique. The experimental results showed that the IOF was the main fraction of particulate under the rated speed or the maximum torque speed with medium or small load. For a constant mode, with the decreasing of sampling temperature, the SOF mass content in the particulates increased; at the same time, the more the kinds of fractions and the more the alkanes content, the less the aromatic hydrocarbons content.