柴油理化特性对高压共轨柴油机微粒粒度分布的影响

Effects of Diesel Physical and Chemical Properties on Particle Size Distribution in Common-rail Diesel Engine

利用TSIEEPS3090微粒粒度测试系统，试验研究了高压共轨柴油机燃用不同理化特性调和柴油时的微粒成分及微粒排放粒度分布特征，揭示了燃料着火性能及燃料组分对微粒排放特性的影响规律。研究结果表明，对于不同着火性能的燃料，中小负荷工况下微粒数量浓度分布曲线大致呈单峰结构，峰值位于30nm附近，排气中绝大多数微粒粒径处于5～300nm之间。适当提高燃料十六烷值，能够缩短滞燃期，增大扩散燃烧期比例，有助于减少核态微粒的排放数量。同时，燃料含硫量对核态微粒排放影响较大，含硫量高将导致核态微粒排放量增加。随十六烷值增加．排气微粒中可溶件有机物质fSOF）比例减小．干碳娴fDS）比例上升。

Tests were conducted by using TSI EEPS3090 particle size spectrometer to study the effect of fuel with different physical and chemical properties on particle size distribution in common-rail diesel engine. For the fuels of different cetane number, the particle size was mostly between 5 nm and 300 nm and the particle size distributions were unimodal with peaks at 30 nm with medium or small load. Increasing cetane number appropriately could make the ignition delay period shorter and the sustained combustion period longer, which would drop the number of nuclei mode particles. Meanwhile, the number of nucleation mode particles increased with more sulphur in the fuel. With the cetane number increased, the percentage of SOF decreased and the percentage of DS increased.