基于分形理论与碳分析的柴油机颗粒物特性

发布时间：2017-12-28 16:14

本文关键词：基于分形理论与碳分析的柴油机颗粒物特性　出处：《内燃机学报》2017年02期 　论文类型：期刊论文

【摘要】：颗粒物外在形貌与内在含碳属性的表征已成为大气颗粒物源解析的重要手段.应用分形理论及热光碳分析法,研究高、低负荷工况下不同粒径级柴油机颗粒物形貌的盒维数及其碳组分特性.结果表明:颗粒物粒径级越小,其吸附的可溶性有机物(SOF)越多,由分形理论计算得到的盒维数数值增大.低负荷工况下的颗粒物聚集现象严重,从而导致其分形盒维数比高负荷的高;在较小粒径级或低负荷工况时,因细颗粒物的吸附效应,最易挥发的OC1组分增多.低负荷工况下,元素碳(EC)中的EC1(char-EC)大量生成,其m(OC)/m(EC)值大于10;而高负荷工况下,EC几乎主要由EC2(soot-EC)组成,其m(OC)/m(EC)值小于1.此外,颗粒物形貌的盒维数与其有机碳与无机碳组分含量具有一定的关联,颗粒物的m(OC)/m(EC)比值越大,其对应形貌图的盒维数越大,反之亦然.
[Abstract]:The external morphology and internal particles of carbon containing property characterization has become an important means of sources apportionment of atmospheric particulates. Analysis of fractal theory and application of thermo carbon, research on high and low load conditions with different particle sizes of diesel particles morphology and box dimension of carbon component characteristics. The results showed that: particle size the smaller the grade, the adsorption of dissolved organic matter (SOF) more, increase the numerical calculated by box dimension of fractal theory. The particles at low load aggregation phenomenon is serious, resulting in the fractal dimension ratio and high load high; in a small size or low load conditions, due to the adsorption effect of fine particles the most easily volatile points in group OC1 increased. The low load condition, elemental carbon (EC) in EC1 (char-EC) generation, the M (OC) /m (EC) value is greater than 10; while the high load condition, EC almost is mainly composed of EC2 (soot-EC), the M (OC /m) (EC) value is less than 1. Besides, the box dimension of particle morphology is related to the content of organic carbon and inorganic carbon component. The larger the M (OC) /m (EC) ratio of particles is, the larger the box dimension of corresponding morphologies is, and vice versa.
【作者单位】：江苏大学汽车与交通工程学院;苏州大学能源学院;
【基金】：国家自然科学基金资助项目(51376095,51506101) 江苏高校优势学科建设工程资助项目(苏财教[2014]72号)
【分类号】：X513;X734.2
【正文快照】： 近年来,大气颗粒物是我国城市大气环境的首要污染物,尤其是空气动力学直径小于2.5,μm的颗粒物(PM2.5)会对大气环境质量造成严重污染,并对人类身体健康造成严重危害[1-2].机动车特别是柴油发动机燃烧排放的颗粒物是大气颗粒物的重要来源之一[3].然而,大气颗粒物的来源识别一直

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