汽油机排放颗粒物微观特性及处理方法设计  

Microscopic Characteristics of Particulate Matter Emitted by Gasoline Engines and Design of Treatment Methods

作　　者：周浩 郑亮[1] 李盛芳 程铭 柳世鸣 王元红 杜文涛 ZHOU Hao;ZHENG Liang;LI Shengfang;CHENG Ming;LIU Shiming;WANG Yuanhong;DU Wentao(Xihua University,Chengdu 610039,China)

机构地区：[1]西华大学,四川成都610039

出　　处：《现代车用动力》2024年第3期30-36,共7页Modern Vehicle Power

摘　　要：使用透射电子显微镜(简称透镜)对道路试验得到的颗粒物样品进行拍摄获得排放颗粒物图像。发现缸内直喷汽油机在高海拔地区正常运行得到的排放颗粒物与在低海拔地区正常运行得到的颗粒物微观形貌特征大致相同。颗粒物大多数由基本碳粒子堆积而成,其中少数颗粒物夹杂着微量硫、氮等元素。颗粒物具有一些典型的微观形状,如云状颗粒物、海拔等高线颗粒物以及枝状颗粒物等。设计了分形维数、灰度值、灰度直方图3类处理排放颗粒物图像方法,并运用了Matlab和Python语言编程实现了对颗粒物图像的处理。处理得到分形维数在1.81~1.88之间,与低海拔试验得到的分形维数(1.58~1.80)相差较大;灰度值在93~196之间,其中5 nm图像灰度值范围在93~124之间、50 nm图像灰度值范围在100~146之间、100 nm图像灰度值范围在99~161之间、200 nm图像灰度值范围在136~158之间以及500 nm图像灰度值范围在180~196之间。经过对比分析发现,50 nm图像的灰度直方图出现的灰度值频率呈正态分布,其余倍数的图像灰度值频率分布混乱。Based on the particulate matter samples obtained from road experiments using electronic lenses,an image of the emitted particulate matter was obtained.Most of the particles are made up of basic carbon particles,a few of which are laced with sulfur,nitro⁃gen,and micronutrient.The particles have some typical microcosmic shapes,such as cloud-like particles,high-altitude-like linear particles and dendritic particles.Finally,the image processing methods of the collected particulate matter under the electron lens are studied and summarized.The methods of fractal dimension,gray scale and gray histogram are obtained by using the image processing function of Matlab and Python,and the particle image is processed by programming.The fractal dimension from 1.81 to 1.88 is quite different from that from 1.58 to 1.80.Processing results in grayscale between 93 and 196,the range of 5 nm image is 93~124,the range of 50 nm image is 100~146,the range of 100 nm image is 99~161,the range of 200 nm image is 136~158,and the range of 500 nm image is 180~196.After contrast analysis of 50 nm image gray histogram gray frequency distribution into normal distribution of other multiples of the image gray frequency distribution confusion.

关 键 词：汽油机 颗粒物 分形维数 灰度直方图 图像处理 

分 类 号：U464.171[机械工程—车辆工程]