大气中碳黑气溶胶形态分析与光散射特性计算

发布时间：2018-05-14 01:15

本文选题：碳黑团聚物 + 电镜图像　；参考：《哈尔滨理工大学》2017年硕士论文

【摘要】：大气中悬浮的固态和液态颗粒物总称为大气气溶胶,碳黑气溶胶作为大气气溶胶的重要构成成分之一,主要来源于化石燃料、生物质燃料的不完全燃烧。碳黑气溶胶不仅损害人体呼吸系统、危害人体健康安全,而且也因其对太阳辐射的吸收与散射作用,加重了全球变暖现象。对碳黑气溶胶光散射特性进行计算分析,对于碳黑气溶胶浓度的监测、大气污染的治理以及环境安全的维护有着至关重要的作用。碳黑气溶胶的形态结构复杂,其光散射特性受到形态等多种因素的影响。本文建立碳黑气溶胶的光散射特性计算模型,对其光散射特性进行数值计算,具体研究内容如下:分析碳黑团聚物形态变化,对煤与生物质燃料燃烧生成烟气进行取样,通过扫描电镜图像(FEI quanta 200F)获取团聚物电镜图片,利用图像处理软件IMAGEJ分析图片,提取碳黑团聚物几何参数并推导团聚物形态参数(粒子数目、分形维数、前向因子);分析碳黑团聚物形态对其光散射特性的影响,基于CCA模型及T矩阵模型,对不同入射波长、粒子数目、分形维数及前向因子条件下的碳黑团聚物进行光散射模拟计算;建立碳黑气溶胶光散射特性计算模型,基于光散射计算方法,建立随粒子数目变化时,消光、散射、吸收系数的计算模型;配置浓度为0.05g/100ml的碳黑悬浊液,通过模型计算其消光系数,同时通过分光光度计测量悬浊液的透过率光谱,计算碳黑团聚物实验消光系数,并对消光系数的计算模型进行修正。
[Abstract]:The suspended solid and liquid particles in the atmosphere are called atmospheric aerosols. As one of the important components of atmospheric aerosols, carbon black aerosols are mainly derived from the incomplete combustion of fossil fuels and biomass fuels. Carbon black aerosol not only damages human respiratory system and human health and safety, but also exacerbates global warming because of its absorption and scattering of solar radiation. The light scattering characteristics of carbon black aerosol are calculated and analyzed, which plays an important role in monitoring the concentration of carbon black aerosol, controlling the air pollution and maintaining the environmental safety. The morphology of carbon black aerosol is complex, and its light scattering property is affected by many factors, such as morphology. A light scattering model of carbon black aerosol is established in this paper. The light scattering characteristics of carbon black aerosol are numerically calculated. The main contents are as follows: the change of carbon black aggregate morphology is analyzed, and the smoke produced by combustion of coal and biomass fuel is sampled. SEM images of aggregates were obtained by FEI quanta 200F. the geometric parameters of carbon black aggregates were extracted by image processing software IMAGEJ, and the morphological parameters of aggregates (particle number, fractal dimension) were deduced. The influence of the morphology of carbon black agglomerates on the light scattering characteristics is analyzed. Based on the CCA model and the T matrix model, the number of particles at different incident wavelengths, Under the condition of fractal dimension and forward factor, the light scattering of carbon black aggregates is simulated, and the calculation model of light scattering characteristics of carbon black aerosol is established. Based on the light scattering calculation method, the extinction and scattering are established when the number of particles varies. The calculation model of absorption coefficient, the extinction coefficient of carbon black suspension with concentration of 0.05g/100ml, and the extinction coefficient of carbon black aggregate were calculated by measuring the transmittance spectrum of suspension by spectrophotometer. The calculation model of extinction coefficient is modified.
【学位授予单位】：哈尔滨理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X513

【相似文献】