颗粒物发生装置与检定系统研究
发布时间：2019-01-23 13:01
【摘要】：国内外都采用标准粒子的方式对PM2.5监测仪器进行校准,但细颗粒在空气中的物理化学性状极易发生变化,导致标准粒子的制作和其应用之间产生较大的偏差。针对这种现状,本文在通常的标准粒子的基础上,研究一种基于Mie散射的无损检测技术,实现对标准粒子粒径和浓度的实时监测。论文首先对Mie散射进行分析,在此基础上推导了Mie散射的基本公式。基于Mie散射的基本公式,利用MATLAB编写程序对Mie散射的散射光强进行仿真,探究球形颗粒物的粒径、折射率以及入射光的波长等几个参数对散射光强的影响。此外,在Mie散射的基本理论的基础上,推导了散射光强与颗粒群质量浓度的关系以及散射光强与单个颗粒粒径的关系。论文以Mie散射为理论基础,将光度法和粒子计数法相结合,设计并研制了一套颗粒物检定装置。通过激光功率的切换,可利用同一装置实现对颗粒物粒径和浓度的监测。利用所研制的检测装置,分别对聚苯乙烯球标准粒子和单分散的气溶胶颗粒物,开展粒径测量的实验研究。随着标准粒子粒径的增大,甄别电压值也逐渐增大,并能很好的识别和区分两个粒径接近的不同粒子。同时,针对气溶胶发生器所发出的单分散气溶胶颗粒,开展质量浓度的测量实验,并利用最小二乘法对电压值与质量浓度之间的线性关系进行拟合,求得质量浓度转换系数K的值。
[Abstract]:The standard particle is used to calibrate the PM2.5 monitoring instrument at home and abroad, but the physical and chemical properties of fine particles in the air are easy to change, resulting in a large deviation between the production and application of standard particles. Aiming at this situation, this paper studies a nondestructive testing technique based on Mie scattering on the basis of normal standard particles, which realizes the real-time monitoring of particle size and concentration. Firstly, the Mie scattering is analyzed, and the basic formula of Mie scattering is derived. Based on the basic formula of Mie scattering, the scattering light intensity of Mie scattering is simulated by MATLAB program, and the influence of some parameters, such as particle size, refractive index and wavelength of incident light, on the scattering light intensity is explored. In addition, based on the basic theory of Mie scattering, the relationship between scattering light intensity and particle mass concentration and the relationship between scattering light intensity and particle size are derived. Based on the theory of Mie scattering, a particle calibration device is designed and developed by combining photometric method with particle counting method. By switching laser power, the particle size and concentration can be monitored by the same device. The particle size measurement of polystyrene standard particles and monodisperse aerosol particles was carried out with the developed detector. With the increase of standard particle size, the discriminant voltage value increases gradually, and can identify and distinguish two different particles with similar particle size. At the same time, a mass concentration measurement experiment is carried out for the monodisperse aerosol particles emitted by the aerosol generator, and the linear relationship between the voltage value and the mass concentration is fitted by the least square method. The value of mass concentration conversion coefficient K is obtained.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X851
本文编号：2413796
[Abstract]:The standard particle is used to calibrate the PM2.5 monitoring instrument at home and abroad, but the physical and chemical properties of fine particles in the air are easy to change, resulting in a large deviation between the production and application of standard particles. Aiming at this situation, this paper studies a nondestructive testing technique based on Mie scattering on the basis of normal standard particles, which realizes the real-time monitoring of particle size and concentration. Firstly, the Mie scattering is analyzed, and the basic formula of Mie scattering is derived. Based on the basic formula of Mie scattering, the scattering light intensity of Mie scattering is simulated by MATLAB program, and the influence of some parameters, such as particle size, refractive index and wavelength of incident light, on the scattering light intensity is explored. In addition, based on the basic theory of Mie scattering, the relationship between scattering light intensity and particle mass concentration and the relationship between scattering light intensity and particle size are derived. Based on the theory of Mie scattering, a particle calibration device is designed and developed by combining photometric method with particle counting method. By switching laser power, the particle size and concentration can be monitored by the same device. The particle size measurement of polystyrene standard particles and monodisperse aerosol particles was carried out with the developed detector. With the increase of standard particle size, the discriminant voltage value increases gradually, and can identify and distinguish two different particles with similar particle size. At the same time, a mass concentration measurement experiment is carried out for the monodisperse aerosol particles emitted by the aerosol generator, and the linear relationship between the voltage value and the mass concentration is fitted by the least square method. The value of mass concentration conversion coefficient K is obtained.
【学位授予单位】：浙江大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X851
【参考文献】
相关期刊论文 前2条
1 任智斌,卢振武,刘玉玲,李凤有,曹召良,孙强;Mie理论归一化散射光强的研究[J];光电子·激光;2003年01期
2 孙国正,孙强,任智斌;基于Mie散射理论的微球体颗粒半径分析[J];红外与激光工程;2005年04期
相关硕士学位论文 前3条
1 许玉凤;基于光度计法的粉尘质量浓度测量系统的研究与开发[D];南京理工大学;2007年
2 白林;激光大气传输理论研究及应用[D];北京邮电大学;2008年
3 李佳颖;大气颗粒物质量浓度自动监测系统的研究[D];上海理工大学;2008年
，本文编号：2413796
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