基于激光散射法悬浮颗粒监测系统的研究

发布时间：2018-03-14 02:07

本文选题：悬浮颗粒　切入点：激光散射法　出处：《哈尔滨理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着中国工业化的快速发展,空气污染越来越严重,环境污染指数中悬浮颗粒浓度过高严重危害到人类的健康,因此对环境中悬浮颗粒的监测势在必行。本文针对国内悬浮颗粒检测仪器的现状和实际需求,结合国内外现有的悬浮颗粒检测理论和方法,研究了基于激光散射法悬浮颗粒浓度监测系统,并通过测试实验验证了系统的准确性。首先,本文分析了悬浮颗粒物取样法和非取样法两大类方法监测仪器的工作原理。在Mie散射理论的基础上,阐述了光散射法测量悬浮颗粒浓度的工作原理,利用MATLAB模拟仿真了入射光波长、悬浮颗粒粒径、悬浮颗粒折射率对散射光强度分布的影响;以Mie散射理论为基础建立了悬浮颗粒物浓度计算的数学模型,对初始分布服从Johnson-SB函数分布的悬浮颗粒运用遗传寻优算法理论反演悬浮颗粒物粒径分布,仿真结果表明数学模型的正确性和可靠性。其次,设计了基于激光散射法悬浮颗粒浓度监测系统的硬件结构和检测电路。根据Mie散射原理和监测环境要求,完成了光路子系统中半导体激光器、透镜组、孔径光阑和气路采样子系统中加热管、进气道、气压传感器、气泵与气体过滤器等主体设计;在系统硬件结构设计的基础上,对悬浮颗粒物浓度检测的硬件电路进行设计,完成系统的整体搭建。最后,对基于激光散射法悬浮颗粒浓度监测系统进行了系统测试。系统测试环境为封闭式试验箱,采用标准称重法与基于激光散射法悬浮颗粒浓度监测系统测试结果进行了对比实验研究,对PM2.5和PM10两种标准颗粒的各100组检测数据进行相关性分析。相关性分析表明两种方法测量数据的相关性较高,没有明显差异;运用MATLAB对两种方法测量数据建立线性回归方程进行数据结果修正,提高了测量数据的准确性。分析了基于激光散射法悬浮颗粒浓度监测系统数据测量的误差原因并提出解决方案。
[Abstract]:With the rapid development of China's industrialization, air pollution is becoming more and more serious, and the high concentration of suspended particles in the environmental pollution index is seriously harmful to human health. Therefore, it is imperative to monitor the suspended particles in the environment. According to the present situation and actual demand of the domestic suspended particle detection instruments, this paper combines the existing theories and methods of suspended particle detection at home and abroad. The concentration monitoring system of suspended particles based on laser scattering method is studied, and the accuracy of the system is verified by testing experiments. In this paper, the working principle of two kinds of monitoring instruments, the sampling method of suspended particulates and the method of non-sampling, are analyzed. Based on the Mie scattering theory, the working principle of the light scattering method for measuring the concentration of suspended particles is expounded. The influence of incident light wave length, suspended particle size and refractive index of suspended particle on the intensity distribution of scattering light is simulated by MATLAB. Based on the Mie scattering theory, a mathematical model for calculating the concentration of suspended particle is established. The particle size distribution of suspended particles with initial distribution from Johnson-SB function distribution is inversed by genetic optimization algorithm. The simulation results show that the mathematical model is correct and reliable. The hardware structure and detection circuit of suspension particle concentration monitoring system based on laser scattering method are designed. According to the principle of Mie scattering and the requirements of monitoring environment, semiconductor lasers and lens sets in optical path subsystem are completed. The heating pipe, inlet port, air pressure sensor, air pump and gas filter in the aperture aperture and gas sampling subsystem are designed, and the hardware circuit for the concentration detection of suspended particulates is designed on the basis of the hardware structure design of the system. Finally, the system is tested based on laser scattering method. The test environment is a closed test chamber. The test results of the standard weighing method and the laser scattering method based on the suspension particle concentration monitoring system are compared and studied. The correlation analysis of each group of PM2.5 and PM10 standard particles showed that the correlation between the two methods was high, and there was no significant difference between the two methods. Using MATLAB to establish linear regression equation for two methods of measuring data, the data result is corrected. The accuracy of the measurement data is improved, and the error causes of the data measurement based on the laser scattering method are analyzed and the solutions are put forward.
【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】：TP274

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