基于光散射法的烟尘发生及浓度测量装置

发布时间：2018-01-21 12:16

本文关键词： 烟尘发生微量进料器光散射法 CCD 浓度测量　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着我国工业化进程的加快,工业粉尘的排放量也日趋增多。为达到环保的目的,需要对工厂排放的粉尘颗粒物的浓度进行监测。烟尘浓度测量分为取样法和非取样法两大类,随着科学技术的快速发展,滤膜称重等传统测量法在实时、非接触等高要求下也暴露出诸多不足。非取样法得到广泛研究与应用,其中光电法测量浓度的优势逐渐凸显。本文对光散射法的烟尘发生及浓度测量进行了研究,主要做了以下几方面工作:(1)理论分析与仿真。由于装置的设计选型和参数选择以及后续实验测量的需要,本文基于Mie散射理论,给出了在一定立体角范围内的散射光通量与质量浓度呈正相关的结论,对粒子粒径、相对折射率与散射光强相位分布的关系进行了仿真分析,结果表明:单独运用前向或后向散射法测量在散射光信号采集阶段受诸多限制,所以提出了一种多传感器信息融合的方法,即将前后向散射结合对较大范围粒径粒子浓度进行测量。仿真分析为装置的设计选型、参数选择以及后续实验测量等提供了理论依据。(2)烟尘发生及浓度测量装置的搭建。在实验阶段,为了模拟实际工况下烟道中的不同颗粒物粒径和浓度,设计了一种可调低浓度烟尘发生装置,该装置由微量进料器与多种元器件、仪器仪表搭建而成,不仅可发生可调浓度的一定量烟尘,还能通过上位机进行实时监控。在Mie散射理论的基础上,基于光散射法设计并搭建了实验装置,将前向和后向散射法相结合,利用CCD相机采集光信号,较准确地实现了实时测量颗粒物浓度。(3)软件部分主要功能的实现。(1)完成了装置各部分的启停调节,实现了模拟烟道数据的采集及记录。技术人员可对系统各部分进行实时监控,以及单步调试,更快速地根据实时数据调控系统运行状态。(2)对散射光强图像进行采集分析后得到烟尘粒子浓度,然后将数据传送到数据界面进行显示并且形成历史曲线存储到上位机中,操作人员可以根据实时上传的各项监测数据,通过上位机进行良好的人机交互。(4)实验研究与分析。进行了可调烟尘浓度发生的实验,在实验环境相对稳定的情况下,对比了装置运行不同时长后烟尘发生的浓度,实验现象符合理论分析。另外又进行了光散射法测量粉尘浓度的实验,进行了多传感器信息融合测量法和单传感器光散射法测量的误差对比等多组实验,通过分析实验数据,结果表明文中设计的光散射法测量颗粒物浓度的方案是切实可行的。
[Abstract]:With the acceleration of industrialization in our country, the emission of industrial dust is increasing day by day, in order to achieve the purpose of environmental protection. It is necessary to monitor the concentration of dust particles emitted by factories. Smoke concentration measurement can be divided into two categories: sampling method and non-sampling method. With the rapid development of science and technology, traditional measurement methods such as filter membrane weighing are in real time. Non-contact and other high requirements also exposed a number of shortcomings. The non-sampling method has been widely studied and applied. Among them, the advantage of photoelectric method to measure the concentration is becoming more and more obvious. In this paper, the occurrence of smoke and the concentration measurement of light scattering method are studied. The main work is as follows: 1) theoretical analysis and simulation. Due to the design and selection of the device and the need of subsequent experimental measurement, this paper is based on Mie scattering theory. A positive correlation between the scattering flux and the mass concentration in a certain range of solid angles is given. The relationship between particle size, relative refractive index and scattering intensity phase distribution is simulated and analyzed. The results show that there are many limitations in the phase of signal acquisition by using forward or backward scattering method alone, so a multi-sensor information fusion method is proposed. The particle concentration of a large range of particle size is measured by the combination of backward and backward scattering. The simulation analysis is the design and selection of the device. The selection of parameters and subsequent experimental measurements provide a theoretical basis for the occurrence of smoke and the establishment of a concentration measurement device. In the experimental stage, in order to simulate the actual working conditions of different particle size and concentration in the flue. A dust-generating device with adjustable concentration is designed. The device consists of a micro feeder, a variety of components, instruments and instruments, which can not only produce a certain amount of smoke dust with adjustable concentration. On the basis of the Mie scattering theory, the experimental device is designed and built based on the light scattering method. The forward and backward scattering methods are combined to collect the light signal with the CCD camera. The realization of the main functions of the software for real-time measurement of the concentration of particulate matter, I. e., the realization of the main functions of the software. 1) the start and stop regulation of each part of the device is completed. The acquisition and recording of simulated flue data are realized. The technicians can monitor and debug all parts of the system in real time, as well as single step debugging. According to the running state of real-time data control system, the scattered light intensity image is collected and analyzed more quickly, and the concentration of soot particles is obtained. Then the data is transmitted to the data interface for display and the historical curve is stored in the upper computer. The operator can upload the monitoring data according to the real-time. The experimental research and analysis are carried out on the host computer with a good human-computer interaction. The experiment of the adjustable smoke concentration is carried out under the condition of relatively stable experimental environment. The experimental phenomenon is in accordance with the theoretical analysis. In addition, the light scattering method is used to measure the dust concentration. Through the analysis of the experimental data, the error comparison between the multi-sensor information fusion measurement method and the single-sensor light scattering method is carried out. The results show that the scheme designed in this paper for measuring the concentration of particulate matter is feasible.
【学位授予单位】：太原理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X851;O436.2

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