基于激光前向散射超低排放烟尘连续在线监测技术研究

发布时间：2018-06-05 23:52

本文选题：前向散射 + 低浓度颗粒物　；参考：《华北电力大学》2017年硕士论文

【摘要】：近年来,中国经济飞速发展,工业化发展进度世界名列前茅,但是随之而来的是各种环境问题日益加剧,特别是近几年一直处于风口浪尖的雾霾天气越来越严重,而产生雾霾的主要元凶就是颗粒物的排放,因此颗粒物的排放及监测越来越受到全社会的重视。在此严峻的环境下,环保部颁发了严格的最新火电厂大气污染物排放标准(GB13223-2011),有些雾霾严重的地区甚至特别对待,排放标准较其他地方还要严格许多,可以称为超低浓度排放也叫“近零排放”。但是如何监测这种超低浓度的颗粒物,这对环保监测行业提出严峻的挑战。本文就超低排放烟尘颗粒物浓度连续在线监测这一课题进行探讨,首先介绍了颗粒物浓度检测各种技术,分析对比其各自优缺点,确定激光前向散射原理作为核心理论依据,并选取λ=630nm波长的红光作为散射光源的方法。其次,介绍了散射理论,浓度反演原理及如何实现超低排放下的连续在线监测。再者设计了系统机械结构,采样预处理过程及软件控制系统与人机操作系统,其中系统机械结构要满足防水、防腐蚀,系统高度集中,便于拆卸安装等要求;采样预处理过程主要要满足等速采样流量控制,烟气预热及保温等,介绍了系统如何实现流量测量与等速采样及预热条件,温度控制等;软件控制主要包括介绍如何用PLC(可编程逻辑控制器)控制系统的采样/反吹切换,温度控制、数据传输,参数报警等;人机操作系统主要是为了方便现场显示及操作整机系统,采用WinCC flexible 2008(Windows Control Center;视窗控制中心)组态软件编译了一组系统监测画面。最后将系统实际应用到华北某火电厂,将现场系统测量数据与环保局测定数据比对,完成“168试运行”,验证了系统的可行性、稳定性与准确性。
[Abstract]:In recent years, with the rapid development of China's economy and the highest progress of industrialization in the world, however, with the rapid development of the world, the environmental problems have become increasingly serious, especially the smog weather, which has been at the forefront of the storm in recent years. The main culprit of haze is the emission of particulate matter, so the emission and monitoring of particulate matter are paid more and more attention by the whole society. In this harsh environment, the Ministry of Environmental Protection has issued a strict latest standard for the emission of atmospheric pollutants from thermal power plants, GB13223-20111.Some areas with severe smog are even given special treatment, and the emission standards are much more stringent than in other places. Can be called ultra low concentration emissions, also known as "near zero emissions." However, how to monitor these ultra-low concentrations of particulate matter poses a serious challenge to environmental protection monitoring industry. In this paper, the continuous on-line monitoring of the concentration of particulates from ultra-low emission soot is discussed. Firstly, various techniques of particle concentration detection are introduced, their respective advantages and disadvantages are analyzed and compared, and the principle of laser forward scattering is determined as the core theoretical basis. The red light at 630nm is selected as the scattering light source. Secondly, the scattering theory, concentration inversion principle and how to realize continuous on-line monitoring under ultra-low emission are introduced. Furthermore, the mechanical structure of the system, the process of sampling and preprocessing, the software control system and the man-machine operating system are designed, in which the mechanical structure of the system should meet the requirements of waterproofing, corrosion resistance, high concentration of the system, easy to disassemble and install, etc. The preprocessing process of sampling is mainly to satisfy the constant sampling flow control, flue gas preheating and heat preservation. This paper introduces how the system can realize the flow measurement and isokinetic sampling and preheating conditions, temperature control and so on. Software control mainly includes how to use PLC (Programmable Logic Controller) to control the sampling / backblow switching, temperature control, data transmission, parameter alarm and so on. A set of system monitoring pictures is compiled with WinCC flexible 2008 Windows Control Center (Windows Control Center) configuration software. Finally, the system is applied to a thermal power plant in North China. The system data are compared with the data measured by the Environmental Protection Bureau, and the "168 trial operation" is completed, which verifies the feasibility, stability and accuracy of the system.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：X831;TM621;TP274

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