基于激光自混频效应的大气颗粒物在线监测技术

项目名称： 基于激光自混频效应的大气颗粒物在线监测技术

项目编号： No.51476104

项目类型： 面上项目

立项/批准年度： 2015

项目学科： 能源与动力工程

项目作者： 沈建琪

作者单位： 上海理工大学

项目金额： 80万元

中文摘要： 大气颗粒物是最重要的大气污染物之一，大气颗粒物的监测是两相流测试技术的重要研究课题，也是当今国际社会的关注热点。对大气颗粒物的监测技术主要有微量振荡天平法、β射线法和光散射法等。微量振荡天平法和β射线法在高温潮湿地区适应性差、故障率高，光散射法在探测效率、测量准确度和系统稳定性等方面存在不足。本申请项目提出一种基于激光自混频效应的大气颗粒物在线监测方案：将颗粒的散射光注入到激光器谐振腔，通过散射光与腔内激光的自混频放大效应提高信号监测灵敏度；采用LDPD模块及其自准直优势实现测量区的定义、系统的简化从而提高系统稳定性。项目研究涉及Lang-Kobayashi速率方程在弱注入和强注入情况下的物理模型、高斯光束照射下颗粒散射光信号处理及优化。项目研究成果可望形成一种新的在线实时监测技术用于大气颗粒物监测、工业洁净空间监测。此外，由于其独特的光学结构，还可应用于分散在液相中的颗粒物原位监测。

中文关键词： 多相流测试；大气颗粒物；在线测量；激光自混频干涉

英文摘要： Particulate matter is one of the most important factors in the air pollution. Monitoring the particulate matter in air is an important topic in the area of measurement of multi-phase flow and it has attracted concerns worldwide. Currently, monitoring systems used are mainly based on the tapered element oscillating microbalance (TEOM), the beta attenuation monitor (BAM), light scattering such as the optical particle counter and etc. However, the TEOM and BAM are usually unable to work properly under the conditions of high temperature and high relative humidity. Techniques based on light scattering are still suffering from the disadvantages of low sensitivity due to the low level of signal, low measurement accuracy, low stability and etc. Therefore, the project proposes a new method for the real-time, on-line measurement of the ambient particulate matter on the basis of laser self-mixing technique. The scattered light is fed into the cavity of the laser wherein the interference between the scattered light and the internal field takes place and hence the signal is amplified so that the signal sensitivity is improved. With the compact LDPD module and its autocollimation, the measurement zone can be defined automatically. The measurement arrangement is very simple and more stable. The investigation will focus on the Lang-Kobayashi rate equations in the cases of both weak and strong feedback, the signal processing of the scattered light of particles illuminated by a focussed Gaussian beam and the relevant optimization. The research will lead to a new realtime and online measurement method which can be used in the monitoring of the air pollution and the clean space. Due to the distinctive design of the optical arrangement, it may also apply to the in-situ measurement of particles suspended in liquid.

英文关键词： Measurement of multiphase flow;particulate in air;online measurement;laser selfmixing interference