空气环境下煤粉流LIBS多元素同时检测中激光能量研究  

Study of Laser Energy in Multi-Element Detection of Pulverized Coal Flow with Laser-Induced Breakdown Spectroscopy

作　　者：郑建平[1] 陆继东[1] 张博[1] 陈世和[2] 姚顺春[1] 潘凤萍[2] 董璇[1] 张曦[2] 

机构地区：[1]华南理工大学电力学院,广东广州510640 [2]广东电网公司电力科学研究院,广东广州510080

出　　处：《光谱学与光谱分析》2014年第1期221-225,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(51206055);煤燃烧国家重点实验室开放基金项目(FSKLCC1106);广东高校优秀青年创新人才培养计划项目(2012LYM_0018)资助

摘　　要：考察了大气环境下激光诱导击穿光谱适用于煤粉流多元素同时检测的激光能量范围,分析了造成煤粉流测量谱线信号波动的原因,得到了适用于煤粉流多元素同时检测的激发区域功率密度范围和最佳功率密度。实验选取能量范围为20～160mJ,粒径小于200μm煤粉颗粒经下料口自由下落形成煤粉流束,通过螺杆式给粉机控制流量,波长1 064nm脉冲激光聚焦后作用于下降的煤粉流束上,产生等离子体,光谱仪采集等离子体发射光谱信号,分析结果表明:实验台架下适于煤粉流LIBS检测的能量范围为30～60mJ,对应激发前沿功率密度选取范围14.4～34.4GW·cm-2,最佳测量功率密度19.5GW·cm-2。The logical range of laser power density and optimum laser power density were explored for multi-element analysis of pulverized coal flow with laser-induced breakdown spectroscopy in the present paper. The range of laser energy was chosen from 20 to 160 mJ in the experiment. Pulverized coal less than 200μm in diameter of particles fell freely through feeder outlet and the rate of flow was controlled by screw feeder. Emissions were collected with pulse laser at 1 064 nm focusing on pulverized coal flow and plasma was generated. The intensity and cause of fluctuation of emission spectra at various laser energy levels were studied. A suitable range of laser power density is from 14.4 to 34. 4 GW . cm-2, and the optimum laser power density is 19.5 GW .cm-2 for the determination of pulverized coal flow with LIBS.

关 键 词：激光能量 煤粉流 激光诱导击穿光谱 等离子体 

分 类 号：O433.1[机械工程—光学工程]