激光诱导击穿光谱法测量煤粉流的控制因素

Controllable factors in detection of pulverized coal flow with LIBS

用激光诱导击穿光谱(LIBS)法直接检测煤粉流时需要对主要控制因素进行优化,本文采用正交实验法考察了3个主要控制因素:功率密度、积分延迟时间和单位截面流量对LIBS测量煤粉流的影响。选用粒径小于0.2mm的煤粉作为实验样品进行了统计分析和方差分析。结果显示:在实验所选取的参数范围内,功率密度、积分延迟时间对有效激发率有显著影响,单位截面流量的影响程度最低。优化后的方案为:功率密度9.4×1011 W/cm2,积分延迟时间1 500ns,煤粉流量根据经济性原则在合理范围内选取。得到的结果表明该方法可用于指导煤粉流的实际在线测量。

It is necessary to optimize operable factors in measurement of pulverized coal flow by Laser-induced Breakdown Spectroscopy（LIBS）.Therefore,this paper investigated the effects of three main operable factors,irradiance,integration delay time and the rate of flow per unit area on the measurement of pulverized coal flow by LIBS based on orthogonal experiments.Pulverized coal was chosen for the experimental sample and the statistic analysis and variance analysis were performed.Experiment indicates that the irradiance and integration delay time are two remarkable factors for the effective excitation rate and the following is the rate of flow per unit area.The optimum parameters of control from the experiment are the irradiance of 9.4×10^11 W/cm^2,the integration delay time of 1 500 ns,and the rate of flow is selected reasonably based on economy principles.The results obtained demonstrate that the method can direct the practical measurement of pulverized coal flows in real time.