激光全散射法测量燃煤颗粒物浓度的实验研究  

Mass Concentration Measurements of the Coal-derived Fly Ash Particles Via Light Extinction Method

作　　者：徐义书[1] 刘小伟[1] 崔江[1] 陈栋[1] 韩金克 徐明厚[1] 

机构地区：[1]华中科技大学能源与动力工程学院煤燃烧国家重点实验室,武汉430074

出　　处：《工程热物理学报》2017年第7期1496-1502,共7页Journal of Engineering Thermophysics

基　　金：国家重点研发计划项目(No.2016YF0600601);国家自然科学基金资助项目(No.51476064);博士后创新人才支持计划(No.BX201700085)

摘　　要：本研究在激光全散射法颗粒物浓度检测系统上进行了不同性质、浓度燃煤飞灰颗粒的质量浓度测量实验。结果显示,联合全散射法颗粒物浓度检测系统和反演计算方法能良好的测算标准颗粒的质量浓度,误差约为7%。对于燃煤飞灰颗粒,测算结果能反映气流中颗粒浓度的变化,然而测算值高于真实值约19.3%~27.2%。并且,对除尘器前级电场飞灰的测算偏差大于第四电场飞灰。进一步的理论计算结果表明,随颗粒粒径增大,散射光分布逐步向前向(即0°方向)集中,导致光电探测器在收集透射光的同时收集部分前向散射光,使得反演计算值大于真实值。而前级电场飞灰中含有更多的大粒径、非球形颗粒且粒径分布范围更宽,偏离了反演算法的假定条件,导致对测算偏差增大。Light extinction method appears as one of those techniques;while its performance and feasibility to detect the real coal-derived fly ash remains to be improved.In the present study,measurements of the real-fly-ash-loaded gases of various concentrations were carried out on a self-designed light-extinction-based particle concentration measuring system.Results showed that the inversion results based on the system and inversion method agreed well with the real value for the standard spherical SiO_2 powders with deviations of -7%.As for the real fly ash,the inversion results reflected the variation of the concentrations;while were 19.3%-27.2%higher than the real values.Further theoretical calculations of the scattering light distribution of particles showed that for the larger particles,the scattering light concentrated to the forward direction（0°）,which resulted in larger detection results.Moreover,the higher contents of the fly ash of larger particle size,nonspherical shape and of broader size distribution led to the worse performance of the inversion method.

关 键 词：全散射法 飞灰 颗粒物 质量浓度 光学测量 

分 类 号：TK16[动力工程及工程热物理—热能工程]