单颗粒煤粉声悬浮全息测量实验研究  

Measurement of a Single Coal Particle in an Acoustic Levitation Field by Digital Holography

作　　者：赵华锋[1] 吴学成[1] 周斌武[1] 薛志亮[1] 陈玲红[1] 邱坤赞[1] 岑可法[1] 

机构地区：[1]浙江大学能源清洁利用国家重点实验室,浙江杭州310027

出　　处：《中国激光》2014年第10期194-200,共7页Chinese Journal of Lasers

基　　金：国家自然科学基金面上项目(51176162);国家自然科学基金重大项目(51390491);浙江省重点科技创新团队项目(2011R50017)

摘　　要：运用数字全息测量技术对声悬浮场中煤粉颗粒的冷态、热态现象进行了实验研究。通过电荷耦合器件(CCD)记录煤粉颗粒的冷热态全息图,应用小波变换对图像进行重建,获得同一煤粉颗粒在不同投影面下的粒径以及空间位置。重点分析了煤粉在CO2激光器照射下,挥发分析出及颗粒破碎现象,挥发分只在竖直方向析出,且主要集中在尖角处。破碎形成的颗粒大小不一,位置比较随机,z轴方向距离较大。通过分析热态时颗粒粒径随时间的变化,获得了颗粒的燃烧速度,同时给出了颗粒z轴位置随时间的变化。实验结果表明数字全息技术可以应用于声悬浮场中煤粉颗粒燃烧时的测量,是研究煤粉燃烧的有力工具。The phenomena of a single coal particle in an acoustic levitation field both cold and hot state are investigated by digital holography.Particle size and three-dimensional location of the same coal particle both cold and hot state are obtained using wavelet transformation for the reconstruction of holograms recorded by charge coupled device（CCD）.The key point is to analyze the phenomenon of volatile release and particle breakage of coal particle irradiated by CO2 laser.Results show that the volatile separates out only in the vertical direction,especially in sharp corners.And the pieces after being broken apart differed in both dimensions and position,particularly distance in z axis.The combustion rate of heated particle is computed through particle size change over time.In addition,the z position change over time of heated particle is presented.The experimental results indicate that digital holography is a feasible tool for the measurement of flaming coal particles in acoustic levitation field.It is proved to be a powerful method for researching the combustion characteristics of coal particle.

关 键 词：全息 声悬浮 单颗粒 煤粉 

分 类 号：TB877.1[一般工业技术—摄影技术]