基于ESMD的浓相气力输送颗粒静电信号分析及速度测量

Analysis of particle electrostatic signals and velocity measurement in dense pneumatic conveying system based on ESMD

针对浓相气力输送中颗粒相的复杂流动特性,采用极点对称模态分解方法分析静电环状和弧状阵列信号.研究了多种工况下输送系统启停过程和过渡过程中不同分解模态静电信号的能量和频率分布信息特性,提出了一种新的浓相气力输送颗粒速度测量方法,并进行实验验证.研究结果表明,环状电极静电信号的能量分布信息能够用来判断输送系统在启停过程中颗粒流动的稳定性;弧状电极静电信号的能量信息可用来判断管道内颗粒相的分布情况.文中提出的静电信号瞬时频率颗粒速度测量方法相比于空间滤波测速法,其特征系数的相对标准差至少降低58%,表明该速度测量方法可以稳定并准确测量浓相气力输送颗粒速度.

Considering the complex flowcharacteristics of particle phase in dense pneumatic conveying system,electrostatic signals of electrostatic ring and arc array sensors were analyzed by using extreme-point symmetric mode decomposition（ ESMD） method. The energy and frequency distribution properties of the electrostatic signals in different decomposed modes were studied during the startup,middle time and shut down process of dense pneumatic conveying system under different conditions. A newmethod for particle velocity measurement in dense pneumatic conveying system was proposed,and experimental verification was conducted. The results showthat the energy distribution of ring electrostatic signal can be used to identify the flowstability of particles in the conveying system during the process of startup and shut down; the energy distribution of arc array electrostatic signal can be used to discern the distribution of solids inside the pipe. Compared with spatial filtering velocity measuring method,the relative standard deviation of the correction factor of the proposed method decreases 58% at least,indicating that the newmethod can measure the solid velocity of pneumatic conveying stably and accurately.