高阶统计量在气固流化床中的应用研究

Applications of higher-order statistics to the study of pressure fluctuation signal of gas-solid fluidized bed

提出了一种基于高阶统计量进行气固流化床流化状态分析的新方法.通过对气固流化床压力波动信号的非高斯性检验,验证了压力波动信号的非高斯性,并以双谱幅值的平均值为特征值,得到了不同流化状态下压力波动信号偏离高斯分布的程度.同时利用高阶谱分析方法对压力波动信号进行分析,讨论了不同流化状态下信号的双谱特性.研究结果表明,利用高阶谱分析方法对气固流化床流化状态进行分析,可以获得更多的关于流化状态的有用信息.

A new method based on higherorder statistics of time series of pressure fluctuations signal is proposed to analyse the characteristics of gassolid fluidized bed. According to the difference of spectrum characteristics between the bubbleplase signal and densephase signal in a gas fluidized bed, the points alternated from one phase to another phase can be determined exactly by using bispectral method and the nonGaussian character of different fluidization regimes can be picked up. Based on this analysis, the average bispectrum amplitude of based on local higherorder statistics of pressure fluctuation signals was presented firstly as an eigenvalue. Pratical processing results showed that the nonGaussian character of the pressure fluctuations signal can be detected by analysis of the signal cumulants.The extent of pressure fluctuation signals daviation from Gaussian distribution is different for different fluidization regimes. Research results showed that the proposed method is effective for identifying the regimes of the gassolid fluidized bed, while the minimum fluidization velocity can also be obtained. Study of gassolid fluidized bed.is facilitated by this new method.