鼓泡流化床风帽压力信号的频谱分析

Frequency Spectrum Analysis on Pressure Signals of Wind Caps in a Bubbling Fluidized Bed

在鼓泡流化床冷态试验台上,采集不同风帽入口的压力信号.基于Matlab软件,利用自相关函数的傅里叶变换对采集的信号进行频谱分析,得到信号主频的分布范围以及对应的功率谱密度,分析了不同静床高和不同表观气速下布风板中心、边壁风帽的压力波动特性.结果表明：风帽入口压力信号的频谱变化与静床高和表观气速的变化密切相关,且压力波动信号的主频集中在0~10 Hz的范围,可为风帽压力信号的测点布置和采样频率的设置提供参考.

Through an experimental setup of cold bubbling fluidized bed,pressure signals were collected at entrances of various wind caps located in different positions of air distributor,of which the frequency spectrum was analyzed based on Matlab software using Fourier transform of autocorrelation function,thus the main frequency distribution and corresponding power density spectrum were obtained,and subsequently the pressure fluctuation characteristics of wind caps respectively at center and side wall area of air distributor were analyzed under conditions of different static bed heights and superficial gas velocities.Results show that the frequency spectrum of pressure signals changes closely with the static bed height and superficial gas velocity,and the energy of pressure fluctuation is mainly governed by low frequency fluctuation（0-10 Hz）.This may serve as a reference for arranging wind cap pressure measurement elements and setting the sampling frequency.