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提出通过采集、分析流化床风帽压力波动信号的方法,实现对床内气固两相流状态监测。借助冷态鼓泡流化床实验台,对不同床层表观气速、不同床料粒径分布和不同静床高工况下采集到的风帽压力波动信号,进行小波分析,计算小波分解后不同频段重构信号的能量值及其占总能量的比值,采用Welch法对信号进行功率谱估计并获取信号的主频,分析运行工况变化对鼓泡流化床风帽压力波动特性的影响。结果发现,风帽压力波动信号低频信号的变化能够反映流化床运行工况变化时的气固流动状态变化,表明所提方法具有可行性,并可为进一步研究循环流化床风帽压力波动特性提供理论基础。
A method of monitoring the gas-solid two-phase flow in the bed is proposed by collecting and analyzing the pressure fluctuation signal of the fluidized bed hood. With the help of the bubbling bubbling fluidized bed experimental platform, the wind pressure fluctuation signals collected at different bed apparent velocities, different bed particle size distributions and different static bed high working conditions were analyzed by wavelet analysis, and after the wavelet decomposition The energy values of reconstructed signals in different frequency bands and their ratios to the total energy were calculated by Welch method. The dominant frequency of the signal was obtained and the influence of operating conditions on the pressure fluctuation characteristics of bubbling fluidized bed was analyzed. The results show that the change of the low frequency signal of the pressure fluctuation signal of the hood cap can reflect the change of the gas-solid flow state when the operating condition of the fluidized bed changes, indicating that the proposed method is feasible and can be used for further research on the pressure fluctuation characteristics of the circulating fluidized bed Theoretical basis.