中文摘要：

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。

英文摘要：

Acquisition and analysis of pressure fluctuation signal of wind cap which is a new method was proposed to realize the condition monitoring of gas-solid flow in fluidized bed. Under the different superficial gas velocity, bed material particle size distribution and static bed height, the pressure fluctuation signal of wind cap in the cold bubbling fluidized bed test rig was analyzed with the wavelet analysis method. Then, the energy of reconstructed signals at different levels and the ratio of energy at different levels to the total energy could be calculated, the main frequencies of signals could be obtained with Welch method for power spectrum estimation. Finally, the influence of the operating conditions change on the characteristic pressure fluctuation in wind cap of bubbling fluidized bed was analyzed. It is finded that the variation of the low-frequency reconstructed signals are related with the variation of the gas-solid flow condition under the operating conditions change. So the proposed method is proved to be practical and the research achievement can be used as theoretical basis for the characteristic pressure fluctuation in wind cap of circulating fluidized bed.