燃煤流化床声发射特性实验研究

Experimental Investigation on Acoustic Emission in the Coal Fired Fluidized Bed

本文通过实验和理论对流化床燃烧过程的声发射现象进行分析，从声学角度对燃煤流化床内的气泡运动特征进行了探讨。实验研究包括热态流化床和冷态流化床对比实验，确定了声波时序与气泡过程的对应性，运用瞬态谱理论获得了气泡爆破过程的能量尺度和时间尺度参数。最后。

There are three kinds of acoustic source,which involves the dipole,quadrupole and monopole source,in the fluidized bed combustion process.Through the experimental study,the dipole source caused by the gas solid tow phase interaction does the majority of the acoustic emission and the others caused by the turbulence and combustion respectively are negligible.The sound wave detection and digital analysis of the signals make up the experimental studies of the paper.The Wigner distribution is used to obtain the power distribution of the sound emission from the bed.The characteristics of the bubbles motion are discussed based on the nonlinear dynamics in the paper.RS method is used to get the fractal dimensions of the bubbles motion in different regimes respectively.The bubbles broken is accompanied by the release of acoustic energy that displays peaks over the power distribution of the sound emission.