声发射信号分析与气-固两相流粒径测量

Analysis of Acoustic Emissions and Measurement of Particle Sizes From Gas-solid Two-phase Flow

气-固两相流相关参数的实时检测对过程控制和高效运行具有重要的意义。针对现有气-固两相流参数检测法的缺陷,依据经典声发射理论,设计一套空气-玻璃微珠的声发射信号检测装置,进行试验并评价。选用不同粒径的玻璃微珠在撞击速度分别为1.98m/s、2.80m/s、3.40m/s和4.00m/s下,获取气-固两相流的速度、粒径的声发射信号,并采用功率谱估计对其进行分析。试验发现,功率谱估计的幅值、面积与固相颗粒的撞击速度、粒径呈良好的线性关系,通过验证试验,粒径检测的相对误差小于8.5%。因此,声发射结合功率谱估计的方法测量固相颗粒粒径是可行的。

The real-time measurement of the relative parameters of the gas-solid two-phase flow has great significance for the process control and efficient operation.For the deficiencies of existing parameters measurement method of gas-solid two-phase flow,a set of acoustic emission signal detecting device with air-glass bead has been designed,tested and evaluated according to the classic acoustic emission theory.The different sizes of glass beads have been chosen for acquisition of acoustic emission（AE）signals of velocity and particle sizes in gas-solid two-phase flow under the impact velocity of 1.98 m/s,2.80 m/s,3.40 m/s and 4.00 m/s respectively,and analyzed by the power spectrum estimation.The result shows that there are good linear relationship between the magnitude and the area of the power spectrum estimation with the impact velocity,particle sizes.The verifying experiment results show that the relative error of particle size measurement is less than 8.5%.Therefore,the combination of AE and power spectrum estimation is feasible and effective for measuring the particle size of the solid phase.