近几年循环流化床锅炉水冷壁磨损较为严重,虽然采用防磨凸台可以有效减缓壁面磨损,然而基于凸台优化设计的文献还鲜见报道,因此文中使用声发射设备研究凸台绕流过程中稠密气固两相流颗粒与壁面接触程度问题,在一冷态实验台密相区,采用...近几年循环流化床锅炉水冷壁磨损较为严重,虽然采用防磨凸台可以有效减缓壁面磨损,然而基于凸台优化设计的文献还鲜见报道,因此文中使用声发射设备研究凸台绕流过程中稠密气固两相流颗粒与壁面接触程度问题,在一冷态实验台密相区,采用声发射对相同尺寸不同截面形状凸台下方颗粒与壁面接触程度进行测量,并用小波包分解处理信号。实验结果表明,0~10.5 k Hz低频段信号可以反应颗粒与壁面接触程度,重点分析该特征频段能量百分比,提出方形凸台为理论优化凸台,对进一步改进循环流化床防磨技术提供指导意见。展开更多
The particle dispersion characteristics of the dense gas-solids two-phase coaxial jets were investigated with high-speed camera.The results showed that with increasing gas velocity,three particle dispersion modes were...The particle dispersion characteristics of the dense gas-solids two-phase coaxial jets were investigated with high-speed camera.The results showed that with increasing gas velocity,three particle dispersion modes were observed:shear dispersion,wave dispersion and oscillating dispersion,after the particle flow passed through the intact length.The normalized intact length decreased with increasing gas velocity.For the wave dispersion,the unstable wavelength increased linearly with axial distance at different gas velocities.For the oscillating dispersion,oscillating frequency decreased at first and then increased with increasing gas velocity,so the oscillating frequency had a minimum when the gas velocity was about 65 m·s-1.展开更多
文摘近几年循环流化床锅炉水冷壁磨损较为严重,虽然采用防磨凸台可以有效减缓壁面磨损,然而基于凸台优化设计的文献还鲜见报道,因此文中使用声发射设备研究凸台绕流过程中稠密气固两相流颗粒与壁面接触程度问题,在一冷态实验台密相区,采用声发射对相同尺寸不同截面形状凸台下方颗粒与壁面接触程度进行测量,并用小波包分解处理信号。实验结果表明,0~10.5 k Hz低频段信号可以反应颗粒与壁面接触程度,重点分析该特征频段能量百分比,提出方形凸台为理论优化凸台,对进一步改进循环流化床防磨技术提供指导意见。
文摘The particle dispersion characteristics of the dense gas-solids two-phase coaxial jets were investigated with high-speed camera.The results showed that with increasing gas velocity,three particle dispersion modes were observed:shear dispersion,wave dispersion and oscillating dispersion,after the particle flow passed through the intact length.The normalized intact length decreased with increasing gas velocity.For the wave dispersion,the unstable wavelength increased linearly with axial distance at different gas velocities.For the oscillating dispersion,oscillating frequency decreased at first and then increased with increasing gas velocity,so the oscillating frequency had a minimum when the gas velocity was about 65 m·s-1.
