关键词: 循环流化床, 提升管, T形弯头, 动态压力, 小波分析, 催化剂, 两相流

Abstract: To investigate the characteristics of pressure fluctuations in the T-abrupt exit, the dynamic pressures of gas-solid two-phase flow in the T-abrupt exit of a CFB riser were measured in a circulating fluidized bed device with FCC catalyst by dynamic pressure sensors. The pressure fluctuations of the blind tube in T-abrupt exit were the strongest and the gas-solid two-phase flow in T-abrupt exit formed a new fluctuation source which was the result of the particles cluster turning back in the blind tube. Wavelet analysis revealed that pressure fluctuations in the T-abrupt exit mainly came from the fluctuation source in the blind tube constituting the main frequency, while the energy ratio of secondary frequency increased with increasing solids mass flux. The standard deviation of the dynamic pressures in the T-abrupt exit was linear with the solids mass flux, and in the inlet of the T-abrupt exit the linear relationship was well-defined. So the real-time solids mass flux could be characterized by the standard deviation of the dynamic pressures in the inlet of the T-abrupt exit.

Key words: circulating fluidized bed, riser, T-abrupt exit, pressure fluctuations, wavelet analysis, catalyst, two-phase flow