关键词:

快速流化床, 提升管, 颗粒含量, 时间序列, 非线性分析

Abstract: A fast fluidized bed riser with 16m height and 0.10m ID was operated with FCC particles and in a wide range of operating conditions.The superficial gas velocity U_g ranged from 3.5m•s^-1 to 8.1m•s^-1, and the solids circulating rate G_s was from 50kg•m^-2•s^-1 to 201kg•m^-2•s^-1.Time series signals of solids holdup fluctuation were measured at a frequency of 900Hz using an optical fiber located at 8 axial and 11 radial positions.The nonlinear method was used to analyze the time series and consequently Kolmogorov entropy was calculated to describe the dynamic characteristics of the gas-solid flow behavior in the annular-core section. The results showed that Kolmogorov entropy could describe the annular-core flow structure. According to three marked characteristics of Kolmogorov entropy in the radial direction, three flow regions were identified：random-particles-controlled core region, chaotic-particles-controlled transitional region, wall-controlled annulus region.The change of Kolmogorov entropy in the radial direction was also interpreted based on the influence of solids on gas turbulence structures.

Key words:

快速流化床, 提升管, 颗粒含量, 时间序列, 非线性分析