气液固三相流化床流区及其过渡的混沌分析

CHAOS ANALYSES OF FLOW REGIME AND REGIME TRANSITION IN GAS-LIQUID-SOLID THREE-PHASE FLUIDIZED BEDS

运用确定性混沌分析技术，研究了气液固三相流化床内压力波动时间序列的混沌动力学行为。结果 表明，非线性特征量最大Ｌｙａｐｕｎｏｖ指数可以用来定量表征三相流化床的流区及其过渡。并给出了以最大 Ｌｙａｐｕｎｏｖ指数为基准的三相流区图。混沌分析还发现，三相流化床内存在着两类混沌特性相差较大的塞状 泡流区。

The chaos hydrodynamic behavior of flow in a gas-liquid-solid three-phase fluidized bed was studied by deterministic chaos analysis of time series data of pressure fluctuations. The fluidized bed was of 0.07m ID with a height of 1. 55m. Tap water and air were used as liquid phase and gas phase, respectively. Spherical glass beads with diameters of 0. 001m^0. 004m and a density of 2500kg· m^(-3) were used as solid phases. The gas-liquid flow was co-current and upward. Superficial gas and liquid velocities were varied over the rang of (0.757~26)×10^(-2)m. s^(-1) and (0. 0~16)×10^(-2)m·s^(-1), respectively. Pressure data were measured with a transducer of IC-Sensor 1220-2psid. A sensor of the probe was placed 0.49m above the plate horizontally. It was shown that flow regime and regime transition in three-phase fluidized beds could be quantitatively characterized by nonlinear characteristic parameter- the largest Lyapunov exponent. The flow regime map that was more detailed than the traditional ones of three-phase fluidized beds was drawn based on the largest Lyapunov exponent values. It was also found that the slug bubble flow regime of three-phase fluidized beds could be divided into two different parts according to the chaos hydrodynamic characteristics.