浓相高密度气固流化床动力学特性模拟研究

气固流化床内部运动状态和流体力学特性是研究者普遍关心的问题。浓相高密气固流化床就有不同于一般化学工业流化床的特点：固相介质密度高（4．0—5．0g／cm^3），空隙率小（0．3～0．42），气相速度小（0．15—0．30m／s）。使用基于物质、质量守恒定律建立了双流体模型对气固流化床动力学特性进行了模拟研究。在二维直角坐标系中用控制容积差分法离散方程。并在气相表观速度为0．157m／s条件下，基于0．1cmm＊0．1cm的交错网格，求解了时间长度为1．2秒的固体介质流动状态。计算结果表明：固相的流动形态为中心上升边界下降的趋势。该结果与试验结果符合的很好。

Numerical Simulation of Dynamic Characteristics in Dense Phase and High Density Gas-solid Fluidized Bed

The flowing patterns and hydrodynamic characteristics in gas-solid fluidized bed is a general concerned problem for researchers.The following features of dense phase and high density gas-solid fluidized bed differ from others used in chemistry industry: higher density of solid phase(4.0-5.0g/cm3),lower porosity(0.3-0.42);lower velocity of gas phase(0.15-0.30m/s).The dynamic characteristics are simulated using two-fluid model(TFM),which is derived from the quality and momentum conservative laws.The derivation of discretization equation is made using finite-volume method based on the Cartesian coordinate system,and flow patterns of solid phase after 1.2 second are obtained on the 0.1cm*0.1cm staggered grid,while the velocity of the gas is 0.157m/s.The results show that the flow patterns of dense phase are ascending near the center and descending near the wall. These results are in a good agreement with experimental data.