关键词: 湍动流化床, 数值模拟, 计算颗粒流体力学, 流化特性

Abstract: The Eulerian-Lagrangian two-fluid model was used to study the fluidization characteristics of the turbulent bed by numerical simulation. The pressure, solid holdup, particle velocity and particle size distribution of the bed were studied. The results show that the central pressure gradually decreases along the axial height, while the solid holdup gradually decreases along the axial elevation, showing a “ε”-type distribution. Accordingly, the bed is divided into a bottom dense phase zone, a middle transition zone, and a top dilute phase zone. In the dilute phase region, the core-annular-structure gradually decreases along axial direction until it disappears. Besides, the axial velocity of the particles fluctuates in the radial direction, which in the central zone is generally greater than that at the wall, and the position where the particles falling moves from side wall to the center. The average particle size gradually decreases along the axial axis, and the particle diameter distribution of the dilute phase zone is relatively uniform.

Key words: turbulent fluidized bed, numerical simulation, computational particle hydrodynamics/CPFD, fluidization characteristics