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为了探寻速度进口边界条件对边壁进风鼓泡流化床床内气泡行为的影响,根据欧拉-欧拉双流体模型,应用标准kε-方程模型处理气体湍流流动,分别采用均匀进风速度边界条件、脉动项按正态分布和脉动项按正弦分布的脉动进风速度边界条件,对鼓泡床内的气固两相流动过程进行了数值模拟.结果表明:采用脉动进风速度边界条件时,在非射流孔道处气体可形成气泡,气泡的上升速度比匀速进风时小;气体能够充分地与固体颗粒相互作用,床层中的空隙率主频较小;在设置边界条件时考虑脉动能够更合理地预测和分析床内气泡的尺寸、速度等特性.
In order to investigate the influence of velocity inlet boundary conditions on bubble behavior in bubbling fluidized bed with inlet air, the standard turbulent flow was treated by standard kε-equation model according to the Euler-Euler dual fluid model. The uniform inlet velocity Boundary condition and pulsation term are used to numerically simulate the gas-solid two-phase flow in the bubbling bed based on the sinusoidal distribution of the pulsating inlet velocity and the boundary condition of the pulsating term.The results show that the boundary conditions , The gas can form bubbles in the non-jet channels, and the bubble rising speed is smaller than that of the uniform inlet air. The gas can fully interact with the solid particles, and the main frequency of the void in the bed is small. When setting the boundary conditions, Fluctuations can be more reasonable to predict and analyze the size of the bubble in the bed, speed and other characteristics.