双锥导流式进气分布器内流场的数值模拟

Numerical Simulation of the Flow Field in Double Cone-Diversion Gas Distributor

双锥导流式进气分布器是针对大型反应器开发的进气均布装置,今利用FLUENT软件采用κ-ε湍流模型,对其在不同结构参数下的流场分布进行了数值模拟。考察了分布器外锥对分布器性能的影响,通过改变外锥上导流槽的尺寸和方位,得出了在既定的床径下达到沿分布器内锥外表面压力均布要求时的外锥最优尺寸。通过模拟分布器内锥在不同的开孔率及四个不同锥角时床内的流场分布,考察了气体分布随内锥开孔率及锥角的变化趋势,分析得出使分布器压降低,流场分布最优时的内锥开孔率及锥角分别为0.89%、60°。并与实验测试结果进行了比较,模拟结果与实验结果基本吻合。

Double cone intake distributor, a new type of symmetric intake device, was designed and developed for large-scale reactor. In order to evaluate the proposed device, FLUENT software was used to simulate the flow fields of the new type distributor with different structural parameters. In this work, the κ-ε turbulent model was adopted to investigate the effect of the size and location of the drained cells on the outside cone. Then, for a given bed dimension, the optimal drained cell size and location on the outside cone were obtained, using them the demand of forming a well pressure distribution along the outside surface of the inside cone of the distributor can be matched. Additionally, the effects of the aperture ratio on the inside cone and the change of the cone angle on the flow distribution were also studied via simulating the flow field distributions of the fluidized bed using various distributors with inside cones having different aperture ratios and cone angles. The results show that the proposed new type device has better flow distribution and lower pressure drop when the aperture ratio of the inside cone is 0.89% and the cone angle is 60°. The measuring results of the experiments agree well with those obtained by simulation, and it indicates that the numerical simulation can forecast the flow field well.