选煤流化床内气固流动的数值建模

Modeling of the gas-solid flow in a coal beneficiation fluidized bed

为了对选煤流化床内低速浓相气固流动进行数值建模,采用Euler-Euler模型对选煤流化床内的气固流动进行了数值模拟。考虑了一系列子模型对流动结构的影响,通过分析各工况下的流动特征并将模拟结果与实验进行对比,最终确定了一套可应用于选煤流化床内浓相低速鼓泡流动行为的数值模型。结果表明,Syamlal气固曳力模型对选煤流化床流动特征的预测更合理,偏微分颗粒温度模型(PDE)能更准确地描述颗粒脉动行为。在浓相气固选煤流化床中,应该选择Dispersed k-ε模型来考虑气相的湍流行为,并采用部分滑移条件分析颗粒-壁面间的相互作用。

The gas-solid flow in a coal beneficiation fluidized bed （CBFB） model is modeled in this work using an Eulerian-Eulerian model. A series of sub-models are validated by comparisons to experimental data. The results show that the Syamlal drag model predicts reasonable flow patterns in the CBFB. The partial differential equation （PDE） granular temperature model accurately predicts the particle kinetics. The dispersed k-ε turbulence model well describes the gas turbulence and the partial slip wall condition should be used to model the particle-wall interactions in the dense flow.