Abstract: In this paper，the particle flow in a combined-moving bed reactor was simulated using the discrete element method（DEM），and the accuracy of DEM simulation was verified by a comparison with the literature results. The effects of rotational speed and open-hole size of two kinds of distributing devices were analyzed. The results showed that：①There are two kinds of flow patterns for the two distributing devices，i.e.，plug flow and funnel flow；②particle mass fluxes increased non-linearly with the increase of rotational speed and open-hole size of the distributing devices；③along the radial direction，particles were distributed more uniformly with increasing the rotational speed and open-hole size，and the distribution showed U and M shapes for the two kinds of distributing devices；④the radial distribution of particles were more uniformly downwardly along the axial direction，with values of the variance coefficient exceeding 1.0 for the fan-shaped hole distributing plate，and 0.5 for another distributing plate.

Key words: discrete element method, numerical simulation, granular flow, moving bed, distributing device

摘要： 针对复合移动床反应器内固体颗粒运动，采用离散单元法模型（DEM）考察布料器分别为扇形开口和矩形开口时，布料器转速和开口对颗粒运动的影响，并基于文献结果论证了本文模型的准确性。模拟结果表明：①对于不同布料器，颗粒在移动床中呈现平推流和汇聚流两种流动形态。②随布料器转速及开口的增加，颗粒质量通量非线性增加。③随布料器转速的增加，下落床径向上颗粒分布更均匀；随布料器开口的增大，下落床径向上颗粒分布范围变大，颗粒分布更均匀；对下落床径向上颗粒分布，布料器扇形开口时分布呈U形、矩形开口时分布呈M形。④沿反应器轴向向下，颗粒分布有均匀化趋势；扇形开口布料器对颗粒分布的离散系数大于1，矩形开口布料器对颗粒分布的离散系数约为0.5。

关键词: 离散单元法, 数值模拟, 颗粒流, 移动床, 布料器