球团流与球流在球床内的混合卸料特性研究

Binary Mixture Discharging Characteristics of Pebble Cluster Flow and Pebble Flow in Pebble Bed

为更好地了解球床中球团与单球的双组分体系的流动特性,本文采用离散单元法模拟分析了球床中球团与单球二元混合颗粒材料的卸料特性。球团由3个粘接的单球通过刚性bond组合而成,形成60°、90°、120°和180°夹角。不同数量占比的球团和单球从球床底部的卸料口混合卸出,定量分析了球团组合夹角和球团数量占比对球床双组分混合球流流动特性的影响。研究结果表明,球团的存在会降低卸料速率,定量分析该降低程度与球团的粘接夹角及球团数量占比的关系后,发现卸料速率与二者均存在一定负相关性,即卸料速率随球团夹角及球团数量占比的增加而减小。

In order to better understand the flow features of binary mixtures in pebble bed which is composed of pebble clusters and pebbles,discharging characteristics of the binary mixture material of pebble cluster and pebbles were simulated by DEM.The pebble cluster was composed of three particles connected by rigid bonds,forming angles of 60°,90°,120°and 180°and being discharged from the discharging hole at the bottom of pebble bed with different number fractions.The discharging characteristics of pebble clusters and pebbles of different number fractions and included angles were quantified.The results show that the existence of pebble clusters can reduce the discharging rate,and the degree of reduction is negatively correlated with the increase of the included angles and the number fraction of pebble clusters.When the included angle and the number fraction of pebble clusters increase,the discharging rate reduces.