不同气速下喷动床喷泉区颗粒特性的模拟分析

Numerical simulation for particle properties in spouted bed at different velocity

以欧拉多项流模型为基础,对底角锥度为60°、床直径为0.44 m的喷动床内气固两相流的动力学特性进行了模拟研究,并对不同气速下喷泉高度、颗粒体积分数、颗粒速率的变化进行分析,结果发现喷泉高度与进口气速在u/ums=1.2～1.8范围内具有良好的线性关系,拟合度可达到0.9997。固体颗粒体积分数在轴心区域较高,随着径向距离的增加逐渐下降,且随高度的增加呈现先减小后增大的趋势;颗粒体积分数受速率的影响较大,随着喷动速率的增大,颗粒体积分数趋于减小,但减小幅度不同。颗粒速度在喷泉核心区随床层高度增大而减小。同一床层高度上的颗粒速度随气速的增加而增大,但增大值不同。

The properties of gas-solid two-phase flow in spouted bed with conical 60°and cylindrical diameter 0.44 m were studied.Influences of air velocity in spouted height of fountain,particle concentration,and particle velocity were also investigated.The results showed that the relationship between fountain and air velocity was linear with a linear coefficient of 0.9997.The particle volume fraction was big and decreased with the increase of radial distance in the center of the fountain.It decreased with the increase of height in the fountain and then increased at a certain point of the fountain height.The particle volume fraction decreased gradually with air velocity increase.The decreasing particle volume fraction depended on the air velocity increase.Particle velocity decreased with the fountain height increase.It increased with the increase of air velocity.And the increasing particle velocity also depended on the air velocity increase.