多尺寸颗粒堆积多孔介质床有效直径研究

Study on the Effective Diameter of Porous Bed Packed with Multi-Sizes Particles

本文针对多尺寸颗粒堆积组成的多孔介质碎片床,研究其冷却性分析模型中有效直径的选取准则。基于Ergun方程和针对性实验,验证多尺寸颗粒组成的多孔介质床的有效直径及其相关计算方法。研究结果表明,多孔介质碎片床的有效直径与流体在多孔介质内的流动雷诺数有关,当雷诺数较低时(Re_p<7),面积平均直径可以表征多孔介质的有效直径;随着流动雷诺数的增加(Re_p>7),长度平均直径更加接近其有效直径。

Motivated by reducing uncertainties in coolability analysis of porous bed,the focus of present study is to find a mean particle diameter(also called effective particle diameter) for the porous bed packed with multi-sizes particles.Based on the Ergun equation and the specific experiment study,the prediction with different mean diameters are compared and the selection rules are proposed.The results showed that,the effective diameter of porous bed packed with multi-sizes particles can be presented by the area mean diameter when the Re number is below 7,while the length mean diameter is more close to the effective diameter when the Re number is above 7.