小管径/粒径比有序填充床流动传热性能及场协同分析

Flow and heat transfer performance and field synergy analysis of structured packed beds with low tube-to-particle diameter ratios

以小管径/粒径比有序填充床为研究对象,分析了管径/粒径比对填充床流动与传热特性的影响规律,并应用场协同理论研究了床层内部不同物理量场之间的耦合协同关系。结果表明,颗粒填充通道内压力沿轴向的变化趋势在入口段、充分发展段及出口段各不相同,且不同管径/粒径比时均具有相似的规律。当雷诺数相同时,努塞尔数与阻力系数均随着管径/粒径比的增大而增加。同时,随着管径/粒径比的增大,速度场与温度梯度场之间的协同性变好,而速度场与压力梯度场之间的协同性变差。此外,拟合得到了适用于小管径/粒径比有序填充床的传热与阻力性能准则关联式,可为其合理设计及校核提供理论依据。

Numerical investigation of structured packed beds with low tube-to-particle diameter ratios was studied to investigate the effects of tube-to-particle diameter ratios on flow and heat transfer performance. The synergy effects of process coupling between physical quantity fields were analyzed using the field synergy theory. The results indicate that pressure variation along the axial direction is different at the inlet region, fully developed region and outlet region of the particle packed channel. Similar results were found for systems with different tube-to-particle diameter ratios. Both the Nusselt number and friction factor increased with the increase of the tube-to-particle diameter ratio at certain Reynolds numbers. The synergy between the velocity field and temperature gradient field increased with larger tube-to-particle diameter ratios, whereas the synergy between the velocity field and pressure gradient field decreased. Finally, Nusselt number correlations and friction factor correlations of structured packed beds with low tube-to-particle diameter ratio were fitted. These results can provide theoretical basis for the design and verification of packed beds.