固定床颗粒堆积空隙结构的重构及其中气液流体流动与传递特征

气液并流向下固定床又称滴流床，是工业中常用的三相反应装置。其普遍存在的局部非均匀现象影响反应性能和生产安全，却难以通过传统的宏观流体力学参数和床层模型准确描述。固定床颗粒堆积构成的空隙结构不规则且呈非均匀分布，其中气液固相间相互作用机理复杂，局部流场的主导机制差异大，流动传递规律尚不明确。本项目拟引入空间统计学理论，实现对CT扫描表征的真实颗粒堆积空隙结构的定量描述和随机重构；基于插值格子-波尔兹曼方法构建复杂壁面约束的气液两相流流动传递数理模型；研究床层结构、物性和操作参数等对气液流体流动与传递特征影响的量化规律。本项目将加深对固定床非均匀空隙尺度上气液流体流动与传递机理的认识，为反应器设计和定向调控提供理论基础。

The gas-liquid cocurrent downflow packed beds or trickle beds are widely applied in chemical engineering processes. The heterogeneous flow and transport characteristics in the packed structure essentially influence the performance and security, which can’t be well described by the traditional bed-scale methods. A deep understanding of the mechanism of the gas-liquid hydrodynamics at pore-scale is obligatory. The main difficulties are the complexity of the heterogeneous packed structures and the influence of irregular geometry. In this project, the spatial multipoint statistical methods will be introduced to abstract and reconstruct the real packed structures represented by a high precision 3D CT, and numerical models will be developed based on lattice Boltzmann method to include the influence of irregular geometry wall on gas-liquid two-phase flows. Based on these theory and methodology, the influence of the shape, size and surface features of the particles, the physical properties of fluids, and the operating parameters on multiphase flows in the pore will be systematically investigated to reveal the inherent relationship. This project will provide new insights into the mechanism of gas-liquid fluid dynamics in the complex packed structures at pore-scale and provide fundamental knowledge for the design, performance estimation and targeted adjustment of reactors.