基于孔隙尺度的填充床内热态流场数值研究

Pore-Level Numerical Simulation of Hot Flow Field in a Packed Bed

利用孔隙尺度介观方法对交错排列的固体小球的三维填充床进行数值模拟。研究高温条件下,考虑小球内部的热传导和小球表面的辐射换热时,固体小球和流体之间热的非平衡性以及孔隙内的流动特性。数值计算与实验结果吻合较好。结果表明:除进出口通道外,填充床内同相和异相之间都存在热的非平衡性,气相处的温度变化比气固两相交替处的温度变化更剧烈;无量纲速度分布呈周期性变化,气相处最大无量纲速度在13~14之间,最小无量纲速度约为0.5。

Numerical simulations of pore-level were used to numerically evaluate the flow and thermal non-equilibrium of staggered sporous medium sphere arranged in a 3 D packed bed,which is under the conditions of the high-temperature,and the heat transfer inside the particles and the radiation heat transfer on the surface of the particles are considered.The simulation results qualitatively agree with the experimental data.The results show that there is thermal non-equilibrium between the in-phase and out-of-phase of the packed bed except for the inlet and outlet channels.The frequency of temperature change at the gas phase is more severe than that at the gas-solid phase.Additional,the dimensionless velocity distribution changes periodically with the maximum dimensionless velocity between 13-14 in the gas phase,and a minimum dimensionless velocity is about 0.5.