球床式高温堆堆芯气固两相流耦合模拟研究  

Simulation study of gas-solid two-phase flow coupling of pebble-bed cores in a high-temperature reactor

作　　者：严安 孙喜明[1] 董玉杰[1] YAN An;SUN Ximing;DONG Yujie(Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing 100084,China)

机构地区：[1]清华大学核能与新能源技术研究院,北京100084

出　　处：《哈尔滨工程大学学报》2022年第12期1743-1749,共7页Journal of Harbin Engineering University

基　　金：国家科技重大专项(ZX069).

摘　　要：针对球床式高温气冷堆球床堆芯稠密气固两相流的热工问题,本文应用计算流体力学耦合离散单元方法进行了建模与分析。应用离散单元方法,模拟了球床堆芯420000个燃料球体在重力驱动下的随机堆积过程,分析了堆积密度的空间分布。应用计算流体力学耦合离散单元方法,结合经验关系式及物性参数模型,建立了高温堆球床堆芯的三维耦合模型,实现了球床式高温气冷堆平衡堆稳态工况模拟。通过球床式高温气冷堆全堆芯流-固-热耦合模拟计算,分析了堆芯的热工特性,得到了氦气温度、球体表面温度等重要热工参数的分布。对比分析了THERMIX与计算流体力学耦合离散单元方法不同模型的堆芯出口中心温度;曳力模型的选取对于球床压降计算结果有影响。结果表明:基于三维CFD-DEM框架的多物理场耦合模拟结果与已有的系统分析软件结果基本一致。该研究可为后续高温堆热工设计和分析软件开发提供思路。To analyze the thermal-hydraulic behaviors of the dense gas-solid two-phase flow of a pebble-bed core inside a high-temperature gas-cooled reactor,the computational fluid dynamics coupled with the discrete element method(CFD-DEM)is applied to its modeling and analysis.The DEM is used to simulate the random stacking process of 420000 spheres of fuel in pebble-bed reactor cores driven by gravity,and the spatial distribution of the packing density is analyzed.Based on the CFD-DEM,combined with the empirical relationship and physical parameter model,a three-dimensional coupled model of the pebble-bed core of a high-temperature reactor is established.The study aims to realize the simulation of the steady-state working condition of the equilibrium reactor of a pebble-bed high-temperature gas-cooled reactor.Through a fluid-solid-heat coupling simulation calculation of the whole core of the pebble-bed high-temperature gas-cooled reactor,the thermal characteristics of the core are analyzed,deriving the distribution of important thermal parameters,such as helium temperature and sphere surface temperature.The center temperatures at the core outlet of the THERMIX and CFD-DEM models are compared and analyzed.The influence of the drag model selection on the calculation results of the pressure drop in the spherical bed is studied.The results show that the multi-physics coupled simulation based on 3D CFD-DEM framework is in general agreement with existing system analysis software.This paper can provide new ideas for subsequent HTR thermal-hydraulics design and analysis software development.

关 键 词：高温气冷堆 球床式反应堆 离散单元法 计算流体力学 堆积密度 温度分布 压降分布 曳力模型 

分 类 号：TL351.1[核科学技术—核技术及应用]