Study of heat transfer by using DEM–CFD method in a randomly packed pebble-bed reactor

作     者：Qiang Niu Na-Xiu Wang 

作者机构：Shanghai Institute of Applied PhysicsChinese Academy of Sciences CAS Innovative Academies in TMSR Energy SystemChinese Academy of Sciences University of Chinese Academy of Sciences 

出 版 物：《Nuclear Science and Techniques》 (核技术（英文）)

年 卷 期：2019年第30卷第2期

页      面：123-134页

核心收录：

学科分类：08[工学] 0827[工学-核科学与技术] 

基　　金：supported by the Chinese TMSR Strategic Pioneer Science and Technology Project(No.XDA02010000) the Frontier Science Key Program of the Chinese Academy of Sciences(No.QYZDY-SSW-JSC016) 

主　　题：Discrete element method Computational fluid dynamics Pebble bed Heat transfer Natural convection 

摘      要：The pebble-bed reactor is one of the most promising designs for the nuclear energy industry. In this paper,a discrete element method-computational fluid dynamics(DEM-CFD) approach that includes thermal conduction, radiation, and natural convection mechanisms was proposed to simulate the thermal-fluid phenomena after the failure of forced circulation cooling system in a pebble-bed core. The whole large-scale packed bed was created using the DEM technique, and the calculated radial porosity of the bed was validated with empirical correlations reported by researchers. To reduce computational costs, a segment of the bed was extracted, which served as a good representative of the large-scale packed bed for CFD calculation. The temperature distributions simulated with two different fluids in this DEM-CFD approach were in good agreement with SANA experimental data. The influence of the natural convection mechanism on heat transfer must be taken into account for coolants with strong convective capacity. The proposed DEM-CFD methodology offers a computationally efficient and widely applied method for understanding the heat transfer process in a pebble-bed core. The method can also be easily extended to assess the passive safety features of newly designed fluoride-salt-cooled pebble-bed reactors.