Coupled CFD-DEM analysis of bouyant pebble bed experiment
No Thumbnail Available
Date
2017-05
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Americian Nuclear Association
Abstract
This study investigates the flow dynamics between a dense fluid and less dense solid pebbles, within a scaled experiment of a pebble bed, molten salt-cooled reactor (PB-MSR). Compared to gas-cooled pebble bed reactors there are differing flow dynamics, particularly of the pebbles themselves due to them being buoyant in the surrounding coolant, and of the fluid due to the much higher density and viscosity, combined with lower flow velocities. Utilising coupled Computational Fluid Dynamics-Discrete Element Methods (CFD-DEM), the packing structure of the pebbles, and the characteristic fluid flow structures through the packed pebble bed are investigated. The current analysis is of the pebble recirculation experiment (PREX) conducted at UC Berkeley, in which polypropylene spheres are used in conjunction with water to simulate a scaled pebble-bed reactor core’s pressure drop and packing structure. Current CFD-DEM results have shown the methods and models used within the simulation are capable of effectively describing the experimental pressure drop results of PREX, with simulation results in agreement with experimental results. The analysis extends to include the localized flow structures that are expected to be observed in flow through a packed bed experiencing spatially varying packing fractions due to wall effects. The coupled nature of the method employed includes the pebble-pebble, and pebble-fluid exchange of physical quantities for the 8,300 discrete pebbles used in the original experiment. This work will build into an effective analysis tool for PB-MSRs, and will later be expanded to incorporate heating profiles determined via neutronic modeling for heat transfer modelling of planned demonstration reactor designs such as the TMSR-SF1. © (2017) by NURETH-17
Description
Keywords
Flow rate, Pebble bed reactors, Dynamics, Coolants, Heating, Reactors, Wall effects
Citation
Mardus-Hall, R., Ho, M., Yeho, G. H., & Timchenko, V. (2017). Coupled CFD-DEM analysis of bouyant pebble bed experiment. Paper presented to the 17th International Topical Meeting on Nuclear Reactor Thermal Hydraulics, NURETH 2017, September 3-8, 2017, Xi'an, Shaanxi, China. In 17th International Topical Meeting on Nuclear Reactor Thermal Hydraulics (NURETH-17), Xi'an, China, 3 - 8 September 2017, (Vol 7, pp. 3652-3662). Red Hook, NY : Curren Associates Inc.