Session: K20-03: APPLICATIONS OF COMPUTATIONAL HEAT TRANSFER I

Paper Number: 121105

121105 - Coupled Flow and Thermal Radiation Simulation for Molten Salt Flow in Random Pebble Bed 

Abstract: 

The design of a pebble bed core cooled by molten salt represents one of the Gen IV nuclear reactor concepts. This design lays the foundation for the Fluoride High-temperature Reactor (FHR), which harnesses the advantages of both pebble bed and molten salt cooling systems. While thermal radiation plays a negligible role in heat transfer under forced convection, it becomes a significant factor under mixed convection and natural convection conditions, profoundly altering the temperature profile.

 

In our earlier investigation of pebble bed behavior, we did not consider the influence of thermal radiation in our simulations. To address this, we incorporated the P1 model into the Spectral Element Code Nek5000/NekRS. The P1 model necessitates an optical length greater than 3, a condition consistent with the characteristics of molten salt within the pebble bed.

 

Our initial step involved verifying and validating the P1 model by comparing it to exact solutions and using OpenFOAM for benchmark cases. Subsequently, we applied the P1 model to simulate heat transfer within a random pebble bed containing 146 pebbles, operating at an exceptionally low Reynolds number. To ensure the accuracy of our findings, we also conducted a parallel simulation of the same scenario using OpenFOAM as a reference.

Presenting Author: Haomin Yuan Argonne National Laboratory

Presenting Author Biography: Haomin Yuan, as known as Kirk, is currently a Principal Nuclear Engineer at the Nuclear Science and Engineering division in Argonne National Laboratory. He graduated from University of Wisconsin Madison at 2015, and joined Argonne shortly after that. His research interested included, computational fluid dynamic, nuclear thermal hydraulic, thermal radiation, and electrochemistry.

Authors:

Haomin Yuan Argonne National Laboratory
Dezhi Dai Argonne National Laboratory
Yu-Hsiang Lan University of Illinois Urbana-Champaign