A novel heterogeneous binding model for simulating nuclear fuel particle FB-CVD coating process based on CFD-DEM concept--颗粒学报PARTICUOLOGY

Jiang, L., Gong, M., Lan, R., Tian, Y., Liu, R., Liu, B., . . . Liu, M. (2025). A novel heterogeneous binding model for simulating nuclear fuel particle FB-CVD coating process based on CFD-DEM concept. Particuology, 103, 1-17. https://doi.org/10.1016/j.partic.2025.05.006

A novel heterogeneous binding model for simulating nuclear fuel particle FB-CVD coating process based on CFD-DEM concept

Lin Jiang^a, Ming Gong^b, Rui Lan^a, Yu Tian^a, Rongzheng Liu^a, Bing Liu^a, Youlin Shao^a, Malin Liu^a *

a Institute of Nuclear and New Energy Technology, Collaborative Innovation Center of Advanced Nuclear Energy Technology, Tsinghua University, Beijing, 100084, China b School of Chemical Engineering, Northwest University, Xi'an, 710069, China

10.1016/j.partic.2025.05.006

Volume 103, August 2025, Pages 1-17

Received 28 February 2025, Revised 21 April 2025, Accepted 12 May 2025, Available online 17 May 2025, Version of Record 27 May 2025.

E-mail: liumalin@tsinghua.edu.cn

Highlights

• A particle-binding-type heterogeneous layer (PBT-HL) coating model was proposed.

• Influence of fluidization on deposition rate was systematically investigated.

• Intra-particle coating uniformity was depicted by non-concentric binding model.

• CFD software was coupled with adjustable in-house code to achieve the novel model.

Abstract

Preparation of coated fuel particles using the fluidized bed-chemical vapor deposition (FB-CVD) process is a key step in the production of nuclear fuel particles for high-temperature gas-cooled reactors (HTGRs). The process of applying four coating layers on high-density uranium dioxide kernel particles results in an increase in particle size and a decrease in density. Most existing coating models at the single-particle scale assume homogeneous coating under thin layer conditions, which makes it difficult to accurately describe the actual evolution process of coated particles preparation. Therefore, this study proposed a particle-binding-type heterogeneous layer (PBT-HL) model combined the binding concept with the CFD-DEM method, which accounts for dynamic changes in the density of coated particles. Then model validation in terms of gas-solid interaction and mass transfer, and coating condition parameter analysis were given at first. The results showed that changes in operational parameters such as the layer density, loading capacity, and inlet gas velocity can affect the spouted fluidization state, further influencing the deposition rate and coating effectiveness. These findings also suggested that the heterogeneous coating model in binding configuration can be further developed to study the anisotropy of single-particle layer thickness quantitatively. In summary, the variable-density PBT-HL model approximates the actual coating layer preparation process more closely, aiding in the acquisition of coating process information and guiding the optimization of coating techniques. The proposed heterogeneous coating model also holds potential for further development to characterize the intra-particle uniformity and the conformality feature of FB-CVD technique in the future.

Graphical abstract

Keywords

Nuclear fuel; Particle coating process; FB-CVD; CFD-DEM; Heterogeneous layer model; Conical spouted bed

文章导读