Nuclear Engineering and Technology

Korean Nuclear Society (한국원자력학회)
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Effect of packing structure on anisotropic effective thermal conductivity of thin ceramic pebble bed

  • Wang, Shuang (School of Mechanical Engineering, Anhui Polytechnic University) ;
  • Wang, Shuai (Department of Radiation Oncology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China) ;
  • Wu, Bowen (School of Mechanical Engineering, Anhui Polytechnic University) ;
  • Lu, Yuelin (School of Mechanical Engineering, Anhui Polytechnic University) ;
  • Zhang, Kefan (School of Nuclear Science and Technology, University of Science and Technology of China) ;
  • Chen, Hongli (School of Nuclear Science and Technology, University of Science and Technology of China)
  • Received : 2020.09.13
  • Accepted : 2021.01.12
  • Published : 2021.07.25
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Abstract

Helium cooled solid breeder blanket as an important blanket candidate of the Tokamak fusion reactor uses ceramic pebble bed for tritium breeding. Considering the poor effective thermal conductivity of the ceramic breeder pebble bed, thin structure of tritium breeder pebble bed is usually adopted in the blanket design. The container wall has a great influence on the thin pebble bed packing structure, especially for the assembly of mono-sized particles, and thin pebble bed will appear anisotropic effective thermal conductivity phenomenon. In this paper, thin ceramic pebble beds composed of 1 mm diameter Li4SiO4 particles are generated by the EDEM 2.7. The effective thermal conductivity of different thickness pebble beds in the three-dimensional directions are analyzed by three-dimensional thermal network method. It is observed that thin Li4SiO4 pebble bed showing anisotropic effective thermal conductivity under the practical design size. Normally, the effective thermal conductivity along the bed vertical direction is higher than the horizontal direction due to the gravity effect. As the thickness increases from 10 mm to 40 mm, the effective thermal conductivity of the pebble bed gradually increases.

Keywords

Acknowledgement

This work was supported by the Research Initiation Foundation of Anhui Polytechnic University (No. 2020YQQ032 and No. 2020YQQ030) and the Anhui Polytechnic University Fund pre research project (No. Xjky2020007).

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