부산대학교 도서관

Helium cooled solid breeder blanket as an important blanket candidate of the Tokamak fusion reactoruses ceramic pebble bed for tritium breeding. Considering the poor effective thermal conductivity of theceramic breeder pebble bed, thin structure of tritium breeder pebble bed is usually adopted in theblanket 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 effectivethermal conductivity phenomenon. In this paper, thin ceramic pebble beds composed of 1 mm diameterLi4SiO4 particles are generated by the EDEM 2.7. The effective thermal conductivity of different thicknesspebble beds in the three-dimensional directions are analyzed by three-dimensional thermal networkmethod. It is observed that thin Li4SiO4 pebble bed showing anisotropic effective thermal conductivityunder the practical design size. Normally, the effective thermal conductivity along the bed vertical directionis higher than the horizontal direction due to the gravity effect. As the thickness increases from10 mm to 40 mm, the effective thermal conductivity of the pebble bed gradually increases