Numerical influence analysis of the packing structure on ceramic breeder pebble beds

摘要

The packing structure of the pebble bed has an impact on its thermomechanical behavior and tritium exaction in the solid blanket, analysis of the packing structure of the pebble bed is of great significance for the design and application of the solid blanket. This paper uses the Discrete Element Method (DEM) for the numerical simulation, the simulation model similar to the shape of tritium breeding pebble bed in the solid blanket was generated by pouring the particles into the prismatic container under the gravity. The effects of the L-y/D ratios (L-y means the smallest thickness of the pebble bed and D refers to the diameter of the particle) and the coefficient of static friction between the particles on the packing structure of Li4SiO4 pebble bed were studied. The change rules of packing fraction and average coordination number of the Li4SiO4 pebble bed were obtained. It is found that the size of the container has a great influence on the packing fraction and the average coordination number of the pebble bed, the influence can be ignored when the L-y/D is higher than 30.