795 / 2019-07-15 17:22:52

CFD-DEM modeling of purge gas flow in ceramic breeder pebble bed

全体主题 > 聚变工程与聚变堆设计

In Helium Cooled Ceramic Breeder (HCCB) blanket of fusion reactors, lithium ceramic breeder pebble bed is used to produce tritium that is purged out by low-pressure helium gas. The purging process of tritium and the helium gas flow behaviors are crucial for solid breeding blanket’s design and operating safety. Moreover, the packing structure of the pebble bed is related to the gas flow behaviors which depends on particle properties and packing history. The challenge of applying the Eulerian method to predict the purge gas flow around particles is the construction of the computation grid, which significantly limits the number of particles could be considered in the simulations. In this work, a novel immersed boundary method (IBM) initially proposed by Zhao et al. is adopted to solve the fluid-particle interaction. The packing of granular assembly in pebble packed bed is modeled through conducting the discrete element simulations. The influences of particle properties and also the packing method on the packing structure are systematically investigated. The packing information is then imported into the Eulerian simulations. The simulation results demonstrated that the non-uniformity of porosity, especially the more porous nature of the region adjacent to the wall,