Abstract: Based on the coupled analysis method of computational fluid dynamics and discrete element method, the flow characteristics such as the velocity distribution and outlet of the helium-cooled solid proliferating blanket pebble bed were studied, as well as the changes in the velocity of the broken lithium orthosilicate powder over time and the variation of the powder quantity with the helium gas inlet flow rate. The results show that the normalized helium velocity with the helium inlet flow rate is independent of the inlet flow rate in the direction of helium flow, with larger changes in velocity near the edge of the pebble bed and smaller changes in the middle of the pebble bed, while the normalized velocity of the powder has little to do with the inlet flow rate and will gradually stabilize with the sweeping time; for small particle size powders, the higher the gas flow rate, the easier to be blown out of the pebble bed, while for large size powders, due to their large volume, there are blockages in the pebble bed.

Key words: Helium cooled blanket, Li₄SiO₄ pebble bed, Computational fluid dynamics, Discrete element method

摘要： 基于计算流体力学和离散元耦合分析，研究了氦冷固态增殖包层球床中吹扫氦气的速度分布和破碎的正硅酸锂粉末速度随时间的变化及粉末数量随氦气入口流速变化。模拟结果表明，在吹扫氦气流动方向上，用入口流速归一化的氦气速度分布与入口流速无关，在靠近球床边缘速度变化较大，在球床中部速度变化较小；用入口流速归一化的粉末平均速度与入口流速关系不大，会随吹扫时间逐渐趋于稳定；对小粒径粉末，吹扫气体流速越大，越容易被吹出球床，对大粒径粉末，因其本身体积过大，易在球床中形成堵塞。

关键词: 氦冷包层, 正硅酸锂球床, 计算流体力学, 离散单元法