双区球床堆芯球流运动二维比例模型唯象实验

Phenomenological experiments on the pebble dynamics in 2-D scaled model of a two-region pebble-bed reactor

为研究燃料元件和慢化球呈双区分布的球床高温气冷堆球流运动规律,建立了实际堆芯的二维比例实验模型。从唯象角度实验研究了双区分布形成过程、中心区/模糊区大小与形状、滞留区等与堆芯物理和结构设计相关问题。结果表明:球流运动具有随机特性,但宏观上具有确定性,本实验条件下可以形成稳定的双区分布;加装导向挡板对双区的形成及其形状、大小没有影响,但对双区交界处的交混有改善作用;本实验条件下存在滞留区,可通过改变本体底部设计加以消除。

Experiments were conducted on a 2-D scale real pebble-bed reactor core to study the pebble dynamics in a two-region pebble-bed high-temperature reactor core with fuel pebble and graphite pebble region. The dynamics related to the reactor core physical calculations and structural design were studied, including the two-region arrangement, the size and shape of the central pebble column, the dispersion in the mixing region, and the stagnant regions characteristics. The results show that a stable two-region distribution can be established for the experimental conditions. Guide plates inserted in the top section can prevent mixing between the two pebble regions, but do not impact the two-region distribution or the size and shape of the central column. Stagnant regions were observed, but they should be improved or even eliminated by improving the cone shape design at the bottom.