固态氚增殖包层中球床堆积性能研究

基于球床堆积实验和离散元数值模拟对包层中球床的堆积性能做了初步研究。圆柱形一元(单尺寸颗粒)球床的堆积性能的结果显示随着球床直径与颗粒直径比的增大，球床的平均堆积因子逐渐增高，实验与模拟结果一致；采用二元颗粒(双尺寸颗粒)、提高颗粒粒度比可以显著提高球床的堆积因子，二元球床的堆积因子随着大颗粒体积分数的增加先增加后减小，在大颗粒体积分数约为60%~80%时达到最大。优化了二元球床的填充工艺，最终二元球床的堆积因子基本达到0.8，但球床的均匀性欠佳。

Investigation of packing behavior of pebble bed in solid tritium breeder blanket

The packing behaviors of pebble bed in blanket were investigated by packing experiment and discrete element modeling. The packing behaviors of cylinder mono-sized pebble beds show that the average packing factor is gradually increased with increase of the diameter ratio of the bed to pebbles. The experimental and simulated results of cylinder mono-sized pebble beds are in good agreement. Using binary-sized pebble packing and increasing the size ratio of binary pebbles can increase the packing factor of pebble bed, significantly. For binary-sized pebble bed, the average packing factor increases first and then decreases with the increase of the large pebble volume fraction. The maximum value is achieved when the larger pebble volume fraction is about 60%~80%. By optimizing the filling process of the pebble bed, the packing factor of the binary-sized pebble bed has reached 0.8, but the uniformity of the binary-sized bed is poor.