Effect of pebble size and bed dimension on the distribution of voidages in pebble bed reactor

The HTR-10 built at Tsinghua University is an advanced pebble bed reactor because of its inherent safety and economic efficiency. It is fundamental to explore the voidage of the pebble bed. The existing experimental bed is limited in depth and contains mono-size pebbles. The effects of pebble size and bed dimension of voidage distribution are still not well known. In this work, the discrete element method is used to simulate the static packing of pebbles of three sizes in 2D and 3D pebble beds under the same load. The effects of bed dimension and pebble size on voidage distribution are analyzed. The results are useful for better understanding of the voidage distribution of pebble bed reactor and the effects of bed dimension and particle size as well as the wall effects.