Analysis of particle shape effect on the discharging of non-spherical particles in HTR-10 reactor core

• Published in: Nuclear engineering and design 2021-01, Vol.371, p.110934, Article 110934
• Main Authors: Cui, Xiyuan, Gui, Nan, Yang, Xingtuan, Tu, Jiyuan, Jiang, Shengyao
• Format: Article
• Language: English
• Subjects: Aspect ratio; Comparative studies; Discharge; Discrete element method; Flow characteristics; Fluidity; High temperature reactor; Industrial applications; Non-spherical particle; Particle flow; Particle shape; Pebble flow; Radial velocity; Reactors; Rotation; Shape effects; Super-ellipsoid model
• ISSN: 0029-5493; 1872-759X
• DOI: 10.1016/j.nucengdes.2020.110934

•Discrete element method and super-ellipsoid model are used to study pebble flow.•Particle shape effect on discharging pebble flow in HTR-10 reactor core is analyzed.•Shape effects on discharge flow rates and velocity distribution are compared.•Shape effects on rotation of particles during discharging process are analyzed.•Proposed shape parameters for optimizing discharge flow performance are given. The discharge flow characteristics of particles are crucial in many industrial applications, and the shape of particle is an important influencing factor to the particle flow behavior. In this study, the discrete element method (DEM) was adopted to analyze the discharge flow of non-spherical particles in HTR-10 reactor core. After model validation, the shape effect on particle flow in hopper was analyzed. The super-ellipsoid model was used to the comparative study of particles with 5 different shapes which can represent a large number of shapes, including oblate ellipsoidal particles, prolate ellipsoidal particles, circular cylindrical particles, elliptical cylindrical particles, and cubical particles, respectively. The results showed that the more stable the packing structure, the higher the efficiency of the stacked volume. But the mobility of these particles was worse than particles with good flow properties. The increase in the blockness (n1 and n2) will make the fluidity of the particles worse, and the particles with aspect ratio (Ra) between 1.5–2 show better discharge behavior. Both the axial and radial velocity can be influenced by particle shape significantly, which will result in different discharge behavior. Rotation angle and direction angle distribution are introduced to analyze the rotation motion. Cylindrical particles showed the most obvious rotation, while the ellipsoidal particles rotated in a relatively small range.