HTR-PM-based 3D pebble flow simulation on the effects of base angle, recirculation mode and coefficient of friction
This work shows basic features of pebble flow in HTR-PM via DEM simulation, in accompany with pebbled beds of varied base angles, friction coefficients and recirculation modes. The effects of base angles, friction coefficients and recirculation modes on the characteristics of pebble flows are explored. Beside phenomenological observation by pebble stripes, the three-dimensional pebble spindles and pebble streamlines defined in the Lagrangian and Eulerian framework respectively are all computed and analyzed quantitatively to give full description of pebble flows. The probability density function of horizontal distribution is computed to quantify pebble diffusion in the pebble spindle. The pebble streamlines are also fitted with modeling functions well to give useful indications for reactor design, and the fitting coefficients under various conditions are provided. The simulation results will be useful for better understanding and predictions of the real pebble beds, as well as their influencing factors.
Keywords: Pebble bed reactor, Pebble flow, HTR-PM, Base angle, Recirculation rate, Discrete element method