Numerical Study on Heat Transfer Characteristic of Granular Flow Around Different Fin Elements

Due to the low cost and the stable operation condition, the gravity-driven moving bed has great application potentials in the waste heat recovery of hot solid granule. However, the relevant technology of heat transfer enhancement is still in advancing. In this work, discrete element method (DEM) was applied to investigate the heat transfer of granular flow around different fin elements. It was found that, the fin can increase the heat transfer area so that the heat transfer is significantly improved, while the detailed characteristics of granular flow will differ with the fin element. The heat transfer between the granular flow and different surfaces, is integrated by the particle update, the particle contact, the competitive particle mixing as well as the surface area. In general, in the upstream side, the inclined plane can increase the area with the relatively smooth flow. Therefore, it is more beneficial to improve the heat transfer. By contrast, the arc surface has more advantages in the downstream, because the particle contact and the competitive particle mixing will account for more roles here.