基于DDPM模型的化学链燃烧中二元颗粒定向分离过程放大模拟

以拉格朗日法为基础，采用耦合离散元法(DEM)颗粒碰撞模型的稠密离散相模型(DDPM)对兆瓦级化学链燃烧放大系统中炭颗粒分离器进行数值模拟研究，探究其中载氧体(OC)/煤焦(Char)二元颗粒物的定向分离特性，进一步研究了热态条件和下降管出口压力对二元颗粒物分离效果的影响，为炭颗粒分离器在热态条件下的运行稳定性以及下端与空气反应器之间的独立性提供数据支撑。结果表明：放大后的炭颗粒分离器因为分离空间与时间的增加，使载氧体/煤焦二元颗粒物的分离效果更好；同时，在热态条件下因气体黏度增大，使得煤焦分离效率进一步提升；此外，下降管出口压力的适度提升也能提高炭颗粒分离器的分离效率。

Scale-up Simulation of Directional Separation Process of Binary Particles in Chemical Looping Combustion Based on DDPM Model

The Lagrangian method in terms of the dense discrete phase model (DDPM) coupled with discrete element method(DEM)collision model was employed to conduct a scale-up numerical study on the carbon particle stripper of the MWth-level chemical looping combustion system. The directional separation characteristics of binary particles of oxygen carrier and char in the large-scale carbon particle stripper were investigated. The effects of the temperature and the outlet pressure of the downcomer on the separation performance of the binary particles were further studied to ensure the operation stability of the carbon particle stripper under the thermal conditions and the independence with the air reactor. The results show that the enlarged carbon particle stripper has a better separation effect due to the increase in the separation space and time. The separation efficiency of char could be further increased under hot conditions because of the increase in gas viscosity. Moreover, a moderate increase in the outlet pressure of the downcomer could also promote the separation efficiency of the carbon particle stripper.