旋流流化床内的流动及传热特性

Flow and heat transfer characteristics in swirling fluidized bed

采用欧拉-拉格朗日混合方法,对旋流流化床的流动及传热性能进行相关研究;对旋流流化床中床层局部空隙率和颗粒旋流速度进行预测,在此基础上探讨反应器内壁面的磨损行为,分析运行状态对于磨损行为的影响;进一步对床层与壁面间的传热行为以及气固相间传热行为、操作速度的影响等进行研究。结果表明:床层空隙率分布以及颗粒旋流速度大小对于操作速度的变化较为敏感,稳定旋流模式下壁面磨损大幅增强;小颗粒相表现出更好的相间传热性能。

In this paper,a hybrid Eulerian-Lagrangian approach was used to study the flow and heat transfer performance of a swirling fluidized bed.Based on the prediction of local bed voidage and particle swirling velocity in the swirling fluidized bed,the wear behavior of the wall was studied,and the influence of operating conditions on the wear behavior was analyzed.Moreover,the bed-to-wall heat transfer and gas-solid interphase heat transfer were analyzed,and the influence of operating speed was also considered.The results show that the bed voidage distribution in the bed and the swirl velocity of particles are sensitive to the change of operation gas velocity,and the wall wear increases greatly in the stable swirling mode.In addition,small particles show better interphase heat transfer performance than others.