竖直管气固鼓泡流化床传热机理的CPFD模拟

发布时间：2018-05-02 18:32

本文选题：计算颗粒流体力学 + 流化床　；参考：《化工学报》2016年05期

【摘要】：针对细颗粒气固鼓泡流化床中床料与竖直传热管壁面间的传热行为,在前期实验的基础上,采用计算颗粒流体力学(CPFD)方法从颗粒在传热壁面更新的角度,深入分析了传热特性与壁面气固流动行为之间的关联性。结果表明,模拟得到的传热管壁面颗粒更新通量和基于颗粒团更新模型的颗粒团平均停留时间均能很好解释实验测得的传热系数变化规律,这证实颗粒团更新是影响传热过程的控制性因素。模拟还发现随加热管从床层中心向边壁的移动,加热管周向方向上颗粒更新通量和传热系数的不均匀性都呈增大趋势。随着表观气速的增大,气泡行为导致床层颗粒内循环流率增大,这是导致颗粒团在加热管壁面上的更新频率增大以及床层与壁面间传热系数增大的根源。
[Abstract]:In view of the heat transfer behavior between the bed material and the vertical heat transfer tube wall in a fine particle gas-solid bubbling fluidized bed, based on the previous experiment, the correlation between the heat transfer characteristics and the dynamic behavior of the wall gas-solid flow is deeply analyzed by using the computational particle hydrodynamics (CPFD) method. The results show that the simulation results are obtained. The particle renewal flux of the wall surface of the heat transfer tube and the average residence time of the pellet based on the particle mass update model can well explain the change law of the heat transfer coefficient measured by the experiment. This confirms that the particle mass renewal is the controlling factor affecting the heat transfer process. The inhomogeneity of the flux and the heat transfer coefficient of the upper particles increases. With the increase of the apparent gas velocity, the bubble behavior leads to the increase in the inner circulation rate of the bed particles, which is the root of the increase in the regeneration frequency of the pellets on the wall of the heated tube and the increase of the heat transfer coefficient between the bed layer and the wall.

【作者单位】：中国石油大学(北京)重质油国家重点实验室;
【基金】：国家自然科学基金项目(21276273) 国家重点基础研究发展计划项目子课题(2012CB215004) 北京高等学校青年英才计划人才专项基金项目(YETP0675) 中国石油大学(北京)科研基金项目(2462015YQ0312)~~
【分类号】：TE96

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