化工学报 ›› 2014, Vol. 65 ›› Issue (9): 3323-3330.DOI: 10.3969/j.issn.0438-1157.2014.09.003

• 流体力学与传递现象 • 上一篇    下一篇

微型流化床内混合特性的数值模拟

杨旭1,2, 刘雅宁2, 余剑2, 蒋富明1, 韩永生2, 许光文2, 葛蔚2   

  1. 1 吉林大学化学学院, 吉林 长春 130012;
    2 中国科学院过程工程研究所多相复杂系统国家重点实验室, 北京 100190
  • 收稿日期:2014-01-16 修回日期:2014-03-25 出版日期:2014-09-05 发布日期:2014-09-05
  • 通讯作者: 刘雅宁,余剑
  • 基金资助:

    国家自然科学基金项目(21306201,21225628,21106156);国家重大科学仪器专项(2011YQ120039)。

Numerical simulation of mixing characteristics of trace sample and bed material in micro fluidized bed reaction analyzer

YANG Xu1,2, LIU Yaning2, YU Jian2, JIANG Fuming1, HAN Yongsheng2, XU Guangwen2, GE Wei2   

  1. 1 School of Chemistry, Jilin University, Changchun 130012, Jilin, China;
    2 State Key Laboratory of Multi-phase Complex System, Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2014-01-16 Revised:2014-03-25 Online:2014-09-05 Published:2014-09-05
  • Supported by:

    supported by the National Natural Science Foundation of China (21306201, 21225628, 21106156) and the National Instrumentation Grant (2011YQ120039).

摘要: 微型流化床反应分析仪是中国科学院过程工程研究所研制的具有等温微分反应特性,且适合于气固反应分析的新仪器。细微样品与高温流化介质的瞬间混合是该仪器实现等温微分的必要条件。针对如何满足该要求,基于欧拉多流体模型对连接不同进样器的微型反应器本体进行了三维数值模拟,得到了不同喷口结构和位置下的流动图景及混合区浓度的相对标准偏差曲线,定量表征了各种进样器的混合质量。同时采用高速摄像手段获得了冷态实验中颗粒流动的快照,验证了模拟计算结果的可靠性。模拟结果对脉冲射流微量进样器结构的优化提出了如下建议:进样细管应避免采用弯角喷口,弯角结构会导致脉冲进样载流气喷出方向与流化气流相逆,使得细微颗粒试样堆积滞留,影响混合效果。

关键词: 微型流化床, 混合, 喷口结构, 数值模拟, 优化

Abstract: The micro fluidized bed reaction analyzer (MFBRA) developed by Institute of Process Engineering, Chinese Academy of Sciences has isothermal differential characteristics and is suitable for gas-solids fast reaction analysis, including the measurement of reaction rate and kinetic parameters. The instantaneously intensive particle mixing between trace sample in milligrams and high-temperature fluidized material is the essential condition to keep isothermal differential characteristics of the micro fluidized bed reactor. Therefore a three-dimensional numerical simulation based on the Eulerian multi-fluid model was performed for the micro fluidized bed connected with different gas jet structures. The instantaneous flow structures and quantitative mixing characterizations for different injector structures and locations were obtained. Experiments were conducted through measurements using high speed camera to capture the instantaneous solids flow pictures in the bed. Comparison revealed good qualitative agreement between experiment and simulation. The simulation results suggested that the injector should avoid the bending angle that confronted the injected gas with the fluidizing gas or left the trace sample in the injector.

Key words: micro fluidized bed, mixing, injector structure, numerical simulation, optimization

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