循环流化床相似准则及数值验证  

Numerical investigation on scale-up rule of circulating fluidized bed

作　　者：谢劲超 张楠[2] 范天博[1] 刘新华[2] Jinchao XIE;Nan ZHANG;Tianbo FAN;Xinhua LIU(College of Chemical Engineering,Shenyang University of Chemical Technology,Shenyang,Liaoning 110142,China;State Key Laboratory of Multiphase Complex Systems,Institute of Process Engineering,Chinese Academy of Sciences,Beijing 100190,China)

机构地区：[1]沈阳化工大学化工学院,辽宁沈阳110142 [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

出　　处：《过程工程学报》2024年第3期326-337,共12页The Chinese Journal of Process Engineering

基　　金：国家自然基金重点联合项目(编号:U1710251)。

摘　　要：基于适用于同一装置的Shi相似准则和适用于不同装置的Horio相似准则,本研究提出了不受颗粒直径与反应器直径比限制的循环流化床流动相似准则。通过数值模拟方式验证了已有Shi准则在同一装置中的适用性,同时也是对所采用数值模型的验证,随后在不同比例装置中对本研究所提出的相似准则进行了模拟。对不同比例装置中气速变化、颗粒直径变化以及气速和颗粒直径同时变化的工况进行模拟,结果表明所提出的相似准则在固相浓度轴向分布、固相浓度径向分布和无因次速度径向分布上具有相似性,进一步通过压力波动特征探讨了宏观相似下的介观分布特征。Circulating fluidized beds have been widely used in industry,and scaling laws have been proposed during research and development from lab-scale units to industry plants.The particle diameter ratio has to be changed to keep the scale-up ratio,which may change the particle classification from Geldart A to Geldart B and even change the fluidization regime,thus limiting the utilization of these scale-up rules.A new scale-up rule,which can keep material properties or operating conditions unchanged,is thus proposed based on the Shi scale-up rule applicable for the same circulating fluidized bed and the Horio scale-up rule suitable for different circulating fluidized beds.The Euler-Lagrange model coupled with the EMMS drag coefficient was used to simulate the flow behavior in a circulating fluidized bed,and the rationality of the Shi scale-up rule was further verified by these simulations.The new scale-up rule proposed was then validated under the conditions of fixed superficial gas velocity,fixed superficial particle diameter and unrestricted combination of the gas velocity and the particle diameter in different circulating fluidized beds.The simulation results showed that the proposed scale-up rule can maintain similarities in the axial solid concentration,radial solid concentration and radial dimensionless velocity distribution.The mesoscopic characteristic distributions were further discussed through the analysis of pressure fluctuations in the time domain and frequency domain.The results showed that the mesoscopic characteristics were different to some extent,which meant that more work should be done to keep the similarities when considering heat and mass transfer in circulating fluidized beds.

关 键 词：循环流化床 相似准则 颗粒佛罗德数 EMMS曳力系数 数值模拟 

分 类 号：TQ051.13[化学工程]