Key Laboratory for Thermal Science & Power Engineering of Ministry of Education,Tsinghua University,Beijing　 100084,China

准确描述气固两相相互作用力——曳力,是解决欧拉方法合理预测循环流化床气固两相流动和化学反应的关键。阐述了基于流态化系统最小能量分析(EMMS)而建立的若干非均匀曳力模型及其应用的研究进展。通过分析颗粒团聚的介尺度特性,改进了颗粒团固含率εsc模型,形成新的曳力模型QC-EMMS。经网格到整体流化床不同尺度的实验验证,表明新模型更准确地体现了有大量颗粒团聚现象的非均匀流动规律。基于该模型,进一步研究了局部颗粒浓度的脉动特性和概率密度分布(PDD),颗粒团出现概率及其演化等介尺度变化规律,深化了对气固流态化过程的认识。

The accurate description of the gas-solid two-phase interaction,drag force,is the key to accurately predict the CFB gas-solid flow and chemical reaction by Euler / Euler method. The present study presents a series of heteroge- neous drag models and their application based on the energy minimum multi-scale method (EMMS) of a fluidization system. The cluster solids holdup,εsc ,was improved through the analysis of meso-scale characteristics,and then a new QC-EMMS drag model was developed. Through the experimental validation of different scales from grid to the macro- scale of reactor,the new model shows a high accuracy to reflect the law of non-uniform flow pattern with a large num- ber of clusters. On this basis,the paper further studies the pulsating characteristics and the probability density distribu- tion of local solids holdup,and the meso-scale characteristics such as the occurrence probability of clusters and the evolution law of a cluster,to enhance the understanding of gas-solid fluidization process.

国家自然科学基金重大研究计划培育资助项目(91334111)；

Dai Qunte,Shi Kai,Qi Haiying. Research progress of simulation methods of fluidization process in CFB based on meso-scale characteristics analysis[J]. Journal of China Coal Society,2016,41(10):2508-2513.