乙烯气相聚合流化床反应器内Geldart B类和Geldart D类颗粒流动特性的三维数值模拟  

3D numerical simulation of flow characteristics for Geldart B and Geldart D particles in gas phase ethylene polymerization fluidized-bed reactor

作　　者：车煜 田洲[2] 张瑞 高宇新 邹恩广 王斯晗 刘柏平[1] 

机构地区：[1]华东理工大学化学工程联合国家重点实验室,上海200237 [2]华东理工大学化工过程先进控制与优化技术教育部重点实验室,上海200237 [3]中国石油石油化工研究院大庆化工研究中心,黑龙江大庆163714

出　　处：《化工学报》2016年第2期519-529,共11页CIESC Journal

基　　金：国家重点基础研究发展计划项目(2012CB720502);国家自然科学基金项目(21406061);上海市自然科学基金项目(14ZR1410600);引智计划项目(B08021);中央高校基本科研业务费专项资金项目~~

摘　　要：乙烯气相聚合流化床反应器的设计、操作和优化依赖于对聚合物颗粒粒径大小和分布、气泡运动特性及聚合反应状况的准确描述。采用Eulerian-Eulerian双流体模型和群体平衡模型耦合方法对某乙烯气相聚合中试规模的工业流化床反应器分别处于常规聚合工艺(属Geldart B类颗粒)和免造粒工艺(属Geldart D类颗粒)时床体的气固流动特征以及不同颗粒类型对反应器操作状态和颗粒运动特性的影响进行了三维数值模拟研究。与传统聚乙烯生产工艺相比,免造粒工艺时的Geldart D类聚合物颗粒更易聚集于气体入口处区域,而且会产生明显的旋涡并出现较大的气泡。研究结果可为免造粒聚乙烯生产工艺的工业推广应用提供参考。The status of polyethylene（PE） particle size and distribution, bubble generation and movement, and polymerization reaction in gas phase ethylene polymerization fluidized-bed reactor（FBR） is significant for PE production process, reactor design, optimization and control. Based on 3 dimensional（3D） Eulerian-Eulerian two-fluid model combined with a population balance model（PBM）, this work aims to explore the two-phase flow characteristics and the effects of traditional PE production process（Geldart B particles） and non-pelletizing PE production process（Geldart D particles） on the operating behaviors in a pilot-plant FBR. The simulation results match well with the industrial measured pressure drop and temperature data. It is also found that the polymer particles observably concentrated on the bed inlet region for the effects of Geldart D particles and superfical gas velocity. In addition, the obvious vortexes and large bubbles can be clearly observed in the bed height direction. The results could provide foundation for the extension and application of the non-pelletizing PE production process.

关 键 词：流化床 聚乙烯 计算流体力学 Geldart D类颗粒 免造粒工艺 粒度分布 

分 类 号：TQ316.3[化学工程—高聚物工业]