摘要
应用计算颗粒流体力学(CPFD)方法对矩形与楔形结构径向移动床内气固两相流动规律进行数值模拟。考察了床型结构、料封高度等关键结构参数对径向移动床内气固两相流场分布的影响。通过优化移动床关键结构参数,改善径向移动床中出现的贴壁、空腔问题。结果表明,模拟结果与相应工况下的实验数据吻合较好,模型可以定性描述径向移动床内气固两相流动规律。楔形结构不但能够提高贴壁临界气速,减小贴壁区域厚度,缓解贴壁现象;而且能够有效减小窜气量,明显提高临界空腔气速,避免或者缓解空腔现象。料封高度是影响空腔现象形成的关键性因素之一,适当增加料封高度可以有效消除空腔现象,提高装置操作弹性和操作稳定性。
The computational particle fluid dynamics （CPFD） method was used to simulate the gas-solid flow rules in both rectangular and wedge radial flow moving beds. The influences of bed type and solid-seal height on two-phase flow field distribution were investigated in moving bed. In this research, the key structure parameters were optimized to minimize the effects of ＂pinning＂ and ＂cavity＂. Results show that the computed values are qualitatively similar to those of experiment, and the gas-solid flow rules can be predicted by using numerical simulation. Moreover, it also shows that there are a rise of the critical gas velocity for ＂pinning＂ and a drop of the ＂pinning＂ thickness in the wedge-shaped bed compared with the rectangular-shaped bed, which relieves the ＂pinning＂ effectively. Thus wedge structure helps to reduce the amount of gas leakage, and it increases the critical gas velocity for ＂cavity＂ significantly to avoid or weaken the ＂cavity＂. Besides, the solid-seal height is one of the key factors that affects the formation of ＂cavity＂. The appropriate increase of solid-seal height can effectively eliminate the ＂cavity＂ phenomenon, enhancing the operating flexibility and stability of the device.
出处
《高校化学工程学报》
EI
CAS
CSCD
北大核心
2015年第1期49-57,共9页
Journal of Chemical Engineering of Chinese Universities
基金
国家重点基础研究973计划项目(2012CB215004)
关键词
楔形径向移动床
关键结构
计算颗粒流体力学
空腔贴壁
wedge radial flow moving bed
key structure
computational particle fluid dynamics（CPFD）
cavity and pinning
