催化裂化提升管进料区新型助流剂技术的CFD模拟  

CFD simulation of novel fluidizer technology in feedstock injection zone of FCC riser

作　　者：陈昇[1,2] 范怡平[1] 闫子涵[1] 李飞[2] 王维[2] 卢春喜[1] 

机构地区：[1]中国石油大学(北京)重质油国家重点实验室,北京102249 [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：《化工学报》2016年第8期3179-3190,共12页CIESC Journal

基　　金：国家重点基础研究发展计划项目(2012CB215000)~~

摘　　要：为改善提升管进料区气固两相混合状况、消除二次流对近壁面处返混的影响,提出了一种新型助流剂技术。该技术在边壁处形成一层助流剂'保护层',可阻止进料射流与催化剂在边壁处过长接触。通过三维CFD模拟对比了3种助流方式(逆流式、顺流式、交叉式)对传统进料区催化剂与进料混合和边壁返混的改进效果,并对最佳方式下助流剂量做进一步的优化。结果表明,逆流式助流方式最理想,交叉式助流方式最差。合适的逆流式助流方式(如助流剂注入量为进料相总流率的15%时)可改善进料区催化剂与进料相混合,抑制二次流扩张,明显减弱近边壁处(|r/R|>0.9)返混强度。To improve the gas-solid two-phase mixing and eliminate the effect of secondary flow on the back-mixing near the riser wall in the feedstock injection zone, a novel fluidizer technology is proposed. A protective layer is produced by fluidizer to prevent long-duration contact between catalysts and feed near the wall. Three schemes for this technology（reverse-impact, concurrent-flow and crossed schemes） are used to improve the catalyst-feed mixing and back-mixing near wall by using 3-D CFD simulation. The amount of fluidizer of the optimal scheme is further optimized. The results show that the best is the reverse-impact scheme and the worst is the crossed scheme. The optimal reverse-impact scheme（when the mass flux of fluidizer is equal to the 15% mass flux of feed） can improve the catalyst-feed mixing, prevent the expanding of secondary flow and weaken the intensity of back-mixing at the ｜r/R｜〉0.9 near the wall.

关 键 词：提升管 进料区 二次流 助流剂 流化催化裂化 能量最小多尺度模型 计算流体力学 

分 类 号：TE624[石油与天然气工程—油气加工工程]