摘要
采用Reynolds应力输运模型对一种催化裂化沉降器内的油气流动状况进行了全尺寸的数值模拟。在计算过程中未对沉降器的复杂结构进行简化,所建立的几何模型包括沉降器内部区域和两级旋风分离系统内部区域的全部流动空间。计算结果表明:粗旋分离器排气管出口的油气呈旋转射流状态喷出,弥漫于庞大的沉降器空间,流动缓慢,经历了较长的停留时间后才能进入顶旋分离器;大量油气在高温下长时间的停留将导致沉降器内大量结焦,对催化裂化的安全长周期运行造成隐患。
A numerical simulation of oil gas flow in a full-size fluid catalytic cracking （FCC） disengager was carried out by applying Reynolds stress model （RSM）. During the calculation process there was no any geometric simplification for the complicated structure of FCC disengager. The modeling domain included all spaces of the disengager： the space inside the two stage separators and the space outside the separators in the disengager. The details of the turbulence flow in all space of the whole disengager were obtained. It was shown that the oil gas rotationally ejected from the outlet of the primary cyclone separator and entered the disengager space. After a long residence time, the oil gas flowed into the secondary cyclone separators. The large quantity of oil gas was subject to longer residence time in a high temperature environment, resulting in a coking reaction which had a potentially adverse effect on the long term operation of FCC units.
出处
《化学反应工程与工艺》
CAS
CSCD
北大核心
2009年第2期104-108,共5页
Chemical Reaction Engineering and Technology
基金
国家重点基础研究发展规划"973"项目资助(2004CB217803)
关键词
流化催化裂化
沉降器
旋风分离器
流动模型
数值模拟
停留时间分布
fluid catalytic cracking
disengager
cyclone separator
flow model
numerical simulation
residence time distribution
