摘要
随着催化裂化装置掺渣比的提高,沉降器内的结焦现象随之加剧,严重影响了装置的长周期稳定运转。采用计算流体力学(CFD)模拟方法,以旋风分离器敞口式加挡板(装置Ⅰ)和旋风分离器软连接加溢流斗(装置Ⅱ)2种典型沉降器为研究对象,建立了全尺寸的CFD模型,以实际生产过程中的集散控制系统(DCS)数据检验了模型的准确性。通过分析沉降器空间内的流场及温度场分布,以及油气在沉降器内的运动轨迹和停留时间分布,对不同结构沉降器的结焦趋势进行了对比分析。结果表明:相比粗旋敞口结构,软连接能有效降低沉降器穹顶空间的油气浓度;装置Ⅰ的粗旋肩部、粗旋升气管上部挡板和提升管上壁面有较多的催化剂堆积,而装置Ⅱ仅在粗旋肩部有少量的催化剂堆积;同时装置Ⅱ的溢流斗结构可明显降低粗旋底部的泄气率,减少油气平均停留时间,降低了结焦风险。
With the increasing of residual oil blending ratio in fluid catalytic cracking(FCC)device,the coking formation inside the FCC disengager is increasingly enhanced,which seriously affects the long-term stable operation of the device.This study focuses on two typical disengagers,i.e.,the open cyclone separator with baffle(DisengagerⅠ)and the soft connection of cyclone separator with overflow bucket(DisengagerⅡ),based on which the full-size CFD model has been established.The accuracy of the model have been verified with the distributed control system(DCS)data in actual production.By analyzing the distribution of flow field and temperature field inside the disengager,as well as the distribution of oil-gas trajectory and residence time in the disengager,the coking trend of disengagers with different internal structures has been analyzed.The results show that as compared with the primary cyclone separator having open structure,the soft connection of cyclone separator can effectively reduce the oil-gas concentration in the top space of disengagers.There is a large amount of catalyst accumulated on the shoulder of the primary cyclone separator,as well as the upper baffle and the upper wall of its riser in DisengagerⅠ,but there is a small amount of catalyst accumulated on the shoulder of the primary cyclone separator in DisengagerⅡ.The overflow bucket structure of DisengagerⅡcan significantly reduce the gas discharge rate at the bottom of primary cyclone separator and shorten the average residence time of oil-gas,thus reducing the risk of coking.
作者
吕明珠
王栋
赵云鹏
张梦轩
石孝刚
高金森
蓝兴英
刘昱
李传坤
L Mingzhu;WANG Dong;ZHAO Yunpeng;ZHANG Mengxuan;SHI Xiaogang;GAO Jinsen;LAN Xingying;LIU Yu;LI Chuankun(State Key Laboratory of Heavy Oil Processing,China University of Petroleum,Beijing 102249,China;General Management Department,SINOPEC,Beijing 100728,China;SINOPEC Guangzhou Engineering Co.,Ltd.,Guangzhou 510620,China;State Key Laboratory of Safety and Control for Chemicals,SINOPEC Research Institute of Safety Engineering Co.,Ltd.,Qingdao 266071,China)
出处
《石油学报（石油加工）》
EI
CAS
CSCD
北大核心
2023年第3期611-621,共11页
Acta Petrolei Sinica(Petroleum Processing Section)
基金
国家自然科学基金项目(220221004)资助。
关键词
催化裂化(FCC)
沉降器
旋风分离器
溢流斗
结焦
停留时间分布
fluid catalytic cracking(FCC)
disengager
cyclone separator
overflow bucket
coking
residence time distribution
