重油催化抑制结焦沉降器内油气流动的数值模拟  

NUMERICAL SIMULATION OF FLOW FIELD IN A RFCC DISENGAGER AFTER ANTI-COKE DEPOSITION RETROFITTING

作　　者：付烜[1] 孙国刚[1] 吴雷[2] 卢松坚[3] 时铭显[1] 

机构地区：[1]中国石油大学重质油加工国家重点实验室,北京102249 [2]中国石化工程建设公司,北京100101 [3]中国石化长岭分公司,湖南岳阳414012

出　　处：《石油学报（石油加工）》2009年第6期883-888,共6页Acta Petrolei Sinica(Petroleum Processing Section)

基　　金：中国石化重油催化沉降器抑制结焦项目(305013)资助

摘　　要：采用k-ε模型和组分输运方程进行数值模拟,考察了重油催化工业沉降器抑制结焦改造后其沉降空间的稳态流场及油气分率。结果表明,改造后的沉降器空间油气以顶部下行、底部上行略带扭摆的纵向流动为主,顶部油气下行速度小于0.15m/s,底部油气上行速度平均为0.5m/s,纵向流速比横向流速高1～2个数量级。中心抽吸管口区域存在较强的油气汇聚,速度10m/s左右。改造后的沉降空间不存在流动死区,绝大部分油气能迅速从中心抽吸管排出沉降器,只有低于10%的油气不能迅速排出沉降器,停留时间稍长。沉降器下部油气摩尔分率较大(平均约50%,顶部低于25%,部分区域甚至小于10%)。改造后沉降器空间的结焦大大减轻。The gas flow field distribution and the molar fraction distribution of oil gas in the RFCC disengager after anti-coke deposition retrofitting were simulated by using k-ε model and species transport equation. Results indicated that the oil gas flow field was not symmetrical and the lengthways velocity was 10 or 102 times larger than the transverse velocity. Gas in the upper space of the disengager flowed downwards with the velocity less than 0. 15 m/s and the upward stream existed in the lower part with the velocity about 0. 5 m/s. Near the center of the disengager gas pooled towards the nozzle of plenum tube with its velocity of 10 m/s. There were no stagnant regions for gas current and most of it was pumped out of the disengager quickly except for a small portion, which only took 10% mass fraction of all the oil gas with some what longer residence time correspondingly. The average molar fraction of oil gas was 50% at the bottom of the disengager and less than 25% in the upper place, even less than 10% in some areas. Total coke deposition in the disengager was reduced after anti-coke amelioration.

关 键 词：重油催化裂化 沉降器 油气 流场 摩尔分率 

分 类 号：TQ021.1[化学工程]