A heavy oil catalytic cracking unit (RFCCU) faces issues such as the deterioration of crude oil quality, coking, and corrosion. To address these problems, a cyclone quick separation system (YQS) was used to retrofit the settler, and a top circulation (top cycle) desalting system was added to the fractionation tower. Measures such as strengthening feedstock management, preventing coking in the settler, optimizing operating conditions, and enhancing equipment management were taken, effectively reducing the occurrence of coking and corrosion. The YQS linear velocity was controlled at 17.5–18.0 m/s, with no significant coking observed in the settler; the average corrosion rate of the top cycle system in the fractionation tower was 0.0131 mm/a. The above solutions effectively resolved the issues of coking and corrosion in the unit, enabling it to operate continuously for 1512 days in the fourth cycle, achieving long-term and stable operation.

margin:0px 0px 16px, padding:0px, border:0px, font-size:16px, vertical-align:baseline, color:rgba(0, 0, 0, 0.9), background-color:#FFFFFF, "> heavy oil catalytic cracking unit, long-term operation, settler anti-coking, top cycle desalting, feedstock management, equipment management, operating conditions, CMTHN catalyst

某重油催化裂化装置面临原油劣质化、结焦、腐蚀等问题，采用旋流快速分离系统（YQS）对沉降器进行改造，增设分馏塔顶循环（顶循）脱盐系统，采取加强原料油管理、防止沉降器结焦、优化操作条件及强化设备管理等措施，有效减少了结焦和腐蚀现象发生。YQS线速度控制在17.5～18.0 m/s，沉降器未见明显生焦；分馏塔顶循系统平均腐蚀速率为0.0131 mm/a。上述方案有效解决了装置的结焦、腐蚀等问题，装置第四周期连续运行1512 d，实现了长周期、稳定运行。

margin:0px 0px 16px, padding:0px, border:0px, font-size:16px, vertical-align:baseline, color:rgba(0, 0, 0, 0.9), background-color:#FFFFFF, "> 重油催化裂化装置, 长周期运行, 沉降器防结焦, 顶循脱盐, 原料油管理, 设备管理, 操作条件, CMTHN型催化剂