甲醇制烯烃装置外取热器磨损分析与优化设计

Wear analysis and optimization design of external heat exchanger in methanol to olefin plant

某厂现有甲醇制烯烃(MTO)装置外取热器运行过程中,存在催化剂入口斜管衬里脱落、器壁磨穿和催化剂泄漏等故障,监测和处理难度较大。根据现有监测技术和临时故障处理方法,对上述故障产生的原因进行分析:从设备内部介质分布状态、操作情况、结构设计和衬里施工等方面出发,确定了设备运行过程中器壁热点监测的最佳方法;基于外取热器床层高度和温度分布情况,对催化剂入口斜管底部松动结构进行了优化;比较了外取热器管束内部不同位置换热管磨损程度,对管束磨损严重部位增加防冲蚀结构。运行结果表明,上述方法可有效解决外取热器磨损问题,延长外取热器的使用寿命。

During the operation of the external heat exchanger of an existing methanol to olefin(MTO)unit in a certain plant,there are some faults,such as falling off of the inclined tube lining at the inlet of catalyst,wear through of the wall of the reactor and leakage of the catalyst,which are difficult to monitor and deal with.According to the existing monitoring technology and temporary fault treatment methods,the causes of the above failures were analyzed.The best method of hot spot monitoring on the wall during the operation of the equipment was determined from the aspects of the medium distribution state,operation condition,structural design and lining construction inside of the equipment.Based on the height and temperature distribution of the bed of the external heat exchanger,the loose structure at the bottom of the inclined tube of the catalyst inlet was optimized.The wear degree of the heat exchange tubes in different positions inside the tube bundle of the external heat exchanger was compared,and the erosion-proof structure was added to the severely worn parts of the tube bundle.The operation results show that the above methods can effectively solve the wear problem of the external heat exchanger and prolong the service life of the external heat exchanger.