100万t/a加氢装置高压换热器E1103换热管失效浅析

FAILURE ANALYSIS ON E1103 HEAT EXCHANGER TUBE IN HIGH PRESSURE HEAT EXCHANGER OF 1 MTA HYDROGENATION UNIT

中国石油化工股份有限公司石家庄炼化分公司100万t/a汽柴油加氢装置高压换热器E1103多根换热管发生泄漏,换热管材质为0Cr18Ni10Ti。通过对换热管开展宏观形貌观察、金相组织分析、EDS成分分析、腐蚀产物分析等试验,判断换热管失效原因为氨盐垢下腐蚀,该腐蚀是从换热管内部点蚀开始,内表面基体分布密集的点蚀坑,最终小的点蚀坑连接成片,形成大的点蚀坑,导致换热管失效。针对分析结果,制定相应的预防措施,避免了腐蚀发生,保证了换热器的长周期运行。

Leakage occurred in several heat exchanger tubes in the high pressure heat exchanger of 1 MTA gasoline and diesel hydrogenation unit of SINOPEC Shijiazhuang Refining &Chemical Company.The material of the heat exchanger tube is 0Cr18Ni10 Ti.Through macro morphology observation,metallographic observation,micro area EDS spectrum analysis and corrosion product analysis on the heat exchanger tube,it is identified that the failure reason of the heat exchanger tube is under-deposit corrosion of ammonia salt.The corrosion starts from internal pitting of heat exchanger tube.Plenty of pits distribute on the inner surface of the tubes and eventually small pits connect to be pieces,which become large pits and result in failure of heat exchanger tube.According to the results of the analysis,pertinent preventive measures are made to avoid corrosion and ensure the long-period operation of heat exchanger.