加氢裂化装置高压换热器的腐蚀与防护

加氢裂化装置的高压换热经常发生腐蚀泄漏,严重影响了装置的平稳运行。文章介绍了加氢裂化装置高压换热器的腐蚀问题。针对高压换热器管束结晶问题,通过对原料性质、运行条件、防腐措施等情况进行了分析,发现原料中硫氯元素严重超标,其中氯质量分数最高为5.6μg/g,是标准的2.3倍,从而认为高压换热器产生腐蚀的主要原因是原料中的氯化物、硫化物超标,运行温度在氯化铵结晶范围内及注水量不足所致。提出了监控原料中的腐蚀介质、采用原油脱氯技术、优化现有防腐措施等建议。

Corrosion of High - pressure Heat Exchanger in Hydrocracking Unit and Prevention

The frequent corrosion leaking of high - pressure heat exchanger in the HP hydrocracking unit has seriously affected the normal operation of the unit. The corrosion of the HP heat exchanger is introduced. The feedstock properties, operating conditions and corresponding corrosion prevention measures are studied based upon the crystallization of heat exchanger tubes. It is found that the sulfur and chlorine in the feed greatly exceeded the specifications, i. e. 5.6 ppm chlorine which is 2.3 times the standard specification. It is therefore, concluded that the main cuprits of the corrosion of the HP heat exchanger are over - specifications of chlorides and sulfides in the feedstock, operating temperature which is within the crystallization temperature of ammonia chloride and insulficient water injection. It is recommended to control the corrosive media in the feed, apply dechlorination process for the feed treatment and optimize the existing corrosion protection measures.