加氢裂化高压空冷器腐蚀分析与防护

100万吨/年中压加氢裂化装置反应产物高压空冷器在新投运16个月后连续2次出现腐蚀泄漏事故,造成装置非计划停工23天。本文对高压空冷器的腐蚀原因进行了分析,并和进口200万吨/年高压加氢裂化装置进行对比分析,认为进料配管设计和高压空冷器结构型式的不合理,导致进料分配不均匀,局部流速偏大,使空冷器管口和Ti衬管产生冲刷腐蚀,在H2-H2S-HCl-NH3双相区加快了冲刷腐蚀。在总结经验的基础上,提出了设备改进和防护措施。

The Corrosion Analysis and Protection of High-pressure Air Cooler in Hydrocracker

Corrosion leakage occurred continuously 2 times to the reactor effluent high-pressure air cooler in 1Mt/a medium-pressure hydrocracker after it had been put into effect for 16 months. It caused shutdown of the system without planning for 23 days. By the analysis of the corrosion of high-pressure air cooler and the contrast to the imported 2Mt/a high-pressure hydrocracker, it was drawn that the inconsequence of the feeding tubing design and the high-pressure air cooler structure brought out the uneven distribute of the feedstock. So the large local velocity of flow appeared which led to the erosion of the pipe mouth of air cooler and the Ti liner. At the same time the erosion was accelerated among the H2-H2S-HCl-NH3 dual-phase zone. The corrosion analysis was summarized and the improving measures for the equipment, the protection of it were given in the article.