天然气管道离心压缩机腐蚀分析及防护措施研究

Corrosion Analysis and Protection Measures of Centrifugal Compressor in Natural Gas Pipeline

针对天然气离心压缩机运转过程中出现的腐蚀磨损现象,在分析了天然气中硫化物质量分数以及压缩机内部腐蚀产物组成的基础之上,提出了添加新型缓蚀剂的防腐蚀措施方案,并优选了性能优良的缓蚀剂。缓蚀剂优选实验结果表明,单一缓蚀剂DT2、ST3、FB1和FB2的缓蚀率均可以达到70%以上;将缓蚀剂FB1和ST3按照1∶1的比例进行复配时缓蚀效果最好,两种缓蚀剂的复配起到了良好的协同增效作用,当其加量为100 mg·L^(-1)时缓蚀率可以达到95%以上,并且缓蚀剂FBST-11的各项性能均明显优于现场原用缓蚀剂YBSJ-2,能够满足天然气离心压缩机内部腐蚀控制的需要。现场应用结果表明,复配型缓蚀剂FBST-11的加入能够有效缓解天然气压缩机内部的腐蚀现象,设备运转300天后压缩机内部各部件均未发现明显的腐蚀磨损现象,达到了良好的现场应用效果。

In view of the corrosion and wear phenomenon during the operation of natural gas centrifugal compressor,based on the analysis of sulfide mass fraction in natural gas and the composition of corrosion products in the compressor, the anti-corrosion measure scheme of adding new corrosion inhibitor was put forward, and the corrosion inhibitor with excellent performance was optimized. The experimental results showed that the inhibition rates of single inhibitors DT2, ST3, FB1 and FB2 could reach more than 70%;When the corrosion inhibitors FB1 and ST3 were compounded in the ratio of 1∶1, the corrosion inhibition effect was the best. The compounding of the two inhibitors had played good synergistic effect. When the dosage was 100 mg·L^(-1), the corrosion inhibition rate could be more than 95%, and the performance of the corrosion inhibitor FBST-11 was significantly better than the original corrosion inhibitor YBSJ-2 on site, which met the needs of internal corrosion control of natural gas centrifugal compressor. The field application results showed that the addition of compound corrosion inhibitor FBST-11 could effectively alleviate the corrosion phenomenon in the natural gas compressor. After 300 days of equipment operation, no obvious corrosion and wear phenomenon was found in all parts of the compressor, which achieved good field application effect.