重油加氢装置高压空冷器管束的腐蚀与防护

通过对重油加氢装置VRDS两台高压空冷器腐蚀泄漏原因进行分析 ,指出工艺条件的变化是造成管束穿孔的主要原因。由于NH4 Cl和NH4 HS的沉积 ,造成管内流速和温度的变化 ,从而使腐蚀加剧。并提出了在高压、临氢、含湿硫化氢、富氯的苛刻条件下空冷器的修复处理办法及采取的防护措施 ,增加注水设施 ,空冷器出口端安装钛保护套管和注多硫化钠缓蚀剂可有效延长空冷器寿命。

Corrosion of High- pressure Air Cooler Tubes in Heavy Oil Hydrodesulfurization Unit and Protection

The analysis of the corrosion leak causes of the two high-pressure air coolers in the vacuum residue hydrodesulfurization unit concluded that the variation of the process conditions was the major culprit of the cooler tube failure. The deposition of NH 4Cl and NH 4HS led to the variation of velocity and temperature inside the tube, which accelerated the corrosion. The repair methods and corrosion protection measures of the coolers in high-pressure, hydrogen, wet sulfide and chlorine-rich service were presented, such as addition of water injection facilities and installation of titanium protection conduit at the outlet of the cooler and injection of polysodium chloride, which could effectively extend the service life of the tubes.