腐蚀性多相流局部冲蚀与壁面润湿过程的关联性研究

The petrochemical industry is the mainstay industry of our national economy. Due to excessive refining of corrosive low-priced oil, the special equipment, such as petrochemical heat transfer equipment and pressure piping, usually encounters frequent unplanned shutdowns and explosion accidents due to multiphase flow corrosion, which has resulted in heavy economic losses. For a long time, the corrosion zone and rate cannot be accurately predicted resulting in the frequent occurrence of production accidents. In this project, the processes of oil- gas-water multiphase flow corrosion in a typical pipe which usually goes bad due to the flow-induce corrosion are studied. The project will reveal the formation mechanism and dynamic process of corrosive water-wetting in the multiphase flow under different working conditions, and establish a correlation between the local multiphase flow characteristics and wall-wetting process. Then, based on the rules of water-wetting, the local multiphase flow corrosion characteristics at high-risk areas with wall water-wetting are established, and a multiphase flow corrosion indication model based on water-wetting law also will be formed, which can provide theoretical support for the multiphase flow corrosion in the petrochemical industry.

石化行业是国民经济的支柱产业，因大量炼制腐蚀性低价油，石化传热设备、压力管道等特种设备频繁出现多相流流动腐蚀引发的非计划停工及火灾爆炸事故，经济损失惨重。长期以来，因流动腐蚀失效区域与腐蚀速率无法精准预测，导致安全生产事故频发。本项目将针对流动腐蚀失效典型管件内油气水多相流冲蚀过程开展研究，揭示不同工况下多相流腐蚀性水润湿的形成机理及动态过程，建立局部多相流流动特征与壁面润湿过程的关联性。然后在水润湿规律的基础上，建立壁面水润湿高风险区域的多相流局部冲蚀特性，形成基于水润湿规律的多相流冲蚀表征模型，为石化行业多相流局部冲蚀失效提供理论支撑。

石化行业是我国国民经济的支柱产业。我国因大量炼制低价腐蚀性原油，石化传热设备、压力管道等特种设备频繁出现多相流冲蚀引发的非计划停工事件，经济损失惨重。因未从局部多相流特征（特别是典型管件内水润湿特征）与壁面腐蚀过程间的关联关系出发，国内外尚无行之有效的多相流冲蚀表征预测方法。因此，本项目通过对水平管、倾斜管及弯管等典型管件中非定常多相流动的实验和数值模拟研究，建立了气液、油气水多相流动过程中壁面润湿过程和腐蚀速率间关联关系。研究表明流体在流经典型管件时会产生不同的壁面润湿状态，壁面润湿状态与物流比例、流速、界面条件、管道走向等均密切相关。在气液两相流动中，液弹和Taylor泡是影响壁面润湿状态的典型流体结构，其与壁面接触后会形成间歇性润湿。间歇性水润湿的金属表面腐蚀产物更加均匀平整，无法产生较大的腐蚀坑或块状结构，因此腐蚀介质不能连续深入到腐蚀坑内，腐蚀速率相比更低。传统单一的腐蚀表征预测参数因未考虑局部壁面水润湿状态，无法准确预测多相流冲蚀风险位置。因此，本项目提出的基于水润湿过程、剪切应力等局部冲蚀表征方法，适用于多相流动过程中冲蚀风险点表征预测，可为石化设备设计、制造及安全运行提供技术指导。