加氢反应流出物空冷器出口配管的弯管冲蚀特性表征及数值预测方法

针对加氢反应流出物空冷器(REAC)出口管道系统频繁发生的冲蚀失效问题，揭示了复杂流动腐蚀环境下管道冲蚀失效机理，提出了以离子传质系数(kc)及三向应力求得的最大剪切应力(τm)作为REAC出口配管的弯管冲蚀特性关键表征参数；采用Mixture多相流模型和SST k-ω湍流模型对空冷系统的出口配管进行流体动力学数值模拟，对比分析获得了各弯管处的传质系数和最大剪切应力的分布规律。结果表明：REAC出口配管的弯管中传质系数kc与最大剪切应力τm的重合位置位于弯管8上的55°≤α≤85°管段，是冲蚀失效的高风险区域；失效案例解剖结果表明，基于传质系数kc、最大剪切应力τm分布预测的冲蚀失效高风险区域与弯管冲蚀泄漏失效的区域基本一致。研究成果有望为空冷器进出口管道系统的耐流动腐蚀优化设计、优化运行和在役风险检验提供理论支撑依据。

Characteristics and Numerical Prediction Method of Elbow Erosion in the Air Coolers Outlet Piping System of Hydrogenation Reaction Effluents

For the frequent erosion failure in the outlet piping system of hydrogenation reaction effluent air coolers (REAC), based on the pipe erosion failure mechanism in the complex flow corrosion environment, ion mass transfer coefficient (kc) and maximum shear stress (τm) calculated by triaxial stress analysis were utilized as key characterization parameters. The fluid dynamics numerical simulation of REAC outlet piping system is performed with Mixture multiphase model and SST k-ω turbulence model, and thus the distributions of kc and τm at all the elbows are obtained and analyzed. Modelling results indicate that the coincide position of maximum kc and τm is located at the pipe section of 55°≤α≤85° of elbow 8, which is the high risk area of erosion failure. Failure case study suggests that the predicted high risk area of erosion failure based on kc and τm is the same area where the elbow erosion leakage actually failed. It is expected that the research results can provide theoretical support for the optimization of flow corrosion resistance design, optimal operation and on-line risk inspection of the air cooler inlet and outlet piping system.