煤液化空冷器系统流动腐蚀参数测定与模拟估算方法研究

Flow-induced corrosion is the widespread failure mode in the coal chemical industry. High pressure air coolers system of coal liquefaction involves insecure factors for the complex process: flow, heat transfer, corrosion. The failure mechanism of such corrosion mechanism and state detection has caused the extensive concern of engineering and academic circles of home and abroad. This project takes coal liquefaction air cooler as the research subject to study on the failure mechanism of flow-induced corrosion due to the coupling of complex process and the hazard source. Numerical predictions for flow-induced corrosion are realized by using NH4HS flow deposition and fluid-solid coupling erosion mode, which considering the coupling of fluid flow, temperature and concentration field ect. The critical parameter of multiphase flow sediment erosion and failure control of flow-induced corrosion control system were obtained by the numerical simulation and experimental methods.Based on the policy of avoiding crystallization and controlling corrosion，the on-line detection techniques in flow-induced corrosion was discussed through the process simulation. And a method for the determination and process simulation of key parameters for the coal liquefaction air cooler system due to flow-induced corrosion has been developed. The research has promising application in optimizing operation and setting related standards and the improvement theoretical of flow-induced corrosion prediction for key equipment in the coal chemical field.

流动腐蚀是煤化工领域普遍存在的失效形式。煤液化温高分高压空冷器系统涉及流动、传热、腐蚀等复杂过程，安全风险很大，其失效机理及状态监测一直是工程界和学术界关注的焦点。本课题拟以煤液化温高分空冷器系统为研究对象，开展复杂过程关联作用下的流动腐蚀失效机理研究，确定根本危害源；建立流动场、温度场及浓度场耦合作用下NH4HS流动沉积和流-固耦合冲蚀数理模型，实现流动腐蚀数值预测；结合多相流动腐蚀实验，确定多相流动沉积-冲蚀临界指标，构建流动腐蚀机理、数值模拟和实验研究相结合的煤液化空冷器失效控制体系，确定表征流动腐蚀失效的控制参数；基于“避免结晶，控制冲蚀”，研究流动腐蚀信号的在线传感测试技术，结合工艺流程的模拟计算，提出空冷器系统关键流动腐蚀控制参数的建模估算方法。研究成果可为煤化工关键装备系统的流动腐蚀预测、优化运行及相关标准的制定完善奠定理论基础。

流动腐蚀是空冷器系统普遍存在的失效形式。本项目以煤液化温高分高压空冷器为研究对象，开展工艺过程关联分析，研究NH4HS盐的平衡转化机制及流动沉积机理。同时基于实际运行工况，计算空冷器系统内多相流物性参数，并构建传热模型揭示温度场、速度场、浓度场之间的耦合关系。通过旋转式冲刷腐蚀实验装置，研究不同温度、浓度、流速以及不同氯离子含量下NH4HS溶液对典型材料10#碳钢和Incoloy 825冲蚀腐蚀速率影响。结果表明：当NH4HS浓度大于8 wt%时，腐蚀速率随流速的增加迅速增大。本项目研究在软测量技术与实验结果的基础上提出控制注水量、Kp值、pH值、平均流速、NH4HS结晶温度和浓度、Fe离子含量等关键参数，构建流动腐蚀在线传感技术及状态监测。研究成果可为空冷器系统失效分析、预测防控、优化设计、在线监测等奠定理论基础，确保石化企业长周期安全稳定运行。