管内流场对流动加速腐蚀有机缓蚀膜结构完整性的损伤机理研究

流动加速腐蚀会导致水和汽-水输运管道壁厚不断减薄并突然破裂，严重威胁相关系统安全。成膜胺可在管道内壁吸附形成有机缓蚀膜，若结构完整，可有效抑制流动加速腐蚀。然而，管内局部流场可能损伤缓蚀膜的结构完整性，使其无法发挥应有缓蚀效能。针对这一问题，本项目拟开展管内流场损伤缓蚀膜结构完整性的机理研究。联合传感器阵列和电化学分析，原位诊断管内壁不同位置处缓蚀膜的结构完整性，并与管内近壁流场分布进行对比，探明典型“损膜”局部流场结构。联合分子动力学模拟和流场模拟，建立考虑流场作用的缓蚀膜微观结构预测模型，解析损膜局部流场结构作用下的缓蚀膜微观结构演化过程，揭示流场损膜微观机制以及由此致使缓蚀膜性能下降的物理本质。在此基础上，指导调整管道几何构型来改变管内流场，消除或削弱损膜局部流场结构的损膜特性，促使管内壁各处的缓蚀膜免受流场损伤。项目可为成膜胺在抑制流动加速腐蚀方面的合理应用提供理论支撑和方法指导。

Flow-accelerated corrosion, which is typically encountered in water and steam-water transporting lines, could lead to wall thinning or even rupture to pipes and consequently influence the safety of the whole system. Film-forming amine molecules could adsorb on the inner surface of the pipes and form a barrier inhibitor film, which could effectively inhibit flow-accelerated corrosion if its structural integrity can be maintained. However, it was found that the local flow field within the pipes may damage the structural integrity of the inhibitor film and consequently degrade its performance. Focusing on this issue, we will investigate the mechanism by which the flow field damages the structural integrity of the inhibitor film. By combining the sensor-array technology and the electrochemical analysis method, the structural integrity of the inhibitor film on various locations of the inner surface can be obtained. Through comparing with the flow field near the inner surface, the typical local flow structures that could damage the inhibitor film can be identified. Employing both the methods of molecular dynamics simulation and computational fluid dynamics simulation, a model that could predict the microstructure of the inhibitor film under the influence of external flow field will be established. This will be used to explore the evolution of the inhibitor film drived by the typical damaging local flow structures. Also, it will help reveal the mechanism by which the flow field damages the inhibitor film, from a microcosmic perspective. Based on the analysis results, the geometry of the pipes will be optimized to modify the inner flow field so as to remove or weaken the damage ability of the typical damaging local flow field structures. This work will help provide more solid theoretical basis for the reasonable application of film-forming amines intending to inhibit flow-accelerated corrosion.