超临界CO2输送管道腐蚀电化学机理与流体动力学特征的相关性研究

碳捕获与封存（CCS）技术是应对CO2排放导致全球气候变化所带来的极端天气和灾难的重要技术途径之一。而CCS技术中超临界CO2输送管道的腐蚀问题不仅是CCS技术安全实施的关键问题，同时也是流体力学－电化学耦合效应下的腐蚀科学问题。本研究拟以CCS技术中超临界CO2碳钢输送管道为研究对象，建立超临界CO2-水系统的水化学热力学模型，建立含水气超临界CO2环境中原位动态电化学测试系统。通过电化学测试和腐蚀产物微观结构表征，从本质上揭示超临界CO2腐蚀电化学机理以及腐蚀产物膜的生长演化模式，同时揭示污染物（Cl-、O2、SO2、MEA等）对超临界CO2腐蚀的交互作用影响机制。另外，结合计算流体动力学（CFD）模拟计算不同流动状态下电极表面流场、剪切应力场、近壁处湍流动能分布，揭示超临界CO2腐蚀电化学机理与流体动力学特征的内在关系，从而为CCS技术中超临界CO2输送管道的腐蚀和防护提供理论依据。

Carbon capture and storage (CCS) is one of the important technological methods to tackle the tough issue that CO2 emission results in global climate change with extreme weather and catastrophe. The corrosion of pipelines for supercritical CO2 transportation in CCS is not only the key problem of the safety of CCS, but also the fundamental problem of corrosion science under the synergistic effect of hydrodynamics and electrodchemistry. In this project, thermodynamic model is established to determine the water chemistry characteristic of supercritical CO2-water system. In situ electrochemical measurement method under dynamic water-containing supercritical CO2 environment is also established. Electrochemical measurements and microstructure characterization of corrosion products are carried out to clarify the essential corrosion mechanism and growth model of corrosion products of carbon steel in supercritical CO2 system. The synergistic effect of impurities （Cl-、O2、SO2、MEA）on the corrosion mechanism of carbon steel under supercritical CO2 environment is also determined. Also,the flow field, stress field, near-wall turbulent kinetic energy on the electrode surface are determined by computational fluid dynamics (CFD) simulation to reveal the relationship between hydrodynamics and electrodchemical corroion mechanism of carbon steel in supercritical CO2 system. It is anticipated that this research would provide an essential insight into establishing the protective method for the corrosion of pipelines in supercritical CO2 system in CCS.