【摘要】 超临界CO₂管道输送是碳捕集、利用与封存（Carbon Capture, Utilization and Storage, CCUS）中的重要环节，由于超临界CO₂水力热力特性与气液有明显差异，为满足实际CO₂管道工艺方案设计要求，需要建立适用于超临界CO₂的水力热力计算模型，为CO₂管道工艺设计参数选择及方案优选提供理论支撑。基于此，以考虑高程差的管道稳态连续性方程、运动方程、能量方程三大守恒方程为基础，结合相平衡实验选择适宜状态方程计算纯CO₂或含杂质CO₂的物性参数，采用四阶龙格—库塔法迭代数值求解，通过C++语言采用自适应步长设置来满足实际高程变化影响，自主编程得到了一维非等温考虑地形起伏的超临界CO₂管输稳态水力热力计算模型，并分别通过实验和OLGA软件从多个方面验证了模型具有较高的精度。利用建立的模型研究杂质含量及种类对CO₂管道稳态输送过程的压降和温降的影响，得到杂质种类对压降和温降的影响规律：O₂、N₂、H₂O、CO、Ar、H₂、CH₄等杂质对温降数据有相同的趋势，几乎不存在影响；在压降数据上发现H₂O杂质会导致压降减少，其余杂质均会造成不同程度的压降增加，影响程度体现为H₂>CO>N₂>CH₄>O₂>Ar。结合CO₂的独特性质，针对超临界CO₂管道稳态运输的计算不应当忽略高程差的影响，同时也应注意杂质导致的温降和压降的变化。更多还原

【Abstract】 Supercritical CO₂ pipeline transportation is an important link in Carbon Capture, Utilization and Storage（CCUS）. Given the significant differences in hydraulic and thermal characteristics between supercritical CO₂ and its gaseous and liquid states, it is necessary to develop a hydraulic and thermal calculation model tailored for supercritical CO₂ in order to meet the process design requirements of the actual CO₂ pipeline. This model aims to satisfy the process design requirements of actual CO₂ pipeline and provide theoretical support for the selection of design parameters and optimization of pipeline scheme. In this study, we have developed a model based on the three conservation equations for the steady-state operation of the pipeline, which take into account elevation differences. Drawing upon phase equilibrium experiments, we selected an appropriate equation of state to calculate the physical property parameters for both pure and impurity-laden CO₂. The numerical solution was obtained using the fourth-order Runge-Kutta method, with an adaptive step size control implemented in C++ to accurately capture the effects of elevation changes. The accuracy of the model was rigorously verified through experimental validation and by comparing its predictions with those of the OLGA software, confirming its high precision. Utilizing the established model, we investigated the effects of impurity content and types on the pressure drop and temperature drop during the steady-state transportation process of CO₂ pipelines. Findings revealed that among the seven components tested—O₂, N₂, H₂O, CO, Ar, H₂, and CH₄—the presence of impurities generally followed the same trend in affecting temperature drop data, with negligible impact observed. Notably, the H₂O component was found to reduce pressure drop, whereas the remaining six impurities were shown to increase it to varying degrees. The influence of these impurities on pressure drop was ranked as follows: H₂>CO>N₂>CH₄>O₂>Ar. In conclusion, the study underscores the critical role of considering elevation differences in the steady-state transportation calculations for supercritical CO₂ pipelines. Additionally, attention should also be paid to the effects of impurity components on temperature and pressure.更多还原