适用于超临界CO2管道的稳态输送水力热力计算模型OACSTPCD

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.