After determining the external and

After determining the external and internal conditions, Aspen Hysys was used to simulate and calculate pipelines with different conveying conditions. Through the calculation, it was found that the pressure drop of the pipeline in the gas state is the highest. When the conveying distance is 37.5km, the pressure drop exceeds 5% of the inlet pressure, dropping to 3.8MPa. Therefore, based on the pressure drop, the effective conveying distance of the gas state pipeline is only 37.5km; The transportation pressure drop of liquid and supercritical states is much smaller than that of gas states. When the pipeline transportation distance is within 204.4km, the pressure drop of these two states is within the allowable range. However, when the distance exceeds this value, a phase change will occur in the liquid pipeline due to pressure reduction, resulting in two-phase fluid and corresponding viscosity increase, causing an increase in the frictional resistance of the pipeline, ultimately leading to an increase in pressure drop, And the supercritical carbon dioxide pipeline will always maintain its small pressure drop, and the pressure drop also shows a linear growth pattern. Therefore, considering the pressure drop alone, the transportation of supercritical pipelines is due to the gas and liquid states.