Characterization of the evolution of leakage and variation of in-pipe parameters in a full-size ethane high-pressure pipeline

There is a risk of leakage of ethane during high-pressure pipeline transportation. In order to investigate the effects of leakage conditions on the free-field ethane concentration distribution, temperature and pressure evolution, a full-size ethane high-pressure gas pipeline experimental platform was constructed, and high-pressure ethane leakage experiments were carried out with different diameters and leakage directions to investigate the effects of different leakage directions and diameters on the free-field ethane diffusion, temperature and pressure inside the pipeline. The experiment results show that in the free field, when the leakage direction is ≥45° to the horizontal plane, the near-surface ethane concentration is close to 0. When the horizontal leakage occurs, compared with the 15 mm leak diameters, the peak concentration of the 25 mm leak diameters rises by 17.7%, and the explosion danger range rises by 75%, and the explosion danger time is extended by 78.6%. It is worth mentioning that the initial pressure drop rate and the overall temperature drop in the pipeline increase and then decrease with the increase of leak diameters during the high-pressure ethane leakage process, and there is a critical diameter, which is 15 mm in this experiment. The results of the study provide a reference for the safe operation of the high-pressure ethane gas pipeline.