Carbon capture, utilization and storage (CCUS) has become a key technology in the process of promoting low-carbon development, where the safe transport-ation of high-pressure pipelines is crucial. In order to study the discharge characteristics of CO2 pipelines, a large-scale experimental pipe with a length of 258 m and an inner diameter of 233 mm was developed to simulate the real leakage scenario as much as possible. The jet morphology generated during the rupture of the pipeline under different leakage sizes (15mm, 50mm, 100mm, 233mm) was photographed from the side of the discharge port with a high-frequency camera, and it was found that there were different degrees of under-expanded jet areas near the leakage outlet in the initial stage of leakage, which gradually developed and formed visible clouds, but there were obvious differences in their development scale and duration. In this paper, we analyzed the theoretical structure of the jet. And we extracted key features such as leak duration and jet length by analyzing the morphology of jets under different calibers. So as to propose the correlation between the morphology of the jet and cracks. When a leakage accident occurs, the scale of the crack can be quickly and accurately estimated from the leakage morphological characteristics of the periphery of the accident, and the degree of the accident can be judged, which provides a basis for the formulation of the early warning plan.
Keywords CCUS, CO2 pipelines, Jet morphology, Leakage sizes