Hydrogen Leakage Effects on Different Leakage Ports of Overhead Hydrogen Pipelines Based on Fluent

To address the research gap in the effects of pure hydrogen pipeline leakage orifice size and shape on hydrogen diffusion, this study constructed four orifice models (small circular, large circular, axial strip-shaped, circumferential strip-shaped) using Ansys Fluent, and simulated the leakage rate and diffusion patterns. The results showed that the projected area of the orifice was positively correlated with the leakage rate; under the same area, strip-shaped leakage presented higher risks, with the circumferential strip-shaped leakage rate being 18.9 times that of the axial one. Analysis of the calibrated combustible mass fraction of leaked hydrogen revealed that the projected area was also positively correlated with the diffusion range, and the diffusion ranges of circumferential and axial leakage were comparable and larger than those of the other two models. This study identified circumferential leakage as the most hazardous scenario, and proposed the time-line voltage condition for axial installation detection to optimize circumferential leakage accident response, providing a reference for pipeline leakage detection and protection.