2025 Spring Meeting and 21st Global Congress on Process Safety

(20a) Experimental and Numerical Studies on Hydrogen Dispersion during Large-Scale Green Hydrogen Production and Pipeline Transportation Processes

Authors

Yi Liu - Presenter, SINOPEC Research Institute of Safety Engineering Co. Ltd.
Guanlin Peng, SINOPEC Research Institute of Safety Engineering Co. Ltd.
Shishuai Nie, SINOPEC Research Institute of Safety Engineering Co. Ltd.
Lin Wang, SINOPEC Research Institute of Safety Engineering Co. Ltd.
Anfeng Yu, SINOPEC Research Institute of Safety Engineering Co. Ltd.
Zhe Yang, SINOPEC Research Institute of Safety Engineering Co. Ltd.
Le Wang, SINOPEC Science and Technology Department
In the large-scale production and transportation of green hydrogen, various complex risk factors are present. Specifically, gas-liquid separation equipment in hydrogen production plants and long-distance pipelines may experience flange or instrument connection failures over prolonged operation, compromising equipment integrity and leading to hydrogen leaks. In confined or obstructed environments, such as hydrogen plants or pipelines passing through tunnels, leaked hydrogen can accumulate and form flammable gas clouds, increasing the risk of explosion. Thus, understanding the hydrogen leakage and dispersion behavior during green hydrogen production and transportation is critical for quantitatively assessing potential consequences.

This study establishes a numerical model to simulate hydrogen leakage and dispersion in green hydrogen production and transportation processes. By analyzing the distribution of turbulent wind field characteristics with typical hydrogen production equipment (such as electrolyzers and gas-liquid separators) and in confined spaces like tunnels, the model accounts for the dual driving forces of buoyancy and concentration gradients caused by hydrogen's low density and viscosity, enabling quantitative predictions of turbulent wind field characteristics and hydrogen concentration distribution in complex structural environments.

To validate the model, an experiment was conducted on hydrogen leakage and dispersion in a scenario where long-distance hydrogen pipelines cross tunnels. Results showed that the relative error between the numerical simulation and experimental data was less than 20-40%, confirming the model’s accuracy. Analysis of hydrogen concentration distribution within the tunnel indicated that leaked hydrogen accumulates at the tunnel’s top, with concentrations gradually decreasing in a stepwise pattern toward both ends. Near the leakage point, the concentration showed a localized decrease due to high-speed jet flow creating a low-pressure area, drawing in external air and displacing hydrogen laterally, with the highest concentration appearing at the tunnel's top (at the 1-meter mark).

Using Sinopec's green hydrogen production facility and a tunnel-crossing pipeline as examples, this study analyzes the distribution and dispersion patterns of gas clouds under actual leakage scenarios, identifying typical high-concentration hydrogen accumulation regions under different leakage conditions (such as leak aperture, flow rate, and jet direction). This research provides theoretical support for developing emergency response plans and ventilation system designs for green hydrogen production and transportation processes.