Analysis of the Consequences of Hydrogen-Blended Natural Gas Leakage Accidents

The safe operation of natural gas stations as complex and dense equipment sites after the mixed transportation of hydrogen will face great challenges. Predicting accident consequences is of importance for emergency rescue. In this work, the evolution law in the accident scenarios of hydrogen-blended natural gas stations was investigated through a computational fluid dynamics (CFD) model. The results suggest that the mix of hydrogen and natural gas increases the explosion intensity of combustible gas clouds, which however also accelerates the diffusion rate of leaked gas into air. Therefore, the peak explosion overpressure fails to show a simple linear relationship with the hydrogen blending ratio in different hydrogen blending ratio scenarios. The worst accident consequences occur in Scenario 2 (hydrogen blending ratio = 20%), where the blast overpressure peak reaches 19.29 kPa. Wind can accelerate the material transmission speed of leaked gas in space. In scenarios with larger wind speeds, the hazard degree of accidents can be significantly reduced.