Hydrogen energy is expanding world-widely in recent years, while hydrogen safety issues have drawn considerable attention. It is widely accepted that accidental hydrogen release in an open-air environment will disperse quickly, hence not causing significant hydrogen hazards. A hydrogen hazard is more likely to occur when hydrogen is accidentally released in a confined place, i.e. parking garages and tunnels. Prediction the main accident process, including the hydrogen release, dispersion, and combustion, is important for hydrogen safety assessment, and ensuring the safety installations during accidents. Hence, a postulated accident scenario induced by the operation of Thermal Pressure Relief Device in a tunnel is analysed for hydrogen fuel cell vehicles with GASFLOW-MPI in this study. GASFLOW-MPI is a well validated parallel CFD code focusing on the transport, combustion, and detonation of hydrogen. It solves compressible Navier-Stokes equations with a powerful all-speed Arbitrary-Lagrangian-Eulerian (ALE) method; hence can cover both the non-compressible flow during the hydrogen release and dispersion phases, and the compressible flow during deflagration and detonation. In this study, a 3D model of real-scaled tunnel is modelled, firstly. Then the hydrogen dispersion in the tunnel is calcu-lated to evaluate the risk of Flame acceleration and the Deflagration-Detonation Transient (DDT). The case with jet fire is analysed with assuming that the hydrogen is ignited right after being injected forming a jet fire in the tunnel, the consequence of this case is limited considering the small hydrogen inventory. The detonation in the tunnel is calculated by assuming a strong ignition at the top of the tunnel at an unfavourable time and location. The pressure loads are calculated to evaluate the consequence of the hazard. The analysis shows that the GASFLOW-MPI is applicable at a widely range for tunnel accidents, meanwhile, the safety issues related to tunnel accidents is worthy further study considering the complexity of tunnels.
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Hydrogen energy is expanding world-widely in recent years, while hydrogen safety issues have drawn considerable attention. It is widely accepted that accidental hydrogen release in an open-air environment will disperse quickly, hence not causing significant hydrogen hazards. A hydrogen hazard is more likely to occur when hydrogen is accidentally released in a confined place, i.e. parking garages and tunnels. Prediction the main accident process, including the hydrogen release, dispersion, and combustion, is important for hydrogen safety assessment, and ensuring the safety installations during accidents. Hence, a postulated accident scenario induced by the operation of Thermal Pressure Relief Device in a tunnel is analysed for hydrogen fuel cell vehicles with GASFLOW-MPI in this study. GASFLOW-MPI is a well validated parallel CFD code focusing on the transport, combustion, and detonation of hydrogen. It solves compressible Navier-Stokes equations with a powerful all-speed Arbitrary-Lagrangian-Eulerian (ALE) method; hence can cover both the non-compressible flow during the hydrogen release and dispersion phases, and the compressible flow during deflagration and detonation. In this study, a 3D model of realscaled tunnel is modelled, firstly. Then the hydrogen dispersion in the tunnel is calculated to evaluate the risk of Flame acceleration and the Deflagration-Detonation Transient (DDT). The case with jet fire is analysed with assuming that the hydrogen is ignited right after being injected forming a jet fire in the tunnel, the consequence of this case is limited considering the small hydrogen inventory. The detonation in the tunnel is calculated by