Analysis of Transient Hydrogen Release, Dispersion and Explosion in a Tunnel with Fuel Cell Vehicles using All-Speed CFD Code

Hydrogen energy is expanding world wide 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 consequences of hydrogen detonation is important for hydrogen safety assessment, and for ensuring the safety of installations during accidents. Hence, an accident scenario of hydrogen release  nd detonation in a tunnel is analysed with GASFLOW-MPI in this paper. GASFLOW-MPI is a well validated parallel CFD code focusing on hydrogen transport, combustion and detonation. GASFLOWMPI solves compressible Navier-Stokes equations with a powerful all-speed Arbitrary-Lagrangian-Eulerian (ALE) method, hence it can cover both the non-compressible flow during the hydrogen relesase and dispersion phases, and the compressible flow during combustion and detonation. A 3D model of a tunnel including eight cars is modelled. Firstly, the hydrogen dispersion in the tunnel is calculated. Then the detonation in the tunnel is calculated by manually igniting the hydrogen at the top of the tunnel when the λ criterion is maximum. The pressure loads are calculated to evaluate the consequence of the hazard.