Hydrogen Leakage Inside a Storage Warehouse and Local Combustion Threats: A Numerical Study

Hydrogen storage and safety are crucial for the envisaged hydrogen economy and sustainable development. In the present study, a CFD-based simulation is performed on a closed storage warehouse (12 m × 5 m × 3.2 m) model to analyze the accidental hydrogen release and subsequent combustion threats. The dispersion of accidental release of hydrogen, hydrogen stratification, and local combustion threats inside a storage warehouse are numerically analyzed. Two important parameters: leakage locations (total 6 locations) and leakage rates (0.91427, 1.82854 g/s) are examined. The dynamics of 4% volume hydrogen concentration iso-surface formation (minimum limit to start hydrogen combustion) and hydrogen distribution at a different time (up to 800s) in the storage warehouse are obtained. It is found that leakage locations near the wall, corners, and roof-top cause more serious safety issues than in the middle of the warehouse. Additionally, hydrogen stratification near the roof-top at the start of the leakage because of the momentum and buoyancy-driven flow increases the chance of hydrogen detonation whereas diffusion-dominated flow at the later time helps in hydrogen distribution. The time at which diffusion starts dominating is found to be a few hundred seconds for the parameter ranges considered in the present study.