This doctoral study investigates and closes a few knowledge gaps within the hydrogen safety engineering associated with the rupture of a stored hydrogen tank in an open atmosphere and a tunnel. Using contemporary numerical methods such as computational fluid dynamics (CFD), the development of a model for simulation of blast wave and fireball dynamics after a high-pressure hydrogen tank rupture in a fire has been outlined. This includes understanding the effect of different sub-models, numerical methods and insights into blast wave propagation and fireball dynamics. The validation of the model against experiments was attained in an open atmosphere, confirming the models’ capability as a predictive tool for assessment of tank rupture in fire consequences. The isolated effect of fire surrounding a stand-alone hydrogen tank prior to rupture was investigated, towards creating a more accurate consequence analysis and harmful criteria. The presence of fire as it may enhance the process towards a conceivable tank rupture, was found to have an adverse effect on the hazard consequences of the generated blast wave and fireball. The validated CFD model was applied to observe the direct effect of a blast wave after hydrogen tank rupture between open atmosphere and the close-in effects of a tunnel confinement. A three-dimensional blast wave decay pattern in open atmosphere was found, vastly different to the more one-dimensional blast wave propagation in a tunnel. Accordingly, numerical experiments were performed in a wide range of tunnels of various cross-section areas including tank ruptures of various volumes and pressures. A novel correlation for blast wave decay in tunnel was proposed using methods of similitude analysis. This resulted in a near linear fit between the two dimensionless parameters, able to predict blast wave decay across various stored hydrogen and tunnel dimensions. In the absence of experiments on hydrogen tank rupture in a tunnel fire, the developed correlation is the only tool available to stakeholders for hazards and associated risk assessment.
- CFD
- Hydrogen safety
- Fire
- Tank rupture
- Blast wave
- Fireball
- Tunnel
- Correlation
High-pressure hydrogen storage tank rupture in confined space
Dery, W. (Author). Nov 2020
Student thesis: Doctoral Thesis