A Dynamic Assessment of Safety Barriers Effectiveness in Fire Protection of Cryogenic Storage Tanks

Liquid hydrogen (LH2) is believed to play a pivotal role in the energy transition. The main issue of this technology is the boil-off of the cryogenic liquid, particularly in the presence of critical heat sources, such as an external fire. Typically, in addition to the insulation system, safety barriers, such as water deluge systems and water curtains, are introduced as shields to protect the vessel from the fire radiation. Thus, the heat received from the cryogenic equipment depends on the effectiveness of those barriers. The present study aims at providing a dynamic quantification of the time to failure of an LH2 cryogenic tank, based on the performance of the abovementioned safety barriers. The results of this analysis highlight how different parameters affect the effectiveness of the safety systems, suggesting how to implement the most effective configurations. Moreover, the results obtained in terms of heat fluxes are precious input data useful for the definition of the boundary conditions in mathematical models (e.g., analytical and computational fluid dynamic models) used to investigate the behavior of cryogenic tanks engulfed in a fire.