Modelling of the consequences of accident scenarios involving liquid hydrogen equipment

In recent years, the application of cryogenic liquid hydrogen as a fuel has grown significantly because of its convenience in terms of storage capacity and energy density. However, its utilization poses relevant safety concerns, whose investigation is crucial to ensure a reliable and safe fuel handling. From this perspective, the sudden failure of a cryogenic equipment is one of the most critical scenarios which could lead to a Boiling Liquid Expanding Vapour Explosion (BLEVE). In such an event, the instantaneous release of the stored mechanical and chemical energy generates a blast wave, whose overpressure and impulse can severely damage humans and structures nearby. Additionally, the hazardous consequences of this phenomenon include the projection of the fragments and, in case of flammable fluid, the fireball, whose radiation can damage targets nearby. In this work, a comparative analysis of different methods for the prediction of the consequences raised from a liquid hydrogen BLEVE is provided. The methods are compared with available experimental data and the most promising ones are used to perform a blind prediction of the forthcoming experimental configurations proposed in the context of the Enhancing Safety of Liquid and Vaporised Hydrogen Transfer Technologies in Public Areas for Mobile Applications (ELVHYS) project. This research is expected to yield innovative insights into the impact of hydrogen combustion on the prediction of the BLEVE blast wave overpressure and impulse. Moreover, significant advancements are carried out in the fragments range estimation considering the effect of a redistribution of the kinetic energy between inner and outer vessel debris. Ultimately, a coefficient to estimate the fraction of the fireball chemical energy that directly contributes to the radiation is proposed.