Safety of Liquid and Cryo-Compressed Hydrogen: Overview of Physical and CFD Models Developed at Ulster University

Transport and storage of liquid hydrogen (LH2) is currently the most attractive option for scaling up the hydrogen supply infrastructure. Hazards and associated risks for compressed gaseous hydrogen applications are relatively well investigated, yet there is less understanding of the hazards and associated risks for cryogenic hydrogen, including LH2. Validated models and tools are needed for hydrogen safety engineering of LH2 systems and infrastructure. This paper presents an overview of models developed and validated at HySAFER Centre of Ulster University, including within the PRESLHY project. These include models for assessment of hazard distances for incident scenarios. Experimental data have been used to validate the contemporary CFD models and build new correlations or reduced models. The analysed phenomena and relevant models are generally separated into three main pillars to assess consequences of incidents involving hydrogen: release and dispersion, ignition, and combustion. The developed and presented models are interconnected and can be used synergistically to provide a unified approach to the assessment of consequences of selected incident scenarios with LH2 starting from an initiating event. The models and tools aim to inform and underpin relevant Regulations Codes and Standards and assist stakeholders in performing hydrogen safety engineering.