A holistic dynamic model for liquid hydrogen transfer process

Liquid hydrogen is a promising carrier for large-scale hydrogen storage and transportation. However, boil-off losses during transfer from trailers to storage tanks at refueling stations pose a significant challenge. Accurate prediction of these losses and dynamic characteristics of the transfer process is crucial for the safe and efficient management of liquid hydrogen systems. In this study, a dynamic model is developed to reveal the temporal and spatial variations of the thermodynamic parameters during key stages of the transfer process, including trailer self-pressurization, pipeline chill-down and station storage tank fast-fill. A multi-node thermal stratification model for the storage tank is developed, incorporating boundary layers effects and condensation-evaporation at the vapor-liquid interface. To improve numerical stability and accuracy, a staggered grids finite volume method is applied to the transfer pipeline. A case study involving a 50 m3 trailer and a 30 m3 station tank indicates that boil-off losses during fast-fill reach 51.7 kg, corresponding to 3.09% of the transferred mass. Parametric studies further quantify the effects of pressure difference, pipeline length, and tank volume on boil-off losses, with venting losses from the receiving tank identified as the dominant contributor (over 74%). This study offers practical guidelines for optimizing the design and operation of liquid hydrogen transfer systems.