Investigation of the non-equilibrium heat transfer and self-pressurization behavior of liquid hydrogen tanks

Liquid hydrogen, due to its low boiling point and low latent heat of vaporization, is highly sensitive to external heat leakage, leading to thermodynamic phenomena such as heat and mass transfer, temperature rise, and selfpressurization within the tank. To accurately predict these behaviors in liquid hydrogen tanks, this study developed an evaporation-pressurization prediction model based on a modified three-zone model. The model is validated against classical experimental data, demonstrating high accuracy and applicability across a wide range of operating conditions, with an average maximum relative error of only 2.18 % for the six sets of predicted conditions. This study separates the influencing parameters into dimensionless form based on the gas state equation, compares the variation patterns of key parameters during the pressurization process, and explores the effects of different heat leakages, filling levels, and storage pressures on evaporation behavior. Finally, this study simulates the entire storage pressurization and depressurization process in liquid hydrogen tanks, precisely describing the evolution of various parameters during depressurization and examining the variations in the thermodynamic characteristics within the tank. This paper can enhance the comprehensive understanding and predictive capability of pressurization behavior in liquid hydrogen storage and transportation systems.