Improvement in predicting the thermal behavior of liquid hydrogen storage through novel thermal modeling

Abstract

Liquid hydrogen (LH2), a key clean energy carrier, requires precise thermal management, especially for longterm storage and long-distance transport. Accurate prediction of thermal stratification, self-pressurization, and Boil-Off Gas (BOG) generation is considered pivotal for optimizing low-temperature cryogenic storage systems. Most of the literature uses the two-zone model, where the vapor-liquid interface is treated as a simple saturation condition. The influence of interfacial thermal behavior on the calculation of thermal stratification, selfpressurization, and Boil-Off Gas (BOG) generation has not been sufficiently analyzed. To overcome such limitations, in this study, the liquid-vapor interface is modeled by establishing a separate governing equation and optimal geometric progression grid discretization instead of treating it as a simple condition. The Diffusion-based Interface Model (DIM) of the present study transcends traditional methods by eliminating the typical saturation condition at the vapor-liquid interface, providing a deeper insight into the thermal dynamics of the interface. The DIM's findings include a daily BOG rate of 0.14%, aligning with literature, and temperature deviations of 0.008% in liquid and 0.13% in vapor near the interface, indicating a greater vapor phase influence on interfacial thermal behavior. Furthermore, a 0.35% deviation is observed in vapor pressure towards the simulation's end. The DIM can be a complementary tool for engineering works. It enables the design of safe storage of liquid hydrogen.