Research on Evaporation Characteristics and Safe Storage Duration of Marine Liquid Hydrogen Storage Tanks Under the Coupling Effect of Heat Leakage and Sloshing

ABSTRACT Liquid hydrogen, a zero‐carbon and high–energy‐density fuel, is a promising option for future oceangoing vessels. During maritime transportation, onboard cryogenic tanks are exposed to ambient heat leakage and ship‐induced roll motion, which can trigger sloshing and fundamentally modify the coupled thermo‐fluid processes governing boil‐off and pressurization. In this study, a transient two‐dimensional multiphysics model is established to simulate a liquid‐hydrogen storage tank under prescribed roll‐type oscillations with heat leakage. A stationary case is considered in parallel as a baseline, enabling quantitative comparisons of temperature evolution, vapor accumulation, free‐surface response, and pressure rise between motionless and oscillatory conditions. The results show that roll‐induced sloshing markedly accelerates pressurization and reduces the safety margin: the lossless storage duration decreases from 9.0 h under stationary conditions to as low as 3.2 h under high‐frequency excitation. Increasing the oscillation amplitude from 5° to 15° intensifies interfacial disturbance and convective transport, thereby accelerating vapor generation and shortening the lossless storage duration from 6.6 to 4.1 h. Decreasing the oscillation period from 12 to 3 s increases the maximum liquid level from 140.9 to 170.7 mm, raises the daily evaporation rate by approximately 2.72%, and reduces the lossless storage duration from 7.6 to 3.2 h. Moreover, the initial fill level is identified as a critical factor under sloshing: At 150 s, the pressure increases from approximately 102.78 kPa at 10% fill to 106.43 kPa at 90% fill due to reduced vapor headspace and enhanced sensitivity to vapor accumulation. Overall, the tank's safe operation is governed by the coupled effects of oscillation intensity (amplitude), excitation frequency (period), and fill level. These findings provide quantitative evidence for establishing safety margins and for mitigating pressurization and boil‐off losses through appropriate motion control and filling/operational strategies for onboard liquid‐hydrogen storage systems.