Numerical Analysis of Temperature Distribution During Charging Process of Vertically Installed Hydrogen Tanks

Recent advancements in hydrogen tank technology have favored the use of composites over metals for weight reduction, although at the cost of a narrower operating temperature range. Therefore, this study aims to establish safety standards for charging tube skids—large tanks positioned vertically within hydrogen transport vehicles—by examining the variations in temperature distribution under different charging environments through numerical analysis. A two-dimensional axisymmetric model was developed based on ANSYS Fluent to incorporate the effect of buoyancy by applying gravitational conditions along the axial direction. The study analyzed the impact of various charging and environmental conditions (charging time (0~240 min), inlet temperature, ambient temperature, initial temperature (−20 °C~40 °C), and initial pressure (5~20 bar)) on temperature distribution, ultimately deriving a regression equation to predict the tank’s maximum temperature. The findings indicate that the initial temperature has the most significant correlation with the tank’s temperature, followed by charging time and ambient temperature. Inlet temperature and initial pressure demonstrated minimal influence within the study’s scope. The derivation of predictive formulas for the maximum temperatures of the tank’s three regions, all showing an R2 value of 0.99 or higher, highlights the practicality of these results. This study’s insights are expected to contribute to further research aimed at optimizing charging conditions for tube skids and other hydrogen tanks.