Thermal and Heat Transfer Dynamics in High Pressure, High Aspect Ratio Hydrogen Tank Filling Processes

A thermodynamic modeling framework is introduced to describe hydrogen refueling station configurations and capture detailed thermal dynamics in vehicle tanks with large aspect ratios. With an aspect ratio larger than three, axial discretization of temperature allows to recover accurate temperature profiles and show that the gas and liner temperature are always highest towards the rear of the tanks. The framework is validated against experimental data and used to investigate the internal heat transfer dynamics. As aspect ratio grows larger, the amount of cooling received by the rear region decreases as the incoming turbulent jet does not reach the latter. The current thermal management strategy of pre-cooling is therefore limited, showing marginal improvements, even with a cooling temperature of -50 ◦C. Potential solutions are to increase the filling duration time, or to carefully design the tank with higher thermal diffusivity and adequate external means of cooling.