Heat Transfer Models for Refueling Safety of Hydrogen Vehicle

Due to the simple structure and quick refueling process of the compressed hydrogen storage tank, it is widely used in fuel cell vehicles at present. However, temperature rise may lead to a safety problem during charging of a compressed hydrogen storage tank. To ensure the refueling safety, the thermal effects need to be studied carefully during hydrogen refueling process. In this paper, based on the mass and energy balance equations, a general heat transfer model for refueling process of compressed hydrogen storage tank is established. According to the geometric model of the tank wall structure, we have built three lumped parameter models: single-zone (hydrogen), dual-zone (hydrogen and tank wall) and triple-zone (hydrogen, tank wall liner and shell) model. These three lumped parameter models are compared with U.S. Naval gas charging model and SAE MC method based refueling model. Under adiabatic and diathermic conditions, four models are built in Matlab/Simulink software to simulate the hydrogen refueling process under corresponding conditions. These four models are: single-zone singletemperature (hydrogen), dual-zone single-temperature (hydrogen), dual-zone dual-temperature (hydrogen and tank wall temperatures), and triple-zone triple-temperature (hydrogen, tank wall liner and tank wall shell temperatures). By comparing the analytical solution and numerical solution, the temperature rise of the compressed hydrogen storage tank can be described. The analytical and numerical solutions on the heat transfer during hydrogen refueling process will provide theoretical guidance at actual refueling station, so as to improve the refueling efficiency and to enhance the refueling safety.