Effect of refueling parameters on state of charge and temperature rise of hydrogen cylinders undergoing fast-filling

Abstract

Abstract High-pressure gaseous hydrogen cylinders have been the mainstream onboard storage technology for hydrogen energy vehicles because they offer the benefits of high energy storage density while maintaining low cost. However, the temperature inside the carbon fiber composite cylinders will rise sharply during the hydrogen charging process because of the throttling effect, which affects the mechanical properties of the composites and leads to an insufficient state of charge (SOC) and other problems. This work presents the establishment of a numerical model that describes the rapid filling progress of 35 MPa hydrogen storage cylinders. Important evaluation criteria of the cylinder, namely the state of charge (SOC) and temperature rise, have been analyzed in relation to the filling rate and other parameters using the computational fluid dynamics (CFD) method and thermodynamic analysis methods. The theoretical analysis results, which are consistent with the outcomes of the CFD simulation and experimental analysis, offer the theoretical foundation for the controlling strategy of the filling rate of the gas source from refueling stations and hydrogen temperature. This consequently lowers the energy demand for hydrogen refueling stations to invest in hydrogen pre-cooling.