Final hydrogen temperature and mass estimated from refueling parameters

The final temperature and mass of compressed hydrogen in a tank after a refueling process can be estimated using the analytical solutions of a lumped parameter thermodynamic model of high pressure compressed hydrogen storage system. The effects of three single refueling parameters (ambient temperature, initial pressure and mass flow rate) and three pairs of the refueling parameters on the final hydrogen temperature are studied, for both 35 MPa and 70 MPa tanks. Overall expressions for the final hydrogen temperature, expressed as a function of the three factors, are obtained. The formulae for the final hydrogen temperature provide an excellent representation of the reference data. The effects of the refueling parameters (mass flow rate, initial pressure and inflow temperature) on the final hydrogen mass are determined from the physical model. An overall expression of the final hydrogen mass is also obtained. The final hydrogen temperature can be controlled by reducing the ambient temperature or the mass flow rate, or increasing the initial pressure. The final hydrogen mass can be maximized by reducing the mass flow rate or the inflow temperature, or increasing the initial pressure. This study provides simple engineering formulae to assist in establishing refueling protocols for gaseous hydrogen vehicles.