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For safe and fast refueling hydrogen to fuel cell vehicles (FCVs) at hydrogen refueling stations (HRSs), a refueling protocol is under discussion at SAE J2601 to be a global standard. In order to realize such a standard, we have to estimate the relation between gas temperature and pressure during a refueling and for an accurate estimation we have to correctly understand the thermal characteristics of hydrogen tank. Fast refueling test data has been offered by BMW-Powertech, some test cases have been analyzed by a simulation model developed by Monde et al. It reveals that the hydrogen temperature at the end of refueling does not exceed 85°C for these analyzed cases. The effect of the pressure drop between storage bank and hydrogen tank was negligible on the gas temperature at the end of refueling, although the gas temperature shows different profile depending on the pressure drop.

Compressed hydrogen gas is currently the most popular choice for a fuel storage mode for fuel cell vehicles (FCVs). For the practical design of suitable vessels and hydrogen filling stations, it is necessary to be able to accurately predict the temperatures of the vessel wall and gas during filling. Recently, Monde et al.[ 1 ] proposed a thermodynamic model for the gas in the vessel during filling. In this paper, on the basis of the Monde et al. model, the temperature of the precooled hydrogen and the filling time are analyzed for a practical vessel and hydrogen filled range. Equations predicting them are derived using the calculated values.

In this study, in order to relax the pre-cooling regulations at hydrogen fueling stations, we develop a software algorithm to simulate an actual hydrogen fueling process to Fuel Cell Vehicle (FCV) tanks. The simulation model in the software consists of the same filling equipment found at an actual hydrogen fueling station. Additionally, the same supply conditions (pre-cooling temperature, pressure and mass flow rate) as at a hydrogen fueling station were set to the simulation model. Based on the supply conditions, the software simulates the temperature and pressure of hydrogen in each part of filling equipment. In order to verify the accuracy of the software, we compare the temperature and pressure simulated at each stage of the filling process with experimental data. We show that by using the software it is possible to accurately calculate the hydrogen temperature and pressure at each point during the fueling process.