Hydrogen Refueling Stations: Safe Filling Procedures

Safety is a high priority for a hydrogen refueling station.Here we propose a method to safely refuel a vehicle at optimised speed of filling with minimum information about it. Actually, we identify two major risks during a vehicle refuelling: over-filling and over-heating. These two risks depend on the temperature increase in the tank during refuelling. But the inside temperature is a difficult information to get from the station point of view. It assumes a temperature sensor in a representative place of the tank and an additional connection between the vehicle and the station for data exchange. The refuelling control may not depend on this parameter only. Therefore, our objective was to effectively control the filling, particularly to avoid the two identified risks independently of optional and safety redundant information from the vehicle. For that purpose, we defined a maximum filling pressure which corresponds to the most severe following conditions: if the maximum temperature is reached in the tank or if the maximum capacity is reached in the tank. This maximum pressure depends on a few filling parameters which are easily available. The method and its practical applications are depicted.