HOW PRESSURE INFLUENCES THE SAFETY
Low pressure implies safety
Low pressure is always beneficial for safety. However, due to the low density of the hydrogen, high pressure is often required for storing or transporting gaseous hydrogen. To enable a low-weight design at high pressure, a carbon fiber-reinforced polymer material is typically used. However, high pressures increase the rate of leakage. Further, if an ignition source is present, there is the potential for an explosion. Preventing the risk of explosions is one of the main challenges when working with high-pressure hydrogen storage solutions. While mitigation is possible to a certain extent, the consequences in case of failure are severe. If a piece of equipment fails and bursts violently, parts of this equipment may take up high kinetic energy and cause harm to persons in the surroundings. The principal effects are shown in the figure below.
State of Health ist ein Parameter, der angibt, in welchem chemische-physikalischen Gesundheitszustand sich die Batterie befindet. Je nach Benutzungsprofil, Lade- und Entladeverhalten und Lagerung, entwickelt sich der Zustand der Batterie sehr unterschiedlich. Nach der Messung des SOH-Wertes wird dieser mit der ursprünglichen Kapazität der Batterie verglichen. Die Angabe wird in Prozent des ursprünglichen Wertes definiert. Je niedriger der SOH ausfällt, desto schlechter wird der Zustand des Energiespeichers bewertet.
While the risk level depends on many factors, the hazard potential is much lower if pressure is lower. GRZ Technologies' solutions (e.g., our DASH M-series storages) work at low to very low pressure and ambient temperatures. GRZ Technologies' design engineers will design storage sytems with the lowest possible pressure matching the requirements of the downstream hydrogen consumer. For example, if the upstream device is an electrolyzer producing hydrogen at 35 bar(g) and the downstream fuel cell consumes hydrogen at 5 bar(g), the pressure level of the storage is designed to be in the range between 5 and 35 bar(g). Therefore, the technology offers the advantages of high-density storage, but at a significantly lower hazard level than currently available high-pressure storage tank technologies.
In conclusion, low-pressure hydrogen storage systems are safer than high-pressure ones for several reasons. They significantly reduce the risk of explosions or ruptures and release hydrogen more slowly in the event of a leak, minimizing immediate hazards. Additionally, the endothermic release process at low pressure results in more manageable temperature changes, enhancing overall system safety. Thus, low-pressure systems offer a more stable and secure hydrogen storage solution.