Solid-state hydrogen is hydrogen gas stored in metal hydrides. The thermal behavior of such systems is of great importance. This is due to the basic physical properties of the compounds.
Physical behavior #
The behavior of a technical system with metal hydrides is determined mainly by three effects:
- The pressure in the system largely depends on the temperature. The relation between these variables is non-linear. In equilibrium, an exponential function of the temperature characterizes the pressure.
- The absorption of hydrogen in a DASH storage releases heat. It is therefore an exothermic process.
- Conversely, the removal of hydrogen is an endothermic process. Therefore, heat is required to
desorb hydrogen from a storage.
Modeling the pressure or temperature of a storage system requires consideration of the material characteristics in equilibrium as well as the effects of the dynamic behavior.
The picture below illustrates how a storage unit cools down, when hydrogen is rapidly removed from it. As a visible effect, it builds ice on its surface:
Technical implications #
The technical behavior is derived from the above physical properties:
- Each DASH storage module is characterized by a thermal limitation of the charging and discharging rates. These limitations depend on both the storage materials and the system design.
- The system behavior of the storage is dynamic. Thus, it depends on the state of charge, the
environmental conditions, the environmental parameters, and previous states. - If hydrogen is extracted for a longer period, heat (possibly at ambient temperature) must be supplied to the system to keep the extraction running. With the right design, this can be done completely passively.
- In a situation of prolonged supply of hydrogen, heat must be removed from the system to keep
charging the system. Again, the right design may allow for a completely passive setup. - The discharge in case of leakage is self-inhibiting. This property is important for the very high
safety level of the systems.
System design #
Our experts are available to support you if you further questions about the integration of DASH
Hydrogen Storage Modules in your system (control and measurement, thermal, etc.). The properties of standardized products such as the M-series storages or C-series storages are well defined and characterized. In addition to these standards, we are also capable of adapting the technology specifically to your requirements.
