Hydrogen-powered vehicles are lighter than battery-powered vehicles, which is why they are of great interest for heavy duty trucking applications. Three different storage technologies are currently being developed for the tank system: the high-pressure tanks (700 bar) at ambient temperature, liquid tanks and Cryogas tanks. As the name already suggests, the Cryogas tank combines the advantages of the first two technologies. Since the hydrogen is stored very cold and at up to 300 bar, the Cryogas storage densities can be higher than in liquid tanks. Additionally the hydrogen is gaseous, which enables a very flexible operating range and does not cause any instabilities through a phase transition from liquid to gas.
The APT works in the development team of Cryomotive GmbH with the goal to make this technology ready for the market by 2024. The APT's expertise is the design and development of the heat management, especially the heat exchangers. The cold hydrogen from the tank must be heated before it flows into the fuel cell. In this process the cooling water for the fuel cell is cooled down and increases the efficiency of the system. On the other hand, the tank must be heated to prevent the hydrogen from liquefying in the event of a pressure drop (fuel extraction).
As with any heat transfer problem, a sufficiently large area has to be provided for the heat transfer. In comparison to chemical plants the space in vehicles is very limited. The first thermodynamic calculations and models of the overall system have shown that the heat transfer required for the application is feasible. Thus, the first successful results have been achieved in design phase I and a targeted optimization of the heat exchangers can be started.