PUB - Development of a Bi-Stable Mechanism for Efficiency Optimization of Pneumatic Pressure Boosters

In hydrogen filling stations, pressure boosters are needed to increase the pressure from the level-dependent storage tank to a constant disposal pressure. Pneumatically driven pressure boosters can easily meet the special requirements of explosion protection in such applications. Thus, despite their actually low efficiency, they offer a worthwhile approach. The attractiveness can be further increased by optimizing the efficiency.

Content

Authors: Schmid, Matthias; Reinertz, Olivier; Schmitz, Katharina

In state-of-the-art units, a considerable part of the expansion energy in drive chambers is lost due to an unfavorable load over the stroke. By increasing the load at the beginning of the stroke by means of a bi-stable mechanism, the amount of previously unused expansion energy can be stored in it. This energy can be released again in the second half of the stroke. This reduces the pressure requirement at the end of the stroke, allows the air in the drive chamber to expand and thus lowers the air consumption and increases the efficiency. In the scope of this paper, an analytical representation of the pressure booster is shown for an understanding of the thermodynamic processes. On the basis of the simulation model, the load compensation is specified and a concept for the prototype is presented. The concept is based on the negative spring stiffness of a plate during mechanical snap-through. Subsequently, the developed mechanism is integrated into the simulation model and the results and achieved progress are elaborated. Finally, the outstanding measurements and already realized preparations are discussed.