I am working on a compressed air energy storage system. The size and weight of the system are heavily constrained; nothing should (ideally) exceed a few pounds. For this reason, I would like to store the energy (compress the gas) and extract the energy (make the gas do work) with the same mechanism in a rotary fashion.
Essentially what I need is a rotary air compressor that, when air is forced through in the opposite direction, doubles as a pneumatic motor. I'm working with fairly high pressures (I'm estimating a few hundred psi) but low volume. In my search, I have found a plethora of compact rotary air compressors and rotary pneumatic motors, but there is hardly comment on what systems would work as both.
To me, it seems very intuitive that an air compressor could have these properties, but I don't want to jump to any conclusions. I have looked at several compressors, and the most applicable to my situation seem to be:
- Centrifugal compressor
- Axial flow compressor
- Rotary screw compressor
- Rotary vane compressor
The centrifugal compressor is ideal, but it seems the least likely in my eyes to be reversible, at least with any efficiency. I also looked at pneumatic motors, of which there were fewer available. Most applicable seemed to be the:
- Rotary vane motor
Other systems, such as the pietro motor, were obviously not applicable in my light weight, compact application. The correlation between the rotary vane compressor and the rotary vane motor is promising, but I would like to know about any options I have.
What rotary gas compression systems can double as motors powered by the gas they compress?
EDIT The answer most likely lies in the similarity between a radial (centripetal) turbine and a centrifugal compressor.