Rotation Heat Pump – Diffusion Bonded Rotor Design
The Rotation Heat Pump (RHP) is based on the principle of compression by centrifugal forces and uses a mixture of noble gases as a working fluid that is neither flammable nor toxic. The core element, the rotor, which previously consisted of individual parts, was replaced in the latest generation by a single block in which heat transfer, compression and expansion take place. This block consists of thin plates with microchannels through which the inert gas mixture flows. These plates are connected by diffusion bonding, creating a block in which almost all the necessary functions are integrated. This system offers the possibility of adapting the thermodynamic cycle to various applications and achieving the greatest possible efficiency through flexible channel routing. This is made possible by the heat transfer during compression and expansion. Different spreads can be achieved at the source and sink, thereby minimizing exergy losses. This design also makes it possible to achieve a significantly higher temperature lift and absolute process temperature compared to the previous system. This paper shows the concept and system of the diffusion bonded rotor as well as the various possibilities for channeling. In particular, it discusses how the channeling of the microchannels can be designed in order to achieve optimum operation for different applications. Sketches of the thermodynamic cycle show and emphasize the flexibility and should serve as an incentive for the investigation of further application possibilities. Furthermore, the prototypes and rotor blocks built so far will be shown and presented.