The Flywheel Storage System utilizes an integrated Non-Flammable Phase-Change Cooling System. Heat generated in the PCB-based hexagonal stator is removed directly through the aluminum backing of the PCB panels and reclaimed as mechanical work via an external Stirling engine.
The stator's cooling is integrated directly into the monocoque structure.
- Cooling Channels: Precision-milled channels on the outer aluminum backing of the PCB panels form a continuous hexagonal conduit circuit when the panels are assembled.
- Internal Boiling: These channels are filled with 3M Novec 7100 (a non-flammable, dielectric Hydrofluoroether).
- Direct Heat Transfer: Heat from the printed coils is conducted through the PCB substrate into the aluminum backing, directly boiling the refrigerant in the milled channels.
- Vaporization: Waste heat boils the Novec 7100 refrigerant, vaporizing it at approximately 61∘C.
- Vapor Transport: High-pressure vapor is collected through the integrated manifold circuit formed by the mated aluminum channels.
- Secondary Work: The vapor drives the "Hot Side" of an external Stirling Engine, converting waste thermal energy into electricity.
- Condensation: Vapor is cooled, condenses into a liquid, and is pumped back into the stator channels.
| Item |
Description |
Purpose |
| Cooling Channels |
Milled in Al-PCB backing |
Integrated structural cooling circuit. |
| Refrigerant |
3M Novec 7100 |
Non-flammable, dielectric boiling medium. |
| Collector Manifold |
Stainless Steel/Aluminum Header |
Collects vapor from the panel circuit. |
| Expansion Bellows |
Flexible Stainless Connectors |
Connects segments while allowing expansion. |
| Stirling Engine |
High-Efficiency Alpha Type |
Converts boiling heat back into electricity. |
- Integrated Heat Path: Direct thermal bonding of PCB-to-Aluminum eliminates thermal resistance of brazed pipe interfaces.
- Structural Sealing: The cooling circuit is inherently sealed as part of the monocoque panel assembly, increasing reliability.
- Enhanced Safety: Novec 7100 is non-flammable, dielectric, and compatible with the aluminum-PCB monocoque assembly.