Phase Change Cooling – electric motors at the physical limit
The world’s most powerful cooling system: With evaporative or phase-change cooling, electric motors reach their physical limits. The cooling system uses the high enthalpy of vaporization of the special cooling medium, which enables heat dissipation of 60 kW/l to be achieved.
The increase in performance compared to water cooling is therefore a factor of 6, compared to oil cooling a factor of 3. The physical properties of the cooling medium enable direct cooling of the stator windings and therefore the best possible heat transfer coefficient. Due to the phase transition to vapor, there is no liquid medium in the air gap, which means that additional components such as containment tubes can be dispensed with.
No derating with continuous power
If heat is introduced during the phase transition, the temperature of the cooling medium does not rise any further, so that the motor operates constantly at a maximum of 120°C. The continuous output of the motor corresponds to the maximum output and there is no derating. The inverter can also be cooled in this way.
The benefits at a glance:
- Constant temperature in the electric motor
- No loss of performance
- Continuous power/maximum power = 100%
- Low complexity
This type of cooling is particularly interesting for applications where maximum power is constantly being used. Additive Drives integrates the heat exchanger into the housing to maximize the power density of the overall system and is thus breaking new ground, for example in electric aviation.
