Electric Machine Cooling Loop Using Bypass Duct Heat Rejection

The cooling system is divided into separate functional components: an evaporator positioned near the electric machine to absorb heat, a condenser located in the bypass duct to reject heat, and interconnected conduits forming a closed-loop coolant circuit. This segmentation allows each component to operate optimally in its specific thermal environment while collectively managing the thermal load of the electric machine.

A dielectric coolant fluid is introduced as an intermediary substance to transfer heat from the electric machine to the bypass duct airflow. The coolant circulates through the evaporator where it absorbs heat from the electric machine, then travels through conduits to the condenser where heat is rejected to the bypass air, effectively mediating the thermal transfer between these two components.

The system changes the thermal parameters of the electric machine environment by actively removing heat through the evaporator, maintaining the electric machine at optimal operating temperatures despite the high-temperature exhaust/tail cone environment. This parameter control enables the use of standard materials rather than expensive high-temperature resistant materials.

The dielectric coolant fluid utilizes phase transitions (evaporation and condensation) to efficiently transfer heat. The coolant evaporates in the evaporator absorbing latent heat from the electric machine, then condenses in the condenser releasing latent heat to the bypass duct airflow. This phase change mechanism provides high heat transfer efficiency with simple component design.