Embedded Evaporative Winding Liner for Low-Resistance Motor Cooling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current electric motor cooling systems face challenges such as high thermal resistance, low copper fill factor, increased manufacturing complexity, and limited application in concentrated wound machines, which hinder efficient heat management and power density in high-power density motors.
Innovation Solution
A cooling system utilizing a winding liner with micro-channels for a dielectric coolant that evaporates and condenses to directly absorb heat from the windings, reducing thermal resistance and enhancing heat extraction with a wick-assisted two-phase flow, allowing for efficient heat transfer without altering the winding configuration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If water jacket cooling is used, then cooling coverage is improved, but thermal resistance between winding and coolant increases
Solution Approach 1:
The patent introduces a winding liner as an intermediary component between the copper winding and the coolant channels. This liner with integrated micro-channels serves as a thermal mediator that conducts heat from the winding to the coolant while maintaining electrical insulation, thereby reducing thermal resistance without compromising safety
Solution Approach 2:
The cooling channels are nested directly within the winding liner structure, which itself is nested around the copper winding. This nested configuration places the coolant in close proximity to the heat source (winding) through multiple nested layers, significantly reducing thermal resistance while maintaining a compact structure
2Reliability
If direct winding heat exchanger is used, then thermal resistance is reduced, but copper fill factor decreases
Solution Approach 1:
The patent transitions from planar cooling approaches to three-dimensional micro-channels within the winding liner. By creating channels in the radial and axial dimensions of the liner, the cooling surface area is dramatically increased without occupying additional slot space, thus maintaining copper fill factor while enhancing heat extraction
3Temperature
If axial cooling channel is used, then temperature reduction is achieved, but manufacturing complexity increases
Solution Approach 1:
The patent segments the cooling function from the winding structure by using a separate winding liner component. The liner is manufactured independently with integrated cooling channels, then assembled around the pre-fabricated Litz wire bundle. This segmentation allows standard winding fabrication processes to be used while adding cooling functionality through a separate manufacturable component
4Productivity
If water cooled DWHX is used, then current density is increased, but leakage risk increases
Solution Approach 1:
The patent employs a dielectric coolant that can be electrically insulating, allowing the cooling system to operate at higher current densities without the risk of water leakage causing electrical shorts or insulation breakdown. The dielectric property provides a safety margin that enables more aggressive cooling at higher power densities
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach improves power density and efficiency by reducing thermal resistance, minimizing manufacturing complexity, and maintaining high copper fill factor, while lowering pumping power requirements and preventing coolant leakage.
Implementation Method 1
The coolant has a heat of evaporation such that at least a portion of the coolant evaporates as the coolant absorbs heat from the electrical winding
Implementation Method 2
A heat exchanger cools the coolant after the coolant has passed through the channels so as to condense the coolant into the liquid state
Implementation Method 3
A cooling system utilizing a winding liner with micro-channels for a dielectric coolant that evaporates and condenses to directly absorb heat from the windings, reducing thermal resistance and enhancing heat extraction with a wick-assisted two-phase flow
Data Source
AI summary
A cooling system for an electrical winding (14) includes a winding liner (100) that has at least one wall (102) that defines a plurality of channels (110) that are in communication with the winding (14). A coolant has a liquid state (112) and a gaseous state (114). The coolant passes through the channels (110) so that the coolant is in contact with at least a portion of the electrical winding (14). The coolant has a heat of evaporation such that at least a portion of the coolant evaporates as the coolant absorbs heat from the electrical winding (14). A delivery mechanism (200) delivers the coolant to the channels (110). A heat exchanger (212) cools the coolant after the coolant has passed through the channels (110) to condense the coolant into the liquid state.