Rotating Machine Rotor Cooling via Segmented Fluid Passages
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Solution Overview
Problem
In rotary machines, increasing the rotor diameter leads to increased weight and cost due to the need for a solid heat conduction structure and longer heat transfer paths, which limits cooling efficiency.
Innovation Solution
The rotary machine design includes separate passages for liquid and gas phase cooling media within the rotor, allowing direct cooling of field poles and reducing the need for a solid heat conduction path, thereby enhancing cooling efficiency without increasing weight or cost.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If the rotor diameter is increased, then the cooling target can be larger, but the weight and cost of the cooling structure increases due to the need for a solid heat conduction structure
Solution Approach 1:
The cooling structure is segmented into multiple independent cooling channels formed within the rotor body. Instead of using a solid heat conduction structure, the rotor is divided into regions with separate liquid phase cooling medium flow passages and gas phase cooling medium flow passages, allowing heat to be removed locally at multiple points rather than requiring a continuous solid conduction path.
Solution Approach 2:
The invention uses liquid phase cooling medium and gas phase cooling medium flowing through passages to transfer heat, replacing the need for solid heat conduction structures. The fluid-based cooling system allows thermal energy to be removed through convection and phase change rather than requiring extensive solid thermal conduction paths.
2Volume of moving object
If the rotor diameter is increased, then the cooling target can be larger, but the material cost and manufacturing cost increases
Solution Approach 1:
The cooling passages are segmented into modular liquid phase and gas phase channels that can be integrated into the rotor design. This segmentation allows for standardized manufacturing processes and reduces the need for complex custom fabrication of solid heat conduction structures, thereby lowering manufacturing costs despite the larger rotor size.
Solution Approach 2:
The invention changes the thermal transport parameter from solid conduction to fluid convection and phase change. This parameter change allows for more cost-effective manufacturing since fluid passages can be formed using conventional machining or additive manufacturing techniques, avoiding the need for expensive solid heat conduction components.
3Temperature
If a heat transfer structure is used to connect the central hollow space and the cooling target, then cooling can be achieved, but the temperature difference between the cooling device and the cooling target increases, reducing cooling efficiency
Solution Approach 1:
The heat transfer path is segmented into multiple short sections with separate liquid phase and gas phase passages positioned close to the cooling target. This segmentation eliminates the need for a single long heat transfer structure, reducing the overall thermal resistance and temperature difference between the cooling device and the cooling target.
Solution Approach 2:
The invention uses fluid flow to transfer heat directly to the cooling target, replacing long solid heat transfer structures. The liquid phase cooling medium absorbs heat through convection and phase change, providing more efficient thermal coupling between the cooling device and the cooling target, thereby reducing the temperature difference.
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 configuration increases cooling efficiency while preventing weight and cost increments, even with larger rotor diameters, by simplifying the cooling structure and improving thermal transport capability.
Implementation Method 1
the field pole can be directly cooled by use of the liquid phase cooling medium
Implementation Method 2
the liquid phase cooling medium is evaporated into a gas phase cooling medium in the central hollow space to cool windings
Implementation Method 3
a cooling structure for cooling the cooling target with latent heat generated by evaporation of a liquid phase cooling medium
Implementation Method 4
the gas phase cooling medium generated by evaporation of the liquid phase cooling medium, inside the central hollow space, is returned to the condenser through the same coupling pipe, cooled and condensed again into the liquid phase cooling medium
Data Source
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AI summary
Provided is a rotary machine capable of increasing cooling efficiency while preventing an increase in the weight and cost of a rotor even in a case where the diameter of the rotor is increased. A rotary machine including a rotor which is rotatable around a rotational axis, and a cooling device, wherein the rotor includes: a hollow cooling medium flow section provided in a center portion of the rotor in a radial direction and extending along the rotational axis; and a cooling target provided outward of the cooling medium flow section in the radial direction, and the rotary machine comprises a stationary section pipe which introduces a liquid phase cooling medium generated by cooling in the cooling device into the cooling medium flow section, and returns a gas phase cooling medium present in an inside of the cooling medium flow section from the cooling medium flow section toward the cooling device, the rotor including: a leading passage which leads the liquid phase cooling medium to a region which is in the vicinity of the cooling target through a first opening formed in a side surface of the cooling medium flow section, the side surface extending along the rotational axis; and a return passage which returns the gas phase cooling medium to the inside of the cooling medium flow section, the gas phase cooling medium being generated by evaporation of the liquid phase cooling medium in the region which is in the vicinity of the cooling target, by heat exchange between the liquid phase cooling medium and the cooling target.