Stator End-Turn Spray Manifold to Cut Generator Windage Losses

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Solution Overview

Problem

High power density electric generators face challenges in effectively cooling their end turns without incurring additional weight and volume penalties, as traditional cooling methods like oil spray-cooling increase windage losses and are inefficient at high power levels.

Innovation Solution

The implementation of manifolds with integrated spray nozzles that atomize cooling fluid to directly impinge on the end turns of stator coils, enhancing heat transfer coefficients and reducing weight and size while maintaining high performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If traditional spray-cooling methods are used to cool end turns, then heat extraction is improved, but windage losses increase due to oil contact with rotating rotor components

Engineering Contradiction:
Improveheat extractionVSAvoidwindage losses
Core Design Contradiction:
TemperatureVSLoss of energy

Solution Approach 1:

The invention extracts the spray cooling function from the rotating rotor and relocates it to the stationary stator end turns. By positioning spray nozzles on the stator to cool only the stationary end turns, the system achieves effective heat extraction without oil contact with rotating components, thereby eliminating windage losses while maintaining cooling effectiveness.

Inventive Principle:
Principle #2Taking out (Extraction)

2Temperature

If conventional cooling methods are used in high power density generators, then cooling capacity is insufficient, but adding traditional cooling systems increases weight and volume

Engineering Contradiction:
Improvecooling capacityVSAvoidcooling system weight
Core Design Contradiction:
TemperatureVSWeight of stationary object

Solution Approach 1:

The invention segments the cooling function by targeting only the end turns rather than cooling the entire generator. By isolating the cooling application to specific high-heat-generation areas (the end turns), the system achieves adequate cooling capacity with a minimized cooling system, reducing overall weight and volume while addressing the critical thermal management need in high power density generators.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention applies local quality by providing concentrated cooling precisely where it is most needed - the end turns of the stator coils. By directing spray nozzles to cool only this specific high-heat-area rather than implementing general cooling throughout the generator, the system achieves effective thermal management with minimal cooling system mass, optimizing the weight-capacity ratio for high power density applications.

Inventive Principle:
Principle #3Local quality

3Power

If high power density is achieved in generators, then power output increases, but heat generation increases making traditional cooling ineffective

Engineering Contradiction:
Improvepower outputVSAvoidheat generation
Core Design Contradiction:
PowerVSTemperature

Solution Approach 1:

The invention introduces spray cooling as an intermediary heat transfer mechanism specifically for the end turns. By adding this intermediate cooling layer between the heat-generating end turns and the surrounding environment, the system can manage the increased heat generation from high power density operation without requiring proportional increases in overall cooling system capacity, thus maintaining effectiveness at high power levels.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 solution enables continuous operation of high power density generators at rated power levels with improved cooling efficiency, reducing heat and minimizing weight and volume impacts.

Implementation Method 1

The manifold includes a ring having a surface with a plurality of spray nozzles formed integral with the ring and extending from the surface. Each spray nozzle of the plurality of spray nozzles includes a channel having a diameter, and a surface having a selected width and an angle, wherein the channel and the surface are configured to spray oil on first end turns of the stator coils.

Methodology Applied
Scientific EffectAtomization:

Implementation Method 2

The spray cooling technique provides very good heat extraction

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

The spray cooling technique provides very good heat extraction

Methodology Applied
Scientific EffectConduction: Conduction (thermal)

Data Source

PatentEP4329165A1Cooling end turns in high power density electric generators
Publication Date: 2024.02.28 HONEYWELL INTERNATIONAL INC
  • EP4329165A1 patent drawingFigure 1
  • EP4329165A1 patent drawingFigure 2A~3A
  • EP4329165A1 patent drawingFigure 3B

AI summary

A manifold for cooling the end turns of stator coils of a generator is provided. The manifold includes a ring having a surface with a plurality of spray nozzles formed integral with the ring and extending from the surface. Each spray nozzle of the plurality of spray nozzles includes a channel having a diameter, and a surface having a selected width and an angle, wherein the channel and the surface are configured to spray oil on first end turns of the stator coils.