Wind Turbine Generator Cooling Air Gap Noise Control

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Solution Overview

Problem

Wind turbines face challenges in reducing noise emissions while maintaining efficient cooling, as larger turbines increase sound propagation and noise immission, and existing cooling designs fail to adequately dampen noise and protect against environmental contaminants.

Innovation Solution

The design incorporates an external rotor generator with an air supply duct and exhaust air chamber, thermally decoupled to route cooling air in a spatially separate manner, using air conveying devices to manage airflow through an air gap between the rotor and stator, and includes silencers and shut-off units to control noise and environmental exposure.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling devices generate air flow to cool the generator, then cooling efficiency is improved, but noise emissions increase

Engineering Contradiction:
Improvegenerator cooling efficiencyVSAvoidnoise emissions
Core Design Contradiction:
TemperatureVSObject-generated harmful factors

Solution Approach 1:

The generator is divided into acoustically isolated segments using sound insulation elements that partition the interior space. This segmentation allows different zones to have different acoustic characteristics, containing noise within specific regions while maintaining effective cooling airflow paths through the rotor and stator components.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Sound insulation elements act as intermediary components between noise sources (cooling devices, air flow paths) and the external environment. These elements mediate the transmission of acoustic energy, absorbing and reflecting sound waves while permitting thermal energy transfer for cooling purposes, thus decoupling noise propagation from heat dissipation functions.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the generator is designed with an open structure to avoid additional cooling systems, then device complexity is reduced, but protection against water and dirt deteriorates

Engineering Contradiction:
Improvecooling system complexityVSAvoidcontaminant ingress
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

Sound insulation elements function as flexible barriers that seal gaps and openings in the generator structure. These elements form protective shells around sensitive internal components, preventing water and dirt ingress while maintaining the open design philosophy. The thin film nature of these insulators allows them to conform to complex geometries without adding significant structural complexity.

Inventive Principle:
Principle #30Flexible shells and thin films

3Productivity

If larger wind turbines are used to improve efficiency, then energy production is improved, but noise propagation and immission increase

Engineering Contradiction:
Improveenergy production efficiencyVSAvoidnoise propagation
Core Design Contradiction:
ProductivityVSObject-generated harmful factors

Solution Approach 1:

Sound insulation elements are nested within the existing generator structure, placing acoustic barriers inside the rotor and stator assemblies. This nested configuration allows the insulation system to be integrated into the compact space of large-scale generators without increasing external dimensions, thereby containing noise propagation while maintaining the high power density required for efficient energy production.

Inventive Principle:
Principle #7Nested doll (Nesting)

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 enables cost-effective and efficient cooling while reducing noise emissions and protecting the generator from environmental contaminants, allowing for adjustable noise compliance with site-specific limits and extended maintenance intervals.

Implementation Method 1

The air supply duct is designed to supply ambient air as cooling air from the vicinity of the generator for cooling the generator

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

the exhaust air chamber is preferably designed to discharge the cooling air 'heated' by the generator in the direction of the surroundings of the generator in order to cool the generator

Methodology Applied
Scientific EffectHeat transfer: Convection

Data Source

PatentEP4167448A1Generator and wind turbine
Publication Date: 2023.04.19 WOBBEN PROPERTIES GMBH
  • EP4167448A1 patent drawingFigure 1
  • EP4167448A1 patent drawingFigure 2
  • EP4167448A1 patent drawingFigure 3

AI summary

Generator (10), in particular generator (10) for a wind turbine (100), the generator (10) comprising: an air supply duct (19) and a separate exhaust air chamber (27), in particular two or more exhaust air chambers (27) which is fluidly connected to the upstream air supply duct (19), a stator segment (20) with a stator active unit (25) and a rotor segment (30) rotatably arranged about an axis of rotation (D) relative to the stator segment (20) with a rotor active unit (36), wherein the rotor active unit (36) and stator active unit (25) are spaced apart from each other by an air gap (S) through which the exhaust air chamber (27) is fluidly connected to the upstream air supply duct (19), characterized in that an air conveying device (60) is arranged downstream of the exhaust air chamber (27), which is used to cool the rotor active unit (36) and the stator active unit (25) is designedwherein the air conveying device (60) supplies cooling air (C) to the air gap (S) through the air supply channel (19) for cooling the rotor active unit (36) and the stator active unit (25), and discharges cooling air (H) heated by the rotor active unit (36) and the stator active unit (25) from the air gap through the exhaust air chamber (27), wherein the exhaust air chamber (27) is configured to discharge the heated cooling air (H) in a radial direction (R) with respect to the axis of rotation (D).