Rotor Blade Airflow Constriction for Faster De-Icing Heat Transfer

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Solution Overview

Problem

Existing wind turbine rotor blade heating systems face inefficiencies in heat transfer due to suboptimal airflow dynamics, leading to ineffective de-icing under icing conditions.

Innovation Solution

The rotor blade incorporates cross-sectional constrictions and flow resistances within its internal volume, enhancing airflow velocity and heat transfer by reducing the free cross-sectional area, utilizing a rotor blade heater to convey heated air through channels with strategically placed flow resistance sections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the internal volume of the rotor blade is reduced to increase airflow velocity, then heat transfer efficiency is improved, but the structural integrity and strength of the rotor blade may be compromised

Engineering Contradiction:
Improveheat transfer efficiencyVSAvoidstructural integrity
Core Design Contradiction:
TemperatureVSStrength

Solution Approach 1:

The internal volume is divided into multiple air channels by introducing webs, which segment the flow path and increase airflow velocity without significantly reducing the overall internal volume. This segmentation allows the heated air to flow through multiple restricted passages, enhancing heat transfer to the blade surface while maintaining structural integrity through the distributed web structure.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Flow resistance elements are strategically placed at specific locations within the air channels where they are most effective for enhancing heat transfer. The webs and flow resistance features are positioned to create localized flow restrictions that maximize thermal efficiency without uniformly reducing the structural volume of the blade.

Inventive Principle:
Principle #3Local quality

2Reliability

If flow resistance elements are added to increase airflow velocity, then de-icing effectiveness is improved, but device complexity increases

Engineering Contradiction:
Improvede-icing effectivenessVSAvoidheating system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The flow resistance elements are integrated directly into the existing air channel structure by forming webs that simultaneously serve as structural supports and flow restriction elements. This merging of functions eliminates the need for separate, additional components, thereby improving de-icing effectiveness while minimizing increases in device complexity.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The webs serve multiple functions: they provide structural support to maintain blade integrity, divide the internal volume into functional air channels, and create flow resistance to enhance airflow velocity and heat transfer. This multi-functionality reduces the need for additional dedicated components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Use of energy by moving object

If the internal volume is narrowed to enhance heat transfer, then energy efficiency is improved, but the rotor blade heater requires more precise control

Engineering Contradiction:
Improveenergy efficiencyVSAvoidheater control precision
Core Design Contradiction:
Use of energy by moving objectVSEase of operation

Solution Approach 1:

The air channel configuration with webs and flow resistance elements creates dynamic airflow patterns that adapt to varying heater output conditions. The flow restrictions ensure that even with precise control, the system maintains optimal airflow velocity and heat transfer efficiency across different operating conditions.

Inventive Principle:
Principle #15Dynamics

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 design significantly improves heat transfer to the rotor blade shell, ensuring effective de-icing by increasing airflow velocity and heat transfer coefficient, thereby enhancing de-icing efficiency.

Implementation Method 1

The flow resistance reduces the free cross-sectional area through which the heated air can be conveyed, which increases the flow velocity

Methodology Applied
Scientific EffectFlow velocity increase through cross-sectional constriction: Venturi Effect

Implementation Method 2

This increased flow velocity leads to improved heat transfer to the rotor blade shells, thus resulting in improved rotor blade heating

Methodology Applied
Scientific EffectHeat transfer convection: Convection

Data Source

PatentEP4656870A1Wind turbine rotor blade
Publication Date: 2025.12.03 WOBBEN PROPERTIES GMBH
  • EP4656870A1 patent drawingFigure 1
  • EP4656870A1 patent drawingFigure 2A~3B
  • EP4656870A1 patent drawingFigure 4A~4C

AI summary

A wind turbine rotor blade (200) is provided with a rotor blade shell (210, 220) surrounding an internal volume (203) and at least one flow resistance (300) within the internal volume (203). The flow resistance (300) leads to a narrowing of the volume required for airflow, which increases the flow velocity, resulting in improved heat transfer and thus better heating of the rotor blades. A rotor blade heating system (500) is provided in or at the root (201) of the rotor blade (200). The rotor blade heating system (500) generates warm air, which is conveyed into the internal volume (203) of the rotor blade (200). The flow resistance (300) can be constructed as a tunnel (350) from a plurality of curved, plastic-reinforced fiber plates (351-356). The ends of the curved plates can be held by means of angles.The volume covered by the tunnel (350) can be at least partially filled.