Wind Turbine Blade Root Section Mold with Pultruded Rods

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Solution Overview

Problem

The existing methods for manufacturing wind turbine blade root sections face challenges in achieving uniform structural properties while being cost-effective and timely, particularly due to increased stresses and deformation issues with larger rotor blades.

Innovation Solution

A method involving a mold with inner and outer cylinder segments and a bottom flange, where pultruded rods are arranged circumferentially and infused with resin, with optional fabric reinforcement to enhance structural integrity and stability, allowing for efficient and automated production of a blade root section with improved strength.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If conventional fiber reinforced plastic blades are used with longitudinal reinforcement fibers, then the manufacturing process is simple, but the root section becomes ovalized under gravity forces

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidroot section circularity
Core Design Contradiction:
Ease of manufactureVSShape

Solution Approach 1:

The patent applies preliminary action by pre-assembling supporting rods in a circular configuration with gaps between them before fiber placement. These rods are positioned and secured within the mold cavity beforehand, creating a rigid framework that maintains circular geometry during the entire molding process, preventing ovalization under gravity forces.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The supporting rods serve as an intermediary structure between the mold cavity and the fiber reinforced plastic material. They provide a mechanical framework that mediates the interaction between gravity forces and the forming material, ensuring the root section maintains its circular shape while the resin and fibers are injected into the gaps between the rods.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Power

If larger rotor blade sizes are used to increase energy production, then the energy production increases, but the stresses at the blade root connection increase

Engineering Contradiction:
Improveenergy productionVSAvoidblade root stress
Core Design Contradiction:
PowerVSStress or pressure

Solution Approach 1:

The patent employs composite materials by combining supporting rods (made of steel, aluminum, or fiber reinforced plastic) with fiber reinforced plastic blade material. This composite construction at the blade root creates a structurally superior connection that can withstand the increased stresses from larger rotor blades, distributing loads more effectively than conventional homogeneous plastic construction.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The blade root connection is segmented into distinct functional components: supporting rods that provide structural framework, gaps that allow fiber placement and resin flow, and hub interface sections. This segmentation allows each component to be optimized for its specific function, with the supporting rods specifically designed to handle the high stresses from larger rotor blades.

Inventive Principle:
Principle #1Segmentation

3Shape

If supporting rods with gaps are used to maintain circular shape, then the root section shape is maintained, but the manufacturing process becomes more complex

Engineering Contradiction:
Improveroot section circularityVSAvoidmold assembly complexity
Core Design Contradiction:
ShapeVSDevice complexity

Solution Approach 1:

The supporting rods are designed with multi-functionality, serving simultaneously as: (1) structural elements that maintain circular geometry, (2) spacers that define gap dimensions for fiber placement, (3) potential attachment points for hub connectors, and (4) reinforcement elements in the final composite structure. This universality reduces the need for separate components and simplifies the overall manufacturing process despite the added structural requirements.

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

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

The method results in a blade root section with enhanced strength and structural properties, manufactured efficiently and cost-effectively, reducing deformation and stress issues associated with larger rotor blades.

Implementation Method 1

The space is evacuated (e.g., a vacuum in drawn in the space), and a resin is infused into the radial space

Methodology Applied
Scientific EffectVacuum infusion: Vacuum

Data Source

PatentEP3345751B1A method for manufacturing a wind turbine rotor blade root section with pultruded rods and associated wind turbine blade
Publication Date: 2024.08.28 GENERAL ELECTRIC RENOVABLES ESPANA SL
  • EP3345751B1 patent drawingFigure 1
  • EP3345751B1 patent drawingFigure 2
  • EP3345751B1 patent drawingFigure 3~4

AI summary

A method for manufacturing a root section 100 of a wind turbine blade assembly 22 includes assembling a mold 122 having an inner cylinder segment 124, an outer cylinder segment 126, and a bottom flange 128, wherein a radial space 132 is defined between the inner and outer cylinder segments. Root hub connectors 136 are attached circumferentially around the bottom flange so that the root hub connectors extend axially into the radial space. A first cartridge 146 of pultruded rods 148 is loaded into the radial space, wherein the first cartridge includes a plurality of first pultruded rods 148 arranged adjacent to the inner cylinder segment. The space is sealed, for example with a lid or top flange 130, and the space is evacuated. A resin 152 is infused into the space so that the resin migrates through the radial space between the pultruded rods, and is then cured. The root section 100 is then removed from the mold 122. A wind turbine blade root section 100 formed by the method is encompassed by the invention.