Wind Turbine Blade Lowering via Segmented Extraction
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Solution Overview
Problem
The high cost and complexity of servicing wind turbines with tall towers, due to the need for heavy crane capacity to lift and lower rotor blades, result in increased repair and replacement costs, and existing solutions fail to provide accurate blade alignment and do not remove weight from the blades or hub once installed.
Innovation Solution
A wind turbine system utilizing a blade pulley system and truss system that are detachably connected to the rotor blade and hub, respectively, allowing for easy mounting and lowering of blades without additional weight or structural weakening, using existing components and no additional openings in the hub, and employing flexible cables and alignment pins for precise alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional cranes are used to lift and lower rotor blades to the top of tall towers, then the blades can be serviced, but the crane capacity required becomes much higher than the actual weight being lifted due to bending moment from reach, making the cost prohibitive
Solution Approach 1:
The blade is divided into two parts: a lower section that remains attached to the hub and an upper section that is detached and lowered to the ground for servicing. This segmentation allows the heavy blade to be broken into manageable portions, eliminating the need for high-capacity cranes to lift the entire blade assembly.
Solution Approach 2:
The upper section of the blade is extracted from the hub assembly and lowered to the ground using a winch mechanism. This extraction removes the blade portion that requires servicing from the high-altitude location, eliminating the need for expensive high-capacity cranes while still allowing access to the blade for maintenance.
2Device complexity
If a cable is stretched between the hub and bottom region with a pulley system to move the blade, then crane capacity is reduced, but the blade cannot be accurately guided into engagement with the hub connection flange
Solution Approach 1:
Alignment pins are provided that protrude from the hub connection flange before the blade is engaged. These pins perform the preliminary action of guiding and aligning the blade connector portion with the hub flange, ensuring precise engagement before the actual connection is made.
Solution Approach 2:
Alignment pins serve as intermediary elements between the blade connector portion and the hub connection flange. These pins mediate the alignment process, providing a precise reference that guides the blade into correct engagement while the winch system handles the lifting and lowering operations.
3Device complexity
If a holding section is added inside the blade to enable mounting without crane, then multiple construction machines are eliminated, but weight is added to each blade that cannot be removed once mounted
Solution Approach 1:
The upper section of the blade is extracted and lowered to the ground for servicing, eliminating the need for permanent holding sections within the blade. The blade can be completely removed from the hub when not in use, avoiding the addition of permanent weight-bearing components that would remain in the blade structure.
4Use of energy by moving object
If tower height is increased to take advantage of greater wind energy, then wind energy capture is improved, but the cost of lowering and lifting rotor blades increases due to greater reach requirements
Solution Approach 1:
The blade is segmented into a lower section remaining at the hub and an upper section lowered to the ground. This segmentation enables servicing of tall towers without requiring proportionally increased crane capacity, as only the upper section needs to be handled by the winch mechanism rather than lifting the entire blade assembly.
Solution Approach 2:
The upper section of the blade is extracted and lowered to the ground for servicing, eliminating the need for high-capacity cranes even at tall tower heights. This extraction approach allows maintenance personnel to access and service the blade at ground level rather than requiring expensive high-altitude lifting equipment.
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
Facilitates cost-effective and efficient repair and replacement of wind turbine blades by eliminating the need for heavy cranes and reducing structural modifications, while ensuring precise alignment and no additional weight is added to the turbine during operation.
Implementation Method 1
A block-and-tackle mechanism for raising and lowering sections of a rotor blade
Implementation Method 2
Means are provided for guiding the blade into engagement with the hub connection flange
Data Source
AI summary
The present invention relates to a wind turbine enabling a cost effective and easy attachment/replacement of rotor blades and to a method of attaching a rotor blade to a hub of a wind turbine. The wind turbine in accordance with the invention comprises a tower resting on a base, at least one rotor blade having a blade connector portion, a nacelle housing a shaft to which a hub is attached, the nacelle being mounted atop the tower. Said hub of the wind turbine comprises a plurality of hub connection flanges, each hub connection flange being adapted to be detachably connected to a blade connector portion of a rotor blade.