Collar Assembly for Wind Turbine Tower Formwork
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Solution Overview
Problem
Current methods for constructing wind turbine towers lack efficient systems for forming towers with varying annular horizontal sections, particularly those that are frustoconical or convergent/divergent, and do not provide a flexible choice for formwork and construction procedures.
Innovation Solution
A collar assembly and formwork system that allows incremental concrete pouring with a jacking arrangement to raise and lower subassemblies, enabling the formation of towers with varying cross-sectional profiles by using different formwork pods for each zone, and a method involving internal and external formwork to define the shape of the tower, allowing for the creation of towers with frustoconical or other non-linear profiles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional slip form methods are used with a fixed supporting structure, then construction of straight cylindrical towers is efficient, but construction of towers with varying cross-sectional profiles (frustoconical, convergent/divergent) is not feasible
Solution Approach 1:
The supporting structure is divided into multiple collars that can be independently positioned at different heights along the tower. Each collar can be selectively indexed to different zones, allowing the system to adapt to varying tower profiles without requiring a completely different supporting structure for each section.
Solution Approach 2:
The collars are designed with selective indexing capability, allowing them to be raised and lowered to different positions along the tower as construction progresses. This dynamic repositioning enables the same collar assembly to accommodate towers with varying cross-sectional profiles at different heights.
2Manufacturing precision
If a single formwork system is used for all tower zones, then device complexity is reduced, but manufacturing precision for varying cross-sectional profiles cannot be achieved
Solution Approach 1:
Different formwork pods are assigned to different zones of the tower based on the specific cross-sectional profile requirements of each zone. This allows each local section to have formwork precisely matched to its geometric requirements, achieving high manufacturing precision for varying profiles.
Solution Approach 2:
The collar assembly provides a universal supporting platform that can accommodate multiple different types of formwork pods. While the supporting structure is universal, the formwork pods are specialized for different zones, combining universal support with localized precision.
3Productivity
If the entire collar assembly is raised together, then construction speed is maintained, but the ability to index to different zones selectively is lost
Solution Approach 1:
The collar assembly is segmented into higher and lower subassemblies that can be independently raised and indexed to different zones. This allows selective positioning of collars at different heights, enabling adaptation to varying tower profiles while maintaining construction progress.
Solution Approach 2:
The collars are raised and indexed periodically as construction progresses through different zones. Rather than raising the entire assembly continuously, the periodic indexing allows the system to adapt to zone-specific requirements while maintaining overall construction speed.
4Ease of manufacture
If formwork is removed and lowered to ground after each pour, then formwork can be reused efficiently, but time is lost in the lowering and repositioning process
Solution Approach 1:
The collar assembly is raised to the next zone before the concrete in the current zone is fully cured. This preliminary action allows formwork to be removed and reused while the concrete gains sufficient strength to support the structure, minimizing idle time in the construction process.
Solution Approach 2:
While formwork is being removed and prepared for reuse at ground level, the collar assembly is simultaneously raised to the next zone and new formwork is being positioned. This continuous workflow eliminates idle time and maintains steady construction progress.
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
Enables the efficient construction of wind turbine towers with varying profiles by allowing incremental pouring and the use of different formwork for each segment, reducing material costs and enabling construction in challenging geometries, while maintaining structural integrity and allowing for the securement of nacelles as the tower rises.
Implementation Method 1
a jacking arrangement whereby (I), when the lower subassembly is zone indexed and the higher subassembly is not, the higher subassembly can be raised relative to the lower subassembly and the zone to a fresh indexing height and (II), when the higher subassembly is zone indexed and the lower subassembly is not, the lower subassembly can be raised to a fresh indexing height
Implementation Method 2
after each pour has set/cured
Data Source
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AI summary
A collar assembly of or for a tower being formed by progressively higher concrete composition pours into reinforcement including formwork defined cavities, the assembly comprising or including; a higher subassembly adapted as a collar to selectively index to a zone of the tower being formed, a lower subassembly adapted as a collar to selectively index to a zone of the tower being formed, and a jacking arrangement whereby (I), when the lower subassembly is zone indexed and the higher subassembly is not, the higher subassembly can be raised relative to the lower subassembly and the zone to a fresh indexing height and (II), when the higher subassembly is zone indexed and the lower subassembly is not, the lower subassembly can be raised to a fresh indexing height.