Offshore Windmill Assembly Using 3D Heave-Compensated Crane
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Solution Overview
Problem
Existing methods for building offshore windmills are not retrofit solutions and cannot be easily scaled up, requiring significant alterations to windmill pedestals and using large, costly ships with heavy-duty cranes.
Innovation Solution
A method utilizing a floating vessel with a 3D-heave-compensated crane to transport and assemble offshore windmill parts, including a lifting jack, which is temporarily fixed to the pedestal, allowing for efficient construction of windmill columns and blade installation without altering the pedestal, using smaller vessels and reducing operational costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If large dedicated ships with heavy-duty cranes are used to install offshore windmills, then the windmills can be installed in as large parts as possible, but the operational costs increase significantly
Solution Approach 1:
The windmill is divided into multiple transportable parts that can be assembled offshore using a smaller crane. The column is segmented into sections, the rotor-hub assembly is separated, and blades are individual components. This allows installation using a smaller vessel with lower operational costs while still achieving large windmill assembly.
Solution Approach 2:
A telescopic column design is used that can be extended vertically after the basic structure is in place. The column starts in a retracted state for transport and assembly, then extends to full height using a telescopic mechanism with multiple nested sections, allowing the windmill to reach its final large size without requiring a crane capable of lifting the complete assembled structure.
2Adaptability or versatility
If existing offshore windmill pedestals are used, then retrofit solutions are needed, but prior art methods require significant alterations to the pedestals
Solution Approach 1:
The windmill assembly is segmented into parts that can be installed on existing pedestals without modification. The column sections, generator house, and blade assembly are designed as separate installable components that interface with standard pedestal mounting points, enabling retrofitting of existing wind farm infrastructure.
3Productivity
If windmills are manufactured in as large parts as possible onshore, then transport efficiency improves, but the crane size required for installation increases
Solution Approach 1:
The windmill is segmented into large but transportable parts including column sections, generator house, and blade assemblies. These segments are large enough to improve transport efficiency compared to smaller components, yet small enough to be handled by a smaller offshore crane.
Solution Approach 2:
The telescopic column mechanism allows the windmill to be assembled in a compact retracted state for efficient transport, then extended to full size offshore. This dynamic transformation enables transport of large-capacity windmills using smaller vessels and cranes.
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 retrofitting of existing windmill pedestals, scaling up windmill size, and reducing operational costs by using smaller vessels and cranes, while maintaining efficient construction processes.
Implementation Method 1
providing a floating vessel comprising a 3D-heave-compensated crane on a deck thereof
Implementation Method 2
the lifting jack is configured for receiving the windmill column in a receiving region thereof
Data Source
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AI summary
The invention relates to a method of building an offshore windmill (100) on a windmill pedestal (50) that is located offshore. The method comprises: i) providing a floating vessel (900) comprising a 3D-heave-compensated crane (910) on a deck (901) thereof; ii) providing at least one offshore windmill assembly (110, 120, 130) and a lifting jack (90), wherein the offshore windmill assembly comprises a windmill generator (120), a plurality of wind- mill blades (130, 130-1..130-3) and at least two windmill column parts (110, 110-1..110-3) for forming a windmill column at a later stage, wherein the lifting jack (90) is configured for receiving the windmill column (110-1..110-3) in a receiving region thereof; iii) moving said floating vessel (900), the lifting jack (90) and the at least one offshore windmill assembly (110, 120, 130) in proximity of the windmill pedestal (50); iv) placing the lifting jack (90) directly on the windmill pedestal (50) using the 3D-heave-compensated crane (910) and fixing the lifting jack (90) to the windmill pedestal (50) such that it can be later removed, and wherein the lifting jack (90) is fixed to the windmill pedestal (50) such that the windmill column (110-1..110-3) can be placed within the receiving region directly on the windmill pedestal (50); v) installing the windmill generator (120) using the 3D-heave-compensated crane (910); vi) partially erecting the windmill column (110-1..110-3) on the windmill pedestal (50) using the 3D-heave-compensated crane (910) and the lifting jack (90); vii) installing the windmill blades (130, 130-1..130-3) on the windmill generator (120) using the 3D-heave-compensated crane (910) at a stage where the windmill column (110-1..110-3) has been partially erected; viii) fully erecting the windmill column (110-1..110-3) on the windmill pedestal (50) using at least the lifting jack (90), and ix) removing the lifting jack (90) from the windmill pedestal (50) using the 3D-heave-compensated crane (910). The invention provides for a further improved retrofit method of building offshore windmills.