Monopile Placement Damping for Rough Sea Control
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Solution Overview
Problem
Existing methods for placing large, slender objects like monopiles for wind turbines on underwater bottoms are hindered by the difficulty of maintaining control in rough sea conditions, leading to inefficiencies and increased time requirements due to the energy from currents, waves, and wind.
Innovation Solution
A device with a lifting means and a separate gripping construction connected to a support structure, featuring movement-damping means that absorb and counteract the energy of the object, allowing for better control and positioning of the object during placement, even in heavier swells.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the monopile is lowered using only lifting means and auxiliary cables, then the equipment complexity is kept simple, but the control stability deteriorates in rough sea conditions
Solution Approach 1:
A gripping construction is introduced as an intermediary device between the lifting means and the monopile. This gripping construction includes gripping members that can engage the monopile and are connected to a support structure via movement-damping means, providing additional control stability without requiring complete redesign of the lifting system
Solution Approach 2:
The damping function is extracted as a separate component (movement-damping means) connected between the gripping members and the support structure. This allows the damping function to be added independently while keeping the lifting means and support structure relatively simple
2Stability of the object's composition
If the monopile is kept under control in rough seas using auxiliary cables and winches, then the control stability is maintained, but the device complexity increases
Solution Approach 1:
The gripping construction acts as a mediator that provides stable control through its connection to the support structure, while the movement-damping means isolates the complexity of the damping mechanism from both the lifting means and the support structure
Solution Approach 2:
The control system is segmented into distinct functional components: lifting means for vertical positioning, gripping construction for lateral control, and movement-damping means for energy absorption. This segmentation allows each component to be optimized independently
3Stability of the object's composition
If the monopile is lowered slowly to maintain control, then the control stability is improved, but the productivity decreases
Solution Approach 1:
The movement-damping means converts the harmful kinetic energy from monopile swinging movements into beneficial damping forces. This allows faster lowering speeds because the damping mechanism actively manages the energy that would otherwise cause instability, rather than requiring slow lowering to passively limit energy accumulation
4Productivity
If the monopile is lowered quickly to improve productivity, then the placement speed increases, but the control stability deteriorates due to swinging movements
Solution Approach 1:
The movement-damping means transforms the harmful swinging movements and kinetic energy into beneficial damping forces. The damping mechanism absorbs and dissipates energy that would cause instability, enabling faster monopile placement while maintaining control stability
Solution Approach 2:
The movement-damping means provides dynamic response to monopile movements, actively adapting to changing conditions during lowering. This dynamic damping capability allows the system to maintain stability even at higher lowering speeds where static control methods would fail
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 placement of large, slender objects in conditions with significant wave heights up to 2-2.5 meters, improving control and reducing the risk of damage by damping swinging movements and allowing for precise angular adjustment, thus facilitating the installation of wind turbine monopiles in more challenging sea conditions.
Implementation Method 1
the movement-damping means are configured to convert the kinetic energy of the gripping members (and an object received therein) moving relative to the support structure to thermal energy
Data Source
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AI summary
The invention relates to a device for placing a sizeable, slender object with a longitudinal direction on a ground surface. The device comprises a lifting means with which the object can be taken up, and a gripping construction which is separate from the lifting means and which is connected to a support structure, comprises gripping members movable relative to this support structure and configured to engage a peripheral part of the object suspended from the lifting means, and comprises movement-damping means configured to damp movements of the gripping members relative to the support structure, whereby swinging movements of the object transversely of the longitudinal direction thereof are damped. The invention likewise relates to a method which makes use of the device.