Floating Wind Turbine Mooring with Asymmetric Catenary Cables
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Solution Overview
Problem
Existing floating type wind turbine generating apparatuses face instability due to drift force and rotational moment from wind loads and tidal currents, with insufficient consideration for environmental factors like tidal currents and wind direction in their mooring systems.
Innovation Solution
A floating type wind turbine generating apparatus with a configuration of multiple columns and mooring cables arranged in a catenary curve, where at least two mooring cables are connected to the upwind column and one each to downwind columns, with rotation-preventing cables extending orthogonally to resist rotational moments, and a ballast water system to adjust the floating body's stability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a floating type wind turbine generating apparatus is employed in deep water regions, then the wind turbine can be installed in deep water where bottom-mounted type is uneconomic, but the floating body becomes unstable against drift force and rotational moment from wind loads and tidal currents
Solution Approach 1:
The floating body is divided into multiple columns (first column on upwind side, second and third columns on downwind side) with multiple mooring cables connected to different columns. This segmentation allows different parts of the floating body to be restrained by specific cables against drift force and rotational moment, improving overall stability while maintaining deep water adaptability
Solution Approach 2:
The mooring cable arrangement is asymmetric with at least two cables connected to the first column on the upwind side and at least one cable each connected to the second and third columns on the downwind side. This asymmetric configuration specifically addresses the directional nature of wind loads and tidal currents, providing enhanced stability against drift force and rotational moment while enabling installation in deep water regions
2Stability of the object's composition
If multiple mooring cables are connected to the first column on the upwind side to resist drift force, then the floating body stability against drift force improves, but the mooring system complexity increases
Solution Approach 1:
The mooring system is segmented into multiple cables connected to different columns, with at least two cables specifically connected to the first column on the upwind side. This segmentation allows the drift force resistance function to be distributed across multiple cables rather than requiring a single complex cable system, thereby improving stability while managing complexity through functional distribution
Solution Approach 2:
The mooring cables serve multiple functions: they restrain the floating body against drift force, prevent rotation, and provide structural support. By designing the cables to fulfill multiple roles, the system achieves enhanced drift force resistance without proportionally increasing complexity, as the same cables perform multiple stabilization functions
3Stability of the object's composition
If mooring cables are arranged to extend radially from the floating body so as not to intersect, then the rotational moment resistance improves, but the installation and maintenance difficulty increases
Solution Approach 1:
The mooring cables are arranged asymmetrically with at least two cables connected to the first column on the upwind side and at least one cable each connected to the second and third columns on the downwind side. This asymmetric radial arrangement effectively resists rotational moment by distributing cable tensions unevenly according to the directional nature of environmental loads, while the radial extension pattern prevents cable intersection that would complicate installation and maintenance
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 apparatus achieves stable mooring against drift force and rotational moment, maintaining stability even if one mooring cable is cut, reducing the risk of instability and allowing for efficient and cost-effective mooring operations.
Implementation Method 1
a plurality of mooring cables each of which connecting the floating body and an anchor fixed on a water bottom in a catenary curve
Data Source
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AI summary
An object is to provide a floating type wind turbine generating apparatus capable of stably mooring the floating body against the drift force and rotational moment acting on the floating body, and a mooring method of the floating type wind turbine generating apparatus. A floating type wind turbine generating apparatus comprises: a wind turbine generator 10; a floating body including a first column 22a which is disposed on an upwind side in a main wind direction and on which the wind turbine generator is disposed, a second column 22b and a third column 22c disposed on a downwind side with respect to the first column in the main wind direction, and two lower hulls 24 one of which connecting the first and second columns and other of which connecting the first and third columns; a plurality of mooring cables 34 each of which connecting the floating body and an anchor 32 fixed on a water bottom in a catenary curve, wherein at least two of the mooring cables are connected to the first column, at least one of the mooring cables is connected to the second column, and at least one of the mooring cables is connected to the third column, and wherein the mooring cables extend radially from the floating body so as not to intersect with one another in a planar view.