Floating Wind Hub Mooring Layout for Deep-Water Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Deep-water floating wind turbines face stability issues due to conventional mooring arrangements, leading to excessive movement and fatigue in power transfer cables, and congestion of mooring lines, which complicates power transmission and storage in offshore windfarms.
Innovation Solution
A floating power-generation group comprising a central hub anchored to subsea foundations by anchor lines, with power producer units connected electrically and mechanically, using a circular array configuration and shared subsea foundations to reduce anchor line complexity and enhance stability, and incorporating subsea energy storage units for efficient power management.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional mooring arrangements are used in deep water, then anchoring is feasible, but stability is insufficient leading to excessive movement and cable fatigue
Solution Approach 1:
The mooring system is segmented into multiple independent mooring lines radiating from the hub to different anchor points on the seabed, allowing each line to work independently to maintain overall system stability and reduce excessive movement
Solution Approach 2:
The mooring arrangement transitions from shallow-water conventional patterns to deep-water radial patterns, adding dimensional complexity to the anchoring geometry to achieve stability in deeper waters where traditional methods fail
2Productivity
If multiple floating wind turbines are grouped in an offshore windfarm, then power generation capacity increases, but mooring lines become congested increasing clash risk
Solution Approach 1:
The mooring lines are arranged in radial patterns extending outward from each hub to perimeter anchor points, utilizing the available seabed space more efficiently and preventing line congestion even as multiple turbines are grouped together
Solution Approach 2:
The radial mooring arrangement creates a circular or spherical distribution pattern of anchor lines around each hub, optimizing spatial utilization and minimizing interference between adjacent turbine mooring systems
3Reliability
If power producer units are connected in series by dynamic umbilicals, then electrical connection is achieved, but cable fatigue increases due to excessive movement
Solution Approach 1:
The electrical connection system is segmented into radial circuits extending from the hub to each power producer unit, with each circuit independently supported by its corresponding radial mooring line, isolating movement stresses and preventing fatigue propagation
Solution Approach 2:
Instead of allowing dynamic umbilicals to accommodate movement, the invention inverts the approach by stabilizing the structure with radial mooring lines first, then using the stabilized configuration to support fixed or semi-fixed electrical connections
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A floating power-generation group comprises a floating hub such as a spar buoy that is anchored to subsea foundations by anchor lines. Floating power producer units such as wind turbines are connected electrically and mechanically to the hub. The power producer units are each moored by mooring lines. At least one mooring line extends inwardly toward the hub to effect mechanical connection to the hub and at least one other mooring line extends outwardly toward a subsea foundation. The groups are combined as a set whose hubs are connected electrically to each other via subsea energy storage units. Anchor lines of different groups can share subsea foundations. The storage units comprise pumping machinery to expel water from an elongate storage volume and generating machinery to generate electricity from a flow of water entering the storage volume. The pumping machinery may be in deeper water than the generating machinery.