Additional weight tensioning type mooring system

Abstract

The invention provides an additional weight tensioning type mooring system which comprises a plurality of mooring cables, each mooring cable comprises an upper-section cable, a lower-section cable and 0-N middle-section cables, every two adjacent cable sections are connected through a weight, the upper end of each upper-section cable can be connected with a fan mounting floating plate, and the lower end of each lower-section cable can be connected with a fan mounting floating plate. And the lower end of the lower-section cable can be connected with an anchoring point on a seabed. The tension type mooring system has the beneficial effects that the tension type mooring system is combined with the heavy block, and the elasticity of the mooring rope on the tension type mooring system and the gravity of the heavy block are combined through reasonable configuration, so that the whole system has the advantages of a catenary type mooring system and the tension type mooring system, the tension distribution state of the whole mooring rope is improved, and the mooring efficiency is improved. Under the conditions of shallow water and large tidal range, the mooring line can keep certain recovery rigidity at a high water level and a low water level, and under the two water levels, the draft change of the platform is small, so that the stability of the platform is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of mooring technology for floating wind turbines in ocean engineering, and particularly to an additional weight tensioned mooring system. Background Art

[0002] In the context of the rapid progress of modern technology, the application scope of offshore floating wind turbines is expanding day by day. Floating wind turbines are often affected by various forces such as wind, waves, and currents. Therefore, an appropriate mooring system must be equipped to control their movement and ensure safety from other structures or organisms in the marine environment.

[0003] Currently, according to the tension state of the mooring cables, the mooring systems of floating wind turbines are mainly divided into two types: catenary type and tensioned type. In areas with relatively shallow water depths, due to large tidal variations, the impact of water level changes on the operating state of the mooring system is particularly significant. The restoring force of the traditional catenary mooring system is provided by the weight of the suspended section of the anchor chain. To prevent the mooring cable from being completely pulled up, a long buried part needs to be set on the seabed. To make the catenary mooring system meet the high water level stiffness requirements in a large tidal range sea area, the buried part needs to be further lengthened, which undoubtedly further increases the cost of the mooring system. Therefore, in shallow waters with large tidal variations, the tensioned mooring system that provides the restoring force through the elastic elongation of the mooring cable has become a more economical and friendly choice. However, if the tensioned mooring system is to meet the stiffness requirements at high water levels and the tension will not be too large at low water levels, the draft of the platform will be reduced at low water levels, which has an adverse impact on the stability of the platform, thereby reducing the safety of the mooring system. Summary of the Invention

[0004] The problem to be solved by the present invention is to provide an additional weight tensioned mooring system, which solves the problems of difficult safety guarantee and cost increase of traditional mooring systems in large tidal ranges in shallow sea areas.

[0005] To solve the above technical problems, the technical solution adopted by the present invention is: an additional weight tensioned mooring system, including multiple mooring cables. Each mooring cable includes an upper section cable, a lower section cable, and 0 - N middle section cables. Adjacent two sections of cables are connected by a weight. The upper end of the upper section cable can be connected to the wind turbine installation floating plate, and the lower end of the lower section cable can be connected to the anchoring point on the seabed.

[0006] Optionally, the connection points of the multiple mooring cables and the wind turbine installation floating plate are evenly distributed circumferentially around the wind turbine installation floating plate.

[0007] Optionally, the number, size, material of the mooring cables, and the number, size, material of the weights on each mooring cable are determined according to the requirements of the wind turbine installation floating plate for the mooring system.

[0008] The advantages and positive effects of the present invention are as follows: By combining the tension mooring system with heavy blocks and through reasonable configuration, the elasticity of the mooring ropes on the tension mooring system and the gravity of the heavy blocks are combined, enabling the entire system to possess the advantages of both the catenary mooring system and the tension mooring system, improving the tension distribution state of the overall mooring line. Under the conditions of shallow water and large tidal differences, the mooring line can maintain a certain recovery stiffness at both high water level and low water level, and the draft change of the platform is small at both water levels, ensuring the stability of the platform. Brief Description of the Drawings

[0009] Figure 1 is a schematic diagram of the overall structure of the specific embodiment of the present invention;

[0010] Figure 2 Specifically, it is a schematic diagram of the heavy block mooring system at high water level in the embodiment;

[0011] Figure 3 Specifically, it is a schematic diagram of the heavy block mooring system at low water level in the embodiment

[0012] In the figure: 1, wind turbine installation floating plate; 2, wind turbine; 3, first mooring cable; 3-1, first heavy block; 4, second mooring cable; 4-1, second heavy block; 5, third mooring cable; 5-1, third heavy block; 6, water surface; 7, seabed. Specific Embodiment

[0013] The following further details the present invention in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are merely used to explain the present invention and are not used to limit the present invention. In the description of the present invention, it should be understood that the orientation or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the present invention. In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation", "connection", and "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood through specific situations.

[0014] Such as Figure 1As shown in the figure, the present invention provides an additional weight tensioned mooring system, which includes three mooring cables circumferentially and evenly distributed around the wind turbine installation floating plate 1, namely the first mooring cable 3, the second mooring cable 4 and the third mooring cable 5. The first mooring cable 3 includes a first upper mooring cable, a first weight 3-1 and a first lower mooring cable connected in sequence. The second mooring cable 4 includes a second upper mooring cable, a second weight 4-1 and a second lower mooring cable connected in sequence. The third mooring cable 5 includes a third upper mooring cable, a third weight 5-1 and a third lower mooring cable connected in sequence. The upper ends of the first upper mooring cable, the second mooring cable and the third mooring cable are all connected to the mooring points on the wind turbine installation floating plate 1, and the lower ends of the first lower mooring cable, the second lower mooring cable and the third lower mooring cable are all fixed to the anchoring points on the seabed 7.

[0015] According to the requirements of the wind turbine installation floating plate 1 for the mooring system, the number, size, material of the mooring cables and the number, size, material of the weights on each mooring cable can all be adjusted according to actual needs.

[0016] As Figure 1 , Figure 2 shown, due to the setting of the weights on the mooring cables, under the action of the gravity of the weights, the angle between the upper mooring cable of each mooring cable and the water surface 6 at high water level ( Figure 1 ) has no obvious difference from the angle between the upper mooring cable of each mooring cable and the water surface 6 at low water level ( Figure 2 ). This characteristic results in similar drafts of the mooring system at high and low water levels, thus ensuring the stability of the floating wind turbine.

[0017] In the present invention, weights are arranged on the elastic mooring cables, and the tension distribution state of the mooring lines is improved through the reasonable configuration of the positions and weights of the weights. Since the self-weight of the weights is relatively large, the angle between the upper section of the mooring line and the horizontal plane is significantly larger than the angle between the lower section of the mooring line and the horizontal plane. Therefore, the horizontal component force of the lower section of the mooring line, that is, the horizontal restoring force, is greater than that of the upper section, which can improve the tension distribution state of the whole mooring line. Under the conditions of shallow water and large tidal range, when the water level changes, due to the action of the self-weight of the weights, the angle between the upper section of the mooring line and the horizontal plane does not change significantly with the change of the water level, so that the mooring line can still maintain sufficient restoring stiffness at high water level. And at the two water levels, the self-regulation of the restoring stiffness of the mooring system with the change of the water level can enable the platform to make a smooth transition, with small draft changes, ensuring the stability of the platform, and effectively reducing the mooring cost compared with the prior art.

[0018] The above has described the embodiments of the present invention in detail, but the content described is only the preferred embodiments of the present invention and cannot be considered as limiting the implementation scope of the present invention. All equivalent changes and improvements made according to the scope of the present invention application should still fall within the scope covered by the patent of the present invention.

Claims

1. An additional weight tension mooring system, characterized in that: It includes multiple mooring cables. Each mooring cable includes an upper-section cable, a lower-section cable, and 0 - N middle-section cables. Adjacent two sections of cables are connected by a weight. The upper end of the upper-section cable can be connected to the wind turbine installation floating plate, and the lower end of the lower-section cable can be connected to an anchoring point on the seabed.

2. The additional weight tension mooring system according to claim 1, characterized in that: The connection points of the multiple mooring cables and the wind turbine installation floating plate are evenly distributed circumferentially around the wind turbine installation floating plate.

3. The additional weight tension mooring system according to claim 2, characterized in that: The quantity, size, material of the mooring cables set, and the quantity, size, material of the weights on each mooring cable are determined according to the requirements of the wind turbine installation floating plate for the mooring system.

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