Floating fan series-connection buoy mooring system suitable for shallow-water large-tidal-range sea area

Abstract

The invention provides a floating fan series buoy mooring system suitable for shallow water and large tidal range sea areas, which comprises a plurality of tensioning mooring cables, two ends of each tensioning mooring cable can be respectively connected with a seabed and a fan mounting floating body, each tensioning mooring cable comprises at least two sections of mooring cables, and two adjacent sections of mooring cables are connected through buoys. Wherein the mooring cable at the lowermost section is a bottom-section mooring cable, the lower end of the bottom-section mooring cable can be connected with a seabed, the mooring cable at the uppermost section is an upper-section mooring cable, and the upper end of the upper-section mooring cable can be connected with a mounting floating body of a fan. The tension type mooring system has the beneficial effects that the tension distribution state of the whole mooring line is improved by adopting the tension type mooring system and reasonably configuring the buoys, so that the mooring line can keep certain recovery rigidity at a high water level and a low water level under the conditions of shallow water and large tidal range, and the service life of the mooring line is prolonged. The displacement of the floating body at the low water level is effectively limited, meanwhile, the tension of the mooring line is effectively prevented from being sharply increased at the high water level, and the mooring cost is effectively reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of mooring technology for floating wind turbines in ocean engineering, and specifically to a series of floating cylinder mooring systems for floating wind turbines applicable to shallow water areas with large tidal differences. Background Art

[0002] With the rapid development of science and technology in today's society, floating wind turbines in the sea have been increasingly widely used. Floating wind turbines are usually subjected to the combined action of various loads such as wind, waves, and currents, and a corresponding mooring system needs to be set up to limit the displacement of the floating wind turbine, so as to ensure the safety of the floating wind turbine and other devices or organisms in the sea.

[0003] At present, floating wind turbine mooring systems are mainly divided into catenary mooring systems and taut mooring systems according to the tension state of the mooring cables. In shallow waters, the tidal difference is large, and the influence brought by the water level change is more obvious. The traditional catenary mooring system relies on the weight of the suspended part of the anchor chain to provide the restoring force. In order to prevent the mooring cable from being completely pulled out of the water surface, a longer buried section needs to be laid on the seabed. However, in order to meet the stiffness requirements at high water levels in areas with large tidal differences, the length of the buried section needs to be further increased, which will undoubtedly further increase the mooring cost. Therefore, in shallow waters with obvious tidal changes, a taut mooring system that uses the elastic elongation of the mooring cable to provide the restoring force has become a more economical choice. However, if the taut mooring system is to meet the stiffness requirements at low water levels, that is, it can better limit the displacement of the floating wind turbine, then the mooring system will have a large mooring tension at high water levels, thus reducing the safety of the mooring system. In order to ensure the performance and safety of the mooring system in shallow water areas with large tidal differences at the same time, it is urgent to develop a taut floating wind turbine mooring system applicable to shallow water areas with large tidal differences. Summary of the Invention

[0004] Aiming at the problems of difficult to guarantee safety and increased cost existing in the traditional mooring system in shallow water areas with large tidal differences, the present invention proposes a series of floating cylinder mooring systems for floating wind turbines applicable to shallow water areas with large tidal differences.

[0005] The technical solution adopted by the present invention is: a series of floating cylinder mooring systems for floating wind turbines applicable to shallow water areas with large tidal differences, including a plurality of taut mooring cables. The two ends of the taut mooring cable can be respectively connected to the seabed and the wind turbine installation floating body. The taut mooring cable includes at least two sections of mooring cables, and adjacent two sections of the mooring cables are connected by floating cylinders. The lowermost section of the mooring cable is the bottom mooring cable, and the lower end of the bottom mooring cable can be connected to the seabed. The uppermost section of the mooring cable is the upper mooring cable, and the upper end of the upper mooring cable can be connected to the wind turbine installation floating body.

[0006] Optionally, a plurality of the taut mooring cables are evenly distributed along the circumferential direction of the wind turbine installation floating body.

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

[0008] The advantages and positive effects of the present invention are as follows: By adopting a tension mooring system and reasonably configuring the buoys, the tension distribution state of the overall mooring line is improved. Under the conditions of shallow water and large tidal range, the mooring line can maintain a certain recovery stiffness at both high water level and low water level, effectively limiting the displacement of the floating body at low water level while effectively avoiding a sharp increase in the tension of the mooring line at high water level. Compared with the traditional catenary mooring that requires a longer buried section, the mooring cost is effectively reduced. Brief Description of the Drawings

[0009] Figure 1 It is a schematic diagram of the mooring system at high water level in the specific embodiment of the present invention;

[0010] Figure 2 It is a schematic diagram of the mooring system at low water level in the specific embodiment of the present invention;

[0011] In the figure: 1, seabed; 2, bottom mooring cable a; 3, buoy a; 4, upper mooring cable a; 5, upper mooring cable b; 6, buoy b; 7, bottom mooring cable b; 8, upper mooring cable c; 9, buoy c; 10, bottom mooring cable c; 11, fairlead a; 12, fairlead b; 13, fairlead c; 14, mooring point a; 15, mooring point b; 16, mooring point c; 17, high water level horizontal plane; 18, low water level horizontal plane; θ, the angle between the upper mooring cable a and the horizontal plane. Specific Embodiment

[0012] The present invention will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only 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 terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They 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 thus cannot be understood as a limitation of the present invention. In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" 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.

[0013] As shown in the figure, the present invention provides a floating wind turbine series floating buoy mooring system applicable to shallow water areas with large tidal differences, including multiple tensioned mooring cables. In this embodiment, three tensioned mooring cables are taken as an example. Each tensioned mooring cable includes two sections of mooring cables, namely the bottom section mooring cable and the upper section mooring cable. A floating buoy is connected between the bottom section mooring cable and the upper section mooring cable. The three tensioned mooring cables are evenly distributed circumferentially around the wind turbine installation floating body to maintain balanced stress. The three tensioned mooring cables are respectively the bottom section mooring cable a2 - floating buoy a3 - upper section mooring cable a4, the bottom section mooring cable b7 - floating buoy b6 - upper section mooring cable b5, and the bottom section mooring cable c10 - floating buoy c9 and upper section mooring cable c8. The lower ends of the bottom section mooring cable a2, the bottom section mooring cable b7, and the bottom section mooring cable c10 are respectively connected to the mooring points a14, b15, and c16 on the seabed 1, and the upper ends of the upper section mooring cable a4, the upper section mooring cable b5, and the upper section mooring cable c8 are respectively connected to the fairlead holes a11, b12, and c13 on the wind turbine installation floating body.

[0014] As Figure 1 , 2As shown, the angle θ between the upper mooring cable on each tensioned mooring cable and the high water level plane 17 is greater than the angle θ between the upper mooring cable and the low water level plane 18; due to the large buoyancy provided by the buoy, when the water level changes, the change in the lower section of the mooring line is not significant. This makes the length of the upper section of the mooring line at high water level significantly greater than that at low water level, that is, the elastic elongation of the mooring line at high water level is significantly greater than that at low water level. Therefore, the mooring system can provide a greater restoring stiffness at high water level, and the stiffness at low water level meets the requirements.

[0015] In the present invention, buoys are arranged on the tensioned mooring cables to change the angle between the mooring line and the horizontal plane, thereby improving the tension distribution state of the overall mooring line. Under the condition of large tidal range in shallow water, the lower section of the mooring line is relatively stable, while the restoring force of the upper section increases with the rising water level, enabling the mooring stiffness to be self-adjusted with the change of water level. That is, the mooring system can maintain a certain restoring stiffness at both high and low water levels, effectively limiting the displacement of the floating body at low water level while effectively avoiding a sharp increase in the tension of the mooring line at high water level. Compared with the traditional catenary mooring that requires a longer lying bottom end, the mooring cost is effectively reduced.

[0016] In practical applications, the number, size, and material of the tensioned mooring cables and the number, size, and material of the buoys on each tensioned mooring cable are determined according to the requirements of the wind turbine installation floating body for the mooring system.

[0017] 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 scope of implementation of the present invention. Any equivalent changes and improvements made within the scope of the application of the present invention should still fall within the scope covered by the patent of the present invention.

Claims

1. A floating wind turbine tandem buoy mooring system suitable for shallow waters with large tidal ranges, characterized by: It comprises a plurality of tensioned mooring cables, both ends of which can be connected to the seabed and the wind turbine installation buoy respectively. The tensioned mooring cables comprise at least two sections of mooring cables, and two adjacent sections of the mooring cables are connected via a buoy, wherein the mooring cable at the lowest section is a bottom section mooring cable, and the lower end of the bottom section mooring cable can be connected to the seabed, and the mooring cable at the highest section is an upper section mooring cable, and the upper end of the upper section mooring cable can be connected to the wind turbine installation buoy.

2. The floating wind turbine series buoy mooring system suitable for shallow waters with large tidal ranges according to claim 1 is characterized in that: The plurality of tensioned mooring cables are evenly distributed along the circumference of the wind turbine installation float.

3. The floating wind turbine series buoy mooring system suitable for shallow waters with large tidal ranges according to claim 2 is characterized in that: The number, size and material of the tensioned mooring cables and the number, size and material of the buoys on each of the tensioned mooring cables are determined according to the requirements of the wind turbine installation buoy for the mooring system.

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