Mooring system

Abstract

Proposed is a mooring system, including a floating unit for floating on the sea surface, a mooring anchor installed on the seabed, a weight unit positioned underwater between the floating unit and the mooring anchor, a plurality of mooring cables each having a closed curve shape for mooring the floating unit, wherein each mooring cable includes a first portion whose middle lower part is caught in a mooring-cable catching part of the weight unit, a second portion which passes through a vertical penetration passage of the weight unit and whose middle lower part is caught in a mooring-cable catching part of the mooring anchor, and a third portion which passes through a vertical penetration passage of the floating unit and is connected to the first portion and the second portion and whose middle upper part is caught in a mooring-cable catching part of the floating unit provided in the floating unit.

Description

Technical Field

[0001] The present disclosure relates to a mooring system for mooring various types of floating units (or offshore floating structures) floating on the sea surface and, more particularly, to a mooring system in which a floating unit, a mooring anchor, and a weight unit are connected by a plurality of mooring cables each having a shape of a closed curve.Background Art

[0002] Various types of floating units designed to float on the sea surface are known. A floating foundation for floating-type offshore wind power generation is a representative example of the floating units.

[0003] Such a floating unit can be moored through connection to a mooring anchor that is installed on the seabed by mooring cables.

[0004] Various types of anchors such as gravity anchors, drag-embedment anchors, and suction anchors are used for a mooring anchor.

[0005] As mooring methods, taut mooring, semi-taut mooring, Tension Leg Platform (TLP) mooring, etc. are used.

[0006] The method of TLP mooring is performed by applying strong tensile force to vertical mooring cables called "tendons", and compared to the typical method of taut mooring or semi-taut mooring, the TLP mooring method has the advantage of being able to stably maintain offshore floating structures even in rough sea conditions.

[0007] However, in the TLP mooring method, a distance between a floating unit and a mooring anchor has to be kept constant in order to maintain tensile force, but there is a problem that maintaining the tensile force is difficult when a position (a height) of the floating unit changes due to the difference in tidal levels.

[0008] The biggest problem in mooring systems is how to connect mooring cables to a mooring anchor.

[0009] As a technology related to this problem, Korean Patent No. 10-1572938, "GRAVITY TYPE MOORING APPARAUS FOR FLOATING OFFSHORE STRUCTURE" (registered on November 24, 2015) has been proposed.

[0010] In the related art, metal rings are provided on a gravity anchor, which is a concrete structure, and mooring cables are connected to the metal rings.

[0011] However, due to the limitation of adhesive force between the metal rings and the concrete structure in such a method, there is a risk that the metal rings can come off from the concrete structure if excessive tensile force is applied to the metal rings.

[0012] In addition, since each mooring cable is usually made of metal material such as a wire rope or chain, the thickness and the like of each mooring cable have to be determined by taking into account corrosion, etc., which occur when each mooring cable is in contact with seawater for a long period of time.

[0013] If mooring cables are to be used only for a short period of time when corrosion does not occur, the thickness of each mooring cable can be relatively thin due to its design with tensile stress as the main factor, but if mooring cables are to be used for a long period of time when corrosion occurs, each mooring cable must be of considerable thickness due to its design in consideration of corrosion along with the tensile stress.

[0014] In addition, no matter how thick a mooring cable is selected, it is required for the mooring cable to be replaced after a certain period of use. In this case, there is a difficulty that a diver must disconnect an old mooring cable from a mooring anchor located at deep water, and also connect a new mooring cable to the mooring anchor at the deep water. Accordingly, replacing the mooring cable is a relatively difficult task, so it is hard to perform the replacement frequently.

[0015] As described above, since the replacement of a mooring cable is difficult, the mooring cable is replaced at relatively long intervals, and thus the mooring cable must be very thick in consideration of corrosion and the like that occur during the long intervals.

[0016] Such a very thick mooring cable does not bend easily, so there is a problem that it is difficult to connect the mooring cable to the mooring anchor located in deep water.Disclosure Technical Problem

[0017] The present disclosure has been devised to solve the problems of the related art as described above, and an objective of the present disclosure is to propose a mooring system in which a floating unit, a mooring anchor, and a weight unit are connected by a plurality of mooring cables each having a shape of a closed curve, so that the restoring force of the floating unit may be increased by using the weight of the weight unit, the tensile force applied to each mooring cable may be maintained as it is even when the sea level changes due to the difference in tidal levels, local shocks may be minimized by changing the shape of each mooring cable even in the event of external shocks due to typhoons, etc., and each mooring cable is able to be easily replaced.

[0018] In addition, another objective of the present disclosure is to propose a mooring system capable of preventing tilting of a weight unit or a floating unit by using the tensile force applied to mooring cables.

[0019] In addition, a yet another objective of the present disclosure is to propose a mooring system in which mooring cables may be connected to each of a weight unit and a mooring anchor with very strong supporting force.Technical Solution

[0020] According to the present disclosure to solve the above problems, there is provided a mooring system including: a floating unit configured to float on the sea surface due to buoyancy; a mooring anchor installed on the seabed; a weight unit positioned underwater between the floating unit and the mooring anchor; and a plurality of mooring cables for connecting the mooring anchor, the floating unit, and the weight unit in order to moor the floating unit, wherein the weight unit is formed with a mooring-cable catching part for the weight unit for allowing a lower part of each mooring cable to be caught and a plurality of vertical penetration passages for the weight unit for allowing the mooring cables to pass vertically, the mooring anchor is formed with a mooring-cable catching part for the anchor for allowing a lower part of each mooring cable to be caught, the floating unit is formed with a mooring-cable catching part for the floating unit for allowing an upper part of each mooring cable to be caught and a plurality of vertical penetration passages for the floating unit for allowing the mooring cables to pass vertically, each of the mooring cables has a shape of a closed curve, each mooring cable may include: a first portion whose both ends extend upward from a middle lower part of the first portion caught in the mooring-cable catching part for the weight unit; a second portion whose both ends pass through the vertical penetration passages for the weight unit as extending upward from a middle lower part of the second portion caught in the mooring-cable catching part for the anchor; and a third portion whose both ends pass through the vertical penetration passages for the floating unit as extending downward from a middle upper part of the third portion caught in the mooring-cable catching part for the floating unit and are connected to the first portion and the second portion so as to allow the mooring cable to form the closed curve.

[0021] In the above, it is preferable that a sum of a distance L1 between the floating unit and the weight unit and a distance L2 between the floating unit and the mooring anchor may be constant, and the distance L2 between the floating unit and the mooring anchor may change according to the sea level.

[0022] In the above, it is preferable that the weight unit may include: a concrete body for the weight unit; and vertical guide pipes for the weight unit made of stainless steel and built into the concrete body for the weight unit in order to form the vertical penetration passages for the weight unit.

[0023] In another aspect of the present disclosure, there is provided a mooring system including: a floating unit configured to float on the sea surface due to buoyancy; a mooring anchor installed on the seabed; a weight unit positioned underwater between the floating unit and the mooring anchor; and a plurality of mooring cables for connecting the mooring anchor, the floating unit, and the weight unit in order to moor the floating unit, wherein the weight unit is formed with a plurality of U-shaped penetration passages for the weight unit for allowing a lower part of each mooring cable to be caught, the mooring anchor is formed with a plurality of U-shaped penetration passages for the anchor for allowing a lower part of each mooring cable to be caught, each of the mooring cables has a shape of a closed curve, and each mooring cable may include: a first portion whose both ends extend upward from a middle lower part of the first portion caught in the U-shaped penetration passage for the weight unit; a second portion whose both ends extend upward from a middle lower part of the second portion caught in the U-shaped penetration passage for the anchor; and a third portion whose both ends extend downward from a middle upper part of the third portion caught in a mooring-cable catching part for the floating unit provided in the floating unit and are connected to the first portion and the second portion so as to allow the mooring cable to form the closed curve.

[0024] In the above, it is preferable that a sum of a distance L1 between the floating unit and the weight unit and a distance L2 between the floating unit and the mooring anchor may be constant, and the distance L2 between the floating unit and the mooring anchor may change according to the sea level.

[0025] In the above, it is preferable that the weight unit may include: a concrete body for the weight unit; and U-shaped guide pipes for the weight unit made of stainless steel and built into the concrete body for the weight unit in order to form the U-shaped penetration passages for the weight unit, and the mooring anchor may include: a concrete body for the anchor; and U-shaped guide pipes for the anchor, the U-shaped guide pipes being made of stainless steel and built into the concrete body for the anchor in order to form the U-shaped penetration passages for the anchor.

[0026] In the above, it is preferable that the weight unit may be formed with a concrete body for the weight unit and a plurality of vertical penetration passages for the weight unit vertically passing through the concrete body for the weight unit, the floating unit may be formed with a plurality of vertical penetration passages for the floating unit vertically passing through the floating unit, the second portion of each mooring cable may be arranged to pass through the vertical penetration passages for the weight unit, and the third portion of each mooring cable may be arranged to pass through the vertical penetration passages for the floating unit.Advantageous Effects

[0027] As described above, the present disclosure may increase the restoring force of a floating unit by lowering the center of gravity of the floating unit by using the weight of a weight unit.

[0028] In addition, the present disclosure may maintain the tensile force applied to each mooring cable by changing the shape of each mooring cable even when the sea level changes due to the difference in tidal levels, thereby minimizing local shocks by changing the shape of each mooring cable even in the event of external shocks due to typhoons, etc.

[0029] In addition, the present disclosure adopts mooring cables each having the form of a closed curve, thereby making it very easy to replace a mooring cable.

[0030] In addition, the present disclosure may prevent a weight unit or a floating unit from tilting by mooring cables that are tautly extended in a vertical direction and also restore the weight unit or the floating unit to its original horizontality.

[0031] In addition, the present disclosure may dramatically increase bonding strength between mooring cables and a weight unit and bonding strength between the mooring cables and a mooring anchor.Description of Drawings

[0032] FIG. 1 is a conceptual cross-sectional view illustrating a mooring system according to a first exemplary embodiment of the present disclosure. FIG. 2 is a conceptual perspective view illustrating a structure shown in FIG. 1. FIG. 3 is a conceptual perspective view illustrating the main structure of a weight unit, a mooring anchor, and a floating unit shown in FIG. 2. FIG. 4 is a view illustrating positional changes of a floating unit and a mooring anchor according to change in the sea levels. FIG. 5 is a view illustrating a state in which tilting of a weight unit and a floating unit is prevented by a mooring cable. FIG. 6 is a conceptual cross-sectional view illustrating a mooring system according to a second exemplary embodiment of the present disclosure. Best Mode

[0033] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the drawings accompanied so that those skilled in the art may easily implement the present disclosure. However, the present disclosure is not limited to the exemplary embodiments described herein and may be embodied in many different forms. In addition, in order to clearly describe the present disclosure in the drawings, parts irrelevant to the description are omitted, and like reference numerals designate like elements throughout the specification.

[0034] Throughout the description of the present disclosure, when a part is said to "include" or "comprise" a certain component, it means that it may further include or comprise other components, rather than excluding other components unless the context clearly indicates otherwise.

[0035] First, a first exemplary embodiment of the present disclosure will be described.

[0036] FIG. 1 is a conceptual cross-sectional view illustrating a mooring system according to the first exemplary embodiment of the present disclosure.

[0037] FIG. 2 is a conceptual perspective view illustrating the structure in FIG. 1, and with respect to one of four mooring cables, the state in which a mooring cable passes through a weight unit and a mooring anchor is illustrated by using hidden lines.

[0038] FIG. 3 is a conceptual perspective view illustrating the main structure of the weight unit, the mooring anchor, and a floating unit in FIG. 2.

[0039] FIG. 4 is a view illustrating positional changes of the floating unit and the mooring anchor according to change in the sea levels.

[0040] FIG. 5 is a view illustrating a state in which tilting of a weight unit and a floating unit is prevented by a mooring cable.

[0041] The present mooring system includes a weight unit 100, a mooring anchor 200, a floating unit 300, and mooring cables 400.

[0042] The floating unit 300 floats on the sea surface due to buoyancy.

[0043] The floating unit 300 may be made of metal, concrete, or a mixture of metal and concrete, and typically has a buoyancy chamber inside thereof.

[0044] The floating unit 300 is provided with a plurality of mooring-cable catching parts 311 for the floating unit and a plurality of vertical penetration passages 312 for the floating unit.

[0045] Each mooring-cable catching part 311 for the floating unit is a part for guiding the movement of a mooring cable 400 in a state where an upper part of the mooring cable 400 is caught. In the present exemplary embodiment, as an example of a mooring-cable catching part 311 for the floating unit, a fairlead provided on the floating unit 300 is presented.

[0046] However, the mooring-cable catching part 311 for the floating unit may be applied to anything as long as it has a capability to guide the movement of a mooring cable 400 in a state where the upper part of the mooring cable 400 is caught.

[0047] A vertical penetration passage 312 for the floating unit is formed so that a mooring cable 400 may vertically penetrate the floating unit 300.

[0048] In order to form the vertical penetration passage 312 for the floating unit, a vertical guide pipe 312a for the floating unit is provided in the floating unit 300.

[0049] The vertical guide pipe 312a for the floating unit is a stainless steel pipe provided in the floating unit 300 in order to form the vertical penetration passage 312 for the floating unit.

[0050] A mooring anchor 200 is installed on the seabed.

[0051] A plurality of mooring-cable catching parts 211 for the anchor is formed in the mooring anchor 200.

[0052] Each of the plurality of mooring-cable catching parts 211 for the anchor is a part for guiding the movement of a mooring cable 400 in a state where the lower part of the mooring cable 400 is caught. In the present exemplary embodiment, as an example of the plurality of mooring-cable catching parts 211 for the anchor, the U-shaped penetration passages 211 for the anchor are formed in the mooring anchor 200.

[0053] According to the exemplary embodiment, a mooring-cable catching part 211 for the anchor may be applied to anything as long as it has a capability to guide the movement of a mooring cable 400 in a state where the lower middle part of the mooring cable 400 is caught, and may also be implemented in the form of a pulley, a fairlead, etc.

[0054] The mooring anchor 200 may be made of metal or concrete.

[0055] If the mooring anchor 200 is made of concrete, the mooring anchor 200 may include: a concrete body 210 for the anchor; and a U-shaped guide pipe 211a built into the concrete body 210 for the anchor.

[0056] The concrete body 210 for the anchor may be manufactured so that an empty space is formed inside of the concrete body 210 or no space is formed therein. In the case of the concrete body 210 for the anchor which has the empty space formed therein, it is preferable to fill the empty space with a filler (i.e., sand, gravel, etc.).

[0057] The U-shaped guide pipe 211a for the anchor is made of stainless steel and built into the concrete body 210 for the anchor in order to form the U-shaped penetration passage 211 for the anchor.

[0058] In the present exemplary embodiment, a gravity anchor is shown as the mooring anchor 200, but a penetration anchor, a suction anchor, etc. may also be used as the mooring anchor 200.

[0059] The weight unit 100 is located underwater between the floating unit 300 and the mooring anchor 200, and is spaced apart from each of the floating unit 300 and the mooring anchor 200.

[0060] The weight unit 100 has the property of sinking in water unless there is a special external force.

[0061] A plurality of mooring-cable catching parts 111 for the weight unit and a plurality of vertical penetration passages 112 for the weight unit are formed in the weight unit.

[0062] Each mooring-cable catching part 111 for the weight unit is a part for guiding the movement of a mooring cable 400 in a state where the lower part of the mooring cable 400 is caught. In the present exemplary embodiment, as an example of the mooring-cable catching parts 111 for the weight unit, U-shaped penetration passages 111 for the weight unit are formed in the weight unit 100.

[0063] According to the exemplary embodiment, a mooring-cable catching part 111 for the weight unit may be applied to anything as long as it has a capability to guide the movement of a mooring cable 400 in a state where the lower middle part of the mooring cable 400 is caught, and may also be implemented in the form of a pulley, a fairlead, etc.

[0064] A vertical penetration passage 112 for the weight unit is formed for vertical penetration of the mooring cable 400.

[0065] The weight unit 100 may be made of metal or concrete.

[0066] If the weight unit 100 is made of concrete, the weight unit 100 may include: a concrete body 110 for the weight unit; a U-shaped guide pipe 111a built into the concrete body 110 for the weight unit; and a vertical guide pipe 112a for the weight unit.

[0067] The concrete body 110 for the weight unit may be manufactured so that an empty space is formed inside the concrete body 110 or no space is formed therein. In the case of the concrete body 110 for the weight unit which has the empty space formed therein, it is preferable to fill the empty space with a filler (i.e., sand, gravel, etc.).

[0068] The U-shaped guide pipe 111a for the weight unit is made of stainless steel and built into the concrete body 110 for the weight unit in order to form a U-shaped penetration passage 111 for the weight unit.

[0069] The vertical guide pipe 112a for the weight unit is a stainless steel pipe built into the concrete body 110 for the weight unit in order to form a vertical penetration passage 112 for the weight unit.

[0070] The mooring cables 400 are used to connect the mooring anchor 200, the floating unit 300, and the weight unit 100 in order to moor the floating unit 300.

[0071] In the present mooring system, a plurality of mooring cables 400 (i.e., four mooring cables in the present exemplary embodiment) is provided in order to moor one floating unit 300, and each mooring cable 400 has a shape of a closed curve.

[0072] Depending on a part to be caught, each mooring cable 400 may be divided into a first portion 410, a second portion 420, and a third portion 430.

[0073] The first portion 410 is a part that is caught in the weight unit 100, the second portion 420 is a part that is caught in the mooring anchor 200, and the third portion 430 is a part that is caught in the floating unit 300.

[0074] The first portion 410 is a part whose both ends extend upward from a middle lower part thereof caught in the U-shaped penetration passage 111 for the weight unit of the weight unit 100.

[0075] The second portion 420 is a part whose both ends pass through the vertical penetration passage 112 for the weight unit of the weight unit 100 while extending upward from a middle lower part thereof caught in the U-shaped penetration passage 211 for the anchor of the mooring anchor 200.

[0076] The third portion 430 is a part whose both ends pass through the vertical penetration passage 312 of the floating unit 300 while extending downward from a middle upper part thereof caught in the mooring-cable catching part 311 of the floating unit 300.

[0077] The third portion 430 is connected to each of the first portion 410 and the second portion 420 so that the mooring cable 400 forms a closed curve. That is, when the third portion 430 is connected between the first portion 410 and the second portion 420, the mooring cable 400 forms the closed curve.

[0078] In such a shape, the mooring cable 400 has the shape of the closed curve with one first portion 410, one second portion 420, and two third portions 430, but the number of these parts may be changed as long as the shape of the closed curve is formed.

[0079] Hereinafter, a description is provided with reference to FIG. 4.

[0080] Since a mooring cable 400 has the shape of the closed curve and is continuously subjected to tensile force, the mooring cable 400 is always maintained in a state of tension.

[0081] Accordingly, a sum (L1 + L2) of a distance L1 between the floating unit 300 and the weight unit 100 and a distance L2 between the floating unit 300 and the mooring anchor 200 is always maintained constant.

[0082] Meanwhile, since the floating unit 300 floats on the sea surface due to buoyancy, the position of the floating unit 300 changes according to the sea level, but the position of the mooring anchor 200 is fixed to the seabed.

[0083] Accordingly, the distance L2 between the floating unit 300 and the mooring anchor 200 changes depending on the sea level.

[0084] As a result, when the distance L2 between the floating unit 300 and the mooring anchor 200 changes depending on the sea level, the distance L1 between the floating unit and the weight unit 100 also changes accordingly.

[0085] That is, when L2 decreases, L1 increases by that amount, and when L2 increases, L1 decreases by that amount.

[0086] The U-shaped guide pipe 111a for the weight unit and the vertical guide pipe 112a for the weight unit that are provided in the weight unit 100, the U-shaped guide pipe 211a for the anchor provided in the mooring anchor 200, and the vertical guide pipe 312a for the floating unit provided in the floating unit 300 are parts which are coming into contact with the mooring cables 400 and where friction occurs when the mooring cables 400 move, and are made of stainless steel.

[0087] This material allows smooth movement of the mooring cables 400, protects the concrete body 110 for the weight unit or the concrete body 210 for the anchor, and prevents corrosion from occurring even after long-term use.

[0088] Meanwhile, at least one of the weight unit 100, the mooring anchor 200, and the floating unit 300 may be manufactured by using the technology described in Korean Patent No. 10-2292821 (i.e., technology invented by the present inventor). The details described in Korean Patent No. 10-2292821 are considered to be incorporated into the present specification, so detailed descriptions are omitted.

[0089] The operation of the present mooring system is described.<Improved Restoring Force by Weight Unit 100>

[0090] When the weight unit 100 is connected to the floating unit 300, the center of gravity of the floating unit 300 is lowered, thereby increasing the restoring force of the floating unit 300. Accordingly, even in a case of being tilted, the floating unit 300 may be easily restored to its original horizontality. Normally, the restoring force of a ship is expressed as the relationship between the center of buoyancy and the center of gravity, and it is considered such that the lower the center of gravity, the higher the restoring force. <Response to Tidal Differences and External Shocks>

[0091] The present mooring system may respond to tidal differences. That is, even when the sea level changes, the shape of each mooring cable 400 changes to match the sea level, so that the tensile force of each mooring cable 400 may be maintained as it is.

[0092] Furthermore, even when very large shocks due to a tsunami, typhoon, etc. is applied to the floating unit 300, the present mooring system may alleviate local shocks applied to the mooring cables 400 by changing the shape of each mooring cable 400 in response to the shocks.<Easy Replacement of Mooring Cable 400>

[0093] Since a mooring cable 400 has a shape of a closed curve, the present mooring system may easily replace the mooring cable 400.

[0094] A case of replacing one of four mooring cables 400 is described. In this case, it should be possible to moor a floating unit 300 with just three mooring cables 400.

[0095] (In some cases, it may be preferable to moor with 6 to 8 mooring cables 400 and replace one of these cables.)

[0096] A mooring cable 400 to be replaced is cut on an upper part of the floating unit 300, and a new mooring cable 400 is connected to one end of the mooring cable 400 to be replaced. That is, the mooring cable 400 to be replaced and the new mooring cable 400 are connected to each other so as to form a continuous line shape.

[0097] Thereafter, by pulling the other end of the mooring cable 400 to be replaced and removing the mooring cable 400 to be replaced, the new mooring cable 400 may be positioned in the original position of the mooring cable 400 to be replaced.

[0098] Thereafter, when both ends of the new mooring cable 400 are connected to each other, the replacement work of the mooring cable is completed.

[0099] As described above, since the replacement work of the mooring cable is performed on the upper part of the floating unit 300, underwater work for replacing the mooring cable is unnecessary, and thus the overall replacement cost may be significantly reduced.

[0100] In addition, as the replacement cost of mooring cables is reduced, a mooring cable can be replaced at frequent intervals, so corrosion problems may be avoided. As a result, only tensile force of mooring can be considered in the design of determining a mooring cable thickness, so a mooring cable may be made thinner.

[0101] In addition, since the mooring cable can be made thinner, the work of connecting a mooring cable to a mooring anchor, a weight unit, or a floating unit becomes much easier.<Prevention of Tilting of Weight Unit 100 or Floating Unit 300 by Mooring Cables>

[0102] In the present mooring system, the mooring cable 400 passes through the vertical penetration passages 112 for the weight unit and the vertical penetration passages 312 for the floating unit while having sufficient tensile force.

[0103] In this state, when the weight unit 100 or the floating unit 300 tilts, the mooring cable 400 that is tautly extended in the vertical direction comes into contact with the weight unit 100 or the floating unit 300, thereby not only preventing the weight unit 100 or the floating unit 300 from tilting but also causing the weight unit 100 or the floating unit 300 to be restored to its original horizontality.

[0104] FIG. 5 is a view conceptually illustrating a state in which tilting of the weight unit and the floating unit is prevented by the mooring cable 400.<Very Large Supporting Force by U-shaped Penetration Passages>

[0105] In the present system, the mooring cable 400 is caught in the weight unit 100 and the mooring anchor 200 through the U-shaped penetration passage 111 for the weight unit formed inside the concrete body 110 for the weight unit and the U-shaped penetration passage 211 for the anchor formed inside the concrete body 210 for the anchor, so the mooring cable 400 is connected to the weight unit 100 and the mooring anchor 200 with a very large supporting force.<Application to Floating-type Offshore Wind Power Generation>

[0106] A floating unit of the present disclosure may be applied as a floating foundation for floating-type offshore wind power generation, and in this case, a wind power generator has to be installed on an upper part of the floating unit.

[0107] Since high restoring force may be obtained by connecting a weight unit to the lower part of a floating unit after manufacturing the floating unit at a dock, the work of installing a wind power generator on the upper part of the float unit connected with the weight unit can be performed at the dock. Thereafter, the float unit with the wind power generator pre-installed thereon is transported to an installation site, and only the work of mooring the float unit to a mooring anchor is required to be performed at the installation site.

[0108] That is, the overall cost may be reduced because there is no need to install the wind power generator on the upper part of the floating unit at sea.

[0109] Below, a second exemplary embodiment of the present disclosure is described.

[0110] The present exemplary embodiment is the same as the first exemplary embodiment except that a plurality of weight units 100 are provided for this embodiment.

[0111] Depending on the exemplary embodiment, a plurality of mooring anchors 200 may also be provided.

[0112] The scope of the present disclosure is indicated by the claims set forth below rather than the detailed description above.Industrial Applicability

[0113] The embodiment of the present disclosure may be applicable for mooring various types of floating units (or offshore floating structures) floating on the sea surface.

Examples

Embodiment Construction

[0033]Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the drawings accompanied so that those skilled in the art may easily implement the present disclosure. However, the present disclosure is not limited to the exemplary embodiments described herein and may be embodied in many different forms. In addition, in order to clearly describe the present disclosure in the drawings, parts irrelevant to the description are omitted, and like reference numerals designate like elements throughout the specification.

[0034]Throughout the description of the present disclosure, when a part is said to "include" or "comprise" a certain component, it means that it may further include or comprise other components, rather than excluding other components unless the context clearly indicates otherwise.

[0035]First, a first exemplary embodiment of the present disclosure will be described.

[0036]FIG. 1 is a conceptual cross-sectional view illustrating a...

Technical Field

[0001] The present disclosure relates to a mooring system for mooring various types of floating units (or offshore floating structures) floating on the sea surface and, more particularly, to a mooring system in which a floating unit, a mooring anchor, and a weight unit are connected by a plurality of mooring cables each having a shape of a closed curve.Background Art

[0002] Various types of floating units designed to float on the sea surface are known. A floating foundation for floating-type offshore wind power generation is a representative example of the floating units.

[0003] Such a floating unit can be moored through connection to a mooring anchor that is installed on the seabed by mooring cables.

[0004] Various types of anchors such as gravity anchors, drag-embedment anchors, and suction anchors are used for a mooring anchor.

[0005] As mooring methods, taut mooring, semi-taut mooring, Tension Leg Platform (TLP) mooring, etc. are used.

[0006] The method of TLP mooring is performed by applying strong tensile force to vertical mooring cables called "tendons", and compared to the typical method of taut mooring or semi-taut mooring, the TLP mooring method has the advantage of being able to stably maintain offshore floating structures even in rough sea conditions.

[0007] However, in the TLP mooring method, a distance between a floating unit and a mooring anchor has to be kept constant in order to maintain tensile force, but there is a problem that maintaining the tensile force is difficult when a position (a height) of the floating unit changes due to the difference in tidal levels.

[0008] The biggest problem in mooring systems is how to connect mooring cables to a mooring anchor.

[0009] As a technology related to this problem, Korean Patent No. 10-1572938, "GRAVITY TYPE MOORING APPARAUS FOR FLOATING OFFSHORE STRUCTURE" (registered on November 24, 2015) has been proposed.

[0010] In the related art, metal rings are provided on a gravity anchor, which is a concrete structure, and mooring cables are connected to the metal rings.

[0011] However, due to the limitation of adhesive force between the metal rings and the concrete structure in such a method, there is a risk that the metal rings can come off from the concrete structure if excessive tensile force is applied to the metal rings.

[0012] In addition, since each mooring cable is usually made of metal material such as a wire rope or chain, the thickness and the like of each mooring cable have to be determined by taking into account corrosion, etc., which occur when each mooring cable is in contact with seawater for a long period of time.

[0013] If mooring cables are to be used only for a short period of time when corrosion does not occur, the thickness of each mooring cable can be relatively thin due to its design with tensile stress as the main factor, but if mooring cables are to be used for a long period of time when corrosion occurs, each mooring cable must be of considerable thickness due to its design in consideration of corrosion along with the tensile stress.

[0014] In addition, no matter how thick a mooring cable is selected, it is required for the mooring cable to be replaced after a certain period of use. In this case, there is a difficulty that a diver must disconnect an old mooring cable from a mooring anchor located at deep water, and also connect a new mooring cable to the mooring anchor at the deep water. Accordingly, replacing the mooring cable is a relatively difficult task, so it is hard to perform the replacement frequently.

[0015] As described above, since the replacement of a mooring cable is difficult, the mooring cable is replaced at relatively long intervals, and thus the mooring cable must be very thick in consideration of corrosion and the like that occur during the long intervals.

[0016] Such a very thick mooring cable does not bend easily, so there is a problem that it is difficult to connect the mooring cable to the mooring anchor located in deep water.Disclosure Technical Problem

[0017] The present disclosure has been devised to solve the problems of the related art as described above, and an objective of the present disclosure is to propose a mooring system in which a floating unit, a mooring anchor, and a weight unit are connected by a plurality of mooring cables each having a shape of a closed curve, so that the restoring force of the floating unit may be increased by using the weight of the weight unit, the tensile force applied to each mooring cable may be maintained as it is even when the sea level changes due to the difference in tidal levels, local shocks may be minimized by changing the shape of each mooring cable even in the event of external shocks due to typhoons, etc., and each mooring cable is able to be easily replaced.

[0018] In addition, another objective of the present disclosure is to propose a mooring system capable of preventing tilting of a weight unit or a floating unit by using the tensile force applied to mooring cables.

[0019] In addition, a yet another objective of the present disclosure is to propose a mooring system in which mooring cables may be connected to each of a weight unit and a mooring anchor with very strong supporting force.Technical Solution

[0020] According to the present disclosure to solve the above problems, there is provided a mooring system including: a floating unit configured to float on the sea surface due to buoyancy; a mooring anchor installed on the seabed; a weight unit positioned underwater between the floating unit and the mooring anchor; and a plurality of mooring cables for connecting the mooring anchor, the floating unit, and the weight unit in order to moor the floating unit, wherein the weight unit is formed with a mooring-cable catching part for the weight unit for allowing a lower part of each mooring cable to be caught and a plurality of vertical penetration passages for the weight unit for allowing the mooring cables to pass vertically, the mooring anchor is formed with a mooring-cable catching part for the anchor for allowing a lower part of each mooring cable to be caught, the floating unit is formed with a mooring-cable catching part for the floating unit for allowing an upper part of each mooring cable to be caught and a plurality of vertical penetration passages for the floating unit for allowing the mooring cables to pass vertically, each of the mooring cables has a shape of a closed curve, each mooring cable may include: a first portion whose both ends extend upward from a middle lower part of the first portion caught in the mooring-cable catching part for the weight unit; a second portion whose both ends pass through the vertical penetration passages for the weight unit as extending upward from a middle lower part of the second portion caught in the mooring-cable catching part for the anchor; and a third portion whose both ends pass through the vertical penetration passages for the floating unit as extending downward from a middle upper part of the third portion caught in the mooring-cable catching part for the floating unit and are connected to the first portion and the second portion so as to allow the mooring cable to form the closed curve.

[0021] In the above, it is preferable that a sum of a distance L1 between the floating unit and the weight unit and a distance L2 between the floating unit and the mooring anchor may be constant, and the distance L2 between the floating unit and the mooring anchor may change according to the sea level.

[0022] In the above, it is preferable that the weight unit may include: a concrete body for the weight unit; and vertical guide pipes for the weight unit made of stainless steel and built into the concrete body for the weight unit in order to form the vertical penetration passages for the weight unit.

[0023] In another aspect of the present disclosure, there is provided a mooring system including: a floating unit configured to float on the sea surface due to buoyancy; a mooring anchor installed on the seabed; a weight unit positioned underwater between the floating unit and the mooring anchor; and a plurality of mooring cables for connecting the mooring anchor, the floating unit, and the weight unit in order to moor the floating unit, wherein the weight unit is formed with a plurality of U-shaped penetration passages for the weight unit for allowing a lower part of each mooring cable to be caught, the mooring anchor is formed with a plurality of U-shaped penetration passages for the anchor for allowing a lower part of each mooring cable to be caught, each of the mooring cables has a shape of a closed curve, and each mooring cable may include: a first portion whose both ends extend upward from a middle lower part of the first portion caught in the U-shaped penetration passage for the weight unit; a second portion whose both ends extend upward from a middle lower part of the second portion caught in the U-shaped penetration passage for the anchor; and a third portion whose both ends extend downward from a middle upper part of the third portion caught in a mooring-cable catching part for the floating unit provided in the floating unit and are connected to the first portion and the second portion so as to allow the mooring cable to form the closed curve.

[0024] In the above, it is preferable that a sum of a distance L1 between the floating unit and the weight unit and a distance L2 between the floating unit and the mooring anchor may be constant, and the distance L2 between the floating unit and the mooring anchor may change according to the sea level.

[0025] In the above, it is preferable that the weight unit may include: a concrete body for the weight unit; and U-shaped guide pipes for the weight unit made of stainless steel and built into the concrete body for the weight unit in order to form the U-shaped penetration passages for the weight unit, and the mooring anchor may include: a concrete body for the anchor; and U-shaped guide pipes for the anchor, the U-shaped guide pipes being made of stainless steel and built into the concrete body for the anchor in order to form the U-shaped penetration passages for the anchor.

[0026] In the above, it is preferable that the weight unit may be formed with a concrete body for the weight unit and a plurality of vertical penetration passages for the weight unit vertically passing through the concrete body for the weight unit, the floating unit may be formed with a plurality of vertical penetration passages for the floating unit vertically passing through the floating unit, the second portion of each mooring cable may be arranged to pass through the vertical penetration passages for the weight unit, and the third portion of each mooring cable may be arranged to pass through the vertical penetration passages for the floating unit.Advantageous Effects

[0027] As described above, the present disclosure may increase the restoring force of a floating unit by lowering the center of gravity of the floating unit by using the weight of a weight unit.

[0028] In addition, the present disclosure may maintain the tensile force applied to each mooring cable by changing the shape of each mooring cable even when the sea level changes due to the difference in tidal levels, thereby minimizing local shocks by changing the shape of each mooring cable even in the event of external shocks due to typhoons, etc.

[0029] In addition, the present disclosure adopts mooring cables each having the form of a closed curve, thereby making it very easy to replace a mooring cable.

[0030] In addition, the present disclosure may prevent a weight unit or a floating unit from tilting by mooring cables that are tautly extended in a vertical direction and also restore the weight unit or the floating unit to its original horizontality.

[0031] In addition, the present disclosure may dramatically increase bonding strength between mooring cables and a weight unit and bonding strength between the mooring cables and a mooring anchor.Description of Drawings

[0032] FIG. 1 is a conceptual cross-sectional view illustrating a mooring system according to a first exemplary embodiment of the present disclosure. FIG. 2 is a conceptual perspective view illustrating a structure shown in FIG. 1. FIG. 3 is a conceptual perspective view illustrating the main structure of a weight unit, a mooring anchor, and a floating unit shown in FIG. 2. FIG. 4 is a view illustrating positional changes of a floating unit and a mooring anchor according to change in the sea levels. FIG. 5 is a view illustrating a state in which tilting of a weight unit and a floating unit is prevented by a mooring cable. FIG. 6 is a conceptual cross-sectional view illustrating a mooring system according to a second exemplary embodiment of the present disclosure. Best Mode

[0033] Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the drawings accompanied so that those skilled in the art may easily implement the present disclosure. However, the present disclosure is not limited to the exemplary embodiments described herein and may be embodied in many different forms. In addition, in order to clearly describe the present disclosure in the drawings, parts irrelevant to the description are omitted, and like reference numerals designate like elements throughout the specification.

[0034] Throughout the description of the present disclosure, when a part is said to "include" or "comprise" a certain component, it means that it may further include or comprise other components, rather than excluding other components unless the context clearly indicates otherwise.

[0035] First, a first exemplary embodiment of the present disclosure will be described.

[0036] FIG. 1 is a conceptual cross-sectional view illustrating a mooring system according to the first exemplary embodiment of the present disclosure.

[0037] FIG. 2 is a conceptual perspective view illustrating the structure in FIG. 1, and with respect to one of four mooring cables, the state in which a mooring cable passes through a weight unit and a mooring anchor is illustrated by using hidden lines.

[0038] FIG. 3 is a conceptual perspective view illustrating the main structure of the weight unit, the mooring anchor, and a floating unit in FIG. 2.

[0039] FIG. 4 is a view illustrating positional changes of the floating unit and the mooring anchor according to change in the sea levels.

[0040] FIG. 5 is a view illustrating a state in which tilting of a weight unit and a floating unit is prevented by a mooring cable.

[0041] The present mooring system includes a weight unit 100, a mooring anchor 200, a floating unit 300, and mooring cables 400.

[0042] The floating unit 300 floats on the sea surface due to buoyancy.

[0043] The floating unit 300 may be made of metal, concrete, or a mixture of metal and concrete, and typically has a buoyancy chamber inside thereof.

[0044] The floating unit 300 is provided with a plurality of mooring-cable catching parts 311 for the floating unit and a plurality of vertical penetration passages 312 for the floating unit.

[0045] Each mooring-cable catching part 311 for the floating unit is a part for guiding the movement of a mooring cable 400 in a state where an upper part of the mooring cable 400 is caught. In the present exemplary embodiment, as an example of a mooring-cable catching part 311 for the floating unit, a fairlead provided on the floating unit 300 is presented.

[0046] However, the mooring-cable catching part 311 for the floating unit may be applied to anything as long as it has a capability to guide the movement of a mooring cable 400 in a state where the upper part of the mooring cable 400 is caught.

[0047] A vertical penetration passage 312 for the floating unit is formed so that a mooring cable 400 may vertically penetrate the floating unit 300.

[0048] In order to form the vertical penetration passage 312 for the floating unit, a vertical guide pipe 312a for the floating unit is provided in the floating unit 300.

[0049] The vertical guide pipe 312a for the floating unit is a stainless steel pipe provided in the floating unit 300 in order to form the vertical penetration passage 312 for the floating unit.

[0050] A mooring anchor 200 is installed on the seabed.

[0051] A plurality of mooring-cable catching parts 211 for the anchor is formed in the mooring anchor 200.

[0052] Each of the plurality of mooring-cable catching parts 211 for the anchor is a part for guiding the movement of a mooring cable 400 in a state where the lower part of the mooring cable 400 is caught. In the present exemplary embodiment, as an example of the plurality of mooring-cable catching parts 211 for the anchor, the U-shaped penetration passages 211 for the anchor are formed in the mooring anchor 200.

[0053] According to the exemplary embodiment, a mooring-cable catching part 211 for the anchor may be applied to anything as long as it has a capability to guide the movement of a mooring cable 400 in a state where the lower middle part of the mooring cable 400 is caught, and may also be implemented in the form of a pulley, a fairlead, etc.

[0054] The mooring anchor 200 may be made of metal or concrete.

[0055] If the mooring anchor 200 is made of concrete, the mooring anchor 200 may include: a concrete body 210 for the anchor; and a U-shaped guide pipe 211a built into the concrete body 210 for the anchor.

[0056] The concrete body 210 for the anchor may be manufactured so that an empty space is formed inside of the concrete body 210 or no space is formed therein. In the case of the concrete body 210 for the anchor which has the empty space formed therein, it is preferable to fill the empty space with a filler (i.e., sand, gravel, etc.).

[0057] The U-shaped guide pipe 211a for the anchor is made of stainless steel and built into the concrete body 210 for the anchor in order to form the U-shaped penetration passage 211 for the anchor.

[0058] In the present exemplary embodiment, a gravity anchor is shown as the mooring anchor 200, but a penetration anchor, a suction anchor, etc. may also be used as the mooring anchor 200.

[0059] The weight unit 100 is located underwater between the floating unit 300 and the mooring anchor 200, and is spaced apart from each of the floating unit 300 and the mooring anchor 200.

[0060] The weight unit 100 has the property of sinking in water unless there is a special external force.

[0061] A plurality of mooring-cable catching parts 111 for the weight unit and a plurality of vertical penetration passages 112 for the weight unit are formed in the weight unit.

[0062] Each mooring-cable catching part 111 for the weight unit is a part for guiding the movement of a mooring cable 400 in a state where the lower part of the mooring cable 400 is caught. In the present exemplary embodiment, as an example of the mooring-cable catching parts 111 for the weight unit, U-shaped penetration passages 111 for the weight unit are formed in the weight unit 100.

[0063] According to the exemplary embodiment, a mooring-cable catching part 111 for the weight unit may be applied to anything as long as it has a capability to guide the movement of a mooring cable 400 in a state where the lower middle part of the mooring cable 400 is caught, and may also be implemented in the form of a pulley, a fairlead, etc.

[0064] A vertical penetration passage 112 for the weight unit is formed for vertical penetration of the mooring cable 400.

[0065] The weight unit 100 may be made of metal or concrete.

[0066] If the weight unit 100 is made of concrete, the weight unit 100 may include: a concrete body 110 for the weight unit; a U-shaped guide pipe 111a built into the concrete body 110 for the weight unit; and a vertical guide pipe 112a for the weight unit.

[0067] The concrete body 110 for the weight unit may be manufactured so that an empty space is formed inside the concrete body 110 or no space is formed therein. In the case of the concrete body 110 for the weight unit which has the empty space formed therein, it is preferable to fill the empty space with a filler (i.e., sand, gravel, etc.).

[0068] The U-shaped guide pipe 111a for the weight unit is made of stainless steel and built into the concrete body 110 for the weight unit in order to form a U-shaped penetration passage 111 for the weight unit.

[0069] The vertical guide pipe 112a for the weight unit is a stainless steel pipe built into the concrete body 110 for the weight unit in order to form a vertical penetration passage 112 for the weight unit.

[0070] The mooring cables 400 are used to connect the mooring anchor 200, the floating unit 300, and the weight unit 100 in order to moor the floating unit 300.

[0071] In the present mooring system, a plurality of mooring cables 400 (i.e., four mooring cables in the present exemplary embodiment) is provided in order to moor one floating unit 300, and each mooring cable 400 has a shape of a closed curve.

[0072] Depending on a part to be caught, each mooring cable 400 may be divided into a first portion 410, a second portion 420, and a third portion 430.

[0073] The first portion 410 is a part that is caught in the weight unit 100, the second portion 420 is a part that is caught in the mooring anchor 200, and the third portion 430 is a part that is caught in the floating unit 300.

[0074] The first portion 410 is a part whose both ends extend upward from a middle lower part thereof caught in the U-shaped penetration passage 111 for the weight unit of the weight unit 100.

[0075] The second portion 420 is a part whose both ends pass through the vertical penetration passage 112 for the weight unit of the weight unit 100 while extending upward from a middle lower part thereof caught in the U-shaped penetration passage 211 for the anchor of the mooring anchor 200.

[0076] The third portion 430 is a part whose both ends pass through the vertical penetration passage 312 of the floating unit 300 while extending downward from a middle upper part thereof caught in the mooring-cable catching part 311 of the floating unit 300.

[0077] The third portion 430 is connected to each of the first portion 410 and the second portion 420 so that the mooring cable 400 forms a closed curve. That is, when the third portion 430 is connected between the first portion 410 and the second portion 420, the mooring cable 400 forms the closed curve.

[0078] In such a shape, the mooring cable 400 has the shape of the closed curve with one first portion 410, one second portion 420, and two third portions 430, but the number of these parts may be changed as long as the shape of the closed curve is formed.

[0079] Hereinafter, a description is provided with reference to FIG. 4.

[0080] Since a mooring cable 400 has the shape of the closed curve and is continuously subjected to tensile force, the mooring cable 400 is always maintained in a state of tension.

[0081] Accordingly, a sum (L1 + L2) of a distance L1 between the floating unit 300 and the weight unit 100 and a distance L2 between the floating unit 300 and the mooring anchor 200 is always maintained constant.

[0082] Meanwhile, since the floating unit 300 floats on the sea surface due to buoyancy, the position of the floating unit 300 changes according to the sea level, but the position of the mooring anchor 200 is fixed to the seabed.

[0083] Accordingly, the distance L2 between the floating unit 300 and the mooring anchor 200 changes depending on the sea level.

[0084] As a result, when the distance L2 between the floating unit 300 and the mooring anchor 200 changes depending on the sea level, the distance L1 between the floating unit and the weight unit 100 also changes accordingly.

[0085] That is, when L2 decreases, L1 increases by that amount, and when L2 increases, L1 decreases by that amount.

[0086] The U-shaped guide pipe 111a for the weight unit and the vertical guide pipe 112a for the weight unit that are provided in the weight unit 100, the U-shaped guide pipe 211a for the anchor provided in the mooring anchor 200, and the vertical guide pipe 312a for the floating unit provided in the floating unit 300 are parts which are coming into contact with the mooring cables 400 and where friction occurs when the mooring cables 400 move, and are made of stainless steel.

[0087] This material allows smooth movement of the mooring cables 400, protects the concrete body 110 for the weight unit or the concrete body 210 for the anchor, and prevents corrosion from occurring even after long-term use.

[0088] Meanwhile, at least one of the weight unit 100, the mooring anchor 200, and the floating unit 300 may be manufactured by using the technology described in Korean Patent No. 10-2292821 (i.e., technology invented by the present inventor). The details described in Korean Patent No. 10-2292821 are considered to be incorporated into the present specification, so detailed descriptions are omitted.

[0089] The operation of the present mooring system is described.<Improved Restoring Force by Weight Unit 100>

[0090] When the weight unit 100 is connected to the floating unit 300, the center of gravity of the floating unit 300 is lowered, thereby increasing the restoring force of the floating unit 300. Accordingly, even in a case of being tilted, the floating unit 300 may be easily restored to its original horizontality. Normally, the restoring force of a ship is expressed as the relationship between the center of buoyancy and the center of gravity, and it is considered such that the lower the center of gravity, the higher the restoring force. <Response to Tidal Differences and External Shocks>

[0091] The present mooring system may respond to tidal differences. That is, even when the sea level changes, the shape of each mooring cable 400 changes to match the sea level, so that the tensile force of each mooring cable 400 may be maintained as it is.

[0092] Furthermore, even when very large shocks due to a tsunami, typhoon, etc. is applied to the floating unit 300, the present mooring system may alleviate local shocks applied to the mooring cables 400 by changing the shape of each mooring cable 400 in response to the shocks.<Easy Replacement of Mooring Cable 400>

[0093] Since a mooring cable 400 has a shape of a closed curve, the present mooring system may easily replace the mooring cable 400.

[0094] A case of replacing one of four mooring cables 400 is described. In this case, it should be possible to moor a floating unit 300 with just three mooring cables 400.

[0095] (In some cases, it may be preferable to moor with 6 to 8 mooring cables 400 and replace one of these cables.)

[0096] A mooring cable 400 to be replaced is cut on an upper part of the floating unit 300, and a new mooring cable 400 is connected to one end of the mooring cable 400 to be replaced. That is, the mooring cable 400 to be replaced and the new mooring cable 400 are connected to each other so as to form a continuous line shape.

[0097] Thereafter, by pulling the other end of the mooring cable 400 to be replaced and removing the mooring cable 400 to be replaced, the new mooring cable 400 may be positioned in the original position of the mooring cable 400 to be replaced.

[0098] Thereafter, when both ends of the new mooring cable 400 are connected to each other, the replacement work of the mooring cable is completed.

[0099] As described above, since the replacement work of the mooring cable is performed on the upper part of the floating unit 300, underwater work for replacing the mooring cable is unnecessary, and thus the overall replacement cost may be significantly reduced.

[0100] In addition, as the replacement cost of mooring cables is reduced, a mooring cable can be replaced at frequent intervals, so corrosion problems may be avoided. As a result, only tensile force of mooring can be considered in the design of determining a mooring cable thickness, so a mooring cable may be made thinner.

[0101] In addition, since the mooring cable can be made thinner, the work of connecting a mooring cable to a mooring anchor, a weight unit, or a floating unit becomes much easier.<Prevention of Tilting of Weight Unit 100 or Floating Unit 300 by Mooring Cables>

[0102] In the present mooring system, the mooring cable 400 passes through the vertical penetration passages 112 for the weight unit and the vertical penetration passages 312 for the floating unit while having sufficient tensile force.

[0103] In this state, when the weight unit 100 or the floating unit 300 tilts, the mooring cable 400 that is tautly extended in the vertical direction comes into contact with the weight unit 100 or the floating unit 300, thereby not only preventing the weight unit 100 or the floating unit 300 from tilting but also causing the weight unit 100 or the floating unit 300 to be restored to its original horizontality.

[0104] FIG. 5 is a view conceptually illustrating a state in which tilting of the weight unit and the floating unit is prevented by the mooring cable 400.<Very Large Supporting Force by U-shaped Penetration Passages>

[0105] In the present system, the mooring cable 400 is caught in the weight unit 100 and the mooring anchor 200 through the U-shaped penetration passage 111 for the weight unit formed inside the concrete body 110 for the weight unit and the U-shaped penetration passage 211 for the anchor formed inside the concrete body 210 for the anchor, so the mooring cable 400 is connected to the weight unit 100 and the mooring anchor 200 with a very large supporting force.<Application to Floating-type Offshore Wind Power Generation>

[0106] A floating unit of the present disclosure may be applied as a floating foundation for floating-type offshore wind power generation, and in this case, a wind power generator has to be installed on an upper part of the floating unit.

[0107] Since high restoring force may be obtained by connecting a weight unit to the lower part of a floating unit after manufacturing the floating unit at a dock, the work of installing a wind power generator on the upper part of the float unit connected with the weight unit can be performed at the dock. Thereafter, the float unit with the wind power generator pre-installed thereon is transported to an installation site, and only the work of mooring the float unit to a mooring anchor is required to be performed at the installation site.

[0108] That is, the overall cost may be reduced because there is no need to install the wind power generator on the upper part of the floating unit at sea.

[0109] Below, a second exemplary embodiment of the present disclosure is described.

[0110] The present exemplary embodiment is the same as the first exemplary embodiment except that a plurality of weight units 100 are provided for this embodiment.

[0111] Depending on the exemplary embodiment, a plurality of mooring anchors 200 may also be provided.

[0112] The scope of the present disclosure is indicated by the claims set forth below rather than the detailed description above.Industrial Applicability

[0113] The embodiment of the present disclosure may be applicable for mooring various types of floating units (or offshore floating structures) floating on the sea surface.

Examples

Embodiment Construction

[0033]Hereinafter, exemplary embodiments of the present disclosure will be described in detail with reference to the drawings accompanied so that those skilled in the art may easily implement the present disclosure. However, the present disclosure is not limited to the exemplary embodiments described herein and may be embodied in many different forms. In addition, in order to clearly describe the present disclosure in the drawings, parts irrelevant to the description are omitted, and like reference numerals designate like elements throughout the specification.

[0034]Throughout the description of the present disclosure, when a part is said to "include" or "comprise" a certain component, it means that it may further include or comprise other components, rather than excluding other components unless the context clearly indicates otherwise.

[0035]First, a first exemplary embodiment of the present disclosure will be described.

[0036]FIG. 1 is a conceptual cross-sectional view illustrating a...

Claims

1. A mooring system comprising: a floating unit configured to float on the sea surface due to buoyancy; a mooring anchor installed on the seabed; a weight unit positioned underwater between the floating unit and the mooring anchor; and a plurality of mooring cables for connecting the mooring anchor, the floating unit, and the weight unit in order to moor the floating unit, wherein the weight unit is formed with a mooring-cable catching part for the weight unit for allowing a lower part of each mooring cable to be caught and a plurality of vertical penetration passages for the weight unit for allowing the mooring cables to pass vertically, the mooring anchor is formed with a mooring-cable catching part for the anchor for allowing a lower part of each mooring cable to be caught, the floating unit is formed with a mooring-cable catching part for the floating unit for allowing an upper part of each mooring cable to be caught and a plurality of vertical penetration passages for the floating unit for allowing the mooring cables to pass vertically, each of the mooring cables has a shape of a closed curve, and each mooring cable comprises: a first portion whose both ends extend upward from a middle lower part of the first portion caught in the mooring-cable catching part for the weight unit; a second portion whose both ends pass through the vertical penetration passages for the weight unit as extending upward from a middle lower part of the second portion caught in the mooring-cable catching part for the anchor; and a third portion whose both ends pass through the vertical penetration passages for the floating unit as extending downward from a middle upper part of the third portion caught in the mooring-cable catching part for the floating unit and are connected to the first portion and the second portion so as to allow the mooring cable to form the closed curve.

2. The mooring system of claim 1, wherein a sum of a distance (L1) between the floating unit and the weight unit and a distance (L2) between the floating unit and the mooring anchor is constant, and the distance (L2) between the floating unit and the mooring anchor changes according to the sea level.

3. The mooring system of claim 1, wherein the weight unit comprises: a concrete body for the weight unit; and vertical guide pipes for the weight unit made of stainless steel and built into the concrete body for the weight unit in order to form the vertical penetration passages for the weight unit.

4. A mooring system comprising: a floating unit configured to float on the sea surface due to buoyancy; a mooring anchor installed on the seabed; a weight unit positioned underwater between the floating unit and the mooring anchor; and a plurality of mooring cables for connecting the mooring anchor, the floating unit, and the weight unit in order to moor the floating unit, wherein the weight unit is formed with a plurality of U-shaped penetration passages for the weight unit for allowing a lower part of each mooring cable to be caught, the mooring anchor is formed with a plurality of U-shaped penetration passages for the anchor for allowing a lower part of each mooring cable to be caught, each of the mooring cables has a shape of a closed curve, and each mooring cable comprises: a first portion whose both ends extend upward from a middle lower part of the first portion caught in the U-shaped penetration passage for the weight unit; a second portion whose both ends extend upward from a middle lower part of the second portion caught in the U-shaped penetration passage for the anchor; and a third portion whose both ends extend downward from a middle upper part of the third portion caught in a mooring-cable catching part for the floating unit provided in the floating unit and are connected to the first portion and the second portion so as to allow the mooring cable to form the closed curve.

5. The mooring system of claim 4, wherein a sum of a distance (L1) between the floating unit and the weight unit and a distance (L2) between the floating unit and the mooring anchor is constant, and the distance (L2) between the floating unit and the mooring anchor changes according to the sea level.

6. The mooring system of claim 4, wherein the weight unit comprises: a concrete body for the weight unit; and U-shaped guide pipes for the weight unit made of stainless steel and built into the concrete body for the weight unit in order to form the U-shaped penetration passages for the weight unit, and the mooring anchor comprises: a concrete body for the anchor; and U-shaped guide pipes for the anchor, the U-shaped guide pipes being made of stainless steel and built into the concrete body for the anchor in order to form the U-shaped penetration passages for the anchor.

7. The mooring system of claim 4, wherein the weight unit is formed with a concrete body for the weight unit and a plurality of vertical penetration passages for the weight unit vertically passing through the concrete body for the weight unit, the floating unit is formed with a plurality of vertical penetration passages for the floating unit vertically passing through the floating unit, the second portion of each mooring cable is arranged to pass through the vertical penetration passages for the weight unit, and the third portion of each mooring cable is arranged to pass through the vertical penetration passages for the floating unit.

Images