SE537490C2 - Mooring buoy - Google Patents

Abstract

SUMMARY The buoy is moored by a floating fabric having a first electrical cable (9) comprising a hollow cylindrical body (1) with a mechanical mooring device (5) and a slack ring device (4) having a ring portion (15) and a brush portion (16) father hagspand power transfer. The mechanical navigating device comprises a girdle (6) mounted around the buoy, and the slack ring device comprises an annular diving bell construction (17).

Description

TECHNICAL FIELD The present invention relates to the mooring of a floating industrial plant for hays. More particularly, the invention relates to a buoy for mooring a floating industrial plant to hays. The invention relates in particular to a mooring buoy for a floating wind turbine system. The invention relates in particular to a mooring buoy with a slack ring device for the transmission of high-voltage electrical power from a floating fabric to a stationary structure or vice versa.

A slap ring device comprises a stationary part and a movable part. One of the parts comprises one or more electrically conductive rings and the other part comprises an arrangement of an equal number of brushes in contact with the rings. The brush device may comprise a plurality of subsequent sets of brushes.

Either the ring part or the brush part can thus constitute the stationary part or the rotating part.

With high voltage in delta contexts, 12 to 36 kV must be understood. Normally, a power plant generates approximately 6 MW, which indicates that all the slapping device must be designed to transfer 100 to 300 A or more. The ground power of such an electric swivel may be high as the generation of three-phase power at 35 kV and 600 amperes per phase may be temporarily required.

BACKGROUND OF THE INVENTION Floating vessels with power generation capacity are used as a power source for equipment for hays. Such vehicles also include 6 floating wind turbines used for electric power generation. The vessel may be fortiijd at a buoy. A cable is laid cla from the buoy to the stable where power is needed. Winds and tides cause the floating vessel to turn in the wind direction around the buoy, which is fixed by anchoring means at the seabed. For this reason, an electric swivel is required for all transmission power generated on the vehicle to a non-rotating cable. A slap ring device may be mounted in an anchored buoy and used to transfer power from a floating power generation vehicle to a hays installation. An underwater cable is used Rile aft connect the slap ring to the installation. The slip ring acts as an electric swivel to allow the floating vessel to turn in the wind direction around the buoy, which may be necessary. The slip ring guides a plurality of high voltage phases through an open stack of rings to spaced apart brushes connected to the submarine cable. Since the weathering condition is harsh and the swivel can become flooded by water, the ring and brush device need to be protected against penetrating water.

According to a known slap ring device, the ring part and the brush part are placed in a container. Insulating oil then completely fills the container in which the ring stack is placed. The oil has an estimate voltage that is more than four times greater than the estimate voltage for air. As a result, the device can have smaller dimensions than what would otherwise be required. The insulating oil can be sampled, filtered and replaced without emptying the container. Access gates and display windows may allow additional maintenance to be performed on the ring without removing the outer surrounding house. In addition to the larger slack ring device, a larger volume of oil is needed.

A prior art high voltage swivel structure includes an annular outer member defining a cylindrical chamber about a longitudinal axis and an inner cylindrical member coaxial with the Ore member and rotatable relative to the outer member about said longitudinal axis. The inner and outer elements each comprise two axially spaced joints which are rotatable with the inner and inner elements. The conductors form two pairs placed with contact surfaces in the inboard electrical contact. A conductor in each pair is arranged at the inner element. The second conductor is arranged at the outer element and is connected to a respective voltage line. The voltage lines extend to an input terminal and an output terminal, respectively. The conductors are surrounded by an insulating material.

By US 4252388 a high power slapping device for transferring high bucket buckets is three phase power to hays previously known. The slap ring device comprises a slap ring mounted in a buoy for power transmission from a power generating vessel to an installation for hays. A vessel at the buoy can turn in the 2 wind direction around the buoy in response to wind and flow conditions. The conductors of the inner element, a rotor, consist of annular plates mounted on a central frame of the dielectric support, alternatively with washer-like dielectric barriers. The conductors of the outer element, a stator, consist of carbon brushes mounted in brush holders and are in contact with the conductive copper rings of the rotor contacts. The opening stack allows highly dielectric insulating oil to circulate through the stack, allowing smaller dimensions compared to air used as the dielectric medium.

U.S. Pat. No. 7,137,7822 discloses a high voltage swivel formerly known, the spirit of which is to provide a high voltage swivel with a compact and reliable construction which can be operated at relatively high voltages. In this case, the paddle voltage swivel comprises the electrical contacts of the outer element arranged in a recess in an annular fixed outer insulating ring. By using solid insulating material in the form of insulating rings, a high dielectric strength can be achieved as high voltages on the electrical contacts are possible, as voltages up to 33 kV at, for example, a ground current of 395 A. The use of the solid insulating material further allows the size and weight of the swivel can be reduced, thereby helping to limit the torque on the tower-shaped swivel stack.

As a result, reduced contamination of the insulating material through particles is achieved due to wear of the electrical contacts, so that the insulating properties are maintained during the life of the swivel.

In one embodiment, the conductors at the outer and inner members include annular contact surfaces. By using annular contact surfaces, instead of known carbon brushes, purification of dielectric oil in the swivel, which can be used within, for example, 11 kV, can be avoided. Dielectric oil is protected from overpressure, overtemperature and leakage via a Buchholz Relay unit which includes a compensation bellows which may allow thermally induced expansion and contraction of the dielectric oil. The present swivel is suitable for high voltages, such as 33 kV at currents of 395 A or higher.

US 6294844 is an artificial wind turbine comprising a framework on a number of platforms previously known. Each platform is connected to a rotatable raft 3 with the help of a bearing. A connecting piece is connected, via a bearing, to a branched raft. The raft is anchored to the hay or seabed through a number of anchoring cables. The connecting piece can rotate freely, via bearings, with respect to the said anchored raft.

The wind generator plant refers to a plant for the conversion of wind energy into electrical energy. The plant comprises a plurality of wind turbines provided with blades which rotate about a substantially horizontal axis. AxIn was carried up by layers in a gondola. The gondola also houses an electric generator. The horizontal axes extend substantially parallel to each other in such a way that said blade rotates in a substantially common plane. Floating bodies are attached to the framework and are intended to keep the installation afloat.

SUMMARY OF THE INVENTION A primary object of the present invention is to provide means for improving a mooring buoy which provides an underwater connection for a floating fabric.

This object is achieved according to the invention by means of a buoy can be characterized by the features of the independent claim 1 or by a method can be characterized by the steps in the independent claim 8. Preferred embodiments are described in the dependent claims.

According to the invention, the mooring buoy contains a slack ring device housed in an air pocket created by a diving bell construction. The diving bell construction includes an aerated chamber that is only open at the bottom. When immersed in water, a volume of air will be trapped in the chamber, which thus prevents water from entering the chamber. The slap ring part is held by insulators in the upper part of the air pocket and the brush part projects into the air pocket from the bottom tip. The electrical components inside the chamber are thus insulated by air.

In an embodiment of the invention, the chamber which holds the air pocket is designed as a ring structure which encloses the mooring buoy. The annular 4 chamber comprises an inner cradle, an outer cradle and a roof. The inner cradle includes a portion of the outer side of the buoy. The outer cradle includes a stable skirt attached to the buoy through the annular roof. Thus, the inner cradle and the outer cradle and the roof form a circular air pocket around the buoy. In one embodiment, a slap ring for the usual phase of electrical power is held by insulators at the upper part of the air pocket. The slack rings are connected to an electrical cable that is led to the inner part of the buoy through an aerated passage. The brush part is fixed to a belt structure below the annular chamber. The belt is stored around the buoy and includes arrangements for mooring the floating fabric.

In one embodiment, the mooring buoy is attached to the seabed by means of anchoring means. At least three anchor cables are fixed at anchorage points around the buoy just below the belt. In one embodiment, the buoy has air injectors with the aid of which the buoy can be raised or sunk in the sea. In a mooring situation, the buoy can be raised in the water so that the belt is positioned above sea level. The floating fabric can then be easily mechanically and electrically fastened at the buoy. After the floating fabric is mechanically crafted at the buoy, the electrical cable from the floating fabric can be connected to the brush portion of the belt through a watertight coupling device. In one embodiment, the brush part forms part of the floating fabric's mooring equipment and is raised to contact with the slack rings in the chamber.

According to a first aspect of the invention, the breathing needle is obtained by means of a buoy anchoring to hays for mooring a floating fabric having an electric cable. The buoy comprises a hollow cylindrical body with a mechanical mooring device and a slack ring device having a ring part and a brush part for high tension force twisting. The mechanical mooring device comprises a belt part which is mounted around a buoy and the slack ring device comprises an annular diving bell construction. In an embodiment of the invention, the ring part is fixed inside the diving bell construction and the brush part is fixed to the belt part and projects into the diving bell construction from below. In one embodiment, the ring part comprises a plurality of slack rings and the brush part comprises an equal number of brushes. In one embodiment, the annular diving bell construction includes an inner cradle, an outer cradle and a roof portion.

In one embodiment, the inner cradle comprises the cradle of the cylindrical buoy, the roof comprises a flat ring attached to the outer surface of the buoy and the outer cradle comprises a stable skirt which hangs down from the roof part. In one embodiment, an electrical cable from the buoyancy fabric is connected through a waterproof contact device on the belt and the electrical cable connected to the ring member passes through the inner cradle of the diving bell structure through a waterproof passage. In one embodiment, the brush member comprises a plurality of subsequent parallel brushes.

According to a second aspect of the invention, the breathing needle is obtained by a method of moving a floating fabric having an electric cable for high-buckle power struts to a buoy having a hollow cylindrical body with a mechanical conveying device and a slack ring device having a ring portion and brush portion. The procedure involved arranging an annular diving bell structure around the buoy to enclose the slack ring device, forcing the floating fabric to the buoy through a belt stored around the buoy, and connecting the cable to the slack ring device. In one embodiment, the arrangement of the annular diving bell structure comprises forming a waterproof chamber of an inner cradle, an outer cradle and a roof portion, enclosing the slack ring assembly by fixing the ring portion within the diving bell structure and fixing the brush portion to the belt portion, and the diving bell construction from below to aft come into contact with the slap rings.

BRIEF DESCRIPTION OF THE DRAWING FIGURES Other features and advantages of the present invention will become more apparent to those skilled in the art from the following detailed description when taken in conjunction with the accompanying drawings, in which: FIG. the invention, and Fig. 3 is a three-dimensional part of an embodiment of the tightening buoy. DESCRIPTION OF PREFERRED EMBODIMENTS A buoy according to the invention is shown in Fig. 1. The buoy comprises a hollow body 1 with a cylindrical cross section. The buoy is anchored at the seabed with a plurality of anchoring cables 2. In the embodiment shown, three anchoring cables are connected to an equal number of anchoring steers 3. The buoy further comprises a slack ring device 4 and a mooring device 5. Mooring device comprises a harness 6. GordeIn provides an andlOs rotation of a fortified floating fabric around the buoy. In the embodiment shown, the belt comprises two pins 7 for connecting a mooring arm 8 from the floating fabric. A first high power cable 9 from the floating fabric is connected to the slack ring device through a contact device (not shown). From the sleeper device the power is transmitted through a second high power cable 10 whose second spirit is connected to an installation on land. In the embodiment shown, the buoy comprises a platform 11 for work spaces or landing of a helicopter. In normal condition, the water level is W Over the mooring device and the slap ring device. In normal condition, both the propulsion device and the sleeper device are located underwater.

The buoy arrangement makes use of the fact that an underwater mooring of a floating fabric results in a more stable behavior of the floating fabric. The sea waves raise and lower otherwise the forehead of the floating fabric on an unfinished sail. Due to an underwater mooring, the waves have less influence on the movement of the floating fabric. When a floating fabric is to be moored, the buoy is first raised by pumping air into the hollow body, so that the mooring device is placed above sea level. The mooring arm and the first cable are connected by work performed on the water surface.

The buoy then sank down to the sift working position by gently relaxing air from the hollow body.

The slap ring device is shown in cross section in Fig. 2. The slap ring device comprises a ring part 15 and a brush part 16 housed in an annular diving bell construction 17. In the embodiment shown, the diving bell construction forms a waterproof chamber 18 comprising an inner rock 19, an outer rock 20 and an annular roof 21. The inner cradle and the outer cradle form an annular opening 22 which is water neat. The brush part comprises three brushes fixed by a solid insulator to a brush holder ring 23. The brush holder ring is mounted around the cylindrical surface of the buoy and connected to the mooring device 5 by a carrier.

The brushes are connected to a first high voltage cable 9. In the embodiment shown, the first cable comprises three phases. However, no number of phases can be present in the sleeper device. The ring part comprises three slack rings fastened through busbars to an insulator 24 attached to the cradle of the buoy. The insulator is formed with an insulated passage through the cradle to the inside of the buoy and through which the slack rings are connected to the second high voltage cable 9.

When immersed in the sea, the seawater freezes to penetrate through the opening 22 to the water-tight chamber 18 of the slapping ring device. An air pocket 25 will often be enclosed by the water-tight chamber and prevent the water from penetrating. Due to gas compression, the water 26 will rise to a certain level 27 inside the chamber, but most of the chamber will still be air-filled.

Even if the slap ring device sank into the sea at equally great depths, the diving bell construction will prevent water from entering the water-tight chamber. The electrical components in the chamber will thus often be air-insulated from each other. In response to hays, the buoy may tilt and water will penetrate the chamber to some extent. By aft constructing the outer and inner cradle of the chamber deeper, such water intrusion aft will be prevented. As a precautionary measure, an air inlet 28 can be inserted through which fresh air is forced into the chamber.

In the embodiment shown in Fig. 3, the first high voltage cable 9 is attached to the hinge part 6 of the mooring device 5. In this embodiment there are no contact devices. The first cable carried on its spirit after several brushes. These brushes are inserted into the chamber when mooring. The brush ring 23 is in this embodiment connected to the belt by a carrier arm 29.

In one embodiment, the dimension of the buoy is about four meters in diameter. The anchoring cables are made of reinforced plastic or carbon fiber. The anchoring cables can be in the order of 500 meters. In this example, the 8 annular waterproof chamber of the slap ring device is like a corridor about 12 meters in length.

The scope of the invention is not limited to the described embodiments, even if these are advantageous, but also contains embodiments obvious to a person skilled in the art. For example, the brush part may comprise a number of subsequent brushes for securing a sufficient resistance-free contact path through the slack ring device. The brush holder can include a number of shots for minimizing water intrusion into the chamber when the buoy is tilted. The outer cradle of the chamber may comprise a rubber skirt instead of a metal plate. The diving bell construction can be made of any formable material such as metal, rubber or plastic. 9

Claims (10)

PATENT REQUIREMENTS A buoy for mooring a floating fabric having a first electrical cable (9) comprising a hollow cylindrical body (1) having a mechanical mooring device (5) and a slack ring device (4) having a ring portion (15) and a brush portion (16). For high-span power transmission, the mechanical mooring device may comprise a girder member (6) mounted around the buoy, and the slack ring device comprises an annular diving bell structure (17). The buoy according to claim 1, wherein the ring part is fixed inside the diving bell construction and the brush part is fixed to the belt and projects into the diving bell construction from below. The buoy of claim 1 or 2, wherein the ring portion comprises a plurality of slack rings and the brush portion comprises an equal number of brushes. The buoy of any preceding claim, wherein the annular diving bell structure comprises an inner cradle (19), an outer cradle (20) and a roof portion (21). The buoy of claim 4, wherein the inner cradle comprises the cradle of the cylindrical buoy (1), the roof comprises a flat ring attached to the outer surface of the buoy and wherein the outer cradle comprises a stable skirt (20) hanging down from the roof portion . The buoy according to any of the preceding claims, wherein the first electrical cable (9) from the buoyancy fabric is connected by a waterproof contact device on the belt and a second electrical cable (10) connected to the ring member passes through the inner cradle of the diving bell structure through a waterproof insulator (24). The buoy according to any one of the preceding claims, wherein the brush part comprises a plurality of subsequent parallel brushes. A method of mooring a buoyancy fabric having a first electric cable (9) for high bucket power transmission to a buoy having a hollow cylindrical body (1) with a mechanical mooring device (5) and a slack ring device (4) having a ring portion (15). ) and a brush part (16), characterized by arranging around the buoy an annular diving bell construction (17) for enclosing the slack ring device, anchoring the floating fabric to the buoy through a belt part (6) stored around the buoy, and connecting the cable to the slack ring device. A method according to claim 8, wherein the arrangement of the annular diving bell structure comprises forming a waterproof chamber (18) of an inner cradle (19), an outer cradle (20) and a roof portion (21), enclosing the slack ring device by fixing the ring portion inside the watertight chamber and fix the brush part to the belt, and arrange everything so that all the brush part projects into the chamber from below so that all come into contact with the slack rings. Use of a buoy according to any one of claims 1 to 7 or a method according to claim 7 or 8 for the construction of a floating wind turbine in shallow water. 11 1/2