EP3950487B1 - Anchoring system for anchoring an offshore structure - Google Patents

Description

The application relates to an anchor system for anchoring an offshore structure, in particular a floating offshore structure, comprising at least one anchor device with at least one anchor base body. In addition, the application relates to an anchor set, a method, a use and an offshore system.

US2015/0360752 A1 reveals an anchor system with simplified installation and deinstallation.

To provide electrical energy from so-called renewable energy sources, wind energy systems with at least one wind turbine are increasingly being used. A wind turbine is designed in particular to convert kinetic wind energy into electrical energy.

In order to increase the energy yield of such systems, wind energy systems are arranged at locations with a high probability of wind. Offshore locations in particular are usually characterized by relatively continuous wind conditions and high average wind speeds, so that so-called offshore wind energy systems or offshore wind farms are increasingly being built.

As a rule, an offshore wind farm has a large number of offshore structures, such as a large number of offshore wind turbines and at least one offshore substation, via which the offshore wind farm is electrically connected, for example, to an onshore substation or another offshore substation or offshore converter station. An onshore substation can in turn be connected to a public power grid. To transmit electrical energy between two offshore structures or an offshore structure and an onshore structure, offshore energy cables are laid in the form of submarine cables.

While it has previously been common practice for offshore wind farms to be anchored to the underwater ground, in particular the seabed, by means of a foundation structure (e.g. monopile, tripod, triple or jacket foundations), there is increasing consideration of installing floating offshore structures, such as floating offshore wind energy structures, in order to install offshore wind farms, particularly in areas with a great water depth, for example more than 150 m.

In order to install the described floating or buoyant (but stationary during operation) offshore wind energy structures, but also other offshore structures (e.g. offshore structures for oil or gas exploration or production platforms), it is known to attach, in particular anchor, them to the underwater floor using anchor systems.

An anchor system usually has an anchor connection, for example in the form of an anchor chain, which is formed by a plurality of chain links. While one end of the anchor chain is attached to the offshore structure, the other end can be attached to an anchor device. In the installed operating state of the anchor system, the anchor device, which has at least one anchor base body, is embedded or buried in the underwater ground. This state of the anchor device can also be referred to as the anchoring state of the anchor device.

As already described, such anchoring devices are usually buried deep in the subsea floor during installation (and may sink further into the subsea floor during the course of their service life). If an offshore structure is uninstalled, or at least the anchoring system, it represents a major The challenge is to dig out the anchor device from the underwater floor.

Furthermore, the current technology can lead to the problem that due to the current or other events such as earthquakes, an anchoring device is no longer sufficiently anchored in the underwater floor, i.e. in particular, is no longer sufficiently buried in the underwater floor. This is a particular danger for the offshore structure, as inadequate anchoring can lead to damage to the offshore structure.

In order to bury or anchor an anchor device sufficiently securely in the underwater floor after it has "come to the surface", a considerable amount of effort and corresponding costs are required.

Therefore, the application is based on the object of providing an anchor system for anchoring an offshore structure in which the aforementioned disadvantages are at least reduced and in particular it is possible to dig out an anchor device and/or re-bury the anchor device in a simpler manner.

The object is achieved according to a first aspect of the application by an anchor system for anchoring an offshore structure according to claim 1, in particular for anchoring a floating offshore structure. The anchor system comprises at least one anchor device with at least one anchor base body. The anchor system comprises at least one flushing arrangement arranged in the anchor base body. The flushing arrangement has at least one inlet opening, set up to receive a flushing fluid. The flushing arrangement has at least one outlet nozzle connected to the inlet opening via a fluid channel, set up to discharge the flushing fluid received.

In contrast to the prior art, according to the application, an anchor system with an anchor device is provided in which the disadvantages of the prior art are at least reduced and in particular it is possible to dig out an anchor device and/or bury the anchor device again in a simpler manner. It has thus been recognized that by arranging a flushing device in or on the anchor device itself, the anchor device can be flushed out and/or flushed in if necessary.

By flushing the anchor device free, at least excavation of the anchor device from the underwater floor (in particular a sea floor) can be supported. By flushing the anchor device in, at least (re-)burying and thus restoring a secure anchoring of the anchor device in the underwater floor (in particular a sea floor) can be supported.

The anchor system according to the application is used for (particularly permanent) anchoring, i.e. in particular fastening, of at least one offshore structure to an underwater bed. Permanent means in particular that the offshore structure is anchored for at least longer than one month, preferably at least longer than one year (up to a maximum of the end of the operational life of the offshore structure).

Preferably, the anchor system is used to attach a floating offshore structure, preferably a floating offshore wind farm device, such as an offshore wind turbine, an offshore substation, an offshore measurement mast, etc., but also other offshore structures, such as offshore structures for oil or gas exploration or production platforms. A floating offshore structure can in particular have at least one floating body.

An offshore structure can be attached to the underwater bed via at least one anchor system as specified in the application, preferably a plurality of anchor systems.

An anchor system according to the application comprises at least one anchor device with at least one anchor base body. In variants of the application, an anchor device can also have two or more anchor base bodies.

The anchor device is designed to protrude at least partially into the underwater ground in an anchored state. Preferably, at least a large part (more than 50%) of the anchor base body can be located in the underwater ground in the anchored state.

The anchor device, in particular the anchor base body, preferably represents a weight element. The anchor device can be formed at least partially from a metal (e.g. steel) and/or at least partially from concrete.

Examples of anchoring devices that are not exhaustive are dead weight anchors, driven piles, torpedo anchors, drag anchors, suction piles and vertical load anchors.

According to the application, the anchor device has at least one flushing arrangement. The flushing arrangement is in particular integrated in the anchor base body, but can also be arranged at least partially on an outer side of the anchor base body.

The flushing arrangement has at least one inlet opening. The at least one inlet opening is designed to receive or receive a provided flushing fluid. The flushing fluid obtained can flow from the inlet opening via at least one fluid channel (preferably running through the anchor base body) to at least one outlet nozzle.

The at least one outlet nozzle is designed to discharge the flushing fluid, in particular to expel the flushing fluid. An outlet nozzle according to the application represents in particular the transition from the at least one fluid channel to the environment (e.g. underwater floor) of the anchor device. In particular, the transition of the fluid channel flow into the environment is influenced by the outlet nozzle.

Preferably, the (passive) outlet nozzle can be formed in such a way that the flushing fluid is accelerated (due to the pressure gradient), i.e. is ejected at an increased speed.

In particular, a conical jet of flushing fluid can be ejected through a correspondingly formed (jet) outlet nozzle. It is understood that other jet shapes can be provided and/or these can change depending on the fluid pressure.

An exit nozzle may have an exit opening with a diameter between 0.1 cm and 10 cm, preferably between 0.5 cm and 1.5 cm.

By expelling the flushing fluid through at least one outlet nozzle, the surrounding material (in particular sediment) can be softened, in particular liquefied, and thus the anchor device can be flushed out and/or washed in. This allows the anchor device to be lifted up or sunk deeper.

The flushing fluid provided is a gas and/or a liquid. According to one embodiment of the anchor system according to the application, the flushing fluid can be air and/or water, in particular sea water.

According to a further embodiment of the anchor system according to the application, the anchor system can comprise at least one elongated hollow supply body connected to the inlet opening (preferably in a fluid-tight manner). The elongated hollow supply body can be designed to supply the flushing arrangement with a flushing fluid, in particular to carry out a flushing process (e.g. flushing process or flushing process).

In particular, one end of the elongated hollow supply body is connected to the at least one inlet opening (preferably in a fluid-tight manner). The elongated hollow supply body can in particular be a hose (preferably a pressure hose) and/or a pipe (preferably a pressure pipe).

According to a further embodiment of the anchor system according to the application, the other end of the elongated hollow supply body can be guided upwards, in particular at least to above the water surface or waterline. The other end can preferably end at the offshore structure which is anchored to the underwater floor by the anchor system comprising this elongated hollow supply body. Such an arrangement enables the flushing arrangement, which is at least partially integrated in the anchor base body, to be supplied with a flushing fluid in a particularly simple manner when a flushing process is carried out.

According to a further embodiment of the anchor system according to the application, the other end of the elongate hollow supply body can be designed to be connected to a (mobile) pressurization device. In particular, the other end of the elongate hollow supply body can be connectable to the pressurization device such that the flushing fluid is conveyed through the elongate hollow supply body to the flushing arrangement.

The pressurizing device may in particular be a high-pressure pump to pump air and/or (sea) water under pressure through the elongated Supply hollow body to the flushing arrangement. In particular, the pressurization device can convey the flushing fluid through the supply hollow body at a pressure of more than 50 bar, in particular more than 120 bar, particularly preferably more than 220 bar (preferably between 500 bar and 2000 bar).

The pressurization device can be arranged on a watercraft or on the offshore structure (preferably temporarily). In particular in an offshore wind farm, the pressurization device can be supplied with electrical energy provided by the offshore wind farm. It is understood that the anchor system can comprise at least one (mobile) pressurization device.

According to a preferred embodiment of the anchor system according to the application, the anchor system can comprise at least one anchor connection. The anchor connection can preferably be an anchor cable or an anchor chain. The anchor connection can be designed to connect the offshore structure to the anchor device. In particular, one end of the anchor connection can be attached to the offshore structure (e.g. to the floating body of the offshore structure) and the other end of the anchor connection can be attached to the anchor device, in particular the anchor base body. The at least one anchor connection can in particular ensure the mechanical attachment of the offshore structure to the anchor device which is at least partially buried in the subsea floor.

In the present case, an anchor cable is in particular an elongated (in particular tubular) element which is at least partially formed from at least one natural fiber and/or synthetic fiber and/or at least one wire or wire cable. The anchor cable can preferably be made from metal, in particular steel, and/or plastic, in particular at least one fiber composite material. Two or more anchor cables can be provided which are twisted together.

In the present case, an anchor chain is in particular an elongated (in particular tubular) element which is formed from a plurality of (movable, interlocking or jointed) chain elements or links. A chain link can preferably be made of metal (e.g. steel). A chain link can be ring-shaped or oval-shaped.

Preferably, at least one supply hollow body guide can be attached to the anchor connection. The at least one supply hollow body guide can be designed to guide the elongated supply hollow body along the anchor connection.

The supply hollow body guide can be formed, for example, from one or more supply hollow body holders or holding element(s) which are designed to hold the at least one supply hollow body in such a way that it is guided along adjacent to the anchor connection (for example with a maximum distance of less than 0.5 m). In other words, the supply hollow body guide can provide a (defined) coupling between the at least one supply hollow body and the anchor connection, so that in particular the supply hollow body can run essentially axially parallel to the anchor connection in an anchored state.

Preferably, the supply hollow body (seen in the longitudinal direction of the anchor connection) can run along substantially the entire anchor connection. In other words, according to an embodiment of the anchor system according to the application, the at least one supply hollow body (in an anchored state) can preferably extend at least from a first end of the anchor connection, which can be attached to the offshore structure, to the further end of the anchor connection, which is connected to the anchor device. The supply hollow body can have a length that corresponds at least to the length of the anchor connection. As already described, the upper end can preferably be guided at least above the waterline in order to enable coupling to a pressurization device in a simple manner.

The supply hollow body guide can in principle be formed in any way (for example, comprise a tubular element in which the supply hollow body is guided), as long as the supply hollow body guide can provide a (mechanical) coupling between the anchor connection and the supply hollow body to be guided.

According to a preferred embodiment of the anchor system according to the application, the supply hollow body guide can be formed by a plurality of eyelets. An eyelet can be attached to the anchor connection, for example welded or soldered. The eyelet can preferably be made of metal, in particular steel. In particular, the eyelet can be made of the same material as the chain link.

For example, an eyelet can have a ring-shaped or oval shape. A mechanical coupling can be achieved by guiding the at least one supply hollow body through the respective opening/recess of the plurality of eyelets. The supply hollow body can be guided directly adjacent to the anchor connection in a simple and safe manner.

The advantage of eyelets as a supply hollow body guide lies in the fact that a virtually contactless supply hollow body guide can be provided. In particular, by providing eyelets on the anchor connection in which the supply hollow body to be guided can be movably mounted, stress states, in particular in the form of tensile and/or shear forces, on the supply hollow body can be avoided or at least reduced. Stress states can occur in particular due to movements of the anchor connection. An anchor connection in the attached state is in (almost) constant movement and can either be under tension or sag to the maximum in certain sea conditions. In order to cover all of these conditions, a virtually contactless supply hollow body guide is desirable, which can be achieved in particular by the eyelet solution described. When using eyelets, the supply hollow body can run freely along an anchor connection regardless of the respective anchor connection position and can follow changes in the anchor connection without damage.

Preferably, the ratio of the (minimum) inner diameter of an eyelet to the (minimum) outer diameter of the supply hollow body to be guided can be at least greater than 1.1, preferably at least greater than 1.5, particularly preferably at least greater than 2. Furthermore, the ratio of the (minimum) inner diameter of an eyelet to the (minimum) outer diameter of the supply hollow body to be guided can be at least less than 10, preferably at least less than 5, particularly preferably at least less than 4. This allows the supply hollow body to be guided along the anchor connection with play. In a simple manner, sufficient coupling and at the same time a virtually contactless supply hollow body guide can be provided. The risk of damage to the supply hollow body can be reduced.

According to a further embodiment of the anchor system according to the application, in the case of an anchor chain as the anchor connection, between two adjacently arranged eyelets between one and ten chain links without an eyelet (arranged on this at least one chain link) can be provided, preferably between one and five chain links, particularly preferably between one and two chain links In. Particularly preferably, every second chain link (in the case of a rope, an analogous distance can be provided) can be provided with an eyelet. This can ensure that the supply hollow body is sufficiently close along the (almost) entire length of the anchor chain can be guided safely.

The flushing arrangement can preferably have two or more outlet nozzles. According to a further embodiment of the anchor system according to the application, the at least one outlet nozzle can be directed essentially downwards (i.e. in a vertical direction pointing away from the water surface) when the anchor device is anchored. The at least one outlet nozzle can preferably be arranged on or in an underside of the anchor base body, preferably in the middle of the underside. In other variants of the application, two or more outlet nozzles can also be arranged on the underside.

Alternatively or additionally, the at least one outlet nozzle can be directed substantially in a horizontal direction in an anchoring state of the anchor device. Preferably, the at least one outlet nozzle can be arranged on or in a side wall of the anchor base body.

According to a particularly preferred embodiment of the anchor system according to the application, at least two outlet nozzles directed in essentially opposite horizontal directions can be provided on or in the anchor device. In particular, the at least two outlet nozzles can be arranged on opposite side walls. A corresponding arrangement of the outlet nozzles is particularly preferred for a flushing process.

Preferably, a plurality of outlet nozzles directed in different horizontal directions can be arranged, which lie in a substantially identical horizontal plane and can preferably have the same angle (between adjacent outlet nozzles) to one another. This means, for example: With two nozzles, an angle of essentially 180° can be provided between two adjacent nozzles. With three nozzles, an angle of Substantially 120° between two adjacent nozzles can be provided. With four nozzles, an angle of substantially 90° can be provided between two adjacent nozzles. Etc.

According to a particularly preferred embodiment of the anchor system according to the application, the flushing arrangement can be operated in a flushing mode and in a flushing mode. In other words, a corresponding anchor device can be both (re)buried and dug out by means of the flushing arrangement.

In the flushing mode, the flushing arrangement can be set up such that the at least one downwardly directed outlet nozzle and the at least one outlet nozzle directed in a horizontal direction (preferably two outlet nozzles directed in opposite horizontal directions) discharge the flushing fluid. Preferably, in this operating mode, all outlet nozzles can be supplied with flushing fluid from the at least one inlet opening via one or more fluid channels, such that the flushing fluid is (uniformly) discharged through all outlet nozzles.

It has been recognized that in order to restore sufficient anchoring of the anchor device, i.e. in particular to support deeper digging of the anchor device, only the downwardly directed outlet nozzles should be operated. According to one embodiment, it can therefore be provided that in the flushing mode, the flushing arrangement is set up such that only the at least one downwardly directed outlet nozzle discharges the flushing fluid (i.e. the nozzle(s) directed in the horizontal direction(s) do not discharge any flushing fluid).

In other variants, the design of the flushing arrangement may also depend on the installation location of the offshore structure. If an installation area is an earthquake risk area, an anchor device with a flushing arrangement with flushing mode (and flush-free mode) can be used, whereas in an installation area where (almost) no earthquakes occur (and there is no other risk of excavation of an anchor device during operation of the anchor system), the anchor device can only have a flushing arrangement with flush-free mode (without flushing mode).

According to a further embodiment of the anchor system according to the application, the anchor system can comprise at least one valve mechanism. The valve mechanism can in particular be arranged in the at least one fluid channel.

The valve mechanism can be adjustable at least between a free-flushing position and a flushing position. In the free-flushing position, the flushing fluid can flow to the at least one downward-facing outlet nozzle and the at least one outlet nozzle directed in a horizontal direction. In the flushing position, the flushing fluid can only flow to the at least one downward-facing outlet nozzle (but not to the horizontally oriented outlet nozzles).

The valve mechanism can in particular be a mechanically controllable mechanism. For example, a cable mechanism (preferably guided along the supply hollow body) can be provided, which enables the valve mechanism to be adjusted at least between the flushing position and the flushing position. The cable mechanism can in particular be actuated by the offshore structure or a watercraft. The actuation can in particular be triggered by a user. It goes without saying that other valve mechanisms and/or control mechanisms are conceivable. For example, if a communication connection to a sensor (or the like) provided in the anchor device is already present, the valve mechanism can also be controlled via this.

In particular, as an alternative to the valve mechanism (but also in addition thereto), according to a further embodiment of the anchor system according to the application, the flushing arrangement (of the anchor device) can have at least one first inlet opening connected to (at least one first downwardly directed outlet nozzle and) at least one first outlet nozzle directed in a horizontal direction via at least one first fluid channel. The flushing arrangement (of this anchor device) can have a second inlet opening connected to at least one second downwardly directed outlet nozzle via at least one second fluid channel.

In this embodiment, a first elongated hollow supply body can be provided which is connected to the first inlet opening, and a second hollow supply body which is connected to the second inlet opening. Depending on whether a flushing process or a free-flushing process is to take place, the flushing fluid can be supplied via the first hollow supply body to the at least one first outlet nozzle and/or via the second hollow supply body to the at least one second outlet nozzle. During a flushing process, flushing fluid is supplied in particular only via the second hollow supply body, while during a flushing process flushing fluid is only supplied to both hollow supply bodies. If the flushing arrangement of the anchor device has at least one first inlet opening connected to at least one first downward-facing outlet nozzle and at least one first outlet nozzle directed in a horizontal direction via at least one first fluid channel, the flushing fluid can also only be supplied via the first hollow supply body during a free-flushing process.

Without the need for a valve mechanism (which may still be functional after 20 years), a flushing arrangement can be provided that can operate in two different operating modes.

According to the invention, the at least one outlet nozzle has an openable closure element.

It has been recognized that over the course of the operating time of an anchor device, the at least one outlet nozzle can become clogged with the material of the underwater ground surrounding the anchor device. This can at least impair the functionality of the flushing arrangement. In order to at least reduce this risk, it is proposed to provide the at least one outlet nozzle with a closure element which can be opened when required, i.e. when a flushing process is to be carried out. In particular, the closure element can be arranged on or in the outlet opening of the outlet nozzle and thus in particular prevent soil material from penetrating the outlet nozzle when it is closed.

In principle, the at least one openable closure element can be designed in any way, as long as it can be opened at least once if necessary. According to a preferred embodiment of the anchor system according to the application, the openable closure element can be set up in such a way that the openable closure element opens when a certain fluid pressure limit value (measured in front of the openable closure element) is exceeded. In other words, if the flushing fluid introduced into the flushing device under pressure exceeds a certain fluid pressure limit value, then the closure element opens so that the flushing fluid is expelled. The fluid pressure limit value or the corresponding closure element is selected in particular depending on the pressure conditions at the installation location of the anchor device (in particular depending on the water depth) and the flushing fluid pressure that can be generated.

In particular, if the flushing arrangement is to be used only once (e.g. for a flushing process), a bursting disk or a bursting membrane can be provided as an openable closure element, which is destroyed when the fluid pressure limit is exceeded, so that the flushing fluid is expelled. This enables the nozzle opening to be covered with particularly simple means. It is possible to reuse the flushing arrangement by renewing or replacing the bursting disc or the bursting membrane.

In particular, if the flushing arrangement is to be used several times (e.g. for flushing processes and a flushing process), a mechanical mechanism (e.g. flap mechanism) with a reset element can be provided as an openable closure element. Such a closure element makes it possible in particular for the opening to be closed again after the closure element has been opened. In particular, if the force exerted by the flushing fluid pressure on the mechanism (e.g. the flap) exceeds the force exerted by the reset element, the closure element is opened. If the flushing fluid pressure or the resulting force then falls below the reset force, the reset element causes the closure element to close (again). It goes without saying that other mechanisms that operate in a similar way can be used.

Another subject of the application is an anchor set. The anchor set comprises at least one anchor system as described above (in particular according to claim 1). The anchor set comprises at least one elongated (in particular as described above) supply hollow body that can be connected to at least one inlet opening of a flushing arrangement of an anchor device of the anchor system.

• Injizieren, unter Druck, eines Spülfluids in mindestens einen mit mindestens einer Eingangsöffnung einer Spülanordnung der Ankervorrichtung des Ankersystems verbundenen länglichen Versorgungshohlkörper.

A further aspect of the application is a method for flushing, in particular flushing or flushing, an anchor device of a previously described anchor system. The method comprises:

• Injecting, under pressure, a flushing fluid into at least one elongated hollow supply body connected to at least one inlet opening of a flushing arrangement of the anchor device of the anchor system.

The method is used in particular to carry out a previously described rinsing process.

Yet another aspect of the application is a use of a previously described anchor system for flushing out at least one anchor device of the anchor system and/or for flushing in at least one anchor device of the anchor system.

A further aspect of the application is an offshore system comprising at least one offshore structure, in particular a floatable offshore structure, and at least one anchor system as described above.

The features of the anchor systems, anchor sets, methods, uses and offshore systems can be freely combined with one another. In particular, features of the description and/or the dependent claims can be independently inventive, even if they completely or partially bypass features of the independent claims, either alone or freely combined with one another.

Fig. 1

eine schematische Ansicht eines Ausführungsbeispiels eines Ankersystems gemäß der vorliegenden Anmeldung,

Fig. 2

eine schematische Ansicht eines Ausführungsbeispiels eines Offshore-Systems gemäß der vorliegenden Anmeldung mit einem weiteren Ausführungsbeispiel eines Ankersystems gemäß der vorliegenden Anmeldung,

Fig. 3

eine schematische Teilansicht eines weiteren Ausführungsbeispiels eines Ankersystems gemäß der vorliegenden Anmeldung,

Fig. 4

eine schematische Teilansicht eines weiteren Ausführungsbeispiels eines Ankersystems gemäß der vorliegenden Anmeldung,

Fig. 5

eine schematische Teilansicht eines weiteren Ausführungsbeispiels eines Ankersystems gemäß der vorliegenden Anmeldung,

Fig. 6

eine schematische Ansicht eines weiteren Ausführungsbeispiels eines Ankersystems gemäß der vorliegenden Anmeldung,

Fig. 7

eine schematische Ansicht eines weiteren Ausführungsbeispiels eines Ankersystems gemäß der vorliegenden Anmeldung, und

Fig. 8

ein Diagramm eines Ausführungsbeispiels eines Verfahrens gemäß der vorliegenden Anmeldung.

There are now a number of possibilities for designing and further developing the anchor system according to the application, the anchor set according to the application, the method according to the application, the offshore system according to the application and the use of an anchor system according to the application. In this regard, reference is made on the one hand to the patent claims subordinate to the independent patent claims and on the other hand to the description of embodiments in conjunction with the drawing. The drawing shows:

Fig.1

a schematic view of an embodiment of an anchor system according to the present application,

Fig.2

a schematic view of an embodiment of an offshore system according to the present application with a further embodiment of an anchor system according to the present application,

Fig.3

a schematic partial view of another embodiment of an anchor system according to the present application,

Fig.4

a schematic partial view of another embodiment of an anchor system according to the present application,

Fig.5

a schematic partial view of another embodiment of an anchor system according to the present application,

Fig.6

a schematic view of another embodiment of an anchor system according to the present application,

Fig.7

a schematic view of another embodiment of an anchor system according to the present application, and

Fig.8

a diagram of an embodiment of a method according to the present application.

In the figures, the same reference numerals are used for the same elements. Furthermore, z denotes the vertical direction and x the horizontal direction.

The Figure 1 shows a schematic (sectional) view of an embodiment of an anchor system 100 according to the present application. The anchor system 100 comprises at least one anchor device 102 with at least one anchor base body 104. According to the application, the anchor device 102 comprises at least one flushing arrangement.

As from the Figure 1 As can be seen, the at least one flushing arrangement 106 can be integrated in the anchor base body 104 (eg made of metal, such as steel, and/or concrete). The flushing arrangement 106 has at least one inlet opening 108 to receive flushing fluid. In other words, the flushing arrangement 106 can be supplied with flushing fluid via the inlet opening 108.

The flushing fluid can flow to the at least one outlet nozzle 110 via at least one fluid channel 112 running through the anchor base body 104 (in other variants, this can also run at least partially along an outer wall of the anchor base body). The outlet nozzle 110 is in particular aligned in a horizontal direction x and in this case is arranged on a side wall 138 of the anchor base body 104.

As can be seen, the outlet nozzle 110 represents in particular the transition from the at least one fluid channel 112 to the environment (eg underwater floor) of the anchor device 102. In particular, the transition of the fluid channel flow into the environment is influenced by the outlet nozzle 110. Preferably, the outlet nozzle 110 can be formed in such a way that the flushing fluid is accelerated (due to the pressure gradient) and in particular is ejected at a high speed for a flushing process. In particular, a conical fluid jet (as in the Figure 1 indicated).

The shape of the anchor base body 104 is shown here (and also in the other embodiments) only schematically for the sake of a better overview. Exemplary and non-exhaustive anchor devices that can comprise at least one (according to the application) flushing arrangement 106 are dead weight anchors, driven piles, torpedo anchors, drag anchors, suction piles and vertical load anchors. In particular, a flushing arrangement according to the application can be attached or installed, in particular integrated, in each of these anchor devices.

The Figure 2 shows a schematic view of an embodiment of an offshore system 201 according to the present application with a further Embodiment of an anchor system 200 according to the present application. To avoid repetition, only the differences from the previous embodiment are explained below and otherwise reference is made to the previous explanations.

The offshore system 201 comprises at least one floating offshore structure 226, which is attached, in particular anchored, to the underwater floor 214 by at least one anchor system 200, preferably by at least two anchor chain systems (particularly preferably four anchor systems 200 can be provided). Here, the reference number 216 designates the floor surface, in particular the sea floor surface, the reference number 218 the water surface or waterline, in particular the sea surface, and the reference number 219 the fluid flow direction during a flushing process.

The offshore structure 226 is in particular a floating offshore structure 228 with a wind turbine 228 arranged on at least one floating body 230.

In the present case, one end of an anchor connection 234 is attached to the floating body 230. The other end of the anchor connection 234 is attached to an anchor device 202, in particular to the anchor base body 204. It is understood that two or more anchor connections can also be arranged.

By way of example, the anchor connection in the present case is an anchor chain 234. It is understood that alternatively or additionally an anchor rope can be provided as an anchor connection.

In other variants of the application, several offshore structures can be attached to one anchor device (e.g. in the form of a foundation), for example four offshore structures.

In further variants of the application, an anchor device can have a monitoring device (not shown). The monitoring device is set up in particular to monitor the structural and/or mechanical state of an anchor device and can, for example, comprise at least one sensor (e.g. motion sensor, vibration sensor, etc.). This can in particular detect whether the anchor device needs to be (re)flushed. This can be the case, for example, if it is determined (e.g. through the sensor signals) that the anchor device has loosened too much (at least one suitable limit value can be set) and/or has lifted too much (at least one suitable limit value can be set).

As can be seen, the anchor system 200 comprises at least one elongated hollow supply body 220. The elongated hollow supply body 220 is, for example, a hose 220. It is understood that alternatively or additionally a pipe or the like can be provided.

The elongated hollow supply body 220 serves to supply the flushing arrangement 206 with flushing fluid. For this purpose, one end 224 of the elongated hollow supply body 220 can be connected (at least temporarily) to a (mobile) pressurization device 232, in particular in a fluid-tight manner. For example, a high-pressure pump 232 can be provided which sucks in seawater and/or air and passes it on under pressure through the hollow supply body 220 as flushing fluid to the flushing arrangement. For this purpose, the other end 222 of the hollow supply body 220 is connected to the inlet opening 208, in particular in a fluid-tight manner.

As can be seen, the upper end 224 of the hollow supply body 220 is preferably located above the waterline 218, in particular in or on the offshore structure 226. For example, the pressurization device 232 can be temporarily arranged in or on the offshore structure 226, at least when required, i.e. when a flushing process is to take place. In other variants of the application The pressurization device can also be arranged on a watercraft.

The at least one elongated supply hollow body 220 is guided in particular by at least one supply hollow body guide 236 along the anchor connection 234, as will be described in more detail by way of example with the aid of the Figure 3 is explained.

In the present case, the flushing arrangement 206 comprises (at least) two outlet nozzles 210.1, 210.2 directed in substantially opposite horizontal directions x, which are provided on or in the anchor device 202. In particular, the at least two outlet nozzles 210.1, 210.2 can be arranged on opposite side walls 238.1, 238.2 of the anchor base body 204.

The anchor device 202 is shown here in an anchored state. In this state, the anchor device 202 is at least partially, preferably predominantly (as shown), for example completely, buried or embedded in the underwater ground 214. As can be seen, at least the outlet nozzles 210.1, 210.2 can be completely surrounded by the ground material 214.

The Figure 3 shows a schematic partial view of another embodiment of an anchor system 300 according to the present application. To avoid repetition, only the differences from the previous embodiments are explained below and otherwise reference is made to the previous explanations.

As can be seen, a supply hollow body guide 336 is attached to the anchor connection 334 formed as an anchor chain 334, which in the preferred embodiment shown is formed in particular by a plurality of ring-shaped eyelets 336. An eyelet 336 can be attached to a chain link 342.1, 342.3, for example by means of welding, soldering, etc. A (mechanical) coupling between the anchor chain 334 and the supply hollow body 320 can be achieved by guiding the supply hollow body 320 to be guided through the respective opening of the plurality of eyelets 336 (in the fastened state). In a simple and safe manner, a supply hollow body 320 to be guided can be guided directly adjacent to the anchor chain 333.

In particular, the supply hollow body guide 336 is configured such that the supply hollow body 320 is guided along the anchor chain 334 at a maximum distance 346 (preferably less than 0.1 m).

Preferably, the ratio of the (minimum) inner diameter 348 of an eyelet 336 to the (minimum) outer diameter 344 of the supply hollow body 320 to be guided can be at least greater than 1.1, preferably at least greater than 1.5, particularly preferably at least greater than 2.

Furthermore, the ratio of the (minimum) inner diameter 348 of an eyelet 336 to the (minimum) outer diameter 344 of the supply hollow body 320 to be guided can be at least less than 10, preferably at least less than 5, particularly preferably at least less than 4. As a result, the supply hollow body guide 320 can be guided along the anchor chain 334 with play. The risk of damage to the supply hollow body 320 can be reduced.

In particular, with such a supply hollow body guide 336, it is achieved that the supply hollow body guide 320 can be guided along the anchor chain 334 without stress conditions occurring that could damage the supply hollow body 320, in particular tear it, since the supply hollow body 320 is movably mounted within an eyelet 336. In other words, the provision of eyelets 336 in particular enables the supply hollow body 320 to be guided along the anchor chain 334 in a virtually contactless manner.

As can also be seen, between two adjacently arranged eyelets 336 there is (exactly) one chain link 342.2 without an eyelet arranged on this at least one chain link 342.2. In other words, in the present preferred example, every second chain link 342.1, 342.3 can be provided with an eyelet 336. This allows the maximum distance between the supply hollow body 320 and the anchor chain 334 to be kept particularly small (less than 0.05 m). It goes without saying that in other variants only every third chain link, every fourth chain link, etc. can be provided with an eyelet.

The Figure 4 shows a schematic (sectional) partial view of another embodiment of an anchor system 400 according to the present application. To avoid repetition, only the differences from the previous embodiments are explained below and otherwise reference is made to the previous explanations.

In this embodiment, a (one-time) openable closure element 450 is arranged on or in the outlet opening of the outlet nozzle 410. In the closed state shown, the closure element 450 prevents the surrounding material, in particular sediment, from entering the outlet nozzle 410 and clogging it.

In the present case, the closure element 450 is formed, for example, as a bursting disk 450. This bursts when the fluid pressure in the fluid channel 412 is above the fluid pressure limit value of the bursting disk 450. A bursting disk can be used in particular in outlet nozzles 410 which serve (exclusively) to flush out the anchor device 402.

The Figure 5 shows a schematic (sectional) partial view of another embodiment of an anchor system 500 according to the present application. To avoid repetition, only the Differences to the previous embodiments are explained and otherwise reference is made to the previous explanations.

In the present case, the closure element 550 is formed, for example, as a flap mechanism 550 with a return element 552. If the force exerted by the flushing fluid pressure on the mechanism 550 (e.g. the flap 550) exceeds the force exerted by the return element 552 on the flap mechanism in the opposite direction, the closure element 550 is opened.

If the flushing fluid pressure or the force resulting therefrom falls below the restoring force, the restoring element 552 causes the closure element 550 to close (again). It is understood that other mechanisms that operate in a similar manner can be used. Such a mechanism can be used in particular in outlet nozzles 510, which at least also serve to flush in the anchor device 502 and in particular are intended to be used several times.

The Figure 6 shows a schematic (sectional) view of another embodiment of an anchor system 600 according to the present application. To avoid repetition, only the differences from the previous embodiments are explained below and otherwise reference is made to the previous explanations.

The anchor device 602 comprises a flushing arrangement 606 which enables both flushing and free flushing of the anchor device 602. In other words, the present flushing arrangement 602 can be operated in a free flushing mode and in a flushing mode.

The flushing arrangement 606 of the anchor device 602 has in the present case at least one first outlet nozzle 610.1 directed downwards (this can also be omitted in other variants of the application) and at least one first outlet nozzle 611.1 directed in a horizontal direction (in this case two outlet nozzles 611.1 arranged on opposite sides) has an inlet opening 608.1 connected via at least one first fluid channel 612.1. A first elongated hollow supply body 620.1 is provided in particular, which is connected to the first inlet opening 608.1 (fluid-tight).

The flushing arrangement 606 of this anchor device 602 can have a second inlet opening 608.2 connected to at least one second downwardly directed outlet nozzle 610.2 via at least one second fluid channel 612.2. Furthermore, a second supply hollow body 620.2 can be provided, which is connected to the second inlet opening 608.2.

Depending on whether a flushing process or a flushing process is to take place, the flushing fluid can be supplied via the first hollow supply body 620.1 to the at least one first outlet nozzle 610.1, 611.1 or via the second hollow supply body 620.2 to the at least one second outlet nozzle 610.2 (or via both hollow supply bodies 620.1, 620.2, in particular if no first downward-directed outlet nozzles 610.1 are present).

As can be seen, the first and the second supply hollow body 620.1, 620.2 can be guided along the at least one anchor connection 634 using (previously described) supply hollow body guides 636.1, 636.2.

Furthermore, in the present case the outlet nozzles 611.1, 611.2 are aligned in the horizontal direction x and are arranged in particular in the side walls 638.1, 638.2. In the present example, the outlet nozzles 610.1, 610.2 are directed downwards and are arranged in particular in the base 638.3 of the anchor base body 604.

The Figure 7 shows a schematic view of another embodiment of an anchor system 700 according to the present application. To avoid repetition, only the differences to the previous embodiments and otherwise reference is made to the previous explanations.

In particular, a valve mechanism 760 is provided here, which allows the flushing arrangement 706 to be operated in a flushing mode and in a flushing mode. The valve mechanism 760 is designed here, for example, as an adjustable flap mechanism 760.

The valve mechanism 760 can be switched at least between a flush position and a (in the Figure 7 shown) induction position can be adjusted.

In the flushing position, the flushing fluid can flow to the at least one downwardly directed outlet nozzle 710.2 and the at least one outlet nozzle 710.1 directed in a horizontal direction through the at least one fluid channel 712.

In the illustrated flushing position, the flushing fluid can only flow to the at least one downward-facing outlet nozzle 710.2. The fluid path to the at least one outlet nozzle 710.1 directed in a horizontal direction is blocked in the flushing position by the valve mechanism 760.

It is understood that two or more downwardly directed outlet nozzles can be provided to which the flushing fluid can flow in a flushing position. As can be seen, however, the fluid path to the horizontally oriented outlet nozzles 710.1 is blocked by the valve mechanism 760.

The valve mechanism 760 can in particular be a mechanically controllable mechanism. For example, a cable mechanism 762 (eg guided along the supply hollow body) can be provided, which enables an adjustment of the valve mechanism 760 at least between the positions mentioned. The cable mechanism 762 can in particular be controlled by the offshore structure or a The valve can be actuated by a watercraft. The actuation can be triggered in particular by a user. It goes without saying that other valve mechanisms are conceivable.

The Figure 8 shows a diagram of an embodiment of a method according to the present application. Preferably, the method can be used to operate an anchor system according to one of the previous embodiments

In an optional first step 801, a (mobile) pressurization device is coupled to at least one supply hollow body. In particular, a mobile pressurization device can initially be provided, for example by a watercraft or a helicopter.

In step 802, a flushing fluid is injected under pressure into the elongated hollow supply body connected to at least one inlet opening of a flushing arrangement of the anchor device of the anchor system. In other words, a flushing process is carried out, such as a flushing process or a flushing process.

The pressurization device can then be dismantled again. In addition, a flushed anchor device can be lifted.

Claims (13)

1. Anchoring system (100, 200, 300, 400, 500, 600, 700) for anchoring an offshore structure (226), in particular a floatable offshore structure (226), comprising:

   - at least one anchor device (102, 202, 402, 502, 602, 702) with at least one anchor base body (104, 204, 404, 504, 604, 704),

   - at least one flushing arrangement (106, 206, 406, 506, 606, 706) arranged in the anchor base body (104, 204, 404, 504, 604, 704),

   - wherein the flushing arrangement (106, 206, 406, 506, 606, 706) comprises at least one inlet opening (108, 208, 608, 708) configured to receive a flushing fluid,

   - wherein the flushing arrangement (106, 206, 406, 506, 606, 706) comprises at least one outlet nozzle (110, 210, 410, 510, 610, 710) connected to the inlet opening (108, 208, 608, 708) via a fluid channel (112, 212, 412, 512, 612, 712) and configured to output the received flushing fluid,
   characterized in that

   - the at least one outlet nozzle (110, 210, 410, 510, 610, 710) comprises an openable closure element (450, 550).
2. Anchoring system (100, 200, 300, 400, 500, 600, 700) according to claim 1, characterized in that

   - the anchoring system (100, 200, 300, 400, 500, 600, 700) comprises at least one elongate hollow supply body (220, 320, 620) connected to the inlet opening (108, 208, 608, 708) and configured to supply the flushing arrangement (106, 206, 406, 506, 606, 706) with the flushing fluid.
3. Anchoring system (100, 200, 300, 400, 500, 600, 700) according to claim 2, characterized in that the anchoring system (100, 200, 300, 400, 500, 600, 700) comprises

   - at least one anchor connection (234, 334, 634) configured to connect the offshore structure (226) to the anchor device (102, 202, 402, 502, 602, 702), and

   - at least one supply hollow body guide (236, 336, 636) attached to the anchor connection (234, 334, 634), arranged to guide the elongate supply hollow body (220, 320, 620) along the anchor connection (234, 334, 634).
4. Anchoring system (100, 200, 300, 400, 500, 600, 700) according to one of the preceding claims, characterized in that

   - the at least one outlet nozzle (110, 210, 410, 510, 610, 710) is directed substantially downwards in an anchoring state of the anchor device (102, 202, 402, 502, 602, 702),
   and/or

   - the at least one outlet nozzle (110, 210, 410, 510, 610, 710) is directed substantially in a horizontal direction in an anchoring state of the anchor device (102, 202, 402, 502, 602, 702).
5. Anchoring system (100, 200, 300, 400, 500, 600, 700) according to one of the preceding claims, characterized in that

   - at least two outlet nozzles (110, 210, 410, 510, 610, 710) directed in substantially opposite horizontal directions are provided.
6. Anchoring system (100, 200, 300, 400, 500, 600, 700) according to one of the preceding claims, characterized in that

   - the flushing arrangement (106, 206, 406, 506, 606, 706) is operable in a free flushing mode and in a flushing in mode,

   - wherein in the free-flushing mode the flushing arrangement (106, 206, 406, 506, 606, 706) is configured in such a way that the at least one downwardly directed outlet nozzle (110, 210, 410, 510, 610, 710) and the at least one outlet nozzle (110, 210, 410, 510, 610, 710) directed in a horizontal direction output the flushing fluid,

   - wherein in the flushing in mode the flushing arrangement (106, 206, 406, 506, 606, 706) is configured in such a way that only the at least one downwardly directed outlet nozzle (110, 210, 410, 510, 610, 710) outputs the flushing fluid.
7. Anchoring system (100, 200, 300, 400, 500, 600, 700) according to claim 6, characterized in that

   - the anchoring system (100, 200, 300, 400, 500, 600, 700) comprises at least one valve mechanism (760),

   - wherein the valve mechanism (760) is adjustable at least between a free flushing position and a flushing in position,

   - wherein in the free flushing position the flushing fluid can flow to the at least one downwardly directed outlet nozzle (110, 210, 410, 510, 610, 710) and the at least one outlet nozzle (110, 210, 410, 510, 610, 710) directed in a horizontal direction, and

   - wherein, in the flushing in position, the flushing fluid can only flow to the at least one downwardly directed outlet nozzle (110, 210, 410, 510, 610, 710).
8. Anchoring system (100, 200, 300, 400, 500, 600, 700) according to claim 6 or 7, characterized in that

   - the flushing arrangement (106, 206, 406, 506, 606, 706) comprises at least one first inlet opening (108, 208, 608, 708) connected to at least one first outlet nozzle (110, 210, 410, 510, 610, 710) directed in a horizontal direction via at least one first fluid channel (112, 212, 412, 512, 612, 712), and

   - the flushing arrangement (106, 206, 406, 506, 606, 706) comprises a second inlet opening (108, 208, 608, 708) connected to at least one second downwardly directed outlet nozzle (110, 210, 410, 510, 610, 710) via at least one second fluid channel (112, 212, 412, 512, 612, 712).
9. Anchoring system (100, 200, 300, 400, 500, 600, 700) according to one of the preceding claims, characterized in that

   - the openable closure element (450, 550) is configured such that the openable closure element (450, 550) opens when a certain fluid pressure limit value is exceeded.
10. Anchoring set, comprising

    - at least one anchoring system (100, 200, 300, 400, 500, 600, 700) according to claim 1, and

    - at least one elongate supply hollow body (220, 320, 620) connectable to at least one inlet opening (108, 208, 608, 708) of a flushing arrangement (106, 206, 406, 506, 606, 706) of an anchor device (102, 202, 402, 502, 602, 702) of the anchoring system (100, 200, 300, 400, 500, 600, 700).
11. Method for flushing, in particular free flushing or flushing in, an anchor device (102, 202, 402, 502, 602, 702) of an anchoring system (100, 200, 300, 400, 500, 600, 700) according to one of the preceding claims 1 to 9, comprising:

    - injecting, under pressure, a flushing fluid into at least one elongate hollow supply body (220, 320, 620) connected to at least one inlet opening (108, 208, 608, 708) of a flushing arrangement (106, 206, 406, 506, 606, 706) of the anchor device (102, 202, 402, 502, 602, 702) of the anchoring system (100, 200, 300, 400, 500, 600, 700).
12. Use of an anchoring system (100, 200, 300, 400, 500, 600, 700) according to any of the preceding claims 1 to 9 for free flushing at least one anchor device (102, 202, 402, 502, 602, 702) of the anchoring system (100, 200, 300, 400, 500, 600, 700) and/or for flushing in at least one anchor device (102, 202, 402, 502, 602, 702) of the anchoring system (100, 200, 300, 400, 500, 600, 700).
13. Offshore system (201), comprising:

    - at least one offshore structure (226), in particular a floatable offshore structure (226), and

    - at least one anchoring system (100, 200, 300, 400, 500, 600, 700) according to any of the preceding claims 1 to 9.

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