WO2021001118A1

WO2021001118A1 - Maritime float

Info

Publication number: WO2021001118A1
Application number: PCT/EP2020/065888
Authority: WO
Inventors: Christian Jahn; Sebastian Obermeyer
Original assignee: Rwe Renewables Gmbh
Priority date: 2019-07-04
Filing date: 2020-06-09
Publication date: 2021-01-07
Also published as: DE102019118103A1

Abstract

The invention relates to a maritime float (18) with a cable attachment (18b) designed for attaching the float (18) to a maritime cable (12, 14), a sensor (18c) that is designed to detect a measuring value dependent on a floating depth (22b) of the float (18) and, a communication device (18d) that is designed to transmit information on the measured value detected by the sensor (18c).

Description

Maritime float

The subject matter relates to a maritime float and a system with such a maritime float. Maritime floats are used in particular in connection with submarine cables. Submarine cables between structures, such as wind turbines among one another, between wind turbines and offshore substations, as well as between the

Substations and the mainland are spanned over several 100 meters. The submarine cables can start from a first structure on the surface of the water or hang just below the surface of the water and run to the sea floor and from there back to the next structure. When a building is mentioned below, it can also mean a system. A structure can be a wind turbine, a substation, a transformer station, a converter or the like. A structure can be founded in the sea floor or be constructed as a floating structure.

In the case of so-called floating structures in particular, which are not anchored in the ground, the submarine cables must be laid hanging down to the sea floor. The submarine cables are often laid in a so-called "lazy S" between two structures. In each case between the structure and the seabed there is at least one maritime float, e.g. a buoy or other

Float connected to the submarine cable. The float is usually balanced so that it floats under water and its buoyancy is sufficient to keep the submarine cable at the desired height.

It is necessary to fasten the submarine cable to the float, because the cable itself, due to the high weight of the cable itself, starts at a certain water depth no longer has a sufficient tear length. To prevent the cable from tearing off, the float is provided along the cable.

If the submarine cable is used continuously, however, maritime events occur

Vegetation. The submarine cables in use have a size of several tens

Centimeters and, given the length of several 100 meters, a large surface on which marine vegetation can settle. The weight of the submarine cable increases due to the marine vegetation. This shortens the tear length and the cable can tear despite the float.

The object of the object was therefore to prevent damage to a submarine cable by sinking.

Maritime vegetation usually develops almost continuously over a long period of time. This means that the weight of the submarine cable increases slowly but continuously due to the marine vegetation. A float connected to the submarine cable is pulled down by this increased dead weight, so that the floating depth of the float also changes with the changed dead weight of the submarine cable.

The float can be used not only with submarine cables, but also with other rope structures. Anchoring of floating structures and systems, such as floating wind turbines, can also be a maritime rope structure in the sense of the subject. Marine vegetation can also form on these anchor ropes. Whenever cables or submarine cables are mentioned in this document, the corresponding statements can also apply to other rope structures.

In order to be able to determine relevant maritime growth at an early stage, it is proposed that the maritime float in question be a

Has rope attachment. The rope attachment is used to attach the float formed on a marine rope. The rope attachment can, for example, encompass the rope, hold the rope in a clamped or clamped manner, screwed or clipped onto the rope, or the like. In addition, the float comprises a sensor set up to detect a measured value that is dependent on a float depth of the float. If the float is lowered into the sea water together with the maritime rope, it will tare itself to a certain floating depth depending on its buoyancy and the weight of the rope. If there is maritime growth or other changes in the dead weight of the maritime rope, this also changes

Hovering depth of the float. Depending on the floating depth, a measured value is recorded by the sensor.

In addition, the float has a communication device set up to transmit information on the measured value recorded by the sensor. The communication device can communicate wirelessly or by wire. In particular in the case of wired communication, the sensor can be supplied with energy via the cable that is already present. The sensor can also be supplied with energy separately via a cable provided for this purpose. The power supply cable can be attached to the rope structure.

According to one exemplary embodiment, it is proposed that the cable attachment is set up for the form-fitting attachment of the float to the cable. A form fit can be achieved by clamping or plastering the rope on the rope attachment.

It is also proposed that the cable attachment is set up for material-locking attachment of the float to the cable. For this purpose, a connection bracket can be provided on the cable attachment via which the float can be connected to the cable. Also can be in the rope, during its manufacture, in the outer Isolation layer a connection console are provided over which the

Rope attachment can be attached to the rope.

The connection bracket can be welded to the rope. Can also

The connection bracket must be welded to the cable attachment.

According to one embodiment it is proposed that the sensor be a

Pressure sensor, in particular a sensor measuring a hydrostatic pressure, is such a pressure sensor measures the hydrostatic pressure. This changes in the water by 0.1 bar per meter depth. At a depth of 20 meters there is a pressure of around 3 bar. When it drops to 21 meters, the pressure changes to around 3.1 bar. With the help of such a pressure sensor, the

Floating depth can be determined. An acceleration sensor can also be provided. With the help of such an acceleration sensor it can be detected, for example, whether the rope structure is being accelerated by vegetation or other events and if there is a

If the acceleration exceeds a limit value, a corresponding measured value can be recorded.

A fiber optic sensor can also be provided. Can on the rope

for example an optical fiber can be arranged. The course and / or the bend of the rope between the structure and the

Float, between two floats and / or between one

Float and the sea floor are almost static. A fiber optic sensor can measure reflective properties of the fibers. If there is a change in the course and / or or bending of the rope due to marine growth or other events, the optical fiber that is attached to the rope also experiences a change

corresponding change in their course and / or their curvature. These

Changes can be detected by the fiber optic sensor and a corresponding measured value can be output. The floating depth can also be detected, for example, with the aid of a sound sensor, in particular a sonar sensor. A distance to the sea floor and / or a distance to the water surface can be measured.

An intermittent measurement can be made with the sensor. This can be useful in order to keep the energy consumption of the sensor low. Measurements at intervals of one to several hours can be sufficient

Reliably detect changes in the floating depth due to marine vegetation.

According to one exemplary embodiment, it is proposed that the sensor be arranged in or on the float. The sensor can be arranged on the outside, on the outer skin of the float or inside the float. In the case of an arrangement inside the float, the sensor can thus be protected directly from the ambient moisture.

Another aspect is a system with a float described above and a maritime rope. The rope is preferably between a system and a float, between two floats or between one

Float and the sea floor arranged. The rope runs in one piece between two structures and is connected to at least one float. In particular, a course called "Lazy S", in which the rope of a

The structure is guided to the sea floor via a float and from there via a further float to the next structure.

As already explained, the maritime rope is, for example, a submarine cable. However, the rope can also be another structure, for example a fastening structure, an anchor rope, a fastening rope or the like. According to one exemplary embodiment, it is proposed that at least two floats are attached to the rope at a distance of at least 100 meters. The float can reduce the maximum free length of the rope so that the breaking length of the rope is always maintained.

According to an exemplary embodiment, it is proposed that an evaluation circuit be provided which is set up to receive the information about the measured value detected by the sensor and to evaluate the received information. The recorded measured value can be compared with at least one limit value. If, for example, a first limit value is reached, a warning signal can be output and an alarm can be output when a second limit value is reached. Limit values can be stored in the evaluation circuit. Becomes a

If the limit value is reached, this can indicate damage to the rope or maritime growth. By evaluating it is possible early on

Take countermeasures to prevent the rope from breaking. The evaluation circuit can be connected to a SCADA system so that the recorded information can be saved and evaluated there.

A target floating depth can be stored in the evaluation circuit and the information on the measured value can be assigned to an actual floating depth. A deviation of the actual floating depth from the target floating depth above a first limit value can trigger a warning signal. A deviation of the actual floating depth from the target floating depth above a second limit value can trigger an alarm signal. It is also possible that when a first

Limit value an alarm signal is issued.

The comparison of the target floating depth with the actual floating depth can in particular take place with an absolute value of the actual floating depth.

It is also possible to receive actual floating depths of a plurality of floating bodies and to evaluate the actual floating depth of a floating body as a relative value relative to the actual floating depths of the other floating bodies. Here can For example, it can be determined when the actual floating depth of an individual floating body changes compared to the actual floating depth of a plurality of other floating bodies. In such a comparison, for example, an average of the plurality of measured values can be used. An average deviation of the actual floating depth from the target floating depth can also be determined from the majority of the measured values. This mean value can be compared with the deviation of the floating depth of the individual float. A difference calculated in this way can be compared with a limit value. A differential of the actual floating depth can also be evaluated. It is possible here that the change in the actual floating depth over time can be evaluated. Especially in the event of an event that is not maritime vegetation, for example if the rope is hit by a ship or is otherwise damaged, the actual floating depth can change quickly. The differential can then one

Exceed limit value so that an alarm signal can be output immediately.

According to one exemplary embodiment, it is proposed that the evaluation circuit adapt a setpoint float depth as a function of a time mean value of the actual float depth. Aging of the float can change its buoyancy. This can be determined using a time average of the actual floating depth and the target floating depth can be adjusted accordingly.

According to an exemplary embodiment, it is proposed that the evaluation circuit match the actual floating depth with actual floating depths of at least two others

Compares floats. As already stated, a change in an individual float compared to other floats can thereby be determined. Depending on the evaluation, a signal, for example a warning signal or an alarm signal, can be output. Based on this signal, a Countermeasures can be taken, for example cleaning the rope, inspecting the rope or the like.

According to one embodiment, it is proposed that the evaluation circuit is arranged in or on the float or spatially remote from the float. The evaluation circuit can carry out the evaluation directly on the float and send corresponding signals via the

Send communication device. The measured values can also be evaluated in a remote evaluation circuit. An evaluation circuit can be formed for evaluating a plurality of measured values, in particular a plurality of floating bodies. Thus, from a plurality of

Float measured values are received and evaluated in a single evaluation circuit. According to one exemplary embodiment, it is proposed that the rope be electrically connected to an offshore structure, in particular a floating offshore structure, in particular a wind power plant and / or a substation.

Floating structures are only anchored to the sea floor, not founded. Such structures can be used in regions where the water depth may be greater than the breaking length of the rope. In order to be able to lay the rope anyway, the float in question is suggested.

The subject matter is explained in more detail below on the basis of a drawing showing exemplary embodiments. In the drawing show:

1 shows a system with maritime structures, floating bodies and ropes;

2 shows a marine float; 3 shows a floating body with a rope; 4 shows the course of measured values;

5a, b the evaluation of measured values. Figure 1 shows a system with two wind turbines 4 and a substation 6. Die

Wind turbines 4 are so-called floating wind turbines 4. These float on the water surface 10. An attachment to the sea floor 8 can be via

Anchoring ropes 12 take place. The wind turbines 4 are connected to the substation 6 via submarine cables 14. Anchoring 12 and submarine cable 14 can be understood as a rope.

An electrical connection between the substation 6 and the wind turbines 4 takes place via the electrically connected submarine cables 14. The submarine cables 14 are designed for high performance and therefore have a large dead weight. The tear length of the cables 14 can be less than either the distance between two wind turbines 4, a wind turbine 4 and a substation 6 and / or one

Wind turbine 4 and the seabed 8. In all cases the cable is over

Secure float 18. A connection between the substation 6 and an energy supply network on the mainland can also be established via a cable 14 with at least one float 8.

It can be seen that the floating bodies 18 are attached to the anchorages 12 and also to the cables 14. The float 18 is balanced in such a way that, as shown in FIG. 2, it holds the cable 14 or the rope 12 at a desired depth 20. For this purpose, the buoyancy of the float 18 is dimensioned such that it counteracts the weight of the cable 14 or rope 12. As shown in FIG. 3, the floating body 18 is provided with a float 18a. This can be in the form of a swim bladder or some other float. The dimension of the Buoyancy body 18 is such that a cable 14 or rope 12 which is attached to the

Floating body 18 is held, in the target depth 20 is held.

As shown in Fig. 3, a fastening means 18b is provided on the floating body 18, which can be formed, for example, as a clamp fastener. The cable 14 or rope 12 can be clamped to the fastening means 18b and the float 18 can thus be firmly fastened to the cable 14 or rope 12.

A sensor 18c can be provided in or on the float 18. With the help of the sensor, which is for example a pressure sensor, the floating depth can be determined. The floating body 18 can use the sensor 18c to measure its distance 22a from the seabed 8 and / or its distance 22b from the water surface 10. The float 18 can also use the sensor 18c to measure its floating depth directly via hydrostatic pressure.

In addition, a communication device 18d is provided in the floating body 18. The communication device 18d is connected to an evaluation circuit 26 via a cable 24. Information on the measured value of the sensor 18c can be transmitted to an evaluation circuit 26 via the cable 24. The communication device 18d and the sensor 18c can be supplied with energy via the cable 24 or a cable (not shown) laid separately therefrom.

The signals from the sensor 18c can be received by the communication device 18d in the evaluation circuit 26, which is arranged, for example, in the substation 6.

FIG. 4 shows an example of the course of a measured value of a floating depth 22b. The course over time can be, for example, several months and / or several years. As can be seen, the floating depth 22b increases over time, ie the floating body 18 sinks. At a time tl can for example, a first limit value XI can be reached. If this limit value XI is reached, the evaluation circuit 26 can output a warning signal. This can mean that a maintenance measure is initiated. In the further course of further maritime vegetation the floating depth 22 can increase further. If such a limit value is detected in the evaluation circuit 26, an alarm signal can be output, whereupon a

Maintenance action is taken. When the limit value X2 is reached at time t2, there can be a risk of the cable 14 being torn off. An alarm signal can be sent by the evaluation circuit. Measures can then be taken to prevent tearing off. FIG. 5a shows the course of a floating depth 22b at which, for example, a short, large change occurs. Between time t3 and

Time t4 changes the position or floating depth 22b of the

Float 18 strong. The differential of the measured value is shown in FIG. 5b. The limit value X3 of the differential can for example

are exceeded, whereupon a corresponding warning signal can be output. An inspection of the cable 14 can be indicated in such a case.

List of reference symbols

4 wind turbine

6 substation

8 seabed

10 water surface

12 anchoring rope

14 submarine cables

18 floats

18a float

18b fasteners

18c sensor

18d communication device

20 target depth

22a distance to the sea floor

22b distance to the water surface

24 cables

26 Evaluation circuit

Claims

Patent claims

1. Maritime float with

a rope attachment, set up to attach the float to a marine rope;

a sensor set up to detect a measured value dependent on a floating depth of the floating body and,

a communication device set up to send out

Information on the measured value recorded by the sensor.

2. float according to claim 1,

characterized,

that the rope attachment is set up for the form-fitting attachment of the float to the rope, in particular that the rope attachment receives the rope in a clamping manner or that the rope attachment for a materially bonded connection

Attaching the float to the rope is set up.

3. float according to claim 1 or 2,

characterized,

the sensor is a pressure sensor, in particular a sensor measuring a hydrostatic pressure, an acceleration sensor, a fiber optic sensor and / or a sound sensor, in particular a sonar sensor.

4. float according to one of the preceding claims,

characterized,

the sensor is arranged in or on the float.

5. System with a float according to one of the preceding claims and a maritime rope.

6. System according to claim 5,

characterized,

the rope is a submarine cable

7. System according to claim 5 or 6,

characterized,

that at least two floats are attached to the rope with a distance of at least 100m.

8. System according to claim 7 with an evaluation circuit set up for

Receiving the information on the measured value recorded by the sensor and for evaluating the received information.

9. System according to claim 8,

characterized,

that the evaluation circuit assigns an actual floating depth to the information on the measured value detected by the sensor and / or that in the

Evaluation circuit information about a target floating depth is stored.

10. System according to claim 8 or 9,

marked by this,

that the evaluation circuit evaluates an absolute value of the actual floating depth and / or a relative value of the actual floating depth and / or a differential of the actual floating depth.

11. System according to one of the preceding claims,

characterized, that the evaluation circuit adjusts the target floating depth depending on a time average of the actual floating depth

12. System according to one of the preceding claims,

characterized,

that the evaluation circuit compares the actual float depth with actual float depths of at least two other floats.

13. System according to one of the preceding claims,

characterized,

that the evaluation circuit outputs a signal depending on the evaluation.

14. System according to one of the preceding claims,

characterized,

that the evaluation circuit is arranged in or on the float or spatially removed from the float, in particular that the

Evaluation circuit for evaluating the information on the measured value detected by the sensor an actual floating depth of a plurality of

Float is set up

15. System according to one of the preceding claims,

characterized,

that the rope is electrically connected to an offshore structure, in particular a floating offshore structure, in particular a wind turbine and / or a substation.