DE102019118103A1 - Maritime float - Google Patents

Abstract

Maritime float 18 with a rope attachment 18b, set up to attach the float 18 to a maritime rope 12, 14, a sensor 18c, set up to detect a measured value dependent on a floating depth 22b of the float 18, and a communication device 18d, set up to send out information to the measured value detected by the sensor 18c.

Description

The subject matter relates to a maritime float and a system with such a maritime float.

Maritime floats are used particularly in connection with submarine cables. Submarine cables between structures, such as wind turbines among themselves, between wind turbines and offshore substations as well as between the substations and the mainland, are stretched 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. At least one maritime float, e.g. a buoy or other floating body, is connected to the submarine cable between the structure and the seabed. 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.

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

If the submarine cable is used continuously, however, maritime growth occurs. The submarine cables in use have a circumference of several tens of centimeters and, given the length of several 100 meters, also have 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 has a rope attachment. The rope attachment is designed to attach the float to a maritime 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. When 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, the floating depth of the float also changes. 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 clipping the rope to 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. A connection bracket can also be provided in the cable during its manufacture in the outer insulation layer, via which the cable attachment can be attached to the cable.

The connection bracket can be welded to the rope. The connection bracket can also be welded to the cable attachment.

According to one exemplary embodiment, it is proposed that the sensor be a pressure sensor, in particular a sensor measuring a hydrostatic pressure. 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 from the measured value.

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

A fiber optic sensor can also be provided. For example, an optical fiber can be arranged on the rope. In the balanced state, the course and / or the bend of the rope between the structure and the float, between two floats and / or between a float and the seabed are quasi-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 vegetation or other events, the optical fiber that is attached to the rope also experiences a corresponding change in its course and / or its bending. This change 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 to reliably determine the change in floating depth caused by 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 arranged between a system and a float, between two floats or between a float and the seabed. The rope runs in one piece between two structures and is connected to at least one float. In particular, a “lazy S” course, in which the rope is led from one structure via a float to the sea floor and from there via another float to the next structure, is preferred.

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 one 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. For example, if 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. If a limit value is reached, this can indicate damage to the rope or marine growth. The evaluation makes it possible to take countermeasures at an early stage 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 for an alarm signal to be output as soon as a first limit value is exceeded.

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. It can be determined, for example, if 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, an average of the plurality of measured values can be used, for example. 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 when the rope is hit by a ship or is otherwise damaged, the actual floating depth can change quickly. The differential can then exceed a 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 target floating depth as a function of a time average value of the actual floating depth. Aging of the float can change its buoyancy. This can be determined on the basis of a time mean value of the actual floating depth and the target floating depth can be adjusted accordingly.

According to one exemplary embodiment, it is proposed that the evaluation circuit compare the actual floating depth with actual floating depths of at least two other floating bodies. 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 countermeasure can then be taken, for example cleaning the rope, inspecting the rope or the like.

According to one exemplary embodiment, it is proposed that the evaluation circuit be 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 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, measured values can be received and evaluated from a plurality of floats 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.

• 1 ein System mit maritimen Bauwerken, Schwimmkörpern und Seilen;
• 2 einen maritimen Schwimmkörper;
• 3 einen Schwimmkörper mit einem Seil;
• 4 den Verlauf von Messwerten;
• 5a, b die Auswertung von Messwerten.

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

• 1 a system with maritime structures, floats and ropes;
• 2 a marine float;
• 3 a float with a rope;
• 4th the course of measured values;
• 5a, b the evaluation of measured values.

1 shows a system with two wind turbines 4th and a substation 6th . The wind turbines 4th are so-called floating wind turbines 4th . These float on the surface of the water 10 . An attachment to the seabed 8th can be via anchoring ropes 12th respectively. The wind turbines 4th are via submarine cables 14th with the substation 6th connected. anchoring 12th as well as submarine cables 14th can be understood as a rope.

An electrical connection between the substation 6th and the wind turbines 4th takes place via the electrically connected submarine cables 14th . The submarine cables 14th are designed for high performance and therefore have a large dead weight. The tear length of the cables 14th can be less than either the distance between two wind turbines 4th , a wind turbine 4th and a substation 6th and / or a wind turbine 4th and the ocean floor 8th . In all cases the cable is over float 18th to secure. A connection between the substation 6th and a power grid on the mainland can also have a cable 14th with at least one float 8th respectively.

It can be seen that the float 18th at the anchorages 12th as well as the cables 14th are attached.

The float 18th is balanced in such a way that, as in 2 shown, at a target depth 20th the cable 14th or the rope 12th holds. This is the buoyancy of the float 18th dimensioned in such a way that it supports the weight of the cable 14th or rope 12th counteracts. The float 18th is like in the 3 shown with a float 18a Mistake. This can be in the form of a swim bladder or some other float. The dimension of the float 18th is such that a cable 14th or rope 12th , which on the float 18th is held in the target depth 20th is held.

As in 3 shown is on the float 18th is a fastener 18b provided, which can be formed for example as a clamp fastener. On the fastener 18b can the cable 14th or rope 12th be clamped and the float 18th can thus be firmly attached to the cable 14th or rope 12th be attached.

In or on the float 18th can be a sensor 18c be provided. With the help of the sensor, which is for example a pressure sensor, the floating depth can be determined. The float 18th can with the sensor 18c its distance 22a to the seabed 8th and / or its distance 22b to the water surface 10 measure up. The float can also 18th with the sensor 18c Immediately measure its floating depth via hydrostatic pressure.

It is also a communication facility 18d in the float 18th intended. The communication facility 18d is through a cable 24 with an evaluation circuit 26th connected. About the cable 24 can provide information on the measured value of the sensor 18c to an evaluation circuit 26th be transmitted. About the cable 24 or a cable (not shown) laid separately therefrom can be a power supply for the communication device 18d as well as the sensor 18c respectively.

In the evaluation circuit 26th , for example in the substation 6th is arranged, the signals of the sensor 18c from the communication device 18d be received.

4th 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 becomes over time 22b larger, ie the float 18th sinks. At a point in time t1, for example, a first limit value X1 can be reached. If this limit value X1 is reached, the evaluation circuit 26th a warning signal will be issued. This can mean that a maintenance measure is initiated.

In the further course of further maritime vegetation the floating depth 22 can increase further. Is such a limit value in the evaluation circuit 26th is detected, an alarm signal can be output, whereupon a maintenance measure is taken immediately.

When the limit value X2 is reached at time t2, there is a risk of the cable tearing off 14th consist. An alarm signal can be sent by the evaluation circuit. Measures can then be taken to prevent tearing off.

5a shows the course of a floating depth 22b in which, for example, a short-term, large change occurs. The position or the floating depth changes between time t3 and time t4 22b of the float 18th strong. The differential of the measured value is in the 5b shown. The limit value X3 of the differential can be exceeded, for example, whereupon a corresponding warning signal can be output. An inspection of the cable 14th may be appropriate in such a case.

List of reference symbols

4th

Wind turbine

6

Substation

8th

Seabed

10

Water surface

12

Anchoring rope

14th

Submarine cables

18th

Float

18a

Floats

18b

Fasteners

18c

sensor

18d

Communication facility

20th

Target depth

22a

Distance to the sea floor

22b

Distance to the water surface

24

electric wire

26th

Evaluation circuit

Claims (15)

Maritime float with - A rope attachment, set up to attach the float to a maritime 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 transmit information on the measured value recorded by the sensor. Float after Claim 1 , characterized in that the rope attachment is set up for the positive 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 is set up for the material-locking attachment of the float to the rope. Float after Claim 1 or 2 , characterized in - 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. Float according to one of the preceding claims, characterized in that - the sensor is arranged in or on the float. System with a float according to one of the preceding claims and a maritime rope. System according to Claim 5 , characterized , - the rope is a submarine cable. System according to Claim 5 or 6th , characterized in - that at least two floats are attached to the rope with a distance of at least 100m. System according to Claim 7 with an evaluation circuit set up to receive the information on the measured value detected by the sensor and to evaluate the received information. System according to Claim 8 , characterized in that the evaluation circuit assigns an actual floating depth to the information on the measured value recorded by the sensor and / or that information on a target floating depth is stored in the evaluation circuit. System according to Claim 8 or 9 , characterized in - 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. System according to one of the preceding claims, characterized in that the evaluation circuit adapts the target floating depth as a function of a time average value of the actual floating depth. System according to one of the preceding claims, characterized in - that the evaluation circuit compares the actual floating depth with actual floating depths of at least two other floating bodies. System according to one of the preceding claims, characterized in that the evaluation circuit outputs a signal as a function of the evaluation. System according to one of the preceding claims, characterized in that the evaluation circuit is arranged in or on the float or spatially remote from the float, in particular that the Evaluation circuit for evaluating the information about the measured value detected by the sensor, an actual floating depth of a plurality of floating bodies is set up. System according to one of the preceding claims, characterized in that the rope is electrically connected to an offshore structure, in particular a floating offshore structure, in particular a wind power plant and / or a substation.

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