EP3612736B1 - Electrohydraulic system for under water use, with an electrohydraulic actuator - Google Patents

Description

The invention relates to an electrohydraulic system for use under water, in particular at great water depths, with an electrohydraulic actuator. The electrohydraulic actuator is used in particular to operate underwater fittings. The system includes a container that has an interior space that is provided to form a volume that is sealed off from the environment and is intended to hold a hydraulic pressure fluid. The system further includes a hydraulic cylinder and a hydraulic machine located inside the container.

Such type of electro-hydraulic systems are mainly used to move an element under water at water depths of up to several thousand meters in connection with the extraction of oil and gas, mining, scientific exploration or infrastructure projects. So there are z. B. in oil or natural gas production systems at sea at great depths, process valves with which the volume flow of the medium to be pumped can be regulated or shut off.

An electro-hydraulic system can, for example, after DE 10 2015 213695 A1 be designed with an electrohydraulic actuator, which comprises a container, in the interior of which a hydrostatic machine that can be operated at least as a pump and an electric machine that is mechanically coupled to the hydrostatic machine are arranged. The main drive of the actuator is an electric motor that drives the pump and thus adjusts a hydraulic cylinder with a linear movement. The electric motor consumes considerable electrical energy z. B. must be introduced via sea cable. The actuator adjusts z. B. Large production valves of oil or gas wells that control the flow rate. So that a process valve can also be operated manually by a robot such as B. by a Remote Operated Vehicle (ROV) or an Autonomous Underwater Vehicle (AUV), z. in an emergency, there is a manual interface on the container from which a rod is coupled to a piston in the cylinder. In the interface, the rod may be threaded for movement and co-operate with an internally threaded and axially fixed nut which is rotated to actuate the process valve. A disadvantage of this arrangement is the outlay in terms of investment. This requires a large installation space. In addition, the limited lifespan is annoying. Furthermore, manual actuation stands in the way of frequent adjustment of a process valve during operation. In addition, the mechanical arrangement is sensitive to shocks and vibrations that can be caused by the submersible.

From the non-generic JP H07 223589 A an electrical charging system for a battery-powered submersible is known. For this purpose, an immersion device can be connected to the immersion body, with the immersion device having a motor which drives a dynamo arranged in the immersion body, so that the battery of the immersion body is charged.

Proceeding from this, it is the object of the present invention to create an electrohydraulic system which alleviates or even avoids the disadvantages mentioned. In particular, a compact design, namely a small installation space and an increased service life, are to be realized in a structurally simple manner. In addition, a frequent adjustment of the actuator should be made possible in a simple manner.

These objects are achieved with an electrohydraulic system according to patent claim 1. Further developments of the invention are specified in the dependent patent claims. It should be pointed out that the description, in particular in connection with the figures, gives further details and developments of the invention which are within the scope of the patent claims.

Contributing to this is an electrohydraulic system for use under water with an electrohydraulic actuator, comprising a hydraulic machine, a rotary drive device and a hydraulic cylinder or hydraulic motor, and with a container, with the hydraulic cylinder or hydraulic motor and the hydraulic machine being present in an interior space of the container. The rotary drive mechanism is mechanically coupled to the hydraulic machine for a common rotating motion. The hydraulic machine can adjust the hydraulic cylinder and/or hydraulic motor. The rotary drive device is used to adjust the hydraulic cylinder. The rotary drive device is arranged outside of the container and set up for coupling to the hydraulic machine and for decoupling from the hydraulic machine. The electrical energy for the rotary drive device located outside the container is independent of the energy consumption of the components inside the container. The components inside the container are supplied with electrical power via an electrical interface on the container.

The electrohydraulic system presented here with the electrohydraulic actuator has the advantage that a smaller installation space is combined with an increased service life in a structurally simple manner. In particular, frequent adjustment by the underwater vehicle, for example a robot, is made possible. Finally, undesired shocks and vibrations on the hydraulic cylinder, which can occur due to the submersible, are avoided.

The rotary drive device is preferably used for the mechanical emergency adjustment of the hydraulic cylinder. The rotary drive device is expediently used for the constant adjustment of the hydraulic cylinder.

The hydraulic cylinder is advantageously a differential cylinder. The hydraulic cylinder is preferably a synchronous cylinder.

The hydraulic cylinder is expediently designed with a longitudinally displaceable piston for adjusting a process valve.

The hydraulic cylinder preferably includes a helical compression spring for resetting the hydraulic cylinder.

At least one solenoid valve is preferably arranged in such a way that a cylinder chamber of the hydraulic cylinder is hydraulically relieved in the event of a failure of the electrical current.

It can be expedient for an electrical interface to be provided and set up for the emergency stop in such a way that it (only) actuates the safety valves and status monitoring via the (planned) sensors (travel sensors, position indicators, pressure sensors, temperature sensors, etc.)

Seat valves or check valves and/or hydraulically lockable valves can be arranged in such a way that when the rotary drive device is decoupled, the position of the hydraulic cylinder remains (essentially) unchanged or is maintained.

At least one pressure-limiting valve can be provided, which is arranged and set up in such a way that the maximum hydraulic system pressure can be effectively limited.

The hydraulic machine is preferably designed as a hydrostatic transmission. The hydraulic machine can preferably be operated as a hydraulic pump.

The rotary drive device expediently comprises an electric motor. The electric motor can be provided outside the container (in the seawater area). It is possible to provide a separate electric motor inside the container as an additional drive.

A remote-controlled underwater vehicle advantageously includes the rotary drive device. The rotary drive means is preferably a torque tool of an underwater robot.

A coupling device is preferably present between the rotary drive device and the hydraulic machine.

A device for arranging under water and for controlling a pumpable volume flow of a gaseous or liquid medium can be provided, which is designed with a process valve. The process valve has a process valve housing, a process valve spool, with which the volume can be controlled. A hydraulic cylinder is also provided, which is assigned to the process valve housing and can be moved with the process valve slide. The device also has an electrohydraulic system with an electrohydraulic actuator, with a rotary drive device being arranged on a remote-controlled underwater vehicle, which drives a hydraulic pump that adjusts the hydraulic cylinder. A rotary hydraulic motor is advantageously used instead of the hydraulic cylinder used. With regard to the description of the structure or the function of the electrohydraulic system, reference can be made to the further descriptions.

Fig. 1:

eine Seitenansicht der Vorrichtung bei geschlossenem Prozessventil;

Fig. 2:

ein Blockschaltbild mit Drehantriebseinrichtung, Drehmomentübertragung und Hydromaschine,

Fig. 3:

ein Blockschaltbild wie Fig. 2, jedoch mit einer Kopplungseinrichtung,

Fig. 4:

eine erste Ausführungsform mit innen angeordnetem Hauptantrieb für einen Hydrozylinder ohne Druckfeder,

Fig. 5:

eine zweite Ausführungsform mit innen angeordnetem Hauptantrieb für einen Hydrozylinder mit Druckfeder und

Fig. 6:

eine dritte Ausführungsform ohne innen angeordneten Hauptantrieb für einen Hydrozylinder.

The invention and the technical environment are explained in more detail below with reference to figures. The same components are marked with the same reference symbols. The illustrations are schematic and not intended to illustrate proportions. The explanations given with reference to individual details of a figure can be extracted and freely combined with facts from other figures or the above description, unless something else is absolutely necessary for a person skilled in the art or such a combination is explicitly prohibited here. They show schematically:

Figure 1:

a side view of the device with the process valve closed;

Figure 2:

a block diagram with rotary drive device, torque transmission and hydraulic machine,

Figure 3:

a block diagram like 2 , but with a coupling device,

Figure 4:

a first embodiment with an internally arranged main drive for a hydraulic cylinder without a compression spring,

Figure 5:

a second embodiment with an internally arranged main drive for a hydraulic cylinder with compression spring and

Figure 6:

a third embodiment without an internally arranged main drive for a hydraulic cylinder.

The embodiments of an electrohydraulic system shown in the figures have according to 1 a process valve 1 with a process valve housing 2, through which a process valve channel 3 runs, which is continued at its mouths by pipes, not shown, and in which a gaseous or liquid medium from the seabed to a part of a derrick protruding from the sea or to a drilling ship flows. The direction of flow is indicated by arrow 4.

A cavity is formed in the process valve housing 2 which crosses the process valve channel 3 and in which a process valve slide 5 with a flow opening 6 can be moved transversely to the longitudinal direction of the process valve channel 3 . In the state after 1 The process valve channel 3 and the flow opening 6 in the process valve spool 5 do not overlap. The process valve is therefore closed. In a state (not shown), the flow opening 6 and the process valve channel 3 largely overlap. The process valve 1 is almost completely open.

A process valve of the type shown and the use described should on the one hand be able to be actuated in a controlled manner and on the other hand also contribute to safety by quickly and reliably assuming a position that corresponds to a safe state in the event of a fault. In the present case, this safe state is a closed process valve.

The process valve 1 is actuated by a compact electro-hydraulic system 7, which is arranged directly on the process valve 1 under water. It is sufficient that only one electrical cable 8 leads from the electro-hydraulic system 7 to the sea surface or another higher-level electrical control located under water.

The electrohydraulic system 7 shown as an exemplary embodiment has a container 9 which is fastened to the process valve housing 2 on an open side, so that there is an interior space 10 which is sealed off from the environment and is filled with hydraulic pressure fluid as the working medium. For attachment to the process valve housing 2 , the container 9 has an inner flange on its open side, with which it is screwed to the process valve housing 2 . A peripheral seal 11 is arranged radially outside the screw connections between the inner flange of the container 9 and the process valve housing 2 and is inserted into a peripheral groove of the process valve housing 2 .

The container 9 is pressure-compensated with respect to the ambient pressure prevailing under water (seawater area 12). For this purpose, a membrane 14 is tightly clamped in a pressure compensator 13 in an opening in the container wall. There are holes in the lid so that the space between the membrane 14 and the lid is part of the environment and is filled with sea water. The interior space 10 is sealed off from the environment by the membrane 14 . The membrane 14 is facing on its first surface of the interior 10 by the pressure in the interior 10 and on its second surface facing the lid, the is about the same size as the first area, is acted upon by the pressure that prevails in the area and always seeks to assume a position and shape in which the sum of all forces acting on it is zero.

In the interior 10 of the container 9 there is a hydraulic cylinder 15 with a cylinder housing 16 which is closed at the end by a cylinder base 17 and a cylinder head 18, with a piston 19 which can be displaced in the interior of the cylinder housing 16 in the longitudinal direction of the cylinder housing 16 and with a piston connected to the piston 19 firmly connected and projecting away from the piston 19 on one side, the first piston rod 20 which passes through the cylinder head 18 in a sealed manner and guided in a manner not shown in detail. The gap between the piston rod 20 and the cylinder head 18 is sealed by two seals (not shown) arranged in the cylinder head 18 at an axial distance from one another. The process valve slide 5 is attached to the free end of the piston rod 20 . Furthermore, there is a second piston rod 21 which is firmly connected to the piston 19 and projects away from the piston 19 on the other side, which is guided in a sealed manner and passes through the cylinder base 17 . The interior of the cylinder housing 16 is divided by the piston 19 into a first cylinder chamber 22 on the cylinder head side and a second cylinder chamber 23 on the bottom side, the volume of which depends on the position of the piston 19 .

A helical compression spring 24 is accommodated in the cylinder chamber 22, which surrounds the piston rod 20 and is clamped between the cylinder head 18 and the piston 19, i.e. it acts on the piston 19 in a direction in which the piston rod 20 is retracted and the process valve slide 5 closes the process valve 1 is moved.

In the interior 10 of the container 9 there is also a hydraulic machine 25 which can be operated as a pump with two conveying directions. The hydraulic machine 25 has a pressure port 26 and a suction port 27 which is open to the interior 10 . When operating as a pump, the hydraulic machine 25 can deliver pressurized fluid drawn in from the interior 10 via the pressure connection 26 to the cylinder chamber 23 . Conversely, pressurized fluid can be displaced from the cylinder chamber 23 via the hydraulic machine 25 into the interior 10 of the container 9 . In this sense, in the exemplary embodiment, the cylinder chamber 23 is the second cylinder chamber. In a corresponding manner, pressure fluid sucked in from the interior 10 by the hydraulic machine 25 in operation as a pump can be conveyed via the pressure connection 26 to the cylinder chamber 22; conversely, pressurized fluid from the cylinder chamber 22 are displaced via the hydraulic machine 25 into the interior 10 of the container 9. Appropriate valves are provided for this purpose, see Figures 4 to 6 .

A rotary drive device 28 is mechanically coupled to the hydraulic machine 25 for a common rotary movement, e.g. B. via a shaft 29. The shaft 29 transmits torque from the rotary drive device 28 to the hydraulic machine 25. The rotary drive device 28 is located outside of the container 9. It is z. B. by a remote-controlled underwater vehicle 31 (ROV) or a robot and preferably has an electric motor as the rotary drive device 28 .

So that the process valve 1 by a robot such. B. by an ROV, an interface 32 is present on the container 9 , starting from which the shaft 29 is coupled to the hydraulic machine 25 in the interior 10 .

2 12 schematically illustrates the torque transmission 30 between the rotary drive device 28 and the hydraulic machine 25. A remote-controlled underwater vehicle which includes the rotary drive device 28 is denoted by 31.

3 Illustrates schematically that the rotary drive device 28 is set up for coupling to and decoupling from the hydraulic machine 25 . For this purpose, between the rotary drive device 28 and the hydraulic machine 25 is a coupling device 33, z. B. a clutch provided. The means for rotating the hydraulic machine 25 are designed in such a way that the tightness of the interior 10 to the outer seawater area 12 is ensured.

4 shows a first embodiment with (optional) internally arranged main drive 34 (automated cylinder drive) for a hydraulic cylinder 15 without a compression spring. The hydraulic cylinder 15 (actuator) works without a spring-loaded opening and closing function. There is a hydrostatic transmission for the hydraulic cylinder 15 working in a straight line. The rotary drive device 28 on the underwater vehicle 31 (see Figures 2 and 3 ) generates a torque that drives the hydraulic machine 25 (hydraulic pump). The coupling device (connection coupling) is denoted by 33 . The hydraulic machine 25 adjusts the hydraulic cylinder 15. For an emergency actuation to retract and extend the process valve spool 5 (see 1 ) the first cylinder chamber 22 closes or opens the external process valve 1 (please refer 1 ). Furthermore, the interior 10 of the container 9 contains: suction valves 37.1, 37.2, check valves 38.1, 38.2, hydraulically lockable valves 39.1, 39.2 and a pressure relief valve 41.

The embodiment after 4 is structurally simple, space-saving, robust and offers a low risk of penetrating sea water. Alternatively, another pump with an electric motor operated by electric power can also be used.

figure 5 illustrates a second embodiment with an internally arranged main drive 34 for a hydraulic cylinder 15, but with a helical compression spring 24 in the first cylinder chamber 22. In figure 5 are - compared to 4 - In addition to the helical compression spring 24 also available: Hydraulically lockable valve 39.3 and solenoid valve 40 (open when de-energized). This training includes a safety lock for the process valve 1 when the function of the helical compression spring 24 is impaired or fails, z. B. in the event of a fracture or the like.

6 illustrates a third (opposite figure 5 somewhat simplified) embodiment without internally arranged main drive (see item 34 in 4 and 5 ) for a hydraulic cylinder 15. The drive function for the hydraulic cylinder 15 takes place only via the external rotary drive device 28 in conjunction with the hydraulic machine 25. This training is suitable both for emergency adjustment and - if necessary - for constant adjustment during operation of the hydraulic cylinder 15. By the Omission of the main drive 34, this embodiment is extremely compact and requires only little electrical energy consumption. Electrical energy within the electro-hydraulic system is only required for safety signals and sensors. The electrical energy for the rotary drive device 28 located outside the container 9 is independent of the energy consumption of the components inside the container 9. The electrical interface shown above only includes the emergency stop for actuating the safety valves and the sensor signals (position encoder, pressures, . ...).

Reference List

1

process valve

2

process valve body

3

process valve channel

4

Arrow

5

process valve spool

6

flow opening

7

electrohydraulic system

8th

Cable

9

container

10

interior of 9

11

poetry

12

lake water area

13

pressure compensator

14

membrane

15

hydraulic cylinder

16

cylinder body

17

cylinder bottom

18

cylinder head

19

Pistons

20

first piston rod

21

second piston rod

22

first cylinder chamber

23

second cylinder chamber

24

helical compression spring

25

hydro machine

26

pressure connection

27

suction port

28

rotary drive device

29

Wave

30

torque transmission

31

remote controlled underwater vehicle

32

interface

33

coupling device

34

Main drive from 15

35

hydro pump

36

electric motor

37.1

suction valve

37.2

suction valve

38.1

check valve

38.2

check valve

39.1

hydraulically lockable valve

39.2

hydraulically lockable valve

39.3

hydraulically lockable valve

40

magnetic valve

41

pressure relief valve

Claims (11)

1. Electrohydraulic system (7) for underwater use, with an electrohydraulic actuating drive, comprising a hydraulic machine (25), a rotary drive device (28) and a hydraulic cylinder (15) or hydraulic motor, and with a container (9), wherein the hydraulic cylinder (15) or hydraulic motor and the hydraulic machine (25) are present in an interior space (10) of the container (9), wherein the rotary drive device (28) and the hydraulic machine (25) are mechanically coupled for a common rotary movement and the hydraulic machine (25) adjusts at least the hydraulic cylinder (15) or hydraulic motor, wherein the rotary drive device (28) serves for adjusting the hydraulic cylinder (15), wherein the electrical supply of energy to the components within the container (9) is realized via an electrical interface at the container (9),
   characterized in that
   the rotary drive device (28) is arranged outside the container (9) and is configured for coupling to the hydraulic machine (25) and decoupling from the hydraulic machine (25), and the electrical energy for the rotary drive device (28) is independent of the electrical energy consumption of the components within the container (9).
2. Electrohydraulic system according to Patent Claim 1, wherein the hydraulic cylinder (15) is a differential cylinder or a synchronous cylinder.
3. Electrohydraulic system according to either of the preceding patent claims, wherein the hydraulic cylinder (15) is designed with a displaceable piston (19) for adjustment of a process valve (1).
4. Electrohydraulic system according to one of the preceding patent claims, wherein the hydraulic cylinder (15) comprises a helical compression spring (24) for resetting the hydraulic cylinder (15).
5. Electrohydraulic system according to one of the preceding patent claims, wherein at least one solenoid valve (40) is arranged in such a way that, in the event of an electrical power failure, a cylinder chamber (23) of the hydraulic cylinder (15) is relieved hydraulically.
6. Electrohydraulic system according to one of the preceding patent claims, wherein at least at least one check valve (38.1, 38.2) or at least one hydraulically blockable valve (39.1, 39.2, 39.3) is arranged in such a way that, when the rotary drive device (28) is decoupled, the position of the hydraulic cylinder (15) remains unchanged.
7. Electrohydraulic system according to one of the preceding patent claims, wherein provision is made of at least one pressure-limiting valve (41) which is arranged and configured in such a way that the maximum hydraulic system pressure can be effectively limited.
8. Electrohydraulic system according to one of the preceding patent claims, wherein the hydraulic machine (25) is in the form of a hydrostatic transmission or hydraulic pump.
9. Electrohydraulic system according to one of the preceding patent claims, wherein the rotary drive device (28) comprises an electric motor (36).
10. Electrohydraulic system according to one of the preceding patent claims, wherein a remote-controlled underwater vehicle (31) comprises the rotary drive device (28).
11. Electrohydraulic system according to one of the preceding patent claims, wherein a coupling device (33) is present between the rotary drive device (28) and the hydraulic machine (25).

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