NO20180568A1 - Arrangement for use underwater with a hydraulic clutch - Google Patents

Abstract

The invention relates to a hydraulic arrangement for use underwater with a hydraulic clutch (32), between a first system (30) and a second system (31), the hydraulic clutch (32) being provided with which a fluid from the first system (30) can be introduced underwater into the second system (31), above, above a certain intake quantity of a fluid-seawater mixture in the cylinder chamber (56), the hydraulic clutch (32) opens a connection from the first system (30) to the second system (31).

Description

Arrangement for use underwater with a hydraulic clutch

Description

The invention relates to a (hydraulic) arrangement for use underwater with a hydraulic clutch, wherein, between a first system and a second system, the hydraulic clutch is present, with which, underwater, a fluid from the first system can be introduced into the second system.

Such types of hydraulic arrangements are primarily used underwater at depths of up to several thousand meters, in connection with the production of crude oil and natural gas, with mining, gathering scientific information, or with infrastructure projects, to move an element or refill a system with fluid or change the fluid. Accordingly, in, for example, oil or natural gas production installations at sea, process valves are found at great depths which can be used to regulate or shut off the volume flow of the medium to be conveyed.

A known hydraulic arrangement with an electro-hydraulic actuator comprises a container, in whose internal space a hydrostatic machine, which can be operated at least as a pump, and an electric motor mechanically coupled to the hydrostatic machine are arranged. The main drive of the actuator is here provided by an electric motor that drives the pump and thus adjusts a hydraulic cylinder with a linear movement. The actuator adjusts, for example, production fittings of oil or gas wells, which regulate the flow rate. The internal space of the container is filled with a hydraulic pressure fluid, e.g., an oil, as working medium. The container is closed off to the surrounding seawater area and pressurecompensated with respect to the ambient pressure prevailing underwater. The container has an interface at which hydraulic pressure fluid can be refilled by a robot, should this be necessary due to previous leakage. What is problematic here is that the known filler rod is introduced directly into the internal space of the container, wherein seawater also undesirably penetrates into the internal space of the container, thereby contaminating the pressure fluid in the internal space. In particular, high demands are made of the seal between the filler rod and the container.

On this basis, it is an aim of the present invention to provide an arrangement which alleviates or even excludes the disadvantages mentioned. In particular, a complete penetration of seawater is to be prevented in a constructively simple manner. In addition, a secure seal between the filler rod and the container is to be achieved in a simple manner.

These aims are achieved with an arrangement according to independent claim 1. Further developments of the invention are specified in the dependent claims. It is to be noted that the description - in particular, in connection with the figures - adduces further details and developments of the invention which can be combined with the features from the claims.

A contribution is made in this regard by a (hydraulic) arrangement for use underwater with a hydraulic clutch, wherein, between a first system and a second system, the hydraulic clutch is provided, by means of which a fluid from the first system can be introduced underwater into the second system, wherein, above a certain intake quantity of a fluid-seawater mixture, the hydraulic clutch opens a connection from the first system to the second system.

The hydraulic arrangement presented here has the particular advantage that, due to the arrangement of the hydraulic clutch between the first system and the second system, a penetration of seawater into the second system is reliably prevented. In particular, in a constructively elegant way, the clutch makes it possible to introduce the fluid - preferably, oil - into the second system, without any contamination by seawater.

Here, a filler rod (hot stab) is provided, which makes it possible to refill fluid in the event of a leak. A further special advantage is that, with the introduction of the filler rod into the clutch, seawater displaced from the clutch is expelled again without being able to flow into the second system along with the oil.

The hydraulic clutch preferably comprises a hydraulic cylinder with a spring-loaded, slidable piston and a cylinder chamber (hereinafter referred to as 'second' cylinder chamber - in particular, also in connection with the figures). Preferably, above a certain intake quantity of a fluid-seawater mixture in the (second) cylinder chamber, the hydraulic clutch opens the (fluidic) connection from the first system to the second system.

A system here means, in particular, a system unit or an apparatus. A hydro-cylinder can also take the form of a hydraulic cylinder. A hydro-cylinder can be configured for operation with hydraulic fluid at higher pressures (from approx.100 bar).

The first system preferably comprises at least one pressurized storage tank for the fluid, e.g., a canister. The storage tank can, usefully, be contained in a remote-controlled underwater vehicle or be stationed at a fixed location. Advantageously, the underwater vehicle is designed as a robot with the filler rod. The stationary storage tank can be stationed on the sea floor or above the sea. The storage tank can take the form of a tank with a pump (with a suction port and a pressure port), which is controlled as required. The storage tank can also take the form of a container-like module.

Furthermore, the first system preferably comprises a remote-controlled, underwater filling device with the filler rod. The underwater filling device is connected to the storage tank (reservoir). In this way, the underwater filling device can be connected via so-called umbilicals with hydraulic lines to a supply from a hydraulic power unit (HPU) above the sea. The filler rod (hydraulic connector) is suitably connected to the umbilical.

Preferably, the filler rod has a filler nozzle in which an internal valve is present.

Preferably, the first system has a hydraulic, closed-loop control device for a delivery of the fluid. The closed-loop control device includes or is in communication with an on/off device for the flow of the fluid from the first system.

Preferably, the second system comprises a container with an internal space that is set up for creating a volume which is closed off to the environment and for receiving a hydraulic pressure fluid. Advantageously, at least one hydraulic component is arranged in the internal space of the container. The hydraulic component usefully includes an electro-hydraulic actuator.

The hydraulic clutch is preferably arranged in the internal space of the container or (directly) on the container.

Advantageously, the fluid is an oil - in particular, a hydraulic oil. The fluid is preferably a dielectric fluid, such as a transformer oil.

A non-return valve is advantageously arranged in the connection from the first system to the second system. The non-return valve, as a rule, has a spring, so that the container with the oil (second system) has an overpressure. In particular, the non-return valve prevents leakage of hydraulic oil from the (second) system that is to be filled.

The hydraulic cylinder preferably has a first cylinder chamber and a third cylinder chamber, to which vacuum or underpressure is applied.

A non-return valve is, appropriately, associated with the first cylinder chamber and prevents the ingress of seawater into the first cylinder chamber (vacuum chamber), but allows residual fluid (oil-seawater mixture) to leak to the outside and restores a vacuum. The non-return valve, as a rule, is loaded by a spring.

Furthermore, the hydraulic clutch is preferably used for the direct operation of a hydraulic cylinder or hydraulic motor (actuator). A direct connection of the filler rod in order to actuate the hydraulic cylinder (of an electro-hydraulic actuator) may be enabled; for this purpose, servo-assisted valves may usefully be employed. The hydraulic motor can be moved in both directions.

In particular, a device for underwater arrangement is proposed, wherein, between a storage tank for oil and a container with a hydraulic actuator, a hydraulic clutch is provided, by means of which the oil from the storage tank can be introduced underwater into the container, wherein the clutch comprises a hydraulic cylinder, which opens a connection from the storage tank to the container.

According to a further aspect, an arrangement is proposed, wherein a fluid from the second system can also be introduced underwater into the first system by means of the hydraulic clutch, wherein the hydraulic clutch opens a connection from the second system to the first system. For this purpose, two bi-directional connections (channels) are preferably provided in order for fluids to be changed in the case of aging or for flushing in the event of contamination. The two hydraulic flow lines (in and out) each have a pressure-relief valve.

The invention and the technical environment are explained in detail below with the aid of figures. Here, the same components are denoted by the same reference numerals. Representations are schematic and are not intended to illustrate relative sizes. The explanations provided with regard to individual details can be extracted and can be freely combined with matter from other figures or from the above description, unless something different necessarily emerges for a person skilled in the art, or such a combination is explicitly forbidden here. They schematically show:

Fig.1: a side view of an arrangement with a hydraulic clutch between an underwater vehicle and an electro-hydraulic actuator,

Fig.2: a block diagram with a first system, a second system, and a hydraulic clutch, as well as flow directions of fluids,

Figs.3a through 3e: a side view in section of an embodiment of the hydraulic clutch in different operating positions,

Figs.4a, 4b: an embodiment with an internal valve in the filler nozzle of the filler rod and a storage tank, and

Fig.5: an arrangement as shown in Fig.1, but with a direct connection of the filler rod to the hydraulic cylinder of an actuator.

Fig.1 shows an actuator for a process valve 1 with a process valve housing 2, through which a process valve channel 3 passes, at whose mouths pipes, not shown, continue, and in which a gaseous or liquid medium flows from the seabed to a drilling ship or to part of a drilling tower which projects from the sea. The flow direction is indicated by the arrow 4.

In the process valve housing 2, a cavity is formed which crosses the process valve channel 3 and within which a process valve slide 5 with a flow-through opening 6 can be moved transversely to the longitudinal axis of the process valve channel 3. In the state shown in Fig.1, the process valve channel 3 and the flow-through opening 6 in the process valve slide 5 do not overlap. In other words, the process valve 1 is closed. In one state (not shown), the flow-through opening 6 and the process valve channel 3 largely overlap. The process valve 1 is almost fully open.

A process valve of the type shown and of the application described should, on the one hand, be capable of controlled actuation and, on the other hand, also make a contribution to safety in the event of a problem by taking up a position which corresponds to a safe state. 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 underwater directly on the process valve 1. The hydraulic system 7 has a container 9, which is attached to the process valve housing 2 on an open side so that an internal space 10 closed to the environment is provided, and which is filled with a hydraulic pressure fluid - for example, oil. For mounting on the process valve housing 2, the container 9 has an inner flange on its open side, by which said container is bolted onto the process valve housing 2. Between the inner flange of the container 9 and the process valve housing 2, a circumferential seal 11 is arranged radially outside the bolted connections and is inserted into a circumferential groove in the process valve housing 2.

The container 9 is pressure-compensated with respect to the ambient pressure (seawater area 12) prevailing underwater. For this purpose, in the case of a pressure compensator 13 in an opening in the container wall, a membrane 14 is clamped so as to be leak proof. The internal space 10 is thus sealed off against the environment by means of the membrane 14. A cable 8 is led out of the container 9.

In the internal space 10 of the container 9, a hydraulic cylinder 15 with a cylinder housing 16 is present that is closed off at the ends by a cylinder bottom 17 and a cylinder head 18, with a piston 19 inside the cylinder housing 16 that is moveable along the longitudinal axis of the cylinder housing 16, and with a first piston rod 20 permanently attached to the piston 19 and at one end extending away from the piston 19, said piston rod being sealed off and, guided in a manner not illustrated, passing through the cylinder head 18. The gap between the piston rod 20 and the cylinder head 18 is sealed by two seals (not shown) in the cylinder head 18 that are arranged at an axial distance from each other. The process valve slide 5 is attached to the free end of the piston rod 20. Furthermore, a second piston rod 21 is present that is permanently connected to the piston 19 and projects from the piston 19 towards the other end, is guided while being sealed off, and passes through the cylinder bottom 17. The interior of the cylinder housing 16 is divided by the piston 19 into a first cylinder chamber 22 at the cylinder head end and a second cylinder chamber 23 at the bottom end whose volumes depend upon the position of the piston 19.

The cylinder chamber 22 accommodates a helical compression spring 24 that surrounds the piston rod 20 and is clamped between the cylinder head 18 and the piston 19, which, in other words, acts on the piston 19 in a direction in which the piston rod 20 is retracted, and the process valve slide 5 is moved so as to close the process valve 1.

The internal space 10 of the container 9 also contains a hydraulic machine 25 that can be operated as a pump with two conveying directions. The hydraulic machine 25 has a pressure port 26 and a suction port 27 that is open to the internal space 10. Pressure fluid sucked out of the internal space 10 by the hydraulic machine 25 operating as a pump can be pumped, via the pressure port 26, to the cylinder chamber 23. Conversely, pressure fluid can be displaced from the cylinder chamber 23, via the hydraulic machine 25, into the internal space 10 of the container 9. An electric machine 28 for a common rotary motion is mechanically coupled to the hydraulic machine 25 - for example, via a shaft.

Furthermore, a hydraulic clutch 32 is provided, by means of which oil from a first system 30 (for example, a tank or refill station, or an emergency-operation robot) can, underwater, be introduced into a second system 31 (an actuator, for example) without contamination with seawater occurring.

The hydraulic clutch 32 includes a block 33 and a filler rod 34 (hot stab). The block 33 is arranged in the internal space 10 of the container 9, while, in the example shown, a rod-shaped filler nozzle 35 inside the block 33 and a connector part 36 outside the block 33 are present. A remote-controlled underwater vehicle 37, which contains a storage tank 38 as a reservoir for oil, is connected to the connector part 36. A closed-loop control device for the oil flow from the underwater vehicle 37 to the clutch 32 is denoted by 39. The closed-loop control device 39 includes or is in communication with an on/off device for the flow of the fluid from the storage tank 38.

The underwater vehicle can take the form of a remotely-operated vehicle (ROV), autonomous underwater vehicle (AUV), or subsea crawler (for example, for mining or laying of cables).

A (hydraulic) arrangement can be installed in a new (hydraulic) device or retrofitted in an existing (hydraulic) device.

Fig.2 shows a block diagram with the hydraulic clutch 32 between the first system 30 and the second system 31. The hydraulic clutch 32 is also connected to the seawater area 12 and to an output area 40. The arrows 41 and 42 denote a stream of oil, the arrow 43 denotes a stream of seawater, and the arrow 44 denotes a stream of oil and seawater. The arrowheads indicate the direction of flow.

According to Fig.3a, the filler rod 34 consists of an essentially cylindrical filler nozzle 35 and a connector part 36 permanently connected to it. The filler nozzle 35 consists of a hollow cylindrical portion and a solid cylindrical portion. In the longitudinal direction, the internal space of the hollow cylindrical portion is formed as a channel 45 closed at one end (blind hole) and which, with the other open end, continues through the connector part 36. In the area of the closed end of the channel 45, the hollow cylindrical portion is formed on its outer side as a circumferential groove 46. In the area of the groove 46, there is a through-channel 47 present that crosses the channel 45. The filler rod 34 is movable in the directions shown by the arrows A and B.

The block 33 (filling module) includes in its interior a hole 48 (interface hole), a hydraulic cylinder 49, and several channels for the flow of fluid. On an outer side of the block 33 and permanently attached to it, an essentially cylindrical filling element 50 is arranged, which - like the filler rod 34 - has a hollow cylindrical portion and a solid cylindrical portion. The hollow cylindrical portion contains a channel 51 which extends with one end into the block 33. In the area of the other end of the channel 51, a circumferential groove 52 is present, wherein the channel 51 is crossed by a through-channel 53. The filling element 50 projects into the internal space 10 of the container 9 (see Fig.1).

The hydraulic cylinder 49 has a piston 54, which divides the internal space into a first cylinder chamber 55 (vacuum chamber) and a second cylinder chamber 56 (see Fig.3c). In the first cylinder chamber 55, there is a compression spring 58 that is supported, with one end, on the piston 54 and, with the other end, on an inner wall of the cylinder chamber 55. On the side facing away from the compression spring 58, at one end of the piston 54, a piston rod 59 is arranged, which engages a hole 60 which is closed at one end. In the area between the end face of the piston rod 59 and the closed end of the hole 60, a third cylinder chamber 57 (vacuum chamber) is formed. In the interior of the hollow-cylindrical piston rod 59, there is, on the longitudinal axis, a channel 61, which extends continuously from the first cylinder chamber 55 to the third cylinder chamber 57. In the end portion of the piston rod 59 that faces the cylinder chamber 57, a circumferential groove 62 is present on the outer side. The piston 54, the compression spring 58, and the piston rod 59 can be moved in the directions of arrows C and D.

The hole 48 is connected to the channel 51 via the channels 63, 64, and 65. In addition, the hole 48 is connected to the second cylinder chamber 56 (see Fig. 3c) via the channel 63 and via a channel 67 branching off from the channel 63. Between the channels 63 and 64, a non-return valve 66 is mounted. Furthermore, between the first cylinder chamber 55 and the outside, two channels 67 and 69 are provided, between which a non-return valve 68 is located.

An embodiment of the hydraulic clutch 32 is illustrated in various operating positions in Figs. 3a through 3e.

According to Fig. 3a, the filler rod 34 lies outside the block 33 in the seawater area 12. There is also seawater in the hole 48.

According to Fig.3b, the filler nozzle 35 of the filler rod 34 is inserted in the hole 48. Seawater is thus present in the circumferential groove 46. A valve (not shown) is then opened so that oil under pressure flows through the channel 45 from the storage tank 38 (see Fig.1) and into the groove 46, whereby, in the groove 46, an oil/seawater mixture is created, which is under pressure.

In Fig. 3c, the oil/seawater mixture - under the pressure of the oil inflowing through the channel 45 and the channel 47 - correspondingly flows through the channel 63 into the channel 67 and pushes the piston 54 with the piston rod 59 against the action of the compression spring 58 in the direction C. This creates the second cylinder chamber 56, into which the oil/seawater mixture flows (arrow 44). At the same time, the piston 54 pushes residual fluid out of the first cylinder chamber 55 through the channel 75, the non-return valve 68, and the channel 69. The pressure of the oil in the channel 63 is not sufficient to open the non-return valve 66. The compressive force of the compression spring 58 is weaker than the compressive force of the compression spring 76 (shown in detail) of the non-return valve 66 (seat valve).

According to Fig. 3d, the piston 54 is moved in direction C until the path for the oil is opened. The second cylinder chamber 56 has initially received a first quantity of the oil/seawater mixture. Above a certain intake quantity, the piston 54 opens a connection to the filling element 50, and thus to the second system 31. This release is effected by the groove 62 being moved along with the piston rod 59 in the direction C, whereby the groove 62 overlaps with the channels 64 and 65. At the same time, the pressure of the oil in the channel 63 causes the non-return valve 66 to open. The oil (arrow 42) thus flows through the channel 65 into the channel 51 of the filler element 50.

According to Fig. 3e, the flow of oil through the channel 45 first stops after a valve (not shown) is closed, and the filler rod 34 then moves in the direction B, and the filler nozzle 35 is thereby withdrawn from the hole 48. The non-return valve 66 is, as a result, closed. Under the pressure of the compression spring 58, the piston 54 moves in the direction D and pushes the oil/seawater mixture out of the second cylinder chamber 56 through the channels 67 and 63, and, via the hole 48, out of the block 33.

Figs.4a, 4b show an embodiment with an internal valve 70 in the filler nozzle 35 of the filler rod 34. For this purpose, a rod-shaped slide 71 with a cylindrical portion 72 and a head portion 73 is present in the channel 45. The cylindrical portion 72 slides within the channel 45 and extends, with one end, past the groove 46 and, with the other end, past the end face of the filler nozzle 35.

Fig.4a shows the valve 70 in the closed position. Correspondingly, in Fig.4b, the filler nozzle 35 of the filler rod 34 has been moved so far in direction A that the channel 47 and the channel 63 overlap, whereby the valve 70 is opened. Here, the head portion 73 contacts the closed end face of the hole 48, whereby the slide 71 and, with it, the cylindrical portion 72 are moved in the direction B. Within the cylindrical portion 72, a channel 74 is provided, which crosses the channel 45 and, in the position shown in Fig.4b, forms a continuous connection with the channel 47 so that oil can flow (arrow 41).

Fig. 5 shows an arrangement as in Fig. 1, but with a direct connection of the filling rod 34 to the hydraulic cylinder 15 of an actuator. Servo-assisted valves can be installed in the lines from the filler element 50 to the first cylinder chamber 22 and to the second cylinder chamber 23. For this purpose, the filler element 50 is designed with two connectors, wherein a first connector is connected to the first cylinder chamber 22, and a second connector is connected to the second cylinder chamber 22. In the connection starting from the second connector, fluid can be conveyed into the second cylinder chamber 22, wherein the piston 19 is moved to the left or held at a stop, and thus the process valve 1 is kept closed. The fluid displaced from the first cylinder chamber 22 can flow away via the branch-off and the safety valve, going from the connection to the first connector in the container 9. To open the process valve 1, fluid can be guided via the first connector into the first cylinder chamber 22, whereby the piston 19 is moved to the right or held at a stop. By a reciprocal operation, filling the container 9 with fluid can thus also be carried out.

List of reference symbols

1 Process valve

2 Process valve housing

3 Process valve channel

4 Arrow

5 Process valve slide

6 Flow-through opening

7 Electro-hydraulic system

8 Cable

9 Container

10 Internal space

11 Seal

12 Seawater area

13 Pressure compensator

14 Membrane

15 Hydraulic cylinder

16 Cylinder housing

17 Cylinder bottom

18 Cylinder head

19 Piston

20 First piston rod

21 Second piston rod

22 First cylinder chamber

23 Second cylinder chamber

24 Helical compression spring

25 Hydraulic machine

26 Pressure port

27 Suction port

28 Electric motor

29 Electro-hydraulic actuator

30 First system

31 Second system

32 Hydraulic clutch

33 Block

34 Filler rod

35 Filler nozzle of 34

36 Connector part of 34

37 Remote-controlled underwater vehicle 38 Storage tank

39 Closed-loop control device

40 Output area

41 Oil stream

42 Oil stream

43 Seawater stream

44 Oil and seawater stream

45 Channel

46 Groove

47 Channel

48 Hole

49 Hydraulic cylinder

50 Filling element

51 Channel

52 Groove

53 Channel

54 Piston

55 First cylinder chamber

56 Second cylinder chamber 57 Third cylinder chamber 58 Compression spring 59 Piston rod

60 Hole

61 Channel

62 Groove

63 Channel

64 Channel

65 Channel

66 Non-return valve

67 Channel

68 Non-return valve

69 Channel

70 Valve

71 Slide

72 Cylindrical part

73 Head part

74 Channel

75 Channel

76 Compression spring

Claims (13)

Claims

1. Arrangement for use underwater with a hydraulic clutch (32), wherein, between a first system (30) and a second system (31), the hydraulic clutch (32) is provided, with which a fluid from the first system (30) can be introduced underwater into the second system (31), wherein, above a certain intake quantity of a fluid-seawater mixture, the hydraulic clutch (32) opens a connection from the first system (30) to the second system (31).

2. Arrangement according to claim 1, wherein the hydraulic clutch (32) [has] a hydraulic cylinder (49) with a spring-loaded, slidable piston (54) which opens the connection of the first system (30) to the second system (31).

3. Arrangement according to one of the preceding claims, wherein the first system (30) comprises at least one pressurized storage tank (38) for the fluid.

4. Arrangement according to claim 3, wherein the storage tank (38) is contained in a remotecontrolled underwater vehicle (37) or is stationed in a fixed location.

5. Arrangement according to one of the preceding claims, wherein the first system (30) includes a remote-controlled, underwater filling device with a filler rod (34).

6. Arrangement according to one of the preceding claims, wherein the first system (30) comprises a hydraulic, closed-loop control device (39) for a delivery of the fluid.

7. Arrangement according to one of the preceding claims, wherein the second system (31) comprises a container (9) with an internal space (10) that is present to form a volume closed off to the environment and provided for receiving a hydraulic pressure fluid.

8. Arrangement according to one of the preceding claims, wherein at least one hydraulic component comprising an electro-hydraulic actuator (29) is arranged in the internal space (10) of the container (9).

9. Arrangement according to one of the preceding claims, wherein the hydraulic clutch (32) is arranged in the internal space (10) of the container (9) or on the container (9).

10. Arrangement according to one of the preceding claims, wherein a non-return valve (66) is arranged in the connection from the first system (30) to the second system (31).

11. Arrangement according to one of the preceding claims, wherein the hydraulic cylinder (49) has a first cylinder chamber (55) and a third cylinder chamber (57) to which vacuum or underpressure is applied.

12. Arrangement according to one of the preceding claims, wherein the hydraulic clutch (32) is used for the direct drive of a hydraulic cylinder (49) or hydraulic motor.

13. Arrangement according to one of the preceding claims, wherein a fluid from the second system (31) can also be introduced underwater into the first system (30) with the hydraulic clutch (32), wherein the hydraulic clutch (32) opens a connection from the second system (31) to the first system (30).