Gas discharge device for an electric line, and system comprising such a gas discharge device

Abstract

The gas discharge device (10) according to the invention for an electric line (11) has a collecting container (12) with a blocking device (16), which is paired with the collecting container (12) and which is designed to press the electric line (11) in the radial direction such that a gas-tight blocking section (18) is formed in the electric line (11). The gas discharge device (10) additionally has a container gas discharge (31) which is connected to the container interior (14) of the collecting container (12) in a gas-tight manner and which is designed to discharge gas collected in the container interior (14), preferably into another ignition protection zone. By pressing the electric line, the radius of the electric line is reduced, and the electric line is deformed such that any intermediate spaces (27) between the individual conductors (26) are closed. The system according to the invention comprises at least one gas discharge device (10) which is arranged between a first zone (Z1) with first ignition protection types and a second zone (Z2) with second ignition protection types such that the blocking section (18) produced by the blocking device (16) seals off the second zone (Z2) from the first zone (Z1) in a gas-tight manner along the electric line.

Description

R. Stahl Schaltgeräte GmbH 24 October 2023 Am Bahnhof 30 STSA P230 WO paza 74638 Waldenburg Keyword: Hydrogen Accumulation AKER Crimp Solution Gas discharge device for an electrical cable and system with such a gas discharge device

[0001] The invention generally relates to a gas discharge device for an electrical line and a system comprising such a gas discharge device.

[0002] Electrical cables, such as electrically conductive cables, traditionally consist of at least one electrical conductor and an electrically insulating sheath and are used in a wide variety of applications for transporting electrical energy or signal transmission. Different ambient pressures can prevail at the connection points of the electrical cable, which can lead to gases migrating along the electrical cable, for example, between the electrical conductor(s) and the insulating sheath.

[0003] Particularly in submarine high-voltage direct current (HVDC) transmission lines, corrosion of the insulating sheath, which is usually made of plastic, can cause parts of the HVDC line to act as a cathode, resulting in the formation of hydrogen. The resulting hydrogen can migrate along the HVDC line, creating an increased risk of ignition or explosion along the HVDC line.

[0004] In addition, in submarine cables with galvanized reinforcements, a reaction of the galvanized reinforcement with salt water can lead to the formation of hydrogen gas, which can spread along the submarine cable.

[0005] KR 20030017 137 A describes an electrical high-voltage line whose insulating sheath is made of cross-linked polyethylene. During production of the high-voltage line, the cross-linking reaction produces methane gas, which at least partially remains in the high-voltage line. Furthermore, during operation, due to the high operating voltage, which can lead to high temperatures and arcing, partial decomposition of the insulating sheath can occur, resulting in the formation of gases such as methane and hydrogen. To remove these gases, KR 2003 0017 137 A proposes a tubular element with a gas outlet hole, which is arranged in the end region of a high-voltage line on either side of a junction where two high-voltage lines are connected.

[0006] Particularly in areas with several separate zones in which different defined types of ignition protection prevail, such as "flameproof enclosure" (Ex-d), "increased safety" (Ex-e), "intrinsic safety" (Ex-i), etc., if the electrical cables bridging the zones are not sufficiently sealed longitudinally, explosive gases can migrate from one zone along the electrical cable to another zone (so-called zone entrainment) and pose an explosion hazard there.

[0007] Based on this, the object of the invention is to provide a gas discharge device for an electrical line and a system with such a gas discharge device, which in particular prevents a controlled discharge of gases, such as hydrogen, which can migrate along an electrical line.

[0008] This object is achieved with the gas discharge device for an electrical line according to claim 1 and the system with at least one gas discharge device according to claim 14:

[0009] The gas removal device according to the invention comprises a collecting container with a blocking device. The collecting container has a container interior formed by a gas-tight container housing, which is arranged around a longitudinal section of the electrical line. The gas removal device also has a container gas outlet, which is connected in a gas-tight manner to the container interior of the collecting container and is designed to remove the gas collected in the container interior. The blocking device is arranged at a location at which the electrical line is led out of the container interior through the container housing. The pressing device is designed to press the electrical line in the radial direction such that a gas-tight blocking section is formed in the electrical line.

[0010] A special feature of the gas discharge device according to the invention is that the gas-tight barrier section formed by the barrier device can prevent gas, which normally flows unhindered along the electrical line, for example between the individual electrical conductors and / or between the Conductors and insulation, can be prevented from migrating (diffusing), so that it accumulates in the collection container and can be removed (discharged) in a controlled manner via the container gas discharge. This prevents the uncontrolled escape of gases such as hydrogen and / or oxyhydrogen, a stoichiometric mixture of hydrogen and air, especially hydrogen and oxygen. Furthermore, the phenomenon of zone entrainment can be counteracted, especially without having to disconnect the electrical line.

[0011] An electrical cable has, in particular, at least one electrical conductor or one electrical cable core and at least one insulating sheath or insulation. The pressing of the electrical cable leads to a preferably permanent, plastic deformation of the individual electrical conductors present in the cable as well as of the electrically insulating sheath, whereby the spaces between the individual electrical conductors and between the electrical conductors and the sheath in the blocking section are closed. The gas-tightness of the electrical cable in the blocking section can thus be improved. The blocking section formed in the cable has a reduced radius and / or a modified circumferential shape compared to the rest of the electrical cable. The pressing of the electrical cable is particularly advantageous when the electrical conductors are designed as cable strands.The insulating sheath of the electrical cable is made, in particular, of plastic, such as a thermoplastic or thermosetting plastic. The collecting container can, for example, be at least substantially cylindrical. Any gas present in the collection container before the gas is collected can mix with the gas that is collected in the collection container, which may result in an explosive gas mixture, such as oxyhydrogen gas, being present in the collection container, which is then discharged in a controlled manner into another ignition protection zone via the container gas discharge.

[0012] By means of the blocking device, the electrical line can be deformed in the radial direction in such a way that a blocking section is formed in the electrical line, which at least reduces, preferably at least substantially completely prevents, gas migration along the electrical line beyond the blocking section.

[0013] Gases such as hydrogen, oxyhydrogen, or methane, which can normally migrate along the electrical line between the individual conductors, the individual wires, or the individual wires and the insulation, are blocked in the barrier section. The barrier section created by the barrier device thus increases the longitudinal tightness of the electrical line, with the gas migrating in the electrical line being collected by the collecting container.

[0014] The blocking device is particularly designed to plastically and permanently deform the electrical line in the radial direction. The collecting container is particularly arranged upstream of the blocking section in the gas flow direction, so that the gas accumulating upstream of the blocking section can be absorbed by the collecting container. The blocking device can be designed as a blocking sleeve that is connected to the container housing in a gas-tight manner. Alternatively, the locking device can also be designed as a cable gland, in which the electrical cable can be compressed in the radial direction by means of a screw mechanism. The cable gland is also preferably connected to the container housing in a gas-tight manner. Preferably, the locking sleeve or the cable gland is seamlessly connected to the container housing. The locking sleeve and the container housing can also be formed as a single piece.

[0015] Preferably, the electrical line is formed by a plurality of individual wires, wherein the individual wires are plastically deformed in the blocking section in such a way that the individual wires are positively connected to one another.

[0016] In particular, the blocking device is designed as a permanently deformable blocking sleeve through which the electrical line is guided and which is connected gas-tight to the container wall.

[0017] It is preferred that the electrical line be encased in an electrically insulating sheath, wherein the sheath is pressed onto the electrical line in the blocking section such that the sheath and the electrical line are positively connected to one another. The electrical sheath is preferably made of a plastic, such as a thermoplastic or thermosetting plastic.

[0018] In particular, the container interior is at least partially filled with a gas-permeable, electrically insulating material, which poses a risk of short-circuits. The risk of short circuits can be reduced. Preferably, the sheath of the electrical cable is at least partially removed in at least one section of the container interior. The at least partial removal of the sheath facilitates the escape of gas from the electrical cable. In this context, filling the container interior with a gas-permeable, electrically insulating material increases the safety of the gas discharge device, as the risk of short circuits can be reduced.

[0019] Preferably, in the section where the sheathing of the electrical cable is removed, a gas-permeable, electrically insulating sheath is arranged around the electrical cable. This can increase the safety of the gas discharge device while minimizing the obstruction of gas escape. The insulating sheath can be designed, for example, as a gas-permeable, perforated shrink tube or a gas-permeable, perforated insulating tape.

[0020] The gas discharge device preferably also comprises a container seal, which is arranged at a point on the container where the electrical line enters the collecting container, between the sheath of the electrical line and the container housing, such that the container interior is sealed gas-tight from the environment. This makes it possible to collect the gas in the collecting container. In particular, the container seal is arranged on an opposite side of the blocking device. The electrical line enters the interior of the container through the container seal and exits the collecting container again through the blocking device.

[0021] The container seal is preferably designed as a sleeve through which the electrical cable is guided into the container interior. The sleeve is compressed in such a way that a gas-tight connection exists between the sheath of the electrical cable and the sleeve. The sleeve is particularly compressed in such a way that the sheath of the electrical cable rests against the sleeve without a gap. The interior of the electrical cable preferably remains at least substantially undeformed.

[0022] In particular, the container gas discharge system comprises a container outlet attached to the collecting container and a pressure relief body through which the gas collected in the inner container space can be discharged into another ignition protection zone. This enables controlled discharge of the gas.

[0023] The container gas discharge preferably has a gas outlet unit that defines an interior space that is fluidly connected to the container interior via the container outlet. The gas outlet unit preferably has an opening in which the pressure relief body is arranged. The pressure relief body can also be formed in the interior space of the gas outlet unit by preferably at least partially filling the interior space of the gas outlet unit with a porous, gas-permeable material. For example, a gas-permeable membrane, a sintered metal disc and / or a labyrinth seal is provided in the interior space of the gas outlet unit. The gas outlet unit is in particular arranged remotely from the collecting container and connected to the container outlet via a gas outlet line.

[0024] The object of the invention is also achieved by a system with an electrical line and at least one gas discharge device of the above type. The system according to the invention has a first zone in which ignition protection types are defined that are appropriate to the probability of occurrence of an explosive mixture, and a second zone, separate from the first zone, in which other ignition protection types are defined, in particular suitable for a higher probability of occurrence, than in the first zone. The electrical line bridges the first and second zones, with the blocking section created by the blocking device sealing the second zone from the first zone along the electrical line.

[0025] All features and advantages described with respect to the gas discharge device according to the invention are also applicable to the system according to the invention.

[0026] Preferably, the electrical line has a plurality of conductor wires, wherein the system provides at least one separate blocking device of the gas discharge device of the above type for each conductor wire.

[0027] Further details of advantageous developments or details of the invention can be found in the drawings, the description, and the dependent claims. They show:

[0028] Figure 1 is a schematic view of an embodiment of the gas discharge device according to the invention;

[0029] Figure 2 is a schematic view of another embodiment of the gas discharge device according to the invention;

[0030] Figure 3 shows a cross-section of an electrical cable in the uncompressed state;

[0031] Figure 4 is a cross-sectional view of the electrical cable in the crimped state;

[0032] Figure 5 is a cross-sectional view of an embodiment of the container seal;

[0033] Figure 6 is a cross-sectional view of another embodiment of the container seal;

[0034] Figure 7 shows an embodiment of the system according to the invention; and

[0035] Figure 8 shows a further embodiment of the system according to the invention.

[0036] Figure 1 shows a schematic view of an embodiment of the gas removal device 10 according to the invention for an electrical line 11. The gas removal device 10 comprises a collecting container 12 with a container interior 14 formed by a gas-tight container housing 13. The gas removal device 10 also comprises a container gas outlet 31, which is connected in a gas-tight manner to the container interior 14 of the collecting container 12 and is designed to remove the gas collected in the container interior 14, preferably into another ignition protection zone. The collecting container 12 is arranged around a longitudinal section 15 of the electrical line 11. The gas discharge device 10 also has a blocking device 16.

[0037] In Figure 1, the arrows 17 schematically depict a gas flow that travels along the electrical line 11 and is discharged via the collecting container 12 through the container gas discharge 31. In the example shown in Figure 1, the blocking device 16 is arranged at the point where the electrical line 11 is guided through the container housing 13 out of the container interior 14. With the blocking device 16, the electrical line can be compressed in the radial direction such that a gas-tight blocking section 18 is formed in the electrical line 11.

[0038] In the example shown in Figure 1, the locking device 16 is designed as a locking sleeve that can be pressed from the outside, for example with pliers, onto the electrical line arranged therein in such a way that the individual conductors 26 of the electrical line 11 are positively connected in the locking section 18. The locking sleeve can be designed as a closed or C-shaped sleeve. In particular, no gap remains between the individual conductors 26 of the electrical line 11 in the formed locking section 18.

[0039] The collection container 12 also has a container outlet 19 through which the gas collected in the collection container 12 can escape. Alternatively, it is also possible for the gas collected in the collection container 12 to be a suction device (not shown).

[0040] In addition, the casing 20 is removed in a section 21 inside the container 12. Alternatively, the casing 20 can also be perforated in this area.

[0041] In Figure 1, the gas discharge device 10 is arranged between a first zone Z1 and a second zone Z2, which are separated from each other by an enclosure 23. In the first zone Z1, for example, the ignition protection type is "flameproof enclosure" (also called ex-d), while in the second zone Z2 the ignition protection type is "increased safety" (also called ex-e). To prevent gas from migrating or creeping from the first zone Z1 into the second zone 2, the blocking device 16 in Figure 1 is pressed onto the line 11 arranged therein in such a way that a gas-tight blocking section 18 is formed in the electrical line 11.

[0042] On the opposite side of the container 12 in Figure 1, a container seal 22 is provided, which is formed by a sleeve through which the electrical line 11 is guided into the container interior 14. The container seal 22 is pressed onto the electrical line 11 in such a way that a gas-tight connection exists between the sheath 20 of the electrical conductor 11 and the sleeve, which allows the gas migrating in the electrical line to be collected in the collecting container 11 and discharged in a controlled manner via the outlet 19 of the container 12.

[0043] Figure 2 shows another embodiment for the gas discharge device 10. What was said above with regard to Figure 1 applies accordingly to Figures 2 to 8, using the reference numerals.

[0044] The example shown in Figure 2 differs from the example shown in Figure 1 in that the collecting container 12 is arranged inside the second zone Z2, whereas the collecting container 12 in Figure 1 is arranged in the zone Z1. In this exemplary embodiment, the gas collected in the collecting container 12 is discharged via the container gas discharge 31, which has a gas outlet line 24 and a gas outlet unit 25, the opening of which points towards the first zone Z1. The gas collected in the collecting container 12 can thus be returned via the gas outlet line 24 into the gas outlet unit 25 and from there into the first zone Z1. The opening of the gas outlet unit 25 can also point into another zone whose type of ignition protection differs from the first zone Z1 and the second zone Z2. A pressure relief body can be provided in the opening of the gas outlet unit 25.The gas outlet unit 25 has an interior space which, in the example shown in Figure 2, is at least partially filled with a porous, gas-permeable material.

[0045] Figure 3 shows a cross-sectional view of an example of the electrical line 11. In the example shown in Figure 3, the electrical line 11 has a plurality of electrically conductive individual conductors 26 which are guided in a bundle within the insulation 20.

[0046] In Figure 3, gaps 27 are schematically shown between the individual wires 26, through which gases can migrate along the electrical line 11.

[0047] Figure 4 shows a cross-sectional view of the blocking section 18 of the electrical line 11. The individual electrical conductors 26 are plastically deformed in Figure 4, so that the individual conductors 26 are positively connected and adjoin one another. There are no gaps 27 between the individual conductors 26.

[0048] The positively connected individual conductors 26 thus form a blocking section 18 which blocks the migration of gas along the electrical line 11.

[0049] The electrical line 11 has a sheath 20, which has been deformed by the locking device 16. The sheath 20 is also positively connected to the individual wires 26, so that here, too, there is no gap between the individual wires 26 and the insulation 20. Gas migration between the individual conductors 26 and the sheath 20 along the electrical line 11 is reduced in the locking section 18, preferably completely prevented.

[0050] In Figure 4, the locking device 16 is also shown around the electrical line 11, which in the example shown is designed as a locking sleeve.

[0051] Figure 5 shows a cross-sectional view of the container seal 22. The container seal 22, like the locking device 16, can be designed as a sleeve.

[0052] In the example shown, the container seal 22 is formed by a sleeve 28 in which the electrical line 11 is arranged. The sleeve 28 of the container seal 22 is pressed onto the electrical line 11, but only to a certain extent, namely to such an extent that gaps 27 continue to exist between the individual wires 26 of the electrical line, whereby the sheath 20 is deformed such that the outer surface of the sheath 20 rests against the inner surface of the sleeve 28, which forms the container seal 22, thereby creating a positive, gas-tight connection.

[0053] Figure 6 shows another example of the container seal 22. In the example shown in Figure 6, in contrast to the example shown in Figure 5, the sleeve 28 is undeformed. A sealing element 29 is arranged between the inner wall of the sleeve 28 and the outer wall of the casing 20 in Figure 6, which seals the transition between the casing 20 of the electrical line 11 and the sleeve 28 in a gas-tight manner in the longitudinal direction of the electrical line 11. The sealing element 29 can be designed, for example, as an O-ring.

[0054] Figure 7 shows an embodiment of the system according to the invention, which comprises an electrical line 11 and a gas discharge device 10.

[0055] In the system shown in Figure 7, the first zone Z1 is separated from the second zone Z2 by the enclosure 23. The example shown in Figure 7 differs from the previous examples in that the electrical line 11 has two conductors 30. For illustrative purposes, only two conductors 30 are shown in Figure 7. However, the electrical line 11 can also comprise a plurality of conductors.

[0056] In Figure 7, the electrical line 11 is guided through the container seal 22 into the interior 14 of the container 12. In the container interior 14, the insulating sheath 20 of the electrical line 11 is removed, exposing the individual conductor wires 30. The individual conductor wires 30 each have their own electrically insulating sheath 20, which is removed in the section 21 within the container 12, so that the individual conductors 26 of the conductor wires 30 are exposed.

[0057] In the example shown in Figure 7, each cable core 30 is assigned its own blocking device 16, with which a blocking section 18 is created for each cable core 30 by pressing the cable core.

[0058] In the example shown in Figure 7, the blocking device 16 forms an outlet for each of the conductors from the collecting container 12, for which the convergence of the conductors 30 to form an electrical line 11 is arranged outside the container in the second zone Z2. The blocking sleeves are C-shaped in Figure 7 so that they can be subsequently attached to the individual conductors.

[0059] Figure 8 shows a further example of the system, wherein in the example shown in Figure 8, the convergence of the cable wires 30 is arranged within the container 12. At the outlet of the container 12, a further blocking device 16 is provided, which is pressed onto the electrical cable 11 in such a way that at least one gap between the cable wires and the sheath 20 of the electrical cable 11 is closed. can be achieved by plastically deforming the electrical line 11.

[0060] The gas discharge device 10 according to the invention for an electrical line 11 has a collecting container 12 with a blocking device 16 assigned to the collecting container 12, which is designed to compress the electrical line 11 in the radial direction such that a gas-tight blocking section 18 is formed in the electrical line 11. The gas discharge device 10 also has a container gas discharge 31, which is connected in a gas-tight manner to the container interior 14 of the collecting container 12 and is designed to discharge the gas collected in the container interior 14, preferably into another ignition protection zone. By compressing the electrical line, the radius of the electrical line is reduced and the electrical line is deformed such that any gaps 27 between the individual conductors 26 are closed.The system according to the invention comprises at least one gas discharge device 10 which is arranged between a first zone Z1 of a first type of ignition protection and a second zone Z2 of a second type of ignition protection such that the blocking section 18 created by the blocking device 16 seals the second zone Z2 in a gas-tight manner with respect to the first zone Z1 along the electrical line. List of reference symbols 10 Gas discharge device 11 Electrical line 12 Vessel 13 Vessel housing 14 Vessel interior 15 Longitudinal section 16 Pressing device 17 Arrows 18 Locking section 19 Vessel outlet 20 Insulation 21 Section 22 Vessel seal 23 Housing 24 Gas outlet line 25 Gas outlet unit 26 Single wire 27 Intermediate spaces 28 Sleeve 29 Sealing element 30 Cable core 31 Vessel gas discharge Z1 first zone Z2 second zone

Claims

Patent claims: 1.Gas discharge device (10) for an electrical line (11) encased in electrical insulation (20), comprising: a collecting container (12) with a container interior (14) formed by a gas-tight container housing (13) and arranged around a longitudinal section (15) of the electrical line (11), wherein the collecting container (12) is assigned a blocking device (16) arranged at a location on the container housing (13) at which the electrical line (11) is guided through the container housing (13) out of the container interior (14), wherein the blocking device (16) is designed to compress the electrical line (11) in the radial direction such that a gas-tight blocking section (18) is formed in the electrical line (11), and a container gas discharge (31) which is connected gas-tight to the container interior (14) of the collecting container (12) and is designed to discharge the gas collected in the container interior (14). 2.Gas discharge device (10) according to claim 1, characterized in that the insulation (20) in the blocking section (18) is pressed onto the electrical line (11) in such a way that the insulation (20) and the electrical line (11) are positively connected to one another.

3. Gas discharge device (10) according to claim 1 or 2, characterized in that the container interior (14) is at least partially filled with a gas-permeable insulating material (20).

4. Gas discharge device (10) according to one of the preceding claims, characterized in that the insulation (20) of the electrical line (11) is at least partially removed in at least one section (21) in the container interior (14).

5. Gas discharge device (10) according to claim 4, characterized in that in the section (21), a gas-permeable, electrically insulating sheath (20) is arranged around the electrical line (11).Gas discharge device (10) according to one of the preceding claims, characterized by a container seal (22) which is arranged at a point on the container (12) at which the electrical line (11) enters the collecting container (12), between the insulation (20) of the electrical line (11) and the container housing (13) in such a way that the container interior (14) is sealed off in a gas-tight manner from the environment.

7. Gas discharge device (10) according to claim 6, characterized in that the container seal (22) is designed as a sleeve (28) through which the electrical line (11) is led into the container interior (14), the sleeve (28) being pressed in such a way that between the insulation (20) of the electrical line (11) A gas-tight connection exists between the line (11) and the sleeve (28).

8. Gas discharge device (10) according to one of the preceding claims, characterized in that the container gas discharge (31) has a container outlet (19) attached to the collecting container (12) and a pressure relief body through which the gas collected in the container interior (14) can be discharged into another ignition protection zone.

9. Gas discharge device (10) according to claim 8, characterized in that the container gas discharge (31) has a gas outlet unit (25) which defines an interior space which is fluidically connected to the container interior (14) via the container outlet (19).

10. Gas discharge device (10) according to claim 9, characterized in that the gas outlet unit (25) has an opening in which a pressure relief body is arranged, and / or the interior of the gas outlet unit (25) is at least partially filled with a porous, gas-permeable material. 11.Gas discharge device (10) according to claim 9 or 10, characterized in that the gas outlet unit (25) is arranged away from the collecting container (12), preferably in another ignition protection zone, and is connected to the container outlet (19) via a gas outlet line (24).

12. Gas discharge device (10) according to one of the preceding claims, characterized in that the electrical line (11) is formed by a plurality of individual wires (26), wherein the individual wires (26) are deformed in the blocking section (18) such that the individual wires (26) are positively connected to one another.

13. Gas discharge device (10) according to one of the preceding claims, characterized in that the blocking device (16) is designed as a permanently deformable blocking sleeve through which the electrical line (11) is guided and which is connected in a gas-tight manner to the container wall.

15. System according to claim 14, characterized in that the electrical line (11) has a plurality of line wires (30), the system having at least one separate blocking device (16) for each line wire (30). the gas discharge device (10) according to one of claims 1 to 13.

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