WO2023213493A1

WO2023213493A1 - Connection assembly for a cryogenic line and cryogenic line

Info

Publication number: WO2023213493A1
Application number: PCT/EP2023/059035
Authority: WO
Inventors: Kevin BENZ; David EHRENBERGER; Alexander LEIPPI; Jörg LUDWIG
Original assignee: Witzenmann Gmbh
Priority date: 2022-05-03
Filing date: 2023-04-05
Publication date: 2023-11-09
Also published as: DE102022110880A1

Abstract

A connection assembly (1) in a cryogenic line (10) having an inner line element (11) and an outer line element (12), which outer line element (12) surrounds the inner line element (11) at least in one section and with a spacing (A), so that a free space (13) is formed between the inner and outer line elements (11, 12); • having: • an inner connection element (2), which is arranged, at least at one end of the line (10), on the inner line element (11); an outer connection element (3) which is arranged, at least at said end of the line (10), on the outer line element (12); a spacer element (4) that is arranged between the inner and the outer connection element (2, 3) and closes off the free space (13) from the surroundings; which spacer element (4) is formed as a grooved membrane disc and is arranged in a plane, which plane extends, at least at said end, transverse to a longitudinal axis of the line (10).

Description

Connection arrangement for a cryogenic line and cryogenic line

Description

The invention relates to a connection arrangement for a cryogenic line according to claim 1 and a cryogenic line according to claim 16.

Currently, a so-called Johnston coupling is generally used in industry and research to connect lines for the transport of cryogenic fluids.

EP 3670999 A1 shows a previously known Johnston coupling, in which the coupling plug is mechanically coupled to a linear displacement unit. The mechanical linear displacement unit makes it possible to insert the coupling plug centered into the coupling socket without the coupling plug or coupling socket rubbing against each other during the coupling process.

In order to sufficiently prevent the ingress of heat, the previously known connection (and basically any other type of Johnston coupling) is designed to be relatively long axially and insulated both with a vacuum and (with appropriate design) with multi-layer insulation (MLI). . To establish the connection, a long male plug part is inserted into an equally long female plug or socket part in order to create the longest possible heat incidence path.

Although good insulating effects can in principle be achieved in this way, the axial length of the coupling is too space-intensive for short cables, which are predominantly used in (auto)mobile applications, for example. There is a need for a connection arrangement for a cryogenic line or for such a line as a whole that is shorter in the axial direction while having the same good thermal insulating effect.

This object is achieved according to the invention by a connection arrangement for a cryogenic line with the features of claim 1 and by a cryogenic line with the features of claim 16.

Advantageous further training is defined in the respective subclaims.

A connection arrangement according to the invention in a cryogenic line with an inner line element and with an outer line element, which outer line element surrounds the inner line element at least in a section and at a distance so that a free space is formed between the inner line element and the outer line element, has: an inner connection member disposed at at least one end of the conduit on the inner conduit member; an outer connecting member disposed on the outer conduit member at at least said end of the conduit; a spacer element which is arranged between the inner connecting element and the outer connecting element and closes off the free space from the environment; which spacer element is designed as a grooved membrane disk and is arranged in a plane which extends, at least at said end, transversely to a longitudinal axis of the line.

A grooved membrane disk is a thin, preferably circular disk that is not flat or flat, but has concentrically circumferential, closed grooves or corresponding wave crests and troughs. The length of a heat conduction path from the center of the disk to its edge is therefore relatively long - much longer than the geometric disk radius. By arranging the disk transversely to the longitudinal axis of the line, the axial length can be significantly shortened without the thermal insulation properties suffering. This connection arrangement is intended and designed to interact releasably with a counterpart connection arrangement. This can be achieved in particular in that the outer connecting element of a given connection arrangement interacts with the outer connecting element of a further connection arrangement in a releasably connectable manner. The same applies to the respective inner connecting elements.

It is particularly advantageous if one of the two connection arrangements mentioned is arranged at each end of a cryogenic line in order to be able to produce a composite cryogenic line.

The connections can, as in the prior art, preferably be secured in the area of external connecting elements by a clamping ring or the like.

In the area of the inner connecting elements, the two connection arrangements mentioned can be designed in such a way that one of the two inner connecting elements can be inserted into the other inner connecting element. Sealing rings or the like can be used for sealing.

A cryogenic line according to the invention with an inner line element and with an outer line element, which outer line element surrounds the inner line element at least in a section and at a distance so that a free space is formed between the inner line element and the outer line element, has at least one end , preferably at both ends, a connection arrangement according to the invention, most preferably at one end a connection arrangement which is complementary to the connection arrangement at the other end. In addition to the representation of a detachable coupling in a line for cryogenic fluids with an axially short extension, the following further aspects should be taken into account in the course of corresponding developments of the invention:

• Isolation with vacuum and MLI as complete as possible, i.e. over the largest part of the cable length;

• Temperature resistance up to 250°C for accelerated evacuation;

• Avoidance of ice formation during operation, preferably through adequate thermal insulation using vacuum and MLI as well as long thermal conduction paths at the ends;

• Prevention of condensation and concentration of atmospheric oxygen, in particular by preventing contact of ambient air with cryogenic components (e.g. by providing an external seal);

• Integration of an adsorber to maintain the vacuum during operation (leakage, outgassing, etc.);

• Integration of a vacuum port for evacuation.

A first development of the connection arrangement according to the invention provides that the grooved membrane disk has a high wave shape. In the present case, this refers to shaft forming that is designed to such an extent that the maximum possible formability of the material used is utilized. To increase the shape, a heat treatment can also be carried out to achieve higher degrees of deformation between individual forming steps. Alternatively, hot forming can be used as a manufacturing process. Preferably, a height difference between a wave crest and a wave trough is approximately 2 times as large, preferably 1 time as large, most preferably 0.5 times as large as a distance between two adjacent wave crests. This makes it possible to provide a sufficiently long path for the incident heat to provide good thermal insulation for the connection. A second development of the connection arrangement according to the invention provides that the grooved membrane disk is thin-walled and made of a metallic material, preferably an austenitic chrome-nickel steel with a thermal conductivity of approximately 15 W/(m K), in order to represent the smallest possible thermal conduction path. This allows good weldability and diffusion tightness to be achieved.

In order to support the grooved membrane disk against the atmosphere, it can be provided that the grooved membrane disk has a number of beads.

It has proven to be particularly advantageous if the grooved membrane disk has beads, preferably three to six radial beads, which are most preferably designed in the direction of folded-in welded edges in order to limit the required axial installation space.

Another development of the connecting arrangement according to the invention provides that the inner connecting element is designed as a substantially smooth cylindrical sleeve part. In this way, a good connection to another connection arrangement can be easily established.

Another further development of the connection arrangement according to the invention provides that the outer connecting element has a larger cross section at its free end than at its other end; and that the grooved membrane disk is arranged in the area of the larger cross section in the outer connecting element. In this way, a relatively large grooved membrane disc can be used, which improves thermal insulation.

In order to further improve the support of the grooved membrane disk, another development of the connection arrangement according to the invention provides that a support element for supporting the grooved membrane disk against an ambient pressure is arranged (axially) adjacent to the grooved membrane disk is. This also makes it possible to achieve shear stiffening when joining the connecting arrangement. The support element is preferably made from a material with low thermal conductivity. It supports the grooved membrane disc and can additionally provide the mentioned shear stiffening for joining the coupling (connection arrangement).

Furthermore, it can also be provided that the support element has at least a first, outer contact section, in which the support element rests on the outer connecting element from the inside, preferably in the area of the larger cross section mentioned; and/or that the support element has at least a second, inner contact section in which the support element rests on the inner connecting element from the outside; and that the support element has at least one connecting section, which connecting section connects the outer contact section and the inner contact section and which connecting section has a course that deviates from a radial course and preferably has a circumferential and / or axial course component, so that preferably a length of the connecting section is maximized is. The support element has the smallest possible cross-sections and contact surfaces in order to further minimize heat transfer.

The support element is preferably designed in such a way as is specifically described below with reference to the figures.

Advantageously, the support element has a number of spring elements for radial tensioning between the inner connecting element and the outer connecting element in order to securely fasten the support element.

In order to achieve in particular a desirable temperature resistance up to 250 ° C for accelerated evacuation, in a further development of the connection arrangement according to the invention it can also be provided that the support element is made of a ceramic material, preferably a porcelain, most preferably titanium dioxide, or of a plastic, preferably of epoxy. Polyamide, polyimide, PEEK, PTFE or PCTFE. In order to improve the stability of the connection arrangement according to the invention, in particular when joining with a further, corresponding connection arrangement, it can also be provided that the support element has an axial extension component which is used to provide shear support for the inner line element and/or the inner connecting element relative to the outer line element and/or or serves as the external connecting element.

In order to evacuate the free space, in another development of the connection arrangement according to the invention it can also be provided that an opening is arranged in the outer connecting element, which opening is preferably arranged within a connecting piece projecting from the outer connecting element.

In yet another development of the connection arrangement according to the invention, it is preferably provided that an adsorber material is arranged in the free space, preferably in fluidic connection with the opening mentioned, which adsorber material preferably surrounds the inner line element in a ring. The adsorber material can preferably be silica gel, most preferably aluminum silicate with a porous microstructure. Its function is the adsorption of free molecules in the vacuum space in order to prevent conductive heat conduction.

It is particularly advantageous if, in a corresponding development of the connecting arrangement according to the invention, the outer connecting element has a receiving structure for receiving and in particular axially positioning the adsorber material, in particular at least one radially retracted section or a receiving area delimited by axial and / or radial walls, in the area of which receiving structure a material of the outer connecting element has openings which establish a fluidic connection between the free space and the adsorber material. The receiving structure can preferably have a (relatively long) axial extension component (based on an extension of the line elements) which is intended and suitable for thermal insulation by creating a long thermal conduction path.

In this way, the adsorber material can be located easily and safely and also does not hinder the evacuation of the free space.

For improved insulation, it is provided that in a further development of the line according to the invention the free space is evacuated or can be evacuated, preferably via the mentioned breakthrough.

In another development of the line according to the invention, the outer line element and/or the inner line element can be designed, at least in sections, as a corrugated hose made of metal. This makes the line flexible.

In yet another development of the line according to the invention, at least the inner line element can be surrounded at least in sections by a protective covering, preferably a braided hose. The line element can be supported and protected in this way. The braid also advantageously serves to increase the compressive strength of the inner hose (inner line element), which would otherwise lengthen in a disadvantageous manner.

In yet another development of the line according to the invention, at least the inner line element and possibly the protective covering mentioned can be surrounded at least in sections by insulation, preferably multi-layer insulation. This further improves the insulating effect against heat radiation.

Finally, in another development of the line according to the invention, the inner connecting element can protrude axially relative to the grooved membrane disk at least at one end of the line, preferably in this way the inner connecting element is guided through a breakthrough in the grooved membrane disk. This makes the connection to a subsequent line element easier.

Further properties and advantages result from the following description of exemplary embodiments based on the drawing.

Figure 1 shows a partial sectional view of a connection arrangement according to the invention;

Figure 2 shows in detail a partial sectional view of another embodiment of the connection arrangement according to the invention;

Figure 3 shows a possible embodiment of the support element in a connection arrangement according to the invention;

Figure 4 shows another possible embodiment of the support element in a connection arrangement according to the invention;

Figure 5 shows yet another possible embodiment of the support element in a connection arrangement according to the invention;

Figure 6 shows a longitudinal section of a connection arrangement according to the invention with the support element from Figure 5;

Figure 7 shows further details of a line arrangement with the connection arrangement from Figure 6;

Figure 8 shows partial images a) to c) possible configurations of the connecting arrangement according to the invention in the area of the outer connecting element;

Figure 9 shows the embodiment according to Figure 8a) in detail; and Figure 10 shows the outer connecting element in isolation according to the embodiment in Figure 9.

In Figure 1, an embodiment of the connection arrangement according to the invention for a cryogenic line is partially shown in a sectional view. Reference number L denotes the longitudinal axis of the connection arrangement, which is designated overall by reference number 1. Reference numeral 10 designates the cryogenic line as a whole.

As can be seen from the illustration in Figure 1, the cryogenic line 10 comprises an inner line element which is designed as an annular corrugated hose and is designated by the reference number 11. It also includes an outer line element, which is also designed as a ring corrugated hose and is designated by the reference number 12. The outer line element 12 surrounds the inner line element 11 at a (radial) distance A, whereby a free space 13 is created between the inner line element 11 and the outer line element 12. The cryogenic line 10 or the connecting arrangement 1 comprises an inner connecting element 2, which is arranged at the end of the line 10 shown on the inner line element 11, preferably in a materially bonded manner. The inner connecting element 2 is essentially designed in the manner of a circular cylindrical sleeve. In addition, the cryogenic line 10 or the connecting arrangement 1 comprises an outer connecting element 3, which is also arranged at the end of the line 10 shown on the outer line element 12, preferably in a materially bonded manner. The outer connecting element 3 is also sleeve-shaped, but has three areas 3.1-3.3 with different diameters. In addition, the connecting arrangement 1 also includes a spacer element 4, which is arranged between the inner connecting element 2 and the outer connecting element 3 - here in the area 3.3 with the largest diameter - and is preferably connected in a materially bonded manner to both the inner connecting element 2 and the outer connecting element 3 is. The spacer element 4 closes the free space 13 to the outside from the environment and is specifically designed as a grooved membrane disk, the grooves 4a of which are arranged concentrically around a central opening 4b. Through the opening 4b, the inner connecting element 2 protrudes outwards relative to the grooved membrane disk 4. The grooves 4a mentioned result from a sequence of concentrically arranged wave crests and wave troughs, the height difference H of which is relatively large relative to a wavelength I (distance between two adjacent wave crests), so that the longest possible heat conduction path between the inner connecting element 2 and the outer one Connecting element 3 results. In this way, the entire connection arrangement 1 is relatively short axially. The grooved membrane disk 4 is arranged in an (indicated or imaginary) plane E, which is oriented perpendicular to the longitudinal axis L of the cryogenic line 10.

A braided hose 14 is arranged around the inner line element 11, which in turn is surrounded by a multi-layer insulation 15. In the axial direction, the braided hose 14 and the multilayer insulation 15 extend up to the grooved membrane disk 4.

Preferably, all of the elements described so far, with the exception of the multilayer insulation 15, are formed in a thin-walled metallic material, preferably steel, in particular stainless steel.

In the area 3.2, the outer connecting element 3 has a receiving structure 3a for an adsorber material, which adsorber material is not shown in Figure 1. The receiving structure 3a is formed from an annular perforated plate with an approximately U-shaped cross section, which interacts with its free legs with the outer connecting element 3, preferably in a form-fitting manner, so that there is an annular circumferential free space 3b for the adsorber material between the outer connecting element 3 and the receiving structure 3a is formed, which reaches the end in the axial direction up to the grooved membrane disk 4. The receiving structure 3a also serves to provide shear support for element 2 relative to element 3, as can be seen even better in Figure 9, for example.

In the area 3.3, the outer connecting element 3 at the end at reference number 3d additionally has a circumferential recess (groove) into which a sealing element, such as an O-ring or the like, can be inserted in order to ensure a tight connection with the outer connecting element (not shown) to create another cryogenic line (not shown). The same applies to the inner connecting element 2.

In the upper area of Figure 1, the outer connecting element 3 advantageously has a radially outwardly pointing opening, which, however, cannot be seen in Figure 1. In the area of this opening there is a connecting piece 3c, of which only the lower end can be seen in the area of the free space 3b in Figure 1. The free space 13 can be evacuated via the mentioned connecting piece 3c for the purpose of vacuum insulation of the inner line element 11, the adsorber material serving to prevent conductive heat conduction by adsorbing free molecules in the vacuum space.

Figure 2 shows a slightly geometrically modified design in the area of the outer connection element 3 and the receiving structure, in which the adsorber material 5 is also shown. Otherwise, the same reference numbers designate the same or at least the same acting elements. For reasons of clarity, not all elements are always provided with reference numbers.

At reference number 6, an additional support element can be seen, which is preferably made of a plastic. It ensures that the grooved membrane disk is supported in the axial direction, if possible without creating a substantial heat conduction path between the inner connecting element 2 and the outer connecting element 3. For this purpose, the support element 6 preferably has lent small contact surfaces in contact with the connecting elements 2, 3 mentioned. The support element 6 is arranged in the central region 3.2 of the outer connecting element.

Figure 3 shows a representation with only an indicated line 10 and a more detailed representation of the support element 6. This comprises two concentric rings 6a, 6b, of which the outer 6a preferably rests on the outer connecting element 3 (see Figure 2) from the inside, while the inner one 6b rests against the receiving structure 3a (see Figure 2) from the outside. The two rings 6a, 6b are connected via curved (connecting) sections 6c with a circumferential course component.

4 shows another variant of the support element 6, which does not have a closed outer ring, but rather a plurality of mushroom-head-like structures 6d that expand outwards in the circumferential direction, which rest against the outer connecting element 3 from the inside and can also provide shear support ( through rear projections). The inner ring 6b is radially spaced from the inner connecting element 2; The system takes place here via radial extensions 6d' of the structures 6d mentioned. These extensions can also contribute to shear support (by resting on a shoulder between elements 14 and 15). Two sealing elements (sealing rings) 2a are arranged at the ends of the connecting element 2 for a sealing connection with a further connecting element (not shown).

Another embodiment of the support ring 6 is shown in FIG. Starting from an inner ring 6b, this has two outer rings 6a and 6a 'with different radii, which are also arranged axially offset. More details can also be found in Figure 6 described below. The rings 6a, 6a' are connected to the inner ring 6b via radial (double) spokes 6c', 6c". For the ring 6a', the relevant spokes 6c" have or create an axial extension component. This axial extension component serves to support the shear of the inner tube (inner line element 11, see Figure 1) opposite the outer hose (outer line element 12, see Figure 1). For this purpose, locking lugs or projections for axial fixation are provided on the inside at reference number 6e (see FIG. 6). The connection is preferably made by sliding and clicking.

Figure 6 shows the interaction of the support element 6 from Figure 5 with an external connecting element 3, which is designed approximately as in Figure 1 or 2 (with the exception of the adsorber receiving structure not present here). The support element lies with the outer ring 6a 'in the area 3.2 and with the outer ring 6a in the area 3.3 of the connecting element 3 (see Figures 1 and 2). Reference number 7 denotes an optional outer sleeve that bridges the connection area of the outer corrugated hose 12 and connecting element 3. The spokes 6c' rest on the grooved membrane disk 4 in a supporting manner. The support element can, at reference number 6e, as already mentioned, engage with a radial projection (preferably circumferential) or several locking lugs in a corresponding recess on the inner connecting element 2 in order to achieve effective thrust support. Radially on the outside, the support element 6 can be shaped spherically in section in order to nestle into a complementary recess in the connecting element 3 (at reference number X).

7 shows an expanded representation of the embodiment according to FIG.

Figure 8 includes three partial images a) to c). Possible configurations of the connection arrangement 1 are shown in a perspective view (upper illustration in each case) and in a longitudinal section (lower illustration in each case). According to partial figure a) corresponds approximately to the design in Figure 1. The mentioned breakthrough at reference number 3e can now also be seen here. The adsorber material 5 is also shown. It is positioned in a form-fitting manner between the adsorber basket (receiving structure 3a, see Figure 1) and the support element.

According to partial figure b), the connecting element 3 has a bulge 3f over a partial circumference, which serves as a positioning structure for the adsorber 5, which, however, leaves the area of the opening 3e free. Otherwise, Figure 8b) corresponds to Figure 8a).

In partial figure c), the bulge 3f is formed over the entire circumference and also extends into the area of the opening 3e, so that the adsorber 5 is also arranged here. The adsorber is clamped radially outwards with a clamping plate 5a.

Figure 9 shows further details of an embodiment that otherwise largely corresponds to Figure 2 (but without the support element there). The connecting piece 3c for evacuation and the design of the receiving structure 3a are clearly visible.

The latter also results from the final Figure 10, which only shows the outer connecting element 3 from Figure 9. The (radial) breakthrough 3e and an (axial) breakthrough 3h are clearly visible here, the latter allowing the connecting element 2 to pass through (see Figure 9). The receiving structure 3a has several openings 3g, which provide a fluidic connection for the purpose of evacuating the free space 13 over/through the adsorber 5.

The adsorber basket (the receiving structure 3a) is designed here in such a way that it additionally provides the axial support (thrust) of the inner line element 11 (FIG. 9) relative to the outer line element 12 and thereby represents the longest possible heat conduction path. An additional support element (cf. element 6 in FIG. 6) for the grooved membrane disk, which takes over the thrust support, can therefore be completely eliminated or at least made smaller.

Claims

Claims connection arrangement (1) in a cryogenic line (10) with an inner line element (11) and with an outer line element (12), which outer line element (12) the inner line element (11) at least in one section and at a distance (A ) surrounds, so that a free space (13) is formed between the inner line element (11) and the outer line element (12); comprising: an inner connecting element (2) arranged on the inner conduit element (11) at at least one end of the conduit (10); an outer connecting member (3) disposed at at least said end of the conduit (10) on the outer conduit member (12); a spacer element (4) which is arranged between the inner connecting element (2) and the outer connecting element (3) and closes off the free space (13) from the environment; which spacer element (4) is designed as a grooved membrane disk and is arranged in a plane (E), which plane (E), at least at said end, extends transversely to a longitudinal axis (L) of the line (10). Connection arrangement (1) according to claim 1, in which the grooved membrane disk (4) has a high wave shape, so that a height difference (H) between a wave crest and a wave trough is approximately 2 times as large, preferably 1 times as large, most preferably 0, 5 times as large is like a distance (I) between two neighboring wave crests.

3. Connection arrangement (1) according to claim 1 or 2, in which the grooved membrane disk (4) is thin-walled and made of a metallic material.

4. Connection arrangement (1) according to one of claims 1 to 3, in which the grooved membrane disk (4) has a number of beads.

5. Connection arrangement (1) according to claim 4, in which the grooved membrane disk has at least one, preferably three to six, preferably radial beads.

6. Connection arrangement (1) according to one of claims 1 to 5, in which the inner connecting element (2) is designed as a substantially smooth cylindrical sleeve part.

7. Connection arrangement (1) according to one of claims 1 to 6, in which the outer connecting element (3) has a larger cross section at its free end than at its other end; and the grooved membrane disk (4) is arranged in the area (3.3) of the larger cross section in the outer connecting element (3).

8. Connection arrangement (1) according to one of claims 1 to 7, in which a support element (6) is arranged adjacent to the grooved membrane disk (4) for supporting the grooved membrane disk (4) against an ambient pressure.

9. Connection arrangement (1) according to claim 8, in which the support element (6) has at least a first, outer contact section in which the support element (6) rests on the outer connection element (3) from the inside, preferably in the area (3.3) of larger cross section according to claim 7; and/or the support element (6) has at least a second, inner contact section has, in which the support element (6) rests on the inner connecting element (2) from the outside; and the support element (6) has at least one connecting section (6c, 6c', 6c"), which connecting section (6c, 6c', 6c") connects the outer contact section and the inner contact section and which connecting section (6c, 6c") has a course which deviates from a radial course and preferably has a circumferential and / or axial course component, so that a length of the connecting section (6c, 6c ', 6c") is preferably maximized. Connection arrangement (1) according to claim 8 or 9, in which the support element (6) has a number of spring elements for radial tension between the inner connecting element (2) and the outer connecting element (3). Connection arrangement (1) according to one of claims 8 to 10, in which the support element (6) is made of a ceramic material, preferably a porcelain, most preferably titanium dioxide, or of a plastic, preferably of epoxy, polyamide, polyimide, PEEK, PTFE or PCTFE , is manufactured. Connection arrangement (1) according to one of claims 8 to 11, in which the support element (6) has an axial extension component (6c") for shear support of the inner line element (11) and / or the inner connecting element (2) relative to the outer line element (12 ) and/or the outer connecting element (3). Connection arrangement (1) according to one of claims 1 to 12, in which an opening (3e) for evacuating the free space (13) is arranged in the outer connecting element (3), which opening (3e) is preferably located within one of the outer connecting element (3 ) projecting connecting piece (3c) is arranged.

14. Connection arrangement (1) according to one of claims 1 to 13, in which an adsorber material (5), preferably a silica gel, is arranged in the free space (13), preferably in fluidic connection with the opening (3e) according to claim 13 preferably aluminum silicate with a porous microstructure, which adsorber material (5) preferably surrounds the inner line element (2) in a ring shape.

15. Connection arrangement (1) according to claim 14, in which the outer connecting element (3) has a receiving structure (3a) for receiving and in particular axially positioning the adsorber material (5), in particular at least one radially retracted section or one through axial and / or radial walls limited receiving area (3b, 3f), in the area of which receiving structure (3a) a material of the outer connecting element (3) has openings (3g) which establish a fluid connection between the free space (13) and the adsorber material (5), wherein preferably the receiving structure (3a) has an axial extension component for thermal insulation by creating a long thermal conduction path.

16. Cryogenic line (10) with an inner line element (11) and with an outer line element (12), which outer line element (12) surrounds the inner line element (11) at least in a section and at a distance (A), so that between a free space (13) is formed in the inner line element (11) and the outer line element (12); comprising: at at least one end, preferably at both ends, a connecting arrangement (1) according to one of claims 1 to 15.

17. Cryogenic line (10) according to claim 16, in which the free space (13) is evacuated or can be evacuated, preferably via the breakthrough (3e) according to claim 13. Cryogenic line (10) according to claim 16 or 17, in which the outer line element (12) and/or the inner line element (11) is/are at least partially designed as a corrugated hose made of metal. Cryogenic line (10) according to one of claims 16 to 18, in which at least the inner line element (11) is at least partially surrounded by a protective covering (14), preferably a braided hose. Cryogenic line (10) according to one of claims 16 to 19, in which at least the inner line element (11) and possibly the protective covering

(14) according to claim 19 at least partially from insulation

(15) is surrounded, preferably by multi-layer insulation. Cryogenic line (10) according to one of claims 16 to 20, in which the inner connecting element (2) protrudes axially relative to the grooved membrane disk (4) at least at one end of the line (10), preferably in that the inner connecting element (11) through a breakthrough (4b) is guided in the grooved membrane disk (4).