Cryostat housing for superconducting wired circuits, and associated superconducting wired circuits

Abstract

The invention relates to a cryostat housing for a superconducting wired circuit, comprising at a minimum: a separating partition (10) delimiting two internal spaces; a first and a second opening on either side of the separating partition, and each configured to fix one end of a cryogenic envelope surrounding at least one superconducting wire (21a) and to allow the passage of the superconducting wire into the internal spaces; a third outlet opening for a cooling fluid circulating in the cryogenic envelope fixed to the first opening; and a fourth inlet opening for a cooling fluid circulating in the cryogenic envelope fixed to the second opening;The separating partition (10) incorporates a cavity forming a partition penetration (T) allowing the passage of the superconducting wire, made sealed against cooling fluids by injection, after the wire has passed through, of an electrically insulating material (17) in polymerizable liquid form via an opening (16) providing access to said cavity. Figure for the abbreviation: Fig.2;

Description

Title of the invention: Cryostat housing for superconducting wired circuit, and associated superconducting wired circuits Technical field

[0001] The present invention relates to the general field of superconducting wired circuits, and more precisely to a cryostat housing particularly suitable for different superconducting wired circuits. Technological background

[0002] A superconducting cable makes it possible to transport high-intensity electrical currents with a cable section much smaller than that of a conventional cable composed of a resistive electrical conductor, while limiting electrical losses along the cable, in particular losses due to the Joule effect since this phenomenon is extremely low in superconductivity.

[0003] A superconducting cable is conventionally made up of at least one central superconducting wire surrounded by a cryogenic envelope. The cryogenic envelope comprises, for example, two concentric envelopes thermally insulated from each other by a vacuum. A cooling fluid, such as helium or nitrogen, in liquid or gaseous form, contained inside the cryogenic envelope, cools the central superconducting wire until it reaches a temperature below the so-called critical temperature at which this wire passes into a state of superconductivity.

[0004] It is known to use wired circuits composed either of a single superconducting cable of great length, or of a plurality of superconducting cables connected to each other in series, so as to achieve a high intensity current transport over a long distance. For this type of circuit, if the coolant is injected under pressure and at the critical temperature at an injection point located at one end of the circuit, it is not guaranteed on the one hand, that the pressure remains sufficient to allow the circulation of the coolant over the entire length of the circuit, and on the other hand, that the coolant does not heat up to reach a temperature higher than the critical temperature as one moves further in the circuit from the injection point of the fluid.

[0005] Other superconducting wired circuits are known to form closed superconducting loops generating strong magnetic fields. Such a circuit comprises a superconducting cable comprising, in a single cryogenic envelope, a superconducting wire wound on several turns, the wire being composed either of a single superconducting wire or of a succession of elementary superconducting wires connected in series, each elementary wire forming one turn of the coil. Such a superconducting coil may for example be used, as described in particular in document EP 2 732 075 B1, as a secondary electrical circuit in an aluminum smelter, to compensate for the magnetic field created by a main electrical circuit carrying an electrolysis current supplying a series of electrolysis tanks intended for the production of aluminum and forming one or more rows. In this type of superconducting coil, a first end of the superconducting wire (or of the elementary wire constituting the first turn) and a second end of the superconducting wire (or of the elementary wire constituting the last turn) must be electrically connected to the two electrical poles of an electrical supply station delivering a supply current of predetermined intensity.The number of turns made by the superconducting wire (or the number of elementary superconducting wires connected in series) depends on the value of the supply current and the value of the magnetic field that one wishes to generate. As a non-limiting example, a superconducting coil comprising a superconducting wire wound on 21 turns passing side by side inside the single cryogenic envelope (or 21 elementary superconducting wires connected in series) and supplied with a current of 5 kA, makes it possible to generate a magnetic field corresponding to 105 kA. Here again, the length of the single cryogenic envelope enclosing the superconducting winding can be quite significant (of the order of several hundred meters) so that it is necessary to provide that the coolant intended to circulate in the loop is injected at a sufficient pressure and remains below the critical temperature. Summary of the invention

[0006] The aim of the present invention is to propose cryostat housing solutions for superconducting wired circuits which are particularly suitable for the management of cooling liquids.

[0007] More particularly, the present invention has as its first object a cryostat housing for a superconducting wired circuit, said cryostat housing comprising: • a separating partition delimiting a first space and a second space internal to the cryostat housing; • a first opening and a second opening of the cryostat housing located on either side of the separating partition, opening respectively onto the first internal space and onto the second internal space and each configured to fix in a sealed manner one end of a cryogenic envelope surrounding at least one superconducting wire and to allow the passage of said at least one superconducting wire respectively into the first internal space and into the second internal space; • a third opening of the cryostat housing, communicating with the first internal space and intended to form an outlet for a cooling fluid circulating in the cryogenic envelope fixed to the first opening; and • a fourth opening of the cryostat housing, communicating with the second internal space and intended to form an inlet for a pressurized cooling fluid circulating in the cryogenic envelope fixed to the second opening; said separating partition incorporating a cavity forming at least one partition crossing to allow the passage of said at least one superconducting wire, and an access opening to said cavity to allow, after passage of said at least one superconducting wire, the filling of said cavity by injection of an electrically insulating material in polymerizable liquid form in order to make said at least one partition crossing watertight to cooling fluids.

[0008] In one possible embodiment, said separating partition incorporates a plurality of cavities each forming a partition crossing to allow the passage of one of a plurality of superconducting wires, and an access opening per cavity to allow separate filling of each cavity by injection of the electrical insulating material into each cavity.

[0009] As a variant, said separating partition incorporates a single cavity forming a plurality of partition crossings each allowing the passage of one of a plurality of superconducting wires, the filling of the single cavity by injection of the electrical insulating material in polymerizable liquid form making it possible to make each partition crossing watertight to cooling fluids.

[0010] In one possible embodiment, the cryostat housing comprises at least a fifth opening to allow the injection, from an electrical input termination external to the cryostat housing, of an electric current onto a first end of a superconducting wire passing through the separating partition.

[0011] The fifth opening may further allow an electric current to be recovered at a second end of the superconducting wire on an electrical output termination external to the cryostat housing. Alternatively, the cryostat housing comprises a sixth opening to allow an electric current to be recovered at a second end of the superconducting wire on an electrical output termination external to the cryostat housing.

[0012] In a possible embodiment, said at least one sealed bulkhead crossing can be sized to accommodate a connector connecting in series two elementary superconducting wires making up said at least one superconducting wire.

[0013] In one possible embodiment, said at least one partition wall crossing has two substantially cylindrical ends extending transversely on either side of the separating partition, each end being equipped with a centering ring made of electrically insulating material.

[0014] The present invention also relates to different superconducting wired electrical circuits using different embodiments of the cryostat housing:

[0015] A first superconducting wired electrical circuit according to the invention comprises: • a first superconducting cable comprising a first cryogenic envelope surrounding at least one first superconducting wire and inside which a first cooling fluid circulates; • a second superconducting cable comprising a second cryogenic envelope surrounding at least one second superconducting wire and inside which a second cooling fluid circulates; • a cryostat housing in accordance with the first subject of the invention, and connecting the first superconducting cable and the second superconducting cable so that: • one end of the first cryogenic envelope is fixed in a sealed manner to the first opening of the cryostat housing; • one end of the second cryogenic envelope is tightly fixed to the second opening of the cryostat housing; • the first cooling fluid exits through the third opening of the cryostat housing; • the second cooling fluid enters through the fourth opening of the cryostat housing; and • said at least one first superconducting wire and / or said at least one second superconducting wire passes through said at least one watertight bulkhead crossing; and • at least one connector inside the cryostat housing electrically connecting in series said at least one first superconducting wire and said at least one second superconducting wire.

[0016] Said at least one connector may be placed in the first internal space or in the second internal space of the cryostat housing. Alternatively, said at least one connector is placed in said at least one sealed bulkhead feedthrough.

[0017] The circuit further advantageously comprises a device for managing cooling fluids external to the cryostat housing, configured to receive the first cooling fluid leaving the third opening, and to inject the second cooling liquid under pressure through the fourth opening.

[0018] Another superconducting wired electrical circuit according to the invention, capable of forming a closed superconducting electrical loop involves: • a superconducting cable comprising a superconducting wire wound on several turns and a single cryogenic envelope inside which said turns pass side by side; • a cryostat housing in accordance with the first subject of the invention and further comprising the fifth, or even the sixth opening, connected to said superconducting cable so that: • a first end of the single cryogenic envelope is sealed to the first opening of the cryostat housing; • a second end of the single cryogenic envelope is tightly secured to the second opening of the cryostat housing; • each turn of the superconducting wire passes through a separate crossing among the plurality of sealed bulkhead crossings of the separating partition of said cryostat housing; • a pressurized cooling fluid enters through the fourth opening of the cryostat housing and circulates in the single cryogenic jacket; • said cooling fluid exits through the third opening of the cryostat housing; • an electrical input termination connected to a first end of the superconducting wire through the fifth opening of the cryostat housing for injecting an electrical current onto said superconducting wire; and • an electrical output termination connected to a second end of the superconducting wire through the fifth opening or the sixth opening of the cryostat housing for the recovery of the electric current flowing in the superconducting wire.

[0019] In one possible embodiment, each turn of said superconducting wire is made up of an elementary superconducting wire, two successive elementary superconducting wires being connected in series by a connector placed inside the housing. cryostat.

[0020] In one possible embodiment, at least one sealed bulkhead crossing of said cryostat housing is sized to accommodate the connector connecting two successive superconducting elementary wires.

[0021] Another superconducting wired electrical circuit according to the invention comprises: • a superconducting cable comprising a cryogenic envelope surrounding at least one superconducting wire and inside which a first cooling fluid circulates; • a cryostat housing in accordance with the first subject of the invention, connected to said cable superconductor so that: • the cryogenic envelope is fixed in a sealed manner on the one hand, to the first opening and on the other hand, to the second opening of the cryostat housing; • said at least one superconducting wire passes through said at least one watertight bulkhead crossing; • a first cooling fluid circulating in the cryogenic envelope and entering the cryostat housing through the first opening exits through the third opening of the cryostat housing; • a second pressurized cooling fluid enters through the fourth opening of the cryostat housing and circulates in the cryogenic envelope via the second opening.

[0022] In a possible embodiment, this other superconducting wired electrical circuit further comprises a device for managing cooling fluids external to the cryostat housing, configured to receive the first cooling fluid exiting the third opening, and to inject the second cooling liquid under pressure through the fourth opening. Brief description of the figures

[0023] The description which follows with reference to the appended drawings, given as non-limiting examples, will make it clear what the invention consists of and how it can be implemented. In the appended figures:

[0024] [Fig-1] [Fig.l] schematically illustrates a view (a) showing a cryostat housing according to a first embodiment of the invention, and a view (b) showing an example of a superconducting wired electrical circuit using this cryostat housing;

[0025] [Fig.2] [Fig.2] is an enlargement of a portion of [Fig.l], showing a bulkhead crossing in accordance with the invention;

[0026] [Fig.3] [Fig.3] illustrates an alternative embodiment of a plurality of crossings watertight within the same dividing wall;

[0027] [Fig.4] [Fig.4] schematically illustrates another example of an electrical circuit superconducting cable using the cryostat box of [Fig.l];

[0028] [Fig.5] [Fig.5] schematically illustrates an example of a wired electrical circuit on superconductor forming a closed superconducting loop and using a cryostat housing according to a second embodiment in accordance with the invention. Description of embodiment(s)

[0029] In the figures, identical or equivalent elements will bear the same reference signs. The various diagrams are not to scale.

[0030] Throughout the description, the term superconducting wire (or elementary wire) is understood to mean superconductor) any longitudinal superconducting element or element comprising a longitudinal metallic core (for example copper) surrounded by at least one superconducting layer (formed for example by several superconducting wires or ribbons surrounding the copper core).

[0031] [Fig.l] schematically illustrates a first embodiment of a cryostat housing 1 according to the invention, particularly suitable for superconducting wired circuits extending between two distant points, and an example of use of this cryostat housing. More specifically, view (a) of [Fig.l] shows the cryostat housing 1 alone, before use in any circuit, and view (b) illustrates a portion of an example of a superconducting wired circuit using this cryostat housing 1.

[0032] As visible in this [Fig.l], the cryostat housing 1, made of any electrically conductive material, preferably stainless steel, comprises a separating partition 10 delimiting a first space 11a and a second space 11b internal to the cryostat housing 1. The housing 1 preferably comprises two concentric envelopes 1a, 1b separated by a vacuum.

[0033] The cryostat housing 1 further comprises a first opening 12a and a second opening 12b for access to the cryostat housing, located on either side of the separating partition 10, and opening respectively onto the first internal space 11a and onto the second internal space 11b. Each of these first and second openings 12a, 12b is configured to allow the sealed fixing of one end of a cryogenic envelope surrounding at least one superconducting wire and to allow the passage of said at least one superconducting wire respectively into the first internal space 11a and into the second internal space 11b. Thus, as more particularly visible in view (b), an example of a superconducting wired circuit using the cryostat housing 1 of view (a) comprises: • a first superconducting cable 2a comprising a first cryogenic envelope 20a surrounding at least one first superconducting wire 21a, and inside which a first cooling fluid circulates; • a second superconducting cable 2b comprising a second cryogenic envelope 20b surrounding at least one second superconducting wire 21b, and inside which a second cooling fluid circulates; the first superconducting cable 2a and the second superconducting cable 2b being connected to the cryostat housing 1 so that one end of the first cryogenic envelope 20a is fixed in a sealed manner, by any known means, to the first opening 12a of the cryostat housing 1 and one end of the second cryogenic envelope 20b is fixed in a sealed manner, by any known means, to the second opening 12b of the cryostat housing 1. As seen in view (b), the two concentric envelopes forming the cryogenic envelopes 20a and 20b of each of the two superconducting cables 2a and 2b are fixed to the two concentric envelopes 1a and 1b forming the housing 1 at the level of the openings 12a and 12b.

[0034] The cryostat housing 1 further comprises a third opening 13a, communicating with the first internal space 11a. This third opening 13a is intended to form an outlet for a cooling fluid circulating in a cryogenic envelope fixed to the first opening 12a. In the circuit example shown schematically in view (b) of [Fig.l], the third opening 13a forms an outlet for the first cooling fluid circulating in the cryogenic envelope 20a of the first superconducting cable 2a and entering the first internal space 11a, as represented by the circulation arrow Fh

[0035] The cryostat housing 1 further comprises a fourth opening 13b, communicating with the second internal space 11b. This fourth opening 13b is intended to form an inlet for a pressurized cooling fluid circulating in a cryogenic envelope fixed to the second opening 12b. In the circuit example shown in view (b) of [Fig.l], the fourth opening 13b forms an inlet for the second cooling fluid entering the second internal space 11b and then circulating in the cryogenic envelope 20b of the second superconducting cable 2b, as represented by the circulation arrow F2.

[0036] The separating partition 10 being designed to be crossed by at least one superconducting wire also crossing the first opening 12a and / or the second opening 12b, such as the superconducting wire 21a or 21b of the first cable 2a or of the second cable 2b, the separating partition 10 incorporates, in accordance with the invention, a cavity 15 forming at least one partition crossing sealed against cooling fluids to allow the passage of said at least one superconducting wire. In the non-limiting example of view (b), it is the superconducting wire 21a of the first cable 2a which crosses the separating partition 10 via the sealed partition crossing.

[0037] To do this, and as more particularly visible in the diagram of [Fig.2] which represents a zoom T on the view (b) of [Fig.l], the separating partition 10 integrates an opening 16 for access to the cavity 15, preferably opening onto the first internal space 11a or, as illustrated in [Fig.l], onto the second internal space 11b, to allow, after passage of said at least one superconducting wire 21a, 21b, the filling of the cavity 15 by injection of an electrically insulating material 17 in polymerizable liquid form. [Fig.2] schematically illustrates the bulkhead crossing made watertight after polymerization of the electrically insulating material 17 around the superconducting wire 21a through the wall 10. The electrically insulating material 17 is for example a two-component epoxy resin polymerizing at room temperature, or any other electrically insulating material polymerizing, preferably at room temperature, and withstanding cryogenic temperatures.

[0038] In order to prevent the superconducting wire passing through the partition 10 from being in contact with the walls of the partition feedthrough during the operation of injecting the electrically insulating material 17 in liquid form, the partition feedthrough comprises two substantially cylindrical ends 18a, 18b extending transversely on either side of the separating partition 10, each end 18a, 18b being equipped with a centering ring 19a, 19b made of electrically insulating material through which the superconducting wire, in the example the wire 21a, can be threaded before the injection operation. The access opening 16 can be carried by one of the ends, for example by the end 18b as shown in [Fig.2]. The material used for the centering rings 19a, 19b is chosen to withstand the critical temperatures of the cooling fluids. For example, you can choose G10 epoxy fiberglass or tetrafluoroethylene.To further improve the sealing of the system during the operation of injecting the electrical insulating material in liquid form, two shrink sleeves (not shown) can be advantageously used, each shrink sleeve forming a tight seal between each centering ring 19a, 19b and the superconducting wire passing through the partition.

[0039] In the non-limiting example of a wired circuit shown diagrammatically in view (b) of [Fig.l] in which the cryostat housing 1 connects two separate superconducting cables 2a and 2b each comprising their own cryogenic envelope 20a, respectively 20b, each surrounding at least one superconducting wire 21a, respectively 21b, the superconducting wired circuit further comprises a connector 3 inside the cryostat housing 1, this connector 3 electrically connecting in series the first superconducting wire 21a and the second superconducting wire 21b.

[0040] In the non-limiting example corresponding to view (b), it is the first wire 21a of the first superconducting cable 2a which passes through the separating partition 10, so that the connector 3 is placed in the second internal space 11b of the cryostat housing 1. In a first variant, it can be envisaged that it is the superconducting wire 21b of the second superconducting cable 2b which passes through the separating partition 10, in which case the connector 3 will be placed in the first internal space 11a. In both cases, the connection operation between the two superconducting wires 21a and 21b can only be carried out after having threaded the first superconducting wire 21a or the second superconducting wire 21b through the separating partition, but indifferently before or after the operation of injecting the material in liquid form.In a second variant (not shown), it is possible to provide for the partition wall crossing to be sized to accommodate the connector 3 connecting the two superconducting wires 21a and 21b in series. Implementations consisting of placing the connector 3 in the second internal space 11b, i.e. on the side where the second cooling fluid is injected through the fourth opening 13b, are nevertheless preferred because they make it possible to. subjecting connector 3, which is likely to generate resistive losses, to a cooling fluid temperature below the critical temperature and promoting the superconducting state.

[0041] In an alternative embodiment not shown, particularly suited to situations in which the cryogenic envelopes fixed to the first and second openings 12a, 12b of the cryostat housing surround, not a single superconducting wire, but a plurality of superconducting wires, the separating partition 10 incorporates as many cavities 15 each forming a partition crossing to allow the passage of a superconducting wire, and each comprising an access opening 16. It is thus possible to make each partition crossing sealed against cooling fluids by separately filling each cavity with the insulating material in liquid form.

[0042] The production of a plurality of partition feedthroughs, each sealed against cooling fluids, can also be facilitated by the alternative embodiment of the separating partition 10 of the cryostat housing shown in section in [Fig. 3]. In this non-limiting example, the separating partition 10 is crossed by three superconducting wires 21i, 212, 213, originating for example from a superconducting cable whose cryogenic envelope has been fixed to the first opening 12a or to the second opening 12b of the cryostat housing. Here, the separating partition 10 is formed not from a single wall, but from two walls 10a, 10b fixed to each other, and configured to define a single cavity 15 forming a plurality of partition feedthroughs (three in the example) each allowing the passage of one of the superconducting wires 211, 212, 213.One of the walls, here the wall 10b, comprises an access opening 16 to the cavity, preferably on the upper part of the wall 10b. After the superconducting wires 21i, 212, 213 have passed through their respective bulkheads, the filling of the single cavity 15 by injecting the electrically insulating material in polymerizable liquid form through the access opening 16 makes it possible to simultaneously make each bulkhead seal tight to the cooling fluids. Centering rings 19a, 19b, similar to the rings described with reference to [Fig.2], are also used at the two cylindrical ends forming each bulkhead to prevent the superconducting wires from being in contact with the internal walls of their respective bulkheads before the injection operation.

[0043] In the configuration shown in view (b) of [Fig.l], with a separating partition according to [Fig.2] or [Fig.3], the cryostat housing makes it possible to carry out both the electrical junction of two superconducting cables 2a, 2b each comprising one or more superconducting wires thanks to the presence of one or more partition crossings, and to allow effective management of the circulation of the cooling fluids thanks to the fact that the partition crossing is made tight to the cooling fluids. cooling.

[0044] The circuit may thus comprise any device 4 for managing cooling fluids external to the cryostat housing 1, configured to receive the first cooling fluid leaving the third opening 13a, and to inject the second cooling liquid under pressure and at a temperature lower than the critical temperature associated with the second superconducting wire 21b through the fourth opening 13b. In a possible implementation, the device 4 may for example recover, via the third opening 13a of the housing, the first cooling fluid coming from the first cable 2a, the temperature of which has risen as it travels in the superconducting cable 2a, then reinject it in the form of the second cooling fluid, after having adapted the pressure and the temperature necessary respectively for the proper circulation of the fluid in the second cable 2b and for the proper cooling of the superconducting wire 1b.Alternatively, the first fluid and the second cooling fluid are of different nature. In particular, it is possible to provide for a very long cable line, by connecting a succession of superconducting cables in such a way that two cables succeeding one another in the line are connected by means of a cryostat box and a fluid management system in accordance with the invention.

[0045] In the schematic representation given in view (b) of [Fig.l], it has been considered that the cryostat housing 1 serves to connect two separate cables 2a, 2b. Another example of use of the cryostat housing 1 of [Fig.l](a) is illustrated schematically in [Fig.4]. This example of a superconducting wired electrical circuit differs from the first example illustrated schematically in [Fig.l](b) only in that it uses a single superconducting cable 2 comprising a superconducting wire 21 surrounded by a cryogenic envelope. References 20a and 20b in [Fig.4] here illustrate two portions of the cryogenic envelope fixed in a sealed manner to the openings 12a, respectively 12b, of the cryostat housing 1. As visible in [Fig.4], the superconducting wire 21 passes through the separating partition 10 via the partition feedthrough made sealed, as explained above, by injection of the electrically insulating material in liquid form into the cavity 15.Here again, a first cooling fluid circulating in the portion 20a of the cryogenic envelope will enter the cryostat housing through the first opening 12a of the cryostat housing 1 then exit through the third opening 13a of the cryostat housing 1 (arrow FJ, and a second pressurized cooling fluid will be able to enter through the fourth opening 13b of the cryostat housing 1 and circulate in the portion 20b of the cryogenic envelope via the second opening 12b (Arrow F2). As in the previous example, a device 4 for managing cooling fluids external to the cryostat housing 1 receives the first cooling fluid exiting from the third opening. 13a, and whose temperature has risen as it travels in the portion 20a of the cryogenic envelope, and injects the second coolant under pressure and at a temperature lower than the critical temperature of the superconducting wire 21 through the fourth opening 13b. As previously, the second coolant may be the first coolant whose temperature has been lowered compared to the temperature reached by the first coolant when it leaves the third opening 13a, so that it again reaches a temperature lower than the critical temperature. Alternatively, the first fluid and the second coolant may be of different natures.

[0046] In a variant embodiment not shown of the circuit of [Fig. 4], the superconducting cable 2 may comprise several superconducting wires passing through the same bulkhead crossing sealed against cooling fluids. In another variant embodiment not shown of the circuit of [Fig. 4], the superconducting cable 2 may comprise several superconducting wires each passing through a sealed bulkhead crossing of the separating partition of the cryostat housing, each crossing being obtained according to the principles explained above with reference to [Fig. 2] or to [Fig. 3].

[0047] Another example of a wired superconducting circuit using a cryostat housing according to a second embodiment in accordance with the invention will now be described with reference to [Fig. 5]. The superconducting wired electrical circuit here produces a closed superconducting electrical loop and comprises a superconducting cable 2 comprising a superconducting wire 21 wound over several turns (three turns in the non-limiting example of [Fig. 5]) and a single cryogenic envelope 20 inside which said turns pass side by side, electrically insulated from each other. The superconducting wire 21 is preferably composed of a succession of elementary superconducting wires connected in series, each elementary wire forming one turn of the winding. In the example of [Fig. 5], three elementary superconducting wires 21i, 212 and 213 are illustrated and each form one turn of the winding.

[0048] The cryostat housing 1 according to the second embodiment is very similar to the cryostat housing of view (a) of [Fig.l], in that it comprises: • two concentric envelopes 1a, 1b separated by a void; • a separating partition 10 delimiting a first space 11a and a second space 11b internal to the cryostat housing 1; • a first opening 12a and a second opening 12b of the cryostat housing 1 located on either side of the separating partition 10, opening respectively onto the first internal space 11a and onto the second internal space 11b; • a third opening 13a communicating with the first internal space 1 la and intended to form an outlet for a cooling fluid; and • a fourth opening 13b communicating with the second internal space 11b and intended to form an inlet for a cooling fluid.

[0049] The separating partition 10 incorporates as many partition feedthroughs as there are turns in the winding. In the example of [Fig. 5], three partition feedthroughs are shown diagrammatically and allow the passage of each superconducting elementary wire 21 b 212 and 213. These partition feedthroughs are made leaktight to cooling fluids in the same way as in the case of the partition feedthrough described in [Fig. 2]. Alternatively, these feedthroughs are formed by a single cavity, the filling of which with an electrically insulating material injected in polymerizable liquid form allows three leaktight feedthroughs to be obtained simultaneously, as explained with reference to [Fig. 3].

[0050] For this circuit forming a closed loop, the cryostat box 1 is thus connected to the superconducting cable 2 so that: • a first end 20a of the single cryogenic envelope 20 is fixed in a sealed manner to the first opening 12a of the cryostat housing 1, the two concentric envelopes forming the first end 20a of the cryogenic envelope 20 of the superconducting cable 2 being fixed for example to the two concentric envelopes 1a and 1b forming the housing 1 at the first opening 12a; • a second end 20b of the single cryogenic envelope 20 is fixed in a sealed manner to the second opening 12b of the cryostat housing 1, the two concentric envelopes forming the second end 20b of the cryogenic envelope 20 of the superconducting cable 2 being fixed for example to the two concentric envelopes 1a and 1b forming the housing 1 at the level of the second opening 12b; • each turn of the superconducting wire passes through a separate crossing among the three watertight bulkhead crossings of the separating partition 10; • a pressurized cooling fluid enters through the fourth opening 13b of the cryostat housing 1 (arrow F2) and circulates in the single cryogenic envelope 20; • the cooling fluid exits through the third opening 13a of the cryostat housing (arrow Fi).

[0051] The cryostat housing 1 shown in [Fig.5] also comprises: • a fifth opening 13c to allow the injection, from an electrical input termination Ti of the electrical circuit, external to the cryostat housing, of an electric current onto a first end of the superconducting wire 21. • a sixth opening 13d to allow an electric current to be recovered at a second end of the superconducting wire on an electrical output termination T2 of the electrical circuit, external to the cryostat housing.

[0052] In a variant not shown, the housing does not have a sixth opening. In this case, the output electrical termination T2 of the electrical circuit is located near the input electrical termination Ti and the fifth opening 13c, the latter making it possible to inject the current onto one end of the wire 21 (here onto the free end of the elementary wire 211 forming the first turn of the winding), and to recover the current on the other end of the wire 21 (here onto the free end of the elementary wire 213 forming the third and last turn of the winding).

[0053] As the wire 21 is here made up of a succession of elementary wires, two successive superconducting elementary wires are connected in series by a connector 3. [Fig.5] thus shows two connectors 3, one for connecting the first elementary wire 21i and the second elementary wire 212, the other for connecting the second elementary wire 212 and the third elementary wire 213.

[0054] Of course, the connectors are not necessary in the case where the superconducting wire 21 is provided to be long enough to be wound on the desired number of turns.

[0055] The connectors 3 are advantageously placed inside the cryostat housing 1, preferably on the side of the internal space 11b into which the cooling fluid is injected. In a variant not shown, at least one sealed bulkhead crossing of said cryostat housing is sized to accommodate the connector connecting two successive superconducting elementary wires.

[0056] In the configuration shown in [Fig.5], the cryostat box advantageously constitutes a connection box which allows both: • to carry out the electrical junction of the different elementary superconducting wires forming the different turns of the winding; • to circulate a current along the elementary wires thanks to the openings 13b / 13c allowing connections to the input termination Ti and output termination T2 • and to allow the circulation of a cooling fluid inside the closed loop, made possible by the presence of a separating partition sealed against the cooling fluid between the opening 13a and the opening 13b.

Claims

Claims

1. Cryostat housing (1) for superconducting wired circuit, said cryostat housing (1) comprising: • a separating partition (10) delimiting a first space (11a) and a second space (11b) internal to the cryostat housing (1); • a first opening (12a) and a second opening (12b) of the cryostat housing (1) located on either side of the separating partition, opening respectively onto the first internal space (11a) and onto the second internal space (11b) and each configured to fix in a sealed manner one end of a cryogenic envelope (20a, 20b; 20) surrounding at least one superconducting wire (21a, 21b; 21) so that at least one superconducting wire (21a, 21b; 21) passes respectively into the first internal space (11a) and into the second internal space (11b); • a third opening (13a) of the cryostat housing (1), communicating with the first internal space (11a) and forming an outlet for a cooling fluid circulating in the cryogenic envelope (20a; 20) fixed to the first opening (12a); • a fourth opening (13b) of the cryostat housing (1), communicating with the second internal space (11b) and forming an inlet for a pressurized cooling fluid circulating in the cryogenic envelope (20b; 20) fixed to the second opening (12b); the cryostat housing (1) being characterized in that said separating partition (10) incorporates a cavity (15) forming at least one partition feed-through through which said at least one superconducting wire (21a, 21b; 21) passes, said at least one partition feed-through comprising two substantially cylindrical ends (18a, 18b) extending transversely on either side of the separating partition (10), each end (18a, 18b) being equipped with a centering ring (19a, 19b) made of electrically insulating material, and an opening (16) for access to said cavity (15) through which, after passage of said at least one superconducting wire- conductor (21a, 21b; 21), said cavity (15) is filled with an electrically insulating material injected in polymerizable liquid form in order to make said at least one bulkhead crossing watertight to cooling fluids.

2. Cryostat housing (1) according to claim 1, characterized in that said separating partition (10) incorporates a plurality of cavities (15) each forming a partition passage through which one of a plurality of superconducting wires passes, and an access opening (16) per cavity (15), through which each cavity is filled separately with the electrically insulating material injected in liquid form.

3. Cryostat housing (1) according to claim 1, characterized in that said separating partition (10) incorporates a single cavity (15) forming a plurality of partition crossings through each of which one of a plurality of superconducting wires (21b 212, 213) passes, the filling of the single cavity (15) by injection of the electrically insulating material in polymerizable liquid form making it possible to make each partition crossing watertight to cooling fluids.

4. Cryostat housing (1) according to any one of claims 2 or 3, characterized in that it comprises at least a fifth opening (13c) to allow the injection, from an electrical input termination (Ti) external to the cryostat housing, of an electric current onto a first end of a superconducting wire (21) passing through the separating partition (10).

5. Cryostat housing (1) according to claim 4, characterized in that the fifth opening (13c) further allows an electric current to be recovered at a second end of the superconducting wire (21) on an electrical output termination (T2) external to the cryostat housing.

6. Cryostat housing (1) according to claim 4, characterized in that it comprises a sixth opening (13d) to allow an electric current to be recovered at a second end of the superconducting wire (21) on an electrical output termination (T2) external to the cryostat housing.

7. Cryostat housing (1) according to any one of the preceding claims, characterized in that said at least one sealed bulkhead crossing is sized to accommodate a connector (3) connecting in series two elementary superconducting wires making up said at least one superconducting wire.

8. Superconducting wired electrical circuit comprising: • a first superconducting cable (2a) comprising a first cryogenic envelope (20a) surrounding at least one first superconducting wire (21a) and inside which a first cooling fluid circulates; • a second superconducting cable (2b) comprising a second cryogenic envelope (20b) surrounding at least one second superconducting wire (21b) and inside which a second cooling fluid circulates; • a cryostat housing (1) according to claim 1, connecting the first superconducting cable (2a) and the second superconducting cable (2b) so that: • one end of the first cryogenic envelope (20a) is fixed in a sealed manner to the first opening (12a) of the cryostat housing (1); • one end of the second cryogenic envelope (20b) is fixed in a sealed manner to the second opening (12b) of the cryostat housing (1); • the first cooling fluid exits through the third opening (13a) of the cryostat housing (1); • the second cooling fluid enters through the fourth opening (13b) of the cryostat housing (1); and • said at least one first superconducting wire (21a) and / or said at least one second superconducting wire (21b) passes through said at least one sealed bulkhead crossing; and • at least one connector (3) inside the cryostat housing (1) electrically connecting in series said at least one first superconducting wire (21a) and said at least one second superconducting wire (21b).

9. A superconducting wired electrical circuit according to claim 8, wherein said at least one connector (3) is placed in the first internal space (11a) or in the second internal space (11b) of the cryostat housing (1).

10. A superconducting wired electrical circuit according to claim 8, wherein said at least one connector (3) is placed in said at least one bulkhead feedthrough.

11. Superconducting wired electrical circuit according to any one of claims 8 to 10, characterized in that it further comprises a device (4) for managing cooling fluids external to the cryostat housing (1), configured to receive the first cooling fluid leaving the third opening (13a), and to inject the second cooling liquid under pressure through the fourth opening (13b).

12. Superconducting wired electrical circuit capable of forming a closed superconducting electrical loop comprising: • a superconducting cable (2) comprising a superconducting wire (21) wound on several turns and a single cryogenic envelope (20) inside which said turns pass side by side; • a cryostat housing (1) according to any one of claims 5 or 6, connected to said superconducting cable (2) so that: • a first end (20a) of the single cryogenic envelope (20) is fixed in a sealed manner to the first opening (12a) of the cryostat housing (1); • a second end (20b) of the single cryogenic envelope (20) is fixed in a sealed manner to the second opening (12b) of the cryostat housing (1); • each turn of the superconducting wire passes through a separate crossing among the plurality of sealed bulkhead crossings of the separating partition (10) of said cryostat housing (1); • a pressurized cooling fluid enters through the fourth opening (13b) of the cryostat housing (1) and circulates in the single cryogenic envelope (20); • said cooling fluid exits through the third opening (13a) of the cryostat housing (1); • an electrical input termination (Ti) connected to a first end of the superconducting wire (21) through the fifth opening (13c) of the cryostat housing (1) for injecting an electric current onto said superconducting wire (21); and • an electrical output termination (T2) connected to a second end of the superconducting wire (21) through the fifth opening (13c) or the sixth opening (13d) of the cryostat housing (1) for the recovery of the electric current flowing in the superconducting wire (21).

13. Superconducting wired electrical circuit according to claim 12, wherein each turn of said superconducting wire consists of an elementary superconducting wire (21 b 212, 213), two successive elementary superconducting wires being connected in series by a connector (3) placed inside the cryostat housing (1).

14. Superconducting wired electrical circuit according to claim 13, in which at least one sealed bulkhead crossing of said cryostat housing (1) is sized to accommodate the connector (3) connecting two successive superconducting elementary wires.

15. Superconducting wired electrical circuit comprising: • a superconducting cable comprising a cryogenic envelope (20a, 20b) surrounding at least one superconducting wire and inside which a first cooling fluid circulates; • a cryostat housing (1) according to claim 1, connected to said superconducting cable so that: • the cryogenic envelope (20a, 20b) is fixed in a sealed manner on the one hand, to the first opening (12a) and on the other hand, to the second opening of the cryostat housing (12b); • said at least one superconducting wire passes through said at least one sealed bulkhead feedthrough (15); • a first cooling fluid circulating in the cryogenic envelope (20a, 20b) and penetrating into the cryostat housing (1) through the first opening (12a) exits through the third opening (13a) of the cryostat housing (1);• a second pressurized cooling fluid enters through the fourth opening (13b) of the housing; cryostat (1) and circulates in the cryogenic envelope (20a, 20b) via the second opening (12b).

16. Superconducting wired electrical circuit according to claim 15, characterized in that it further comprises a device (4) for managing cooling fluids external to the cryostat housing (1), configured to receive the first cooling fluid leaving the third opening (13a), and to inject the second cooling liquid under pressure through the fourth opening (13b).

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