CRYOGENIC REFRIGERATION METHOD AND DEVICE

The invention relates to a cryogenic refrigeration facility comprising an enclosure (2) delimiting a sealed volume under vacuum and closed by a cover (3), the enclosure (2) housing at least two thermally conductive trays (4, 5, 6, 7) distributed in a distribution direction within the enclosure (2) and forming thermal stages, the facility (1) comprising a system for cooling to cryogenic temperature that is configured to cool at least part of the trays (4, 5, 6, 7) and/or support plate(s) (24, 25, 26, 27) mounted on the tray(s), the cooling system being configured to provide a flow of expanded and/or stored cryogenic fluid.

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Description
CROSS REFERENCE TO RELATED APPLICATIONS

This application is a §371 of International PCT Application PCT/FR2024/000006, filed Jan. 18, 2024, which claims the benefit of FR2300459, filed Jan. 18, 2023, and FR2300688, filed Jan. 25, 2023, all of which are herein incorporated by reference in their entireties.

FIELD OF THE INVENTION

The invention relates to a cryogenic refrigeration device.

The invention relates more particularly to a cryogenic refrigeration device comprising an enclosure delimiting a vacuum-sealed volume closed by a cover, the device comprising at least one cryogenic cooler that is mounted through the cover and has a first end situated outside the enclosure and a second end situated inside the enclosure, the cryogenic cooler being configured to supply cold at its second end, the device comprising at least two thermally conductive trays that are distributed along a distribution direction in the enclosure and form thermal stages, at least some of the trays being cooled by the cryogenic cooler to respective given temperatures, the cryogenic cooler being of the type which uses a cold source of liquefied cycle fluid such as helium or nitrogen.

The invention also relates to a cryogenic refrigeration installation comprising an enclosure delimiting a vacuum-sealed volume closed by a cover, the enclosure accommodating at least two thermally conductive trays that are distributed along a distribution direction in the enclosure and form thermal stages, at least one of the trays being connected to a heat shield forming a thermal insulation volume, the installation comprising a set of support plate(s) that are mounted on the trays and form a support for a set of cable(s) and/or samples to be cooled, the installation comprising a system for cooling to a cryogenic temperature, which is configured to cool at least some of the trays and/or support plate(s), the system for cooling to a cryogenic temperature comprising a refrigerator comprising a cryogenic cycle fluid and a cooling circuit for putting the cycle fluid in circulation and into a heat-exchange relationship at at least a part of the periphery of at least one support plate.

The invention also relates to a cryogenic refrigeration installation comprising an enclosure delimiting a sealed volume closed by a cover, the enclosure accommodating at least two thermally conductive trays that are distributed along a distribution direction in the enclosure and form thermal stages, at least one the trays being connected to a heat shield forming a thermal insulation volume, the installation comprising a system for cooling to a cryogenic temperature, which is configured to cool at least some of the trays and/or one or more plate(s) that is/are connected to the trays and form(s) a support for a set of cable(s) or samples to be cooled, the system for cooling to a cryogenic temperature comprising a refrigerator having a refrigeration cycle for a cycle fluid, said refrigerator comprising a cycle circuit containing a cycle fluid comprising helium, the cycle circuit being configured to subject the cycle fluid to a thermodynamic cycle that brings the cycle fluid to a given cold temperature at at least one cold end of the cycle circuit, the cycle circuit putting a flow of cycle fluid at the cold end into a heat-exchange relationship with at least some of the trays and/or plates, the cycle circuit comprising a mechanism for compressing the cycle fluid, at least one member for cooling the cycle fluid, a mechanism for expanding the cycle fluid and at least one member for reheating the expanded cycle fluid, characterized in that the cycle circuit comprises a first vessel for storing a reserve of liquefied cycle fluid, the cycle circuit comprising, downstream of the heat-exchange relationship with at least some of the trays and/or plates, a bypass pipe for diverting at least a part of the flow of cycle fluid to the first storage vessel, the bypass pipe comprising a member for expanding the flow of cycle gas that is configured to expand the cycle gas before supplying the first storage vessel, and in that the cycle circuit comprises, upstream of the heat-exchange relationship with at least some of the trays and/or plates, a portion in a heat-exchange relationship with the liquefied cycle fluid contained in the first storage vessel.

The invention relates in particular to a cryogenic refrigeration device comprising an enclosure in which trays are refrigerated by a cryogenic refrigerator with a cryogenic fluid, which is preferably expanded.

The invention relates to a refrigeration device for cooling elements or equipment to a cryogenic temperature below 100 K, in particular below 50 K and/or below 4 K.

In particular, the invention relates to refrigeration devices for cooling to very low temperatures, of around a few kelvin or millikelvin (“sub-kelvin refrigeration”). These very low temperatures are conventionally obtained using a cryogenic cooler refrigerator of the He4 or He3 or dilution Joule-Thomson type.

BACKGROUND OF THE INVENTION

In these devices, it is necessary to supply a cooling power down to a temperature of, for example, 4 K to one or more refrigeration stages.

This cooling power must also be able to rapidly cool the device (cooling down from a hot state). The device must also be able to be reheated for the purpose of maintenance, for example.

Known dilution refrigerators require cooling powers at least down to 4.2 K in order to function. This cooling power is conventionally obtained from cryogenic refrigerators of the pulse tube type or the like, which are referred to as “dry”. According to another solution, referred to as “wet”, a bath of liquid helium is used in the enclosure to cool the trays or the like. This solution presents problems of managing the sealing between the various parts, this complicating access for the samples and cables in the enclosure. These known “wet” solutions also require relatively long cooling and reheating times.

One problem is to increase the cooling power and/or to distribute it correctly in the enclosure, in particular at the trays or equipment to be cooled.

SUMMARY OF THE INVENTION

It is an aim of the present invention to overcome all or some of the drawbacks of the prior art that are set out above.

In an effort to overcome the deficiencies of the prior art discussed, supra, the device according to the invention, which is otherwise in accordance with the generic definition thereof that is given in the above preamble, may comprise a refrigerator comprising a cryogenic cycle fluid and a cooling circuit for putting the cycle fluid in circulation and into a heat-exchange relationship at at least a part of the periphery of at least one support plate.

In another embodiment of the device according to the invention, which is otherwise in accordance with the generic description thereof that is given in the above preamble, the cycle circuit may comprise a first vessel for storing a reserve of liquefied cycle fluid, the cycle circuit comprising, downstream of the heat-exchange relationship with at least some of the trays and/or plates, a bypass pipe for diverting at least a part of the flow of cycle fluid to the first storage vessel, the bypass pipe comprising a member for expanding the flow of cycle gas that is configured to expand the cycle gas before supplying the first storage vessel, and in that the cycle circuit comprises, upstream of the heat-exchange relationship with at least some of the trays and/or plates, a portion in a heat-exchange relationship with the liquefied cycle fluid contained in the first storage vessel.

Moreover, embodiments of the invention may have one or more of the following features:

    • the cryogenic cooler comprises a refrigerator having a refrigeration cycle for a cycle fluid, said refrigerator comprising a cycle circuit made up of the following elements disposed in series: a mechanism for compressing the cycle fluid, at least one member for cooling the cycle fluid, a mechanism for expanding the cycle fluid and at least one member for reheating the expanded cycle fluid, wherein the cycle fluid comprises at least one of the following: helium, hydrogen, nitrogen, argon, the cycle circuit being configured to subject the cycle fluid to a thermodynamic cycle that brings the cycle fluid to a given cold temperature at at least one end of the cycle circuit, the flow of cycle fluid in a heat-exchange relationship with said plates in the set of heat exchangers comprising the cycle fluid at the cold temperature, the device comprising a set of pipe(s) for supplying at least part of the fluid from the cycle circuit to the set of exchangers and for returning said fluid from the set of exchangers to the cycle circuit of the refrigerator,
    • the cycle circuit is configured to subject the cycle fluid to a thermodynamic cycle that brings the cycle fluid to a plurality of different cold temperatures at, respectively, a plurality of ends of the cycle circuit, a plurality of separate flows of the cycle fluid at said different cold temperatures being put into a heat-exchange relationship with, respectively, the at least two separate trays via two respective sets of heat exchangers,
    • the cycle fluid is or contains predominantly helium, the cycle circuit being configured to bring the cycle fluid to at least one of the following cold temperatures: approximately 80 K, between 20 and 70 K, between 2 K and 5 K and/or into a supercritical state,
    • the device comprises a dilution refrigerator in a heat-exchange relationship with at least one tray,
    • the trays are made of a thermally conductive material, for example copper or any other alloy or any suitable material,
    • the trays can be spaced apart from one another by rods of low thermal conductivity,
    • the trays are configured to be the support for various apparatuses or samples to be cooled to a low temperature,
    • the device comprises one or more electrically insulating elements that provide electrical insulation between the enclosure and the cooler,
    • at least some of the set of support plate(s) are mounted at the edge of the respective trays, in a plane situated above or below the tray in question or in the plane of the tray in question in respective housings provided in the tray,
    • at least some of the set of support plate(s) are mounted in a removable manner relative to their tray,
    • the installation comprises a set of heat exchanger(s) in a heat-exchange relationship both with the tray and the associated support plate, the cooling circuit passing through said heat exchanger(s),
    • the installation comprises a set of exchangers interposed between the tray and the associated support plates, the cooling circuit passing through said heat exchangers,
    • the cooling circuit is in a heat-exchange relationship with a heat shield associated with a tray, directly in the body of the heat shield and/or in a set of heat exchanger(s) in contact with the heat shield, which is/are interposed, for example, between the shield and the tray,
    • the cooling circuit is in a heat-exchange relationship with at least one tray, directly in the body of the tray and/or in a set of heat exchangers in contact with the tray,
    • at least some of the set of heat exchangers are removable from the tray in question together with the support plates in question or independently of the support plates in question,
    • the cooling circuit makes several separate passes around at least a part of the periphery of at least one support plate,
    • the cooling circuit puts the cycle fluid in circulation and into a heat-exchange relationship in series with at least a part of the periphery of a plurality of support plates of one and the same tray,
    • the cooling circuit puts the cycle fluid in circulation and into a heat-exchange relationship in parallel with at least a part of the periphery of a plurality of support plates of one and the same tray,
    • the cooling circuit puts the cycle fluid in circulation and into a heat-exchange relationship firstly at at least a part of the periphery of at least one support plate of a first tray and then, sequentially, puts the fluid in circulation and into a heat-exchange relationship at at least a part of the periphery of at least one other support plate of a second tray,
    • at least a part of a peripheral edge of the set of support plate(s) coincides with the edge of the tray in question, the cooling circuit passing around the periphery of at least one support plate except for the edge that coincides with the edge of the tray,
    • the set of plate(s) and heat exchangers of a tray are situated in the same plane as the tray in question,
    • the set of plate(s) or the corresponding heat exchangers of a tray are situated in the same plane as the tray in question,
    • in the use configuration of the installation, the set of plate(s) and heat exchangers and the tray in question are horizontal,
    • in the use configuration, the set of plate(s) and the tray in question are horizontal, while the corresponding heat exchangers are vertical,
    • the cooling circuit circulating in said heat exchangers passes through the heat exchangers via inlet(s) and outlet(s) that open out at the edge of the heat exchangers and are situated adjacently to the peripheral edge of the corresponding tray and/or the central part of the corresponding tray,
    • at least some of the trays are made of a thermally conductive metal or alloy, for example aluminum and/or copper, optionally gold-plated,
    • at least some of the support plates are made of a thermally conductive metal or alloy, for example aluminum and/or copper, optionally gold-plated,
    • at least some of the heat exchangers are made of a thermally conductive metal or alloy, for example aluminum and/or copper,
    • the portion for heat exchange between the liquefied cycle fluid contained in the vessel and the cycle fluid of the cycle circuit comprises a passage of the cycle circuit in the liquefied cycle fluid inside the first storage vessel,
    • the portion for heat exchange between the liquefied cycle fluid contained in the vessel and the cycle fluid of the cycle circuit comprises a passage of the cycle circuit in an exchanger cooled by a liquefied cycle fluid circulation loop supplied by the first storage vessel, for example a thermosiphon,
    • the cycle circuit comprises, downstream of the heat-exchange relationship with at least some of the trays and/or plates, a return pipe which is configured to return the fraction of the flow of cycle fluid that has not been diverted to the first storage vessel to the compression mechanism,
    • the cycle circuit comprises a return pipe connecting an outlet of the first storage vessel to the compression mechanism,
    • the return line comprises a cryogenic compressor or pump,
    • the cycle circuit comprises a second vessel for storing a reserve of liquefied cycle fluid that is connected to the return pipe and/or the bypass pipe,
    • the cycle circuit is configured to store, in the second storage vessel, a reserve of liquefied cycle fluid at a given temperature greater than the given temperature of the cycle fluid stored in the first storage vessel,
    • the cycle circuit comprises a pipe that connects the second storage vessel to the first storage vessel and is configured to allow the transfer of liquefied cycle fluid from the second storage vessel to the first storage vessel,
    • the cycle circuit of the refrigerator comprises a plurality of separate pipes that put different flows of cycle fluid into a heat-exchange relationship with separate trays and/or plates,
    • the cycle circuit comprises at least one pipe that puts the cycle fluid into a heat-exchange relationship in series with a plurality of separate trays and/or plates of one and the same enclosure and/or of a plurality of separate enclosures,
    • the cycle circuit is configured to subject the cycle fluid to a thermodynamic cycle that brings the cycle fluid to a plurality of different cold temperatures at, respectively, a plurality of cold ends of the cycle circuit, the cycle circuit of the refrigerator comprising a plurality of separate pipes that put different flows of cycle fluid at different temperatures into a heat-exchange relationship in parallel with respective separate trays and/or plates.

The invention also relates to a refrigeration method using such an installation and comprising a step of storing and/or producing a liquid cryogenic cycle fluid at the refrigerator, a step of putting said cryogenic fluid in circulation and putting this fluid into a heat-exchange relationship at at least a part of the periphery of at least one support plate, and, following heat exchange(s), a step of returning this fluid to the refrigerator or transferring it to a collector.

The invention also relates to a refrigeration method using an installation in accordance with any one of the features above or below, the method comprising a step of producing a cooling power determined by the refrigerator, using some of this cooling power produced to cool a set of tray(s) and/or plate(s) by heat exchange with a flow of cycle fluid, a step of collecting this flow of cycle fluid after heat exchange and a step of expanding a fraction of this flow of cycle fluid collected to the first storage vessel in order to form a reserve of cold, the method comprising a step of cooling the flow of cycle fluid with the cycle fluid from the first storage vessel.

The invention may also relate to any alternative device or method comprising any combination of the features above or below that is within the scope of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, claims, and accompanying drawings. It is to be noted, however, that the drawings illustrate only several embodiments of the invention and are therefore not to be considered limiting of the invention's scope as it can admit to other equally effective embodiments.

Further particular features and advantages will become apparent upon reading the following description, which is provided with reference to the figures, in which:

FIG. 1 shows a schematic and partial view in vertical section illustrating one exemplary embodiment of a cooling device according to the invention,

FIG. 2 shows a schematic and partial view illustrating one exemplary embodiment of a cryogenic cooler that can be used in such a cooling device,

FIG. 3 is a schematic and partial view, in vertical section, illustrating another exemplary embodiment of a refrigeration installation according to the invention,

FIG. 4 is a schematic and partial view, in vertical section, illustrating another exemplary embodiment of a refrigeration installation according to the invention,

FIG. 5 is a schematic and partial top view of a detail of such an installation, illustrating a first exemplary embodiment of a tray,

FIG. 6 is a schematic and partial top view of a detail of such an installation, illustrating a second exemplary embodiment of a tray,

FIG. 7 is a schematic and partial view, in vertical section, of a detail of such a tray in a first possible embodiment variant,

FIG. 8 is a schematic and partial view, in vertical section, of a detail of such a tray in a second possible embodiment variant,

FIG. 9 is a schematic and partial view, in vertical section, of a detail of such a tray in a third possible embodiment variant,

FIG. 10 is a schematic and partial view, in vertical section, of a detail of such a tray in a fourth possible embodiment variant,

FIG. 11 is a schematic and partial view, in vertical section, of a detail of such a tray connected to a heat shield in a first possible embodiment,

FIG. 12 is a schematic and partial view, in vertical section, of a detail of such a tray connected to a heat shield in a second possible embodiment,

FIG. 13 is a schematic and partial view, in vertical section, of a detail of such a tray connected to a heat shield in a third possible embodiment,

FIG. 14 is a schematic and partial view, in vertical section, of a detail of such a tray connected to a heat shield in a fourth possible embodiment,

FIG. 15 is a schematic and partial view, in vertical section, of a detail of such a tray connected to a heat shield in a fifth possible embodiment,

FIG. 16 is a schematic and partial view illustrating an example of the structure and operation of an installation in accordance with another embodiment of the invention,

FIG. 17 is a schematic and partial view illustrating an example of the structure and operation of an installation in accordance with another embodiment of the invention,

FIG. 18 is a schematic and partial view illustrating an example of the structure and operation of an installation in accordance with another embodiment of the invention.

 DETAILED DESCRIPTION OF THE INVENTION

The cryogenic refrigeration device 1 illustrated comprises an enclosure 2 delimiting a vacuum-sealed volume closed by a cover 3.

The device 1 comprises at least one cryogenic cooler 70 that is mounted through the cover 3 and has a first end situated outside the enclosure 2 and a second end situated inside the enclosure 2.

The cryogenic cooler 70 is configured to supply cold at its second end. For example, a or the cooling power is stored and/or produced at the first end of the cryogenic cooler.

The first and second ends of the cryogenic cooler can form a single physical entity. In a variant or in combination, the cooling power could be produced in another installation/device (another physical entity) and be transferred to this first end, for example by a heat-transfer fluid or any other heat-transfer member. Thus, the cooling power (or cold source) is produced or stored outside the enclosure 2.

At least some of this cooling power can be transferred from the first end to the second end.

The cryogenic cooler 4 is, for example, a refrigerator of the type that uses a cycle fluid subjected to a thermodynamic cycle in a closed cycle circuit (other than a dilution refrigerator). The cycle fluid is brought to a relatively colder temperature at a cold end of the cycle in order to provide cooling power. At least part of the cycle circuit may be situated outside the enclosure 2, in particular the cold end. Thus, the cycle fluid is cooled outside the enclosure 2 and can be put in circulation in the enclosure in order to provide cooling power therein (at at least one tray 4, 5, 6). The cooling power is thus produced outside the enclosure 2. The reheated cycle fluid which has undergone heat exchange with the trays in the enclosure 2 can pass back out of the enclosure in order to be cooled again (the cycle starts again). In particular, the compression and expansion members of the cycle can be situated outside the enclosure 2.

This configuration limits the number of components of the cryogenic refrigerator 4 in the enclosure 2 under vacuum, which preferably comprises a dilution refrigerator. This makes it possible for a very high vacuum to be provided in the enclosure 2, this being favorable for the dilution refrigerator. This limits the risk of leakage and increases the operating time of the dilution refrigerator.

The device 1 comprises, in this example, three thermally conductive trays 4, 5, 6 that are distributed vertically in the enclosure 2 and form thermal stages at given temperatures. The trays are configured to receive and to cool elements or samples.

The device 1 preferably comprises a set of passages 170 formed through the cover 3 and the trays 4, 5 for the sealed passage of cable(s) and/or equipment to be cooled into the enclosure 2.

At least some of the trays 4, 5 (two in this example) are cooled by the cryogenic cooler 70 to respective given temperatures that decrease from top to bottom (for example a first tray 4 can be cooled to a temperature of between 20 K and 80 K, in particular around 50 K, and the other tray 5 can be cooled to a temperature of between 2 K and 5 K, in particular around 4 K).

The invention is not limited to this embodiment and further configurations for the trays are possible. For example, the trays could be thermalized at a temperature that decreases from bottom to top, or they could be arranged along a horizontal direction and be thermalized at temperatures that decrease from left to right or vice versa or with another distribution.

As illustrated, the tray(s) 4, 5, 6 can be connected to a heat shield 14, 15 forming a volume that encloses at least one following lower plate.

This means that the shields can form volumes that are contained one inside another (“nested” volumes). Some or all of the shields can be cooled by a cryogenic cooler 70 by thermal coupling as mentioned above.

According to one advantageous particular feature, the cryogenic cooler 70 is of the type that uses a cold source of liquefied cycle fluid such as helium, hydrogen or nitrogen, at least some of the trays 4, 5, 6 being cooled by the cycle gas via a set of heat exchangers in an exchange relationship with said trays and with a flow of the cycle fluid. This means that the cryogenic cooler 70 is connected to a cold source situated outside the enclosure 2, this cold source supplying a flow of liquefied fluid that is cooled outside the enclosure 2, this flow circulates in the cryogenic cooler 4 and is put into a heat-exchange relationship with at least some of the trays 4, 5, 6 in the enclosure 2.

The flow of cycle fluid is brought into the enclosure via a sealed circuit such that the cycle fluid does not communicate with the interior of the enclosure 2 (in contrast to the known wet solutions).

The set of heat exchangers in an exchange relationship with said trays comprises, for example, a plurality, for example, of separate heat exchangers mounted respectively on the plates 4, 5, 6. In addition, the exchangers of at least two adjacent trays 5, 6 are preferably connected mechanically (so as to form a single mechanical entity which is introduced into or removed from the enclosure 2).

Preferably, these elements are held together by the rigid pipes for the cycle fluid and/or via additional supports made of thermally insulating material such as glass fiber, and/or via a frame. This allows the set to be inserted and removed in a single easy operation.

The heat exchangers are, for example, arranged in a line and spaced apart along a distribution direction, for example a stacking direction which is vertical in the operating position in the enclosure 2.

These cooling stages are disposed one above the other in a spaced-apart manner, but the heat exchangers are not necessarily aligned on the same vertical axis as shown in the non-limiting example.

The heat exchangers can be mounted in the enclosure 2 via one and the same passage through the cover 3, for example via one and the same support flange 150 of the cover 3.

At least some of the set of heat exchangers can be disposed in a sealed casing 210 delimiting, for example, a volume that is independent of the rest of the volume of the enclosure 2, and which can contain gas at a pressure of between a few millibar and a few bar, or can be placed under vacuum, that is to say at a pressure below 0.01 mbar.

The heat exchangers can be in an exchange relationship with said trays by conduction and direct or indirect contact, for example via at least one of the following: bolting, at least one thermal connecting braid, a clamp, etc.

In the non-limiting example illustrated, the heat exchangers may comprise a block 700 of conductive material, for example made of copper, in contact with the tray 4, 5, 6, and a tube 80, 180 or circuit of conductive material that transports the flow of cycle fluid (for example made of copper, aluminum or the like).

This tube or circuit can be soldered to the block 700 and/or machined in the block 700 and/or molded in the block 700 and/or cast in the block 700.

Likewise, at least some of the heat exchangers may comprise (in particular at the junction between two elements) a layer of gilt configured to increase heat exchange with the tray in question.

As illustrated schematically in FIG. 2, the cryogenic cooler 70 which produces the cooling power (flow of cold cycle fluid) may comprise a cryogenic refrigerator having a continuous refrigeration cycle for a cycle fluid.

Such a refrigerator comprises a cycle circuit 8 made up of the following elements disposed in series: a mechanism 9 for compressing the cycle fluid (one or more compressors in series and/or in parallel), at least one member 130 for cooling the cycle fluid (heat exchanger(s)), a mechanism 19 for expanding the cycle fluid (one or more turbine(s) or valve(s) in series and/or in parallel) and at least one member 130 for reheating the expanded cycle fluid (exchanger(s), in particular countercurrent exchanger(s) for cooling and reheating two parts of the circuit 8 at the same time).

The cycle fluid preferably comprises at least one of the following: helium, hydrogen, nitrogen, argon.

The cycle circuit 8 is configured to subject the cycle fluid to a thermodynamic cycle that brings the cycle fluid to a given cold temperature at at least one cold end of the cycle circuit 8.

The flow of cycle fluid which is put into a heat-exchange relationship with said plates 4, 5, 6 in the set of heat exchangers comprises at least one fraction of this cycle fluid at the cold temperature. For example, the cooled liquefied fluid that circulates in the pipes 80, 180 is a portion removed from the flow circulating in the cycle circuit 8.

The device 1 comprises a set of pipe(s) 80, 180 for supplying the fluid from the cycle circuit 8 to the set of exchangers and for returning said fluid from the set of exchangers to the cycle circuit 8 of the refrigerator 70 (through the cover 3).

The cycle circuit 8 can be configured to subject the cycle fluid to a thermodynamic cycle that brings the cycle fluid to a plurality of different cold temperatures at, respectively, a plurality of cold ends of the cycle circuit 8.

Thus, a plurality of separate flows of the cycle fluid at said different cold temperatures can be put into a heat-exchange relationship with, respectively, a plurality of separate trays via respective sets of heat exchangers (two or more).

In the example illustrated, two sets of pipes 80, 180 supply a cooling power at different temperatures at, respectively, two trays 4, 5. The two sets form separate circulation loops of the cycle fluid which pass into the enclosure 2.

The device 1 preferably comprises one or more electrically insulating elements 220 that provide electrical insulation between the enclosure 2 and the cold source of the cooler 4 (in particular with respect to the electric voltages of the cold source of the cooler 4). For example, insulating elements 220 are interposed at the junction between the tubes or pipes 80, 180 and the flange 150, and/or at an intermediate position along the pipe portion between the cold source of the cooler 70 and the flange 150. These elements 220 may be, for example, sleeves or tube portions made of ceramic or any other suitable material. For example, some of the tubes or pipes 80, 180 incorporate an electrically insulating portion of this type.

As shown schematically in FIG. 1, the device may also comprise, in the enclosure 2, connected to the tray 6, a sub-kelvin refrigerator 90, for example a dilution refrigerator or a JT (Joule-Thomson) refrigerator, in a heat-exchange relationship with this at least one tray 6 in order to reach temperatures lower than 4 K, notably lower than 1 K, and in particular around a millikelvin.

Such a dilution refrigerator 90 conventionally uses a mixture of helium-3 and helium-4 in a working circuit comprising a boiler, a mixing chamber and a member for putting the helium flow in circulation. The cooling is achieved in the mixing chamber as a result of the enthalpy of mixing when the helium-3 is diluted in the helium-4.

For example, the refrigeration device has a working circuit in the form of a loop containing a cycle fluid comprising a mixture of helium-3 (3He) and helium-4 (4He). The working circuit comprises a mixing chamber, a boiler and a fluid transfer member, which are disposed in series and fluidically connected via a first set of pipe(s). The first set of pipe(s) is configured to transfer cycle fluid from an outlet of the mixing chamber to an inlet of the boiler and from an outlet of the boiler to an inlet of the transfer member. The working circuit comprises a second set of pipe(s) connecting an outlet of the transfer member to an inlet of the mixing chamber. The working circuit comprises at least a first heat-exchange portion between at least some of the first set of pipe(s) and the second set of pipe(s), this first heat-exchange portion being situated between the boiler and the mixing chamber. A cooling member is generally provided in a heat-exchange relationship with the working circuit and configured to transfer cold energy to the cycle fluid.

The device 1 thus incorporates a set of heat exchangers in the enclosure 2 which are cooled by an external cold source that supplies cooling power down to 4 K or even down to 2 K, in particular via a flow of cryogenic fluid.

This configuration makes it possible to supply more power than a pulse tube.

As mentioned above, the heat exchangers can be supplied, for example, by a helium refrigerator or liquefier (open or closed loop), or by liquid nitrogen (open or closed loop connected to a liquid nitrogen tank) or some other liquefied fluid.

The set of exchanger(s) can be installed in any installation that uses a pulse tube. This makes it possible to easily modify installations that already exist and use pulse tubes.

The invention may make it possible to avoid the rigidity of a pulse tube. The exchangers can be disposed along a horizontal direction and/or be mounted in such a manner that they are not attached to one another.

As mentioned above, the set of heat exchangers can have one or more stages (for example one at a temperature of approximately 4 K, approximately 20 K, 50 to 70 K, 80 K, etc.).

This makes it possible for the need for cooling power to be stepped depending on the temperatures and thus for the power required for operation of the installation to be limited. The more the device has to cool samples or equipment, for example cables, the more advantageous it is to add cooling stages of this type.

The set of heat exchangers can be supplied (cooled) by one or more flows of cycle fluid at different temperatures. Likewise, one and the same flow of cycle fluid can supply a plurality of cooling stages in series.

In particular towards temperatures of about 4 K, the cycle fluid (typically helium) may be in a supercritical and subcooled state in order to limit the vibrations that result from the vaporization thereof when it is reheated.

The set of heat exchangers can be inserted into the enclosure via a single tap on the flange or top cover. This facilitates installation and optimizes the experimental space in the enclosure. The set of exchanger(s) can be incorporated into a volume or space that is separate from the rest of the enclosure 2 in order to limit the risk of of cycle fluid leaking into the enclosure 2.

The thermal interface between the enclosure 2 and the heat exchangers can be produced by bolting the exchanger to a panel of the associated stage or tray, and/or with the aid of conductive thermal braids.

The cryogenic refrigeration installation 1 illustrated in FIG. 3 comprises an enclosure 2 delimiting a sealed volume closed by a cover 3, made, for example, of aluminum. Preferably, the volume is under vacuum and accommodates a plurality of thermally conductive trays 4, 5, 6, 7 that are distributed along a distribution direction in the enclosure 2 and form thermal stages at, for example, decreasing temperatures (for example vertically from top to bottom). The trays can be spaced apart from one another via supports 40, made, for example, of composite material.

In the example schematically illustrated, the enclosure 2 accommodates four trays 4, 5, 6, 7. Each tray 4, 5, 6, 7 is preferably connected to a respective heat shield 14, 15, 16, 17 forming a thermal insulation volume. The tray 4, 5, 6, 7 and the corresponding shield 14, 15, 16, 17 may enclose the following trays and shields along a distribution direction. This means that the trays 4, 5, 6, 7 and shields 14, 15, 16, 17 can be interconnected in the manner of “nested” parts.

For example, in the operating configuration, the cover 3 can be at ambient temperature (at least on its outer face) and the four interior trays 4, 5, 6, 7 are cooled to temperatures that decrease from top to bottom (for example to 90 K, 50 K, 10 K and 3 K, respectively).

The installation 1 comprises a set of support plates 24, 25, 26, 27 mounted on the trays 4, 5, 6, 7. These plates 24, 25, 26, 27 form a support for a set of cable(s) 30 or samples to be cooled. As illustrated, a bundle of cables 30 is mounted on the set of support plates 24, 25, 26, 27 mounted respectively on the different trays 4, 5, 6, 7 (along the distribution direction). In other words, the cables 30 extend vertically downward in the enclosure 2 and are mounted in a heat-exchange relationship with the increasingly cold trays 4, 5, 6, 7. Thus, the thermally conductive trays 4, 5, 6, 7 are distributed along the distribution direction in the enclosure 2 and form thermal stages. At least some of the trays 4, 5, 6, 7 are cooled to respective given temperatures by the cooler or cryogenic refrigerator 70.

To this end, the installation 1 preferably comprises a set of passages formed through the cover 3 and the trays 4, 5, 6, 7 for the sealed passage of cable(s) and/or equipment into the enclosure 2.

The support plates 24, 25, 26, 27 for the different trays 4, 5, 6, 7 are, for example, arranged in a line and spaced apart along a distribution direction, for example a stacking direction which is vertical in the operating position in the enclosure 2.

The installation 1 has at least one system for cooling to a cryogenic temperature that is configured to cool at least some of the trays 4, 5, 6, 7 and/or support plate(s) 24, 25, 26, 27.

This system for cooling to a cryogenic temperature preferably comprises a refrigerator 70 comprising a cryogenic cycle fluid (for example based on helium) and a cooling circuit 20 for putting the cycle fluid in circulation and into a heat-exchange relationship at at least a part of the periphery of at least one support plate 24, 25, 26, 27.

The cooling circuit 20 may, in particular, comprise a set of pipe(s) for supplying the cycle fluid produced by the refrigerator to the elements to be cooled in the enclosure 2 and a set of pipes for returning said fluid that has cooled these elements to the refrigerator 70.

This means that, instead of cooling the trays 4, 5, 6, 7 by conduction only via pulse tubes, for example, or a helium bath, the installation 1 provides for the cooling power to be transferred via a flow of cycle fluid as close as possible to the support plates 24, 25, 26, 27 (as described in detail below) and in particular preferably in contact with the plates 24, 25, 26, 27.

Preferably, the cycle fluid contains or consists of helium. The cycle fluid can be cooled in a supercritical or superfluid state before being put into a heat-exchange relationship with the plates. This circulation of a flow of supercritical helium as close as possible to the plates makes it possible to distribute the cooling power very effectively to the location where it is required. For example the refrigerator 70 is mounted through the cover 3 and has a first end situated outside the enclosure 2 and a second end situated inside the enclosure 2. The refrigerator 70 is configured to supply cold at its second end.

The refrigerator 70 is, for example, of the type that uses a cold source of liquefied cycle fluid such as helium or nitrogen. The cooling power of the refrigerator is stored and/or produced at its first end and this cooling power is transferred to the trays via a flow of cycle fluid that transfers the cooling power from the first end to the second end of the refrigerator. Following heat exchange with the plate(s), the cycle fluid is returned in order to restart the cycle (compression, etc.).

The refrigerator 70 comprises, for example a cycle circuit configured to subject the cycle fluid to a thermodynamic cycle that brings the cycle fluid to a given cryogenic temperature at at least one cold end of the cycle circuit. The circuit of cycle fluid has a mechanism 9 for compressing the cycle fluid (compressor(s)), at least one member for cooling the cycle fluid (heat exchanger(s)), a mechanism 19 for expanding the cycle fluid (valve(s) and/or turbine(s)) and at least one member (heat exchanger(s)) for reheating the expanded cycle fluid. The reheating and cooling can be carried out in part at least by one or more countercurrent heat exchanger(s) for cooling and reheating two parts of the cycle circuit at the same time.

The refrigerator 70 uses, for example, a cycle fluid comprising at least one of the following: helium, hydrogen, nitrogen, argon. The installation comprises a set of pipe(s) for supplying at least some of the fluid of the cycle circuit to the plates to be cooled that form the cooling circuit 20.

As illustrated in FIG. 5 and FIG. 6, all or some of the support plates 24, 25, 26, 27 may be situated at the edge of their respective tray 4, 5, 6, 7. For example, the support plates 24, 25, 26, 27 bearing the cables are mounted removably on the trays 4, 5, 6, 7 (interlocking, screwing, etc.).

The heat exchange between the flow of cold cycle fluid (preferably in a supercritical state) and the plates 24, 25, 26, 27 can be effected by a set of heat exchanger(s) 21 in a heat-exchange relationship both with the tray 4, 5, 6, 7 in question and the support plate 24, 25, 26, 27 in question (direct or indirect heat exchange between the exchanger(s) and the plates or trays). The support plates 24, 25, 26, 27 with cables 30 and heat exchangers 21 can be mounted in the enclosure 2 via one and the same passage through the cover 3, for example via one and the same flange of the cover 3.

For example, the cooling circuit 20 passes through said heat exchanger(s) 21. For example, the heat exchangers 21 are interposed between the tray 4, 5, 6, 7 and the support plates 24, 25, 26, 27 (direct or indirect contact).

The heat exchangers 21 can be mounted on the trays/plates in order to exchange heat by conduction and contact.

In the example in FIG. 7, the exchanger 21 is situated in the same plane as the plate 24, 25, 26, 27 and the tray 4, 5, 6, 7. For example, the plate 24, 25, 26, 27 is encased (surrounded) in its exchanger 21, which is itself encased in a housing of the tray 4, 5, 6, 7. In this configuration, the plate 24, 25, 26, 27 does not bear on the tray 4, 5, 6, 7 directly (but via the heat exchanger 21).

As can be seen in FIG. 5, a part of a peripheral edge of the support plate 24, 25, 26, 27 may coincide with the edge of the tray 4, 5, 6, 7 in question. The cooling circuit 20 (the exchanger 21) passes, for example, around the periphery of the support plate 24, 25, 26, 27 apart from the edge that coincides with the edge of the tray. For example, the inlet/outlet of the cooling circuit 20 are situated at this edge of the plate and of the tray.

In the example in FIG. 8, the plate 24, 25, 26, 27 is situated above the tray 4, 5, 6, 7, and the exchanger 21 is interposed vertically therebetween. For example, the heat exchanger 21 has a vertical structure (which extends perpendicularly to the plane of the tray). This configuration makes it possible to limit the space requirement of the exchanger on the tray 4, 5, 6, 7 while ensuring optimal cooling.

The example in FIG. 9 differs from that in FIG. 8 in that the heat exchanger 21 has a horizontal structure (which extends parallel to the plane of the tray 4, 5, 6, 7). In addition, as illustrated, the cooling circuit 20 can make several separate passes (outward/return) in the heat exchanger 21 around at least a part of the periphery of at least one support plate 24, 25, 26, 27.

In the example in FIG. 10, the plate 24, 25, 26, 27 is situated in the plane of the tray 4, 5, 6, 7 (in a housing provided for this purpose), and the exchanger 21 is interposed therebetween (along the vertical direction). For example, the heat exchanger 21 has a flat or horizontal structure.

Preferably, the heat exchanger 21 cools the tray 4, 5, 6, 7 by thermal conduction, via contact with the plate, for example in particular at at least a part of its periphery.

Of course, other embodiments are also conceivable.

Thus, the cooling circuit 20 can be arranged so as to be in a heat-exchange relationship with the heat shield 14, 15, 16, 17 associated with a tray 4, 5, 6, 7, for example between the tray (or plate) and the heat shield 14, 15, 16, 17 as illustrated in FIG. 11.

As illustrated in FIG. 12, the cooling circuit 20 can pass directly through the body of the heat shield 14, 15, 16, 17 close to the plate or tray.

In the example in FIG. 13, the heat exchanger 21 containing the cooling circuit 20 is disposed on the outer peripheral surface of the heat shield 14, 15, 16, 17 close to the periphery of the tray or plate.

In the example in FIG. 14, the cooling circuit 20 can pass directly through the body of the tray 4, 5, 6, 7

In the example in FIG. 15, one or more heat exchangers 21 containing the cooling circuit 20 are disposed on the upper and/or lower surface of the tray and/or of the plate and optionally also in contact with the heat shield 14, 15, 16, 17.

As illustrated in FIG. 5, the cooling circuit 20 can be configured to cool plates 24 of one and the same tray 4, 5, 6 in series. This means that the cooling circuit puts the cycle fluid in circulation and into a heat-exchange relationship with the plates 24 one after another (in this example via respective heat exchangers 21). This means that the cooling circuit 20 cools a first plate 24 of the tray, then a second, a third, etc., before being discharged (to another tray or to the refrigerator 70). The cooling circuit 20 can thus define a peripheral path all around the tray 4.

In a variant shown in FIG. 6, the cooling circuit 20 is distributed in parallel in order to simultaneously cool the different plates 24 of the tray 4 with separate flows.

Likewise, the cooling circuit 20 can cool the different trays 4, 5, 6, 7 and corresponding plates 24, 25, 26, 27 in parallel and/or in series.

Thus, the cooling circuit 20 can put the cycle fluid into a heat-exchange relationship firstly at at least a part of the periphery of at least one support plate of a first tray 7 and then, sequentially, puts the fluid in circulation and into a heat-exchange relationship at at least a part of the periphery of at least one other support plate 6 of a second tray, and so on. In the example in FIG. 3, the cooling circuit 20 first of all cools the the coldest plates 27/tray 7 (which are the innermost ones along the distribution direction) and then this flow cools the preceding plates 26/tray 6 (opposite to the distribution direction) and so on, before returning in a hotter state to the cycle of the refrigerator in order to be recooled therein.

Of course, and as shown in FIG. 4, one or more trays/plates can be cooled via dedicated cooling circuits 20 (in parallel). For example, a flow of very cold cycle fluid is guided to cool the coldest plate 7/plates 27 before returning directly to the cycle of the refrigerator 70, while the other plates 6, 5, 4/plates 26, 25, 24 are cooled (in parallel or in series) by one or more separate flows originating from the refrigerator 70 (for example relatively less cold flows). For example, the cycle circuit of the refrigerator 70 is configured to subject the cycle fluid to a thermodynamic cycle that brings the cycle fluid to a plurality of different cold temperatures at, respectively, a plurality of ends of the cycle circuit. Thus, a plurality of separate flows of the cycle fluid at said different cold temperatures can be put into a heat-exchange relationship with, respectively, the support plates of separate trays via respective separate pipes (separate circulation loops). The cycle fluid is, for example, configured to bring the cycle fluid to at least one of the following cold temperatures: approximately 80 K, between 20 and 70 K, between 2 K and 5 K and/or into a supercritical state.

The installation 1 may also comprise, in the enclosure 2, connected, for example, to the coldest tray 4, a sub-kelvin refrigerator, for example a dilution refrigerator or a JT (Joule-Thomson) refrigerator, in a heat-exchange relationship with this tray 7 in order to reach temperatures lower than 4 K, notably lower than 1 K, and in particular around a millikelvin. Such a dilution refrigerator conventionally uses a mixture of helium-3 and helium-4 in a working circuit comprising a boiler, a mixing chamber and a member for putting the helium flow in circulation. The cooling is achieved in the mixing chamber as a result of the enthalpy of mixing when the helium-3 is diluted in the helium-4.

In a variant or in combination, the cooling power could be produced in another installation/device (another physical entity) and be transferred to this first end, for example by a heat-transfer fluid or any other heat-transfer member. Thus, the cooling power (or cold source) is produced or stored outside the enclosure 2.

The invention is not limited to these embodiments and further configurations for the trays/plates are possible. For example, the trays 4, 5, 6, 7 and plates 24, 25, 26, 27 could be thermalized at a temperature that decreases from bottom to top, or they could be arranged along a horizontal direction and be thermalized at temperatures that decrease from left to right or vice versa or with another distribution.

The cryogenic refrigeration installation 1 illustrated in FIG. 16 comprises an enclosure 2 delimiting a sealed volume closed by a cover 3. In this example, the enclosure 2 accommodates three thermally conductive trays 4, 5, 6 that are distributed along a distribution direction in the enclosure 2 (which is vertical in this case) and form thermal stages. The trays 4, 5, 6 are preferably each connected to a respective heat shield 14, 15, 16 forming a thermal insulation volume. For example, along the distribution direction, each heat shield encloses (accommodates) the heat shield and the following tray (in a “nested” manner).

The installation 1 comprises a system for cooling to a cryogenic temperature that is configured to cool at least some of the trays 4, 5, 6 and/or one or more support plate(s) 24, 25, 26 which can be connected (30) to the trays 4, 5, 6. These support plates 24, 25, 26 may be mounted removably or detachably on the trays 4, 5, 6 in question to form a support for a set of cable(s) or samples to be cooled (not shown for the sake of simplicity).

The system for cooling to a cryogenic temperature comprises a refrigerator 70 having a refrigeration cycle for a cycle fluid.

The refrigerator 70 comprises a cycle circuit 8 containing a cycle fluid comprising helium. The cycle fluid could be made up of other gas(es), for example a mixture comprising helium and at least one of the following: hydrogen, nitrogen, neon, one or more hydrocarbons.

The cycle circuit 8 is configured to subject the cycle fluid to a thermodynamic cycle that brings the cycle fluid to a given cold temperature at at least one cold end of the cycle circuit 8.

The cycle circuit 8 has a mechanism 9 for compressing the cycle fluid (one or more compressors in series and/or in parallel), at least one member 11, 12, 13, 114 for cooling the cycle fluid (for example one or more heat exchangers), a mechanism 10, 115 for expanding the cycle fluid (one or more valve(s) and/or turbine(s) in series and/or in parallel) and at least one member 114, 13, 12, 11 for reheating the expanded cycle fluid (one or more heat exchangers). As illustrated, the cooling and reheating of the cycle fluid may carried out by one or more heat exchangers that exchange heat between two flows of cycle fluid at different temperatures (for example in countercurrent).

Some of the cycle circuit 8 and in particular the relatively hot portions may be situated outside the enclosure 2.

The cycle circuit 8 has pipes that put at least one flow of cycle fluid at the cold end into a heat-exchange relationship with at least some of the trays 4, 5, 6 and/or plates 24, 25, 26. For example, pipes transfer the cold cycle fluid into heat exchangers 34, 35, 36 in contact with the trays and/or plates. Alternatively or in addition, the pipes conveying the cycle circuit 8 may have portions in direct contact with (and/or in the thickness of) the trays 4, 5, 6 and/or plates 24, 25, 26 and/or heat shield.

For example, the cycle circuit 8 of the refrigerator 70 comprises a plurality of separate pipes 108, 208 that put different flows of cycle fluid into a heat-exchange relationship with separate trays 4, 5, 6 and/or plates 24, 25, 26 of one and the same enclosure 2 (cf. FIG. 3) or of a plurality of separate enclosures 2 (cf. FIG. 4 or FIG. 5).

For example, the cycle circuit 8 may be configured to subject the cycle fluid to a thermodynamic cycle that brings the cycle fluid to a plurality of different cold temperatures at, respectively, a plurality of cold ends of the cycle circuit, the cycle circuit 8 of the refrigerator 70 comprising a plurality of separate pipes 108, 208 that put different flows of cycle fluid at different temperatures into a heat-exchange relationship in parallel with respective separate trays 4, 5, 6 and/or plates 24, 25, 26.

This makes it possible to produce and send supercritical cycle fluid that is pressurized (for example at a pressure of greater than 3.5 bar) to one or more stages of one or more enclosures 2, for example in parallel.

The supercritical fluid may be produced in the cycle circuit 8 by an arrangement of exchangers, in order to best collect the available cooling power.

Thus, the cycle circuit 8 can supply cycle fluid at intermediate temperatures, for example between 4 K and 100 K, in order to cool intermediate stages in one or more enclosures 2.

This allows independent operations for different enclosures 2 with one and the same common refrigeration system 70.

This solution makes it possible to provide a cooling power that can be adapted in a simple manner.

To this end, the different pipes supplying the different stages or enclosures 2 may be provided with flow rate regulating valves. These valves can be regulated depending on the temperature of the element to be cooled (expected cooling power). The flow rates of cycle fluid can be regulated in order to increase or decrease the cooling power requirement in the enclosure 2.

The cycle circuit 8 comprises a first vessel 117 for storing a reserve of liquefied cycle fluid.

The cycle circuit 8 comprises, downstream of the heat-exchange relationship with at least some of the trays 4, 5, 6 and/or plates 24, 25, 26, a bypass pipe 18 for diverting at least a part of the flow of cycle fluid to the first storage vessel 117.

This means that the at least one pipe that returns the cycle fluid that has undergone heat exchange with the elements to be cooled in the enclosure 2 to the reheating members (exchangers 114, 13, 12, 11) and the compression members (compressor 9) has a bypass 18 for diverting to the first storage vessel 117. This bypass pipe 18 preferably has a member 119 for expanding the flow of cycle gas (valve(s) or the like) that is configured to expand the cycle gas before supplying the first storage vessel 117.

The installation 1 may be rated or the operating conditions may be such that the cooling in the enclosure 2 uses only some of the power available in the flow of cold cycle fluid. This cycle fluid returns relatively cold and the cooling power that has not been used to cool the components in the enclosure 2 can be reused.

This is achieved by expanding some of this cycle fluid to the first storage vessel 117.

This arrangement makes it possible to optimize the cooling power produced while minimizing the flow rate of working fluid at low pressure (gas originating from the first storage vessel 117).

In addition, this makes it possible to maximize the flow rate of cold cycle fluid put in circulation in the enclosure(s) 2 (maximizes the available power).

The flow of cycle fluid not used for this bypass can be returned to the cycle compressor of the refrigerator while releasing cold energy to the cycle fluid downstream of the compression. To this end, the cycle circuit 8 comprises, downstream of the heat-exchange relationship with at least some trays 4, 5, 6 and/or plates 24, 25, 26, at least one return pipe 28 that is configured to return the fraction of the flow of cycle fluid that has not been diverted to the first storage vessel 117 to the compression mechanism 9.

This expanded fluid produces liquid at a very low temperature (typically between 1 K and 4 K) that is put into a heat-exchange relationship with the cycle fluid before it exchanges heat with the components in the enclosure 2.

This means that the cycle circuit 8 comprises, upstream of the heat-exchange relationship with at least some of the trays 4, 5, 6 and/or plates 24, 25, 26, a portion in a heat-exchange relationship with the liquefied cycle fluid contained in the first storage vessel 117. The cold reserve formed by the first storage vessel 117 supplies cold to the cycle fluid before it is used to cool the element(s) in the enclosure 2.

In the example in FIG. 16, the heat exchange between the liquefied cycle fluid contained in the vessel 117 and the cycle fluid of the cycle circuit 8 comprises a passage of the cycle circuit 8 in the liquefied cycle fluid inside the first storage vessel 117. This means that some of the cycle circuit 8 is submerged in the liquid bath of the first storage vessel 117, for example describing a coil or several passages or bends therein.

In the example in FIG. 18, the heat exchange between the liquefied cycle fluid contained in the vessel 117 and the cycle fluid of the cycle circuit 8 is effected via a passage of the cycle circuit 8 in a heat exchanger 1150 cooled by a liquefied cycle fluid circulation loop 47 supplied by the first storage vessel 117, for example a thermosiphon. This is a more indirect heat exchange than in the preceding embodiment.

The cycle circuit 8 preferably also comprises a return pipe 38 connecting an outlet (for example an upper outlet) of the first storage vessel 117 to the compression mechanism 9. This allows the boil-off gas to be returned to the compression within the first storage vessel 117.

As illustrated in FIG. 18, the return pipe 38 may comprise a cryogenic compressor or pump 110.

As illustrated in FIG. 17 and in FIG. 18, the cycle circuit 8 may have a second vessel 127 for storing a reserve of liquefied cycle fluid. This second storage vessel 127 is, for example, connected in parallel with the first storage vessel 117 to the bypass line 18. The flow of fluid returning from the enclosure 2 via the return pipe 28 can be sent to the first storage vessel 117 (via the valve 119) or to the second vessel 127 (via the valve 128). A pipe and valve 1127 can be provided for transferring liquid from the second storage vessel 127 to the first vessel 117. This valve 1127 can be used to regulate the liquid level in the second vessel 127. The gas formed in the second storage vessel 127 is sent to the compressor 9.

This return pipe 28 may, for example, supply the second storage vessel 127 at an intermediate level between its upper and lower ends. As illustrated, an upper outlet of this second storage vessel 127 can be connected to the compression of the cycle circuit, for example at an intermediate pressure level between the low pressure at the inlet and the high pressure at the outlet (between two compressors 9 in series).

The second storage vessel 127 can be configured to store a reserve of liquefied cycle fluid at a given temperature (for example around 4 K) greater than the given temperature of the cycle fluid stored in the first storage vessel 117 (for example around 2 K).

As illustrated, the cycle circuit 8 preferably does not comprise a thermosiphon at the second storage vessel 127, but a thermosiphon could, of course, be provided at the second storage vessel 127. An exchanger 114 may be placed on the circuit 8 before the second storage vessel 127 in order to take advantage of the low temperature of the return fluid. This makes it possible to improve the energy efficiency of the system.

All or some of the components of the refrigerator and/or of the enclosure 2 may be accommodated in a thermally insulated cold box, for example under vacuum. The operation can be at least partially automated, thereby limiting the handling of cryogenic fluid by the user. The structure of the installation 1 allows cooling power along a capillary in the enclosure, unlike more localized cooling of known solutions with a bath of cryogenic liquid.

The above structure is more efficient and flexible than solutions that use exclusively pulse tubes to cool stages of the enclosures 2.

This type of installation requires less maintenance than the prior art solutions.

In addition, this solution affords higher cooling power (and lower available cold temperature), and this can be used to reduce the pre-cooling/cooling time of the installation at start-up. In particular, such an installation can provide a flow of very cold cycle fluid, for example at a temperature of around 1 K.

The installation can use one or more cryogenic compressors in the cycle circuit 8 for better heat energy recovery in the cycle exchangers.

The cycle fluid in the enclosure(s) can be drained rapidly, thereby significantly reducing the reheating time of the installation during shutdown (compared with a conventional “wet” solution).

While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alternatives, modifications, and variations as fall within the spirit and broad scope of the appended claims. The present invention may suitably comprise, consist or consist essentially of the elements disclosed and may be practiced in the absence of an element not disclosed. Furthermore, if there is language referring to order, such as first and second, it should be understood in an exemplary sense and not in a limiting sense. For example, it can be recognized by those skilled in the art that certain steps can be combined into a single step.

The singular forms “a”, “an” and “the” include plural referents, unless the context clearly dictates otherwise.

“Comprising” in a claim is an open transitional term which means the subsequently identified claim elements are a nonexclusive listing (i.e., anything else may be additionally included and remain within the scope of “comprising”). “Comprising” as used herein may be replaced by the more limited transitional terms “consisting essentially of” and “consisting of” unless otherwise indicated herein.

“Providing” in a claim is defined to mean furnishing, supplying, making available, or preparing something. The step may be performed by any actor in the absence of express language in the claim to the contrary.

Optional or optionally means that the subsequently described event or circumstances may or may not occur. The description includes instances where the event or circumstance occurs and instances where it does not occur.

Ranges may be expressed herein as from about one particular value, and/or to about another particular value. When such a range is expressed, it is to be understood that another embodiment is from the one particular value and/or to the other particular value, along with all combinations within said range.

All references identified herein are each hereby incorporated by reference into this application in their entireties, as well as for the specific information for which each is cited.

Claims

1-26. (canceled)

27. A cryogenic refrigeration installation comprising:

an enclosure (2) delimiting a vacuum-sealed volume closed by a cover (3), the enclosure (2) accommodating at least two thermally conductive trays (4, 5, 6, 7) that are distributed along a distribution direction in the enclosure (2) and form thermal stages;
a system for cooling to a cryogenic temperature, which is configured to cool at least some of the trays (4, 5, 6, 7) and/or support plate(s) (24, 25, 26, 27) mounted on the tray(s), the cooling system being configured to supply a flow of cryogenic fluid which has been expanded and/or stored, wherein at least one of the trays (4, 5, 6, 7) is connected to a heat shield (14, 15, 16, 17) forming a thermal insulation volume; and
a set of support plate(s) (24, 25, 26, 27) that is/are mounted on the trays (4, 5, 6, 7) and form(s) a support for a set of cable(s) (30) and/or samples to be cooled,
wherein the system for cooling to a cryogenic temperature is configured to cool at least some of the trays (4, 5, 6, 7) and/or support plate(s) (24, 25, 26, 27),
wherein the system for cooling to a cryogenic temperature comprises a refrigerator (70) comprising a cryogenic cycle fluid and a cooling circuit (20) for putting the cycle fluid in circulation and into a heat-exchange relationship at at least a part of the periphery of at least one support plate (24, 25, 26, 27).

28. The installation as claimed in claim 27, wherein at least some of the set of support plate(s) (24, 25, 26, 27) are mounted at the edge of the respective trays (4, 5, 6, 7), in a plane situated above or below the tray (4, 5, 6, 7) in question or in the plane of the tray (4, 5, 6, 7) in question in respective housings provided in the tray.

29. The installation as claimed in claim 27, wherein at least some of the set of support plate(s) (24, 25, 26, 27) are mounted in a removable manner relative to their respective tray (4, 5, 6, 7).

30. The installation as claimed in claim 27, further comprising a set of heat exchanger(s) (21) in a heat-exchange relationship both with the tray (4, 5, 6, 7) and the associated support plate (24, 25, 26, 27), the cooling circuit (20) passing through said heat exchanger(s) (21).

31. The installation as claimed in claim 27, further comprising a set of exchangers (21) interposed between the tray (4, 5, 6, 7) and the associated support plates (24, 25, 26, 27), the cooling circuit (20) passing through said heat exchangers (21).

32. The installation as claimed in claim 27, wherein the cooling circuit (20) is in a heat-exchange relationship with a heat shield (14, 15, 16, 17) associated with a tray (4, 5, 6, 7), directly in the body of the heat shield and/or in a set of heat exchanger(s) (21) in contact with the heat shield, which is/are interposed, for example, between the shield (14, 15, 16, 17) and the tray (4, 5, 6, 7).

33. The installation as claimed in claim 27, wherein the cooling circuit (20) is in a heat-exchange relationship with at least one tray (4, 5, 6, 7), directly in the body of the tray (4, 5, 6, 7) and/or in a set of heat exchangers (21) in contact with the tray (4, 5, 6, 7).

34. The installation as claimed in claim 27, wherein the cooling circuit (20) puts the cycle fluid in circulation and into a heat-exchange relationship in series with at least a part of the periphery of a plurality of support plates (24, 25, 26, 27) of one and the same tray (4, 5, 6, 7).

35. The installation as claimed in claim 27, wherein the cooling circuit (20) puts the cycle fluid in circulation and into a heat-exchange relationship in parallel with at least a part of the periphery of a plurality of support plates (24, 25, 26, 27) of one and the same tray (4, 5, 6, 7).

36. The installation as claimed in claim 27, wherein the cooling circuit (20) puts the cycle fluid in circulation and into a heat-exchange relationship firstly at at least a part of the periphery of at least one support plate (24, 25, 26, 27) of a first tray (4, 5, 6, 7) and then, sequentially, puts the fluid in circulation and into a heat-exchange relationship at at least a part of the periphery of at least one other support plate (24, 25, 26, 27) of a second tray (4, 5, 6, 7).

37. A refrigeration method using an installation as claimed in claim 27, the method comprising the steps of:

storing and/or producing a liquid cryogenic cycle fluid at the refrigerator (70);
putting said cryogenic fluid in circulation and putting this fluid into a heat-exchange relationship at at least a part of the periphery of at least one support plate (24, 25, 26, 27); and
following heat exchange(s), a step of returning this fluid to the refrigerator (70) or transferring said fluid to a collector.

38. A cryogenic refrigeration installation comprising:

an enclosure (2) delimiting a vacuum-sealed volume closed by a cover (3), the enclosure (2) accommodating at least two thermally conductive trays (4, 5, 6, 7) that are distributed along a distribution direction in the enclosure (2) and form thermal stages,
the installation (1) comprising a system for cooling to a cryogenic temperature, which is configured to cool at least some of the trays (4, 5, 6, 7) and/or support plate(s) (24, 25, 26, 27) mounted on the tray(s), the cooling system being configured to supply a flow of cryogenic fluid which has been expanded and/or stored, wherein at least one of the trays (4, 5, 6) is connected to a heat shield (14, 15, 16) forming a thermal insulation volume, the system for cooling to a cryogenic temperature comprising a refrigerator (70) having a refrigeration cycle for a cycle fluid, said refrigerator (70) comprising a cycle circuit (8) containing: a cycle fluid comprising helium, the cycle circuit (8) being configured to subject the cycle fluid to a thermodynamic cycle that brings the cycle fluid to a given cold temperature at at least one cold end of the cycle circuit (8), the cycle circuit being further configured to put a flow of cycle fluid at the cold end into a heat-exchange relationship with at least some of the trays (4, 5, 6) and/or plates (24, 25, 26), the cycle circuit (8) comprising a compression mechanism (9) configured to compress the cycle fluid, at least one cooling member (11, 12, 13, 114) configured to cool the cycle fluid, an expansion mechanism (10, 115) configured to expand the cycle fluid and at least one reheating member (114, 13, 12, 11) configured to reheat the expanded cycle fluid, the cycle circuit (8) further comprising a first vessel (117) configured to store a reserve of liquefied cycle fluid, the cycle circuit (8) further comprising, downstream of the heat-exchange relationship with at least some of the trays (4, 5, 6) and/or plates (24, 25, 26), a bypass pipe (18) configured to divert at least a part of the flow of cycle fluid to the first storage vessel (117), the bypass pipe (18) comprising a bypass expansion member (119) configured to expand a flow of cycle gas that is configured to expand the cycle gas before supplying the first storage vessel (117), the cycle circuit (8) comprises, upstream of the heat-exchange relationship with at least some of the trays (4, 5, 6) and/or plates (24, 25, 26), a portion in a heat-exchange relationship with the liquefied cycle fluid contained in the first storage vessel (117).

39. The installation as claimed in claim 38, wherein the portion for heat exchange between the liquefied cycle fluid contained in the vessel (117) and the cycle fluid of the cycle circuit (8) comprises a passage of the cycle circuit (8) in the liquefied cycle fluid inside the first storage vessel (117).

40. The installation as claimed in claim 38, wherein the portion for heat exchange between the liquefied cycle fluid contained in the vessel (117) and the cycle fluid of the cycle circuit (8) comprises a passage of the cycle circuit (8) in an exchanger (1150) cooled by a liquefied cycle fluid circulation loop (47) supplied by the first storage vessel (117), for example a thermosiphon.

41. The installation as claimed in claim 38, wherein the cycle circuit (8) comprises, downstream of the heat-exchange relationship with at least some of the trays (4, 5, 6) and/or plates (24, 25, 26), a return pipe (28) which is configured to return the fraction of the flow of cycle fluid that has not been diverted to the first storage vessel (117) to the compression mechanism (9).

42. The installation as claimed in claim 38, wherein the cycle circuit (8) comprises a return pipe (38) connecting an outlet of the first storage vessel (117) to the compression mechanism (9).

43. The installation as claimed in claim 38, wherein the cycle circuit (8) comprises a second vessel (27) configured to store a reserve of liquefied cycle fluid that is connected to the return pipe (28) and/or the bypass pipe (18), wherein the cycle circuit (8) is configured to store, in the second storage vessel (27), a reserve of liquefied cycle fluid at a given temperature greater than the given temperature of the cycle fluid stored in the first storage vessel.

44. The installation as claimed in claim 43, wherein the cycle circuit (8) further comprises a pipe that connects the second storage vessel (27) to the first storage vessel (117) and is configured to allow the transfer of liquefied cycle fluid from the second storage vessel (27) to the first storage vessel (117).

45. The installation as claimed in claim 38, wherein the cycle circuit (8) of the refrigerator (70) comprises a plurality of separate pipes (108, 208) that put different flows of cycle fluid into a heat-exchange relationship with separate trays (4, 5, 6) and/or plates (24, 25, 26).

46. The installation as claimed in claim 38, wherein the cycle circuit (8) comprises at least one pipe that puts the cycle fluid into a heat-exchange relationship in series with a plurality of separate trays (4, 5, 6) and/or plates (24, 25, 26) of one and the same enclosure (2) and/or of a plurality of separate enclosures (2).

47. The installation as claimed in claim 38, wherein the cycle circuit (8) is configured to subject the cycle fluid to a thermodynamic cycle that brings the cycle fluid to a plurality of different cold temperatures at, respectively, a plurality of cold ends of the cycle circuit, the cycle circuit (8) of the refrigerator (70) comprising a plurality of separate pipes (108, 208) that put different flows of cycle fluid at different temperatures into a heat-exchange relationship in parallel with respective separate trays (4, 5, 6) and/or plates (24, 25, 26).

Patent History
Publication number: 20260227101
Type: Application
Filed: Jan 18, 2024
Publication Date: Aug 6, 2026
Inventors: Camille BOUVIER (Sassenage), Florian MARTIN (Sassenage), Noelle BESSE (Sassenage), Luc GAFFET (Sassenage), Mathieu SZMIGIEL (Sassenage), Jean-Marc BERNHARDT (Sassenage), Simon CRISPEL (Sassenage), Olivier GUIA (Les Ulis), Gaetan COLEIRO (Sassenage), Guillaume DELAUTRE (Sassenage)
Application Number: 19/149,017
Classifications
International Classification: F25B 9/00 (20060101); F25B 9/14 (20060101);