Cryogenic refrigeration installation and process

Abstract

The invention relates to a cryogenic refrigeration installation comprising an enclosure housing at least two thermally conductive trays (4, 5, 6, 7) forming thermal stages, the installation (1) comprising a cryogenic temperature cooling system for the trays (4, 5, 6, 7) and / or one or more plates (24, 25, 26) connected (30) to the trays (4, 5, 6, 7), the cooling system comprising a refrigerator (70) with a cycle refrigeration system for a cycle fluid with a cycle circuit (8) comprising a storage pot (17) for a reserve of liquefied cycle fluid, the cycle circuit (8) comprising a bypass line (18) for diverting at least a portion of the cycle fluid flow to the first storage pot (17), the bypass line (18) comprising an expansion device (19) configured to expand the cycle gas before feeding the pot (17) storage, the cycle circuit (8) includes,upstream of the heat exchange with at least a portion of trays (4, 5, 6) and / or plates (24, 25, 26), a portion in heat exchange with the liquefied cycle fluid contained in the storage pot (17) and a bypass line (308) located in the enclosure (2) and equipped with an expansion device (408) configured to ensure expansion of the cycle fluid that has exchanged heat in the pot (17) to produce a cooler bypass cycle fluid flow, said bypass cycle fluid being put in heat exchange with at least one additional tray or plate (27) of the installation (1). Abbreviated figure: Fig. 1,

Description

Title of the invention: Cryogenic refrigeration installation and method

[0001] The invention relates to a cryogenic refrigeration installation and method.

[0002] The invention relates more particularly to a refrigeration installation cryogenic comprising an enclosure defining a sealed volume closed by a lid, the enclosure housing at least two thermally conductive trays distributed in a distribution direction within the enclosure and forming thermal stages, at least one of the trays being connected to a thermal screen forming a thermally insulated volume, the installation comprising a cryogenic temperature cooling system configured to cool at least part of the trays and / or one or more plates connected to the trays and forming a support for a set of cable(s) or samples to be cooled, the cryogenic temperature cooling system comprising a cycle refrigerator for refrigerating 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 bringing the cycle fluid to at least one cold end of the cycle circuit at a determined cold temperature, the cycle circuit putting a flow of cycle fluid from the cold end into heat exchange with at least a part of the trays and / or plates, the cycle circuit comprising a cycle fluid compression mechanism, at least one cycle fluid cooling element, a cycle fluid expansion mechanism and at least one cycle fluid heating element, the cycle circuit comprising a first storage pot for a reserve of liquefied cycle fluid, the cycle circuit (8) comprising, downstream of the heat exchange with at least a part of the trays and / or plates, a bypass line for at least a part of the cycle fluid flow to the first storage pot,the bypass line including a cycle gas flow expansion device configured to expand the cycle gas before feeding the first storage pot, the cycle circuit including, upstream of the heat exchange with at least some of the trays and / or plates, a portion in heat exchange with the liquefied cycle fluid contained in the first storage pot, the cycle circuit including, downstream of the passage inside the first storage pot, at least a first line located within the enclosure ensuring heat exchange with at least some of the trays and / or plates... ,

[0003] In particular, the invention relates to refrigeration devices that allow cooling to very low temperatures, on the order of millikelvins (“refrigeration subKelvin"). These very low temperatures are classically obtained via a dilution refrigerator or a Joule Thomson type cryogenic cooler with He4 or He3.

[0004] In these devices, it is necessary to supply cooling power down to a temperature of, for example, 4 K to one or more refrigeration stages. Such an installation must be able to cool rapidly upon startup. Furthermore, the experimental surface area available for the samples or cables to be cooled must be optimized.

[0005] Dilution refrigerators require a cooling power supply down to a temperature of 4.2K or lower to operate. This cooling power is generally supplied from pulsed gas tubes (dry dilution refrigerators) or via a liquid helium bath (wet dilution refrigerators).

[0006] Increasing the number of pulsed gas tubes limits the experimental surface area available for integrating elements to be cooled. Furthermore, this solution does not provide sufficient cooling power to cool a cable assembly or samples and to pre-cool the working fluid of the dilution stage. In addition, this solution generates vibrations.

[0007] The known installations are also poorly suited to provide, in addition to cooling power at a low temperature (for example around 3K), cooling power at an even lower temperature (for example around 1K).

[0008] One object of the present invention is to overcome all or part of the disadvantages of the prior art noted above.

[0009] To this end, the installation according to the invention, which also conforms to the generic definition given in the preamble above, is essentially characterized in that the cycle circuit comprises a bypass line from the first line, the bypass line being located in the enclosure and equipped with an expansion device configured to ensure expansion of the cycle fluid to produce a flow of cooler bypass cycle fluid, for example at a temperature between 1 and 2K, said bypass cycle fluid being put in heat exchange with at least one additional plate or tray of the installation.

[0010] Furthermore, embodiments of the invention may include one or more of the following features: - the cycle circuit includes, downstream of the heat exchange with the additional plate or tray, a return line for the bypass cycle fluid to the cycle fluid compression mechanism, - the return line directs the bypass cycle fluid to the inlet of a dedicated compressor of the cycle fluid compression mechanism which is arranged in series upstream of the compression mechanism for the rest of the cycle fluid, - the cycle circuit includes a heat exchange portion between the return pipe and a pipe of the cycle circuit which supplies a portion of the trays and / or plates, - the cycle circuit includes, downstream of the heat exchange with the additional plate or tray, a transfer line for the bypass cycle fluid to the first storage pot, - the cycle circuit includes a heat exchange portion between the bypass cycle fluid transfer line and a line of the cycle circuit that supplies a portion of the trays and / or plates, - the cycle circuit includes, downstream of the heat exchange with at least a portion of trays and / or plates, a return line which is configured to return to the compression mechanism the fraction of the cycle fluid flow which has not been diverted to the first storage pot, - The cycle circuit includes a return line connecting a first storage pot outlet to the compression mechanism, - the return line includes a cryogenic pump or compressor, - The refrigerator's circulation circuit comprises several separate pipes putting different cycle fluid flows into heat exchange with separate trays and / or plates - the cycle circuit includes at least one pipe that exchanges heat from the cycle fluid in series with several distinct trays and / or plates of the same enclosure and / or several distinct enclosures, - the cycle circuit is configured to subject the cycle fluid to a thermodynamic cycle bringing the cycle fluid to several distinct cold temperatures at the respective cold ends of the cycle circuit, the refrigerator cycle circuit comprising several separate pipes putting in parallel heat exchange different flows of cycle fluid at different temperatures with respective distinct trays and / or plates.

[0011] The invention also relates to a refrigeration method using an installation conforming to any one of the above or below characteristics, the method comprising a step of producing a specific cooling capacity by the refrigerator, using a portion of this produced cooling capacity to cool a set of tray(s) and / or plate(s) by heat exchange with a cycle fluid stream, and a step of recovering this cycle fluid stream after heat exchange and a step of expanding a fraction of this recovered cycle fluid flow back to the first storage pot to constitute a cold reserve, the process including a step of cooling the cycle fluid flow with the cycle fluid from the first storage pot.

[0012] According to one possible embodiment, the process includes a step of cooling the cycle fluid by heat exchange with the liquefied cycle fluid contained in the first storage pot, a step of cooling at least a part of trays and / or plates to a first temperature with a first fraction of this cooled cycle fluid, the process including a step of expansion, in the enclosure of a second fraction of this cooled cycle fluid, this second fraction of cycle fluid being used for cooling at least one tray and / or plates to a second temperature lower than the first temperature.

[0013] The invention may also relate to any alternative device or method comprising any combination of the above or below features within the scope of the claims.

[0014] Other features and advantages will become apparent from the following description, given with reference to the figures in which: Brief description of the figures

[0015] The invention will be better understood upon reading the following description, given solely by way of example and made with reference to the accompanying drawings in which:

[0016] [Fig. 1] is a schematic and partial view illustrating an example of the structure and operation of an installation according to a first embodiment of the invention,

[0017] [Fig.2] is a schematic and partial view illustrating an example of the structure and operation of an installation according to a second embodiment of the invention,

[0018] [Fig.3] is a schematic and partial view illustrating an example of the structure and operation of an installation according to a third embodiment of the invention. Detailed description

[0019] In all figures, the same references refer to the same elements.

[0020] In this detailed description, the following embodiments are examples. Although the description refers to one or more embodiments, this does not mean that the features apply only to a single embodiment. Simple features from different embodiments can also be combined and / or interchanged to provide other embodiments.

[0021] The cryogenic refrigeration installation 1 illustrated in [Fig. 1] comprises an enclosure 2 defining a sealed volume closed by a lid 3. In this example, the enclosure 2 houses several thermally conductive trays 4, 5, 6, 7 distributed along a distribution direction within the enclosure 2 (here vertical) and forming thermal stages. Preferably, all or part of the trays 4, 5, 6, 7 are connected to a respective thermal screen 14, 15, 16 forming a thermal insulation volume. For example, depending on the distribution direction, each thermal screen encompasses (contains) the thermal screen and the next tray (in a nested fashion).

[0022] Installation 1 includes a cryogenic temperature cooling system configured to cool at least part of the trays 4, 5, 6, 7 and / or one or more support plates 24, 25, 26, 27 which can be connected (30) to the trays 4, 5, 6. These support plates 24, 25, 26, 27 can be mounted removably or detachably on the trays 4, 5, 6, 7 concerned to form a support for a set of cable(s) or samples to be cooled (not shown for the sake of simplicity).

[0023] The cryogenic temperature cooling system includes a 70 cycle refrigerator with a cycle refrigeration fluid.

[0024] The refrigerator 70 includes a cycle circuit 8 containing a cycle fluid comprising helium. The cycle fluid could be composed of other gas(es): hydrogen, nitrogen, neon, one or more hydrocarbons, or a mixture thereof. The cycle circuit 8 is configured to subject the cycle fluid to a thermodynamic cycle bringing the cycle fluid to at least one cold end of the cycle circuit 8 at a predetermined cold temperature.

[0025] The cycle circuit 8 comprises a cycle fluid compression mechanism 9 (one or more compressors in series and / or parallel), at least one cycle fluid cooling device 11, 12, 13, 14 (for example, one or more heat exchangers), a cycle fluid expansion mechanism 10, 150 (one or more valve(s) and / or turbine(s) in series and / or parallel), and at least one cycle fluid heating device 14, 13, 12, 11 (one or more heat exchangers). As illustrated, the cooling and heating of the cycle fluid can be achieved by one or more heat exchangers providing heat exchange between two cycle fluid flows at different temperatures (for example, counter-current).

[0026] Part of the cycle circuit 8 and in particular the relatively hot portions may be located outside enclosure 2.

[0027] The cycle circuit 8 has conduits that exchange heat from at least one cycle fluid stream from the cold end with at least a portion of the trays 4, 5, 6, 7 and / or plates 24, 25, 26, 27. For example, conduits transfer the cold cycle fluid into heat exchangers 34, 35, 36 in contact with the trays and / or plates. Alternatively or cumulatively, the conduits carrying the circuit 8 cycle parts may have portions in direct contact (and / or in the thickness) with trays 4, 5, 6, 7 and / or plates 24, 25, 26, 27 and / or thermal screen.

[0028] For example, the refrigerator 70 cycle circuit 8 includes one or more separate lines 208 putting different cycle fluid flows into heat exchange with separate trays 4, 5, 6, 7 and / or plates 24, 25, 26, 27 of the same enclosure 2 or of several separate enclosures.

[0029] For example, the cycle circuit 8 can be configured to subject the cycle fluid to a thermodynamic cycle bringing the cycle fluid to several distinct cold temperatures at the respective cold ends of the cycle circuit and the cycle circuit 8 of the refrigerator 70 comprising several distinct pipes 208 putting in parallel heat exchange different cycles of fluid flows at different temperatures with respective distinct trays 4, 5, 6, 7 and / or plates 24, 25, 26, 27.

[0030] This makes it possible to produce and send supercritical cycle fluid under pressure (for example at a pressure greater than 3.5 bar) to one or more stages of one or more enclosures 2, for example in parallel.

[0031] The supercritical fluid can be produced in the cycle circuit 8 by an arrangement of exchangers, in order to recover the best possible of the available cold power.

[0032] Thus, the cycle circuit 8 can supply cycle fluid at intermediate temperatures, for example between 4K and 100K, to cool intermediate stages in one or more enclosures 2.

[0033] This allows independent operation for different enclosures 2 with the same common refrigeration system 70.

[0034] This solution makes it possible to provide a cooling capacity that can be easily adapted.

[0035] To this end, the various pipes supplying the different stages or enclosures 2 can be equipped with flow control valves. These valves can be regulated according to the temperature of the element to be cooled (expected cooling capacity). The cycle fluid flow rates can be regulated to increase or decrease the cooling capacity demand in enclosure 2.

[0036] The cycle circuit 8 includes a first pot 17 for storing a reserve of liquefied cycle fluid.

[0037] The cycle circuit 8 includes, downstream of the heat exchange with at least part of trays 4, 5, 6, and / or plates 24, 25, 26, a bypass conduit 18 for at least part of the cycle fluid flow to the first storage pot 17.

[0038] That is to say, at least one pipe which returns to the heating elements (heat exchangers 14, 13, 12, 11) and the compression elements (compressor 9, 8) the cycle fluid which has exchanged heat with the elements to be cooled in the enclosure 2 has a branch 18 to the first storage pot 17. This branch line 18 preferably has a cycle gas flow relief device 19 (valve(s) or equivalent) configured to relieve the cycle gas before feeding the first storage pot 17.

[0039] Installation 1 can be sized, or operating conditions can lead to cooling in enclosure 2 using only a portion of the available power in the cold cycle fluid flow. This cycle fluid returns relatively cold, and the cooling power that was not used to cool the components in enclosure 2 can be recovered.

[0040] This is achieved by expanding part of this cycle fluid towards the first storage pot 17.

[0041] This arrangement optimizes the cooling power produced by minimizing the flow of low-pressure working fluid (gas coming from the first storage pot 17).

[0042] In addition, this allows the flow rate of cold cycle fluid to be maximized in the chamber(s) 2 (maximizes the available power).

[0043] The cycle fluid flow not used for this bypass can be returned to the refrigerator's cycle compressor, transferring cooling energy to the cycle fluid downstream of the compression. For this purpose, the cycle circuit 8 includes, downstream of the heat exchange with at least a portion of trays 4, 5, 6 and / or plates 24, 25, 26, at least one return line 28 which is configured to return to the compression mechanism 9 the fraction of the cycle fluid flow that has not been diverted to the first storage pot 17.

[0044] This expanded fluid produces liquid at very low temperature (typically between 1K and 4K) which is put in heat exchange with the cycle fluid before its heat exchange with the components in enclosure 2.

[0045] That is to say, the cycle circuit 8 includes, upstream of the heat exchange with at least a portion of the trays 4, 5, 6, 7 and / or plates 24, 25, 26, 27, a portion in heat exchange with the liquefied cycle fluid contained in the first storage pot 17. The cooling reserve constituted by the first storage pot 17 provides cooling to the cycle fluid before its use to cool the element(s) in the enclosure 2.

[0046] In the example of [Fig. 1], the heat exchange between the liquefied cycle fluid contained in the pot 17 and the cycle fluid of the cycle circuit 8 includes a passage of the cycle circuit 8 through the liquefied cycle fluid inside the first storage pot 17. That is to say, a portion of the cycle circuit 8 is immersed in the liquid bath of the first storage pot 17, for example by describing a coil or several passages or bends.

[0047] Alternatively or in combination, the heat exchange between the liquefied cycle fluid contained in the pot 17 and the cycle fluid of the cycle circuit 8 could be achieved via a passage of the cycle circuit 8 through a heat exchanger 15 cooled by a liquefied cycle fluid circulation loop 47 supplied by the first storage pot 17, for example a thermosiphon. This constitutes a more indirect heat exchange than in the previous embodiment.

[0048] The cycle circuit 8 includes, downstream of the passage inside the first storage pot 17 and upstream of the heat exchange with at least part of trays 4, 5, 6, 7 and / or plates 24, 25, 26, 27, at least one conduit 208 which may be equipped with a first expansion device 808 for example an expansion valve.

[0049] The optional expansion valve 808 may preferably be provided if the cycle fluid is two-phase (liquid and gas), in fact in this case an expansion reduces the temperature of the fluid.

[0050] This possible expansion 808 of the cooled cycle fluid flow in the storage pot 17 makes it possible to produce a cycle gas flow at a predetermined temperature, for example between 2 and 4 K (helium at 3 K, for example). This working fluid can be distributed to cool the tray(s) or plate(s) or any element to be cooled.

[0051] As illustrated, the cycle circuit 8 includes in enclosure 2 a bypass line 308 equipped with an expansion device 408 configured to expand the cycle fluid to produce an even colder bypass cycle fluid flow, for example at a temperature between 1 and 2K. This colder bypass cycle fluid can be heat exchanged with at least one additional tray or plate 27 of the installation 1 which requires a colder cooling temperature.

[0052] That is to say, the bypass pipe 308 adds a loop portion to produce a lower temperature.

[0053] This configuration without expansion (without expansion valve 808) or with single expansion (expansion valve 808) offers the advantages of supercritical cooling: easily distributed over a large area by circulating a pipe, for example (single expansion circuit). However, the cold temperature obtained is generally limited by the flow rates to be circulated, which can be relatively high. This stage can effectively absorb heat inputs from the upper stages and from any active components, such as amplifier electronics.

[0054] With the bypass (and the expansion 408 in the enclosure 2) it is possible to produce and isolate a liquid at a lower temperature than the initial cycle fluid and to have thermal power at a stable temperature (for example at a lower flow rate than in the part of the cycle circuit not subjected to this expansion 408 in the enclosure 2).

[0055] As illustrated in [Fig. 1], the cycle circuit may include, downstream of the heat exchange with the additional tray or plate 27 (or other, for example with storage in another container), a bypass cycle fluid return line 608 to the cycle fluid compression mechanism 9. The bypass cycle fluid return line 608 may return the cycle fluid to the inlet of a dedicated compressor 90 of the cycle fluid compression mechanism 9, for example, an ambient temperature or cryogenic temperature compressor that is arranged in series upstream of the compression mechanism for the remaining cycle fluid.

[0056] According to the embodiment of [Fig. 2], the cycle circuit comprises, downstream of the heat exchange with the additional tray or plate 27 (and / or other storage or cooling element), a bypass cycle fluid transfer line 508 to the first storage pot 17. That is to say, the helium is returned to the first pot 17 (for example at a temperature of 2 K), using only a pumping or compression unit.

[0057] This configuration minimizes the number of compression stages in the cycle circuit.

[0058] In the embodiment of [Fig. 2], this colder cycle gas flow (which was used to cool to a lower temperature) is returned to the dedicated pumping (compression) system, which advantageously allows the operating pressure to be selected upstream (for example, in a container). This makes it possible to control the temperature of the cycle fluid that has undergone both expansions, if applicable.

[0059] The installation thus makes it possible to distribute power to a 3K stage over a relatively large area (single expansion cycle fluid circuit) and to have an additional colder reserve, for example at a temperature between 1K and 2K in the part of the cycle fluid circuit undergoing expansion 408 in enclosure 2.

[0060] The cycle circuit 8 also preferably includes a return line 38 connecting an outlet (for example, an upper one) of the first storage pot 17 to the compression mechanism 9. This allows the vaporization gas to be returned to the compression mechanism within the first storage pot 17.

[0061] The return line 38 could include a cryogenic pump or compressor.

[0062] Similarly, the cycle circuit 8 may include a second storage tank for a reserve of liquefied cycle fluid. This second storage tank could, for example, be connected in parallel with the first storage tank 17 on the bypass line 18. The fluid flow returning from the enclosure 2 via the return line 28 can thus be sent to the first storage tank 17 (via a valve) or to the second tank (via another valve). A line and valve may be provided to transfer liquid from the second storage tank to the first tank. This can be used to regulate the liquid level in the second tank. The gas formed in the second storage tank may to be sent to compressor 9. Preferably, the cycle circuit 8 does not include a thermosiphon at the second storage tank, but of course, a thermosiphon could be provided at the second storage tank. A heat exchanger can be placed on the cycle circuit 8 before the second storage tank to take advantage of the low temperature of the return fluid. This improves the system's energy efficiency.

[0063] All or part of the components of the refrigerator and / or enclosure 2 can be housed in a thermally insulated cold box, for example under vacuum. Operation can be at least partially automated, which limits the handling of cryogenic fluid by the user.

[0064] The structure of the installation 1 allows for cooling power along a capillary tube in the enclosure, unlike more localized cooling of known solutions with a cryogenic liquid bath.

[0065] The above structure is more efficient and flexible than solutions that exclusively use pulsed gas tubes to cool stages of enclosures 2.

[0066] This type of installation requires less maintenance than prior art solutions.

[0067] Furthermore, this solution offers superior cooling capacity (and a lower available cooling temperature), which can be used to reduce the pre-cooling / cooling time of the installation at startup. In particular, such an installation can provide a very cold cycle fluid flow, for example at a temperature on the order of 1 K.

[0068] The installation may use one or more cryogenic compressors in the cycle circuit 8 for better heat recovery in the cycle exchangers.

[0069] Draining the cycle fluid in the enclosure(s) can be done quickly, which significantly reduces the warm-up time of the installation when shutting down (compared to a conventional "wet" solution).

[0070] The embodiment of [Fig. 3] differs from that of [Fig. 1] in that it includes a heat exchanger 708 which ensures heat exchange between the cycle fluid circulating in the return line 608 and the cycle fluid circulating in the first storage pot 17. That is to say, the very cold cycle fluid (for example, around 2 K) which has exchanged heat with the additional plate or tray 27, transfers cooling energy to the cooled cycle fluid (for example, around 3 K) which flows towards the chamber 2 (in particular before the expansion 408 in the chamber 2).

[0071] Of course, this example is not limiting. Thus, this heat exchanger could be located at other points in the cycle circuit, for example further downstream, just before the bifurcation of the bypass pipe 308. Similarly, this heat exchanger 708 could be located downstream of the bifurcation of the 308 bypass pipe, on a portion of the cycle circuit pipe that carries the first fraction of cycle fluid.

[0072] Similarly, this heat exchanger 708 could be located downstream of the branch line bifurcation, on the branch line 308 itself.

[0073] Similarly, the return line 608 could exchange heat with a line 208 which supplies a part of trays 4, 5, 6, 7 and / or plates 24, 25, 26, 27 via a coaxial arrangement of said lines and / or by thermal links such as braids.

Claims

1. Demands A cryogenic refrigeration installation comprising an enclosure (2) defining a sealed volume closed by a lid (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, at least one of the trays (4, 5, 6, 7) being connected to a thermal screen (14, 15, 16) forming a thermally insulated volume, the installation (1) comprising a cryogenic temperature cooling system configured to cool at least a portion of the trays (4, 5, 6, 7) and / or one or more plates (24, 25, 26, 27) connected (30) to the trays (4, 5, 6, 7) and forming a support for a set of cable(s) (30) or samples to be cooled, the cryogenic temperature cooling system comprising a refrigerator (70) with a refrigeration cycle refrigeration of 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 bringing the cycle fluid at at least one cold end of the cycle circuit (8) to a predetermined cold temperature, the cycle circuit exchanging heat with a flow of cycle fluid from the cold end with at least a portion of the trays (4, 5, 6, 7) and / or plates (24, 25, 26), the cycle circuit (8) comprising a cycle fluid compression mechanism (9), at least one cycle fluid cooling element (11, 12, 13, 14), a cycle fluid expansion mechanism (10, 150), and at least one expanded cycle fluid heating element (14, 13, 12, 11), the cycle circuit (8) comprising a first storage pot (17) for a reserve of liquefied cycle fluid, the cycle circuit (8) comprising,downstream of the heat exchange with at least a portion of the trays (4, 5, 6, 7) and / or plates (24, 25, 26, 27), a bypass line (18) diverting at least a portion of the cycle fluid flow to the first storage pot (17), the bypass line (18) comprising a cycle gas flow expansion device (19) configured to expand the cycle gas before feeding the first storage pot (17), the cycle circuit (8) comprising, upstream of the heat exchange with at least a portion of the trays (4, 5, 6, 7) and / or plates (24, 25, 26, 27), a portion in exchange, thermal with the liquefied cycle fluid contained in the first storage pot (17), the cycle circuit (8) comprising, downstream of the passage inside the first storage pot (17) at least a first pipe (208) located in the enclosure (2) ensuring heat exchange with at least a part of trays (4, 5, 6, 7) and / or plates (24, 25, 26, 27), characterized in that the cycle circuit (8) comprises, a bypass pipe (308) of the first pipe, the bypass pipe (308) being located in the enclosure (2) and equipped with an expansion device (408) configured to ensure expansion of the cycle fluid to produce a flow of cooler bypass cycle fluid, for example at a temperature between 1 and 2K, said bypass cycle fluid being put in heat exchange with at least one additional tray or plate (27) of the installation (1).

2. Installation according to claim 1 characterized in that the cycle circuit comprises, downstream of the heat exchange with the additional plate or tray (27), a return line (608) of the bypass cycle fluid to the cycle fluid compression mechanism (9).

3. Installation according to claim 2 characterized in that the return line (608) directs the bypass cycle fluid to the inlet of a dedicated compressor (90) of the cycle fluid compression mechanism (9) which is arranged in series upstream of the compression mechanism for the remainder of the cycle fluid.

4. Installation according to claim 2 or 3, characterized in that the cycle circuit comprises a portion (708) of heat exchange between the return pipe (608) and a pipe (208, 308) of the cycle circuit which supplies a portion of trays (4, 5, 6, 7) and / or plates (24, 25, 26, 27).

5. Installation according to claim 2 or 3 characterized in that the cycle circuit comprises, downstream of the heat exchange with the additional tray or plate (27), a bypass cycle fluid transfer conduit (508) to the first storage pot (17).

6. Installation according to claim 5, characterized in that the cycle circuit comprises a heat exchange portion (708) between the bypass cycle fluid transfer line (508) and a conduit (208, 308) of the cycle circuit which supplies a part of the plates (4, 5, 6, 7) and / or plates (24, 25, 26, 27).

7. Installation according to any one of claims 1 to 6 characterized in that the cycle circuit (8) comprises, downstream of the heat exchange with at least a portion of trays (4, 5, 6) and / or plates (24, 25, 26), a return line (28) which is configured to return to the compression mechanism (9) the fraction of the cycle fluid flow which has not been diverted to the first storage pot (17).

8. Installation according to any one of claims 1 to 7, characterized in that the cycle circuit (8) comprises a return line (38) connecting a first storage pot outlet (17) to the compression mechanism (9).

9. Installation according to claim 8, characterized in that the return line (38) comprises a cryogenic pump (10) or compressor.

10. Installation according to any one of claims 1 to 9, characterized in that the refrigerator (70) cycle circuit (8) comprises several separate conduits (208) putting different cycle fluid flows into heat exchange with separate trays (4, 5, 6) and / or plates (24, 25, 26).

11. Installation according to any one of claims 1 to 10, characterized in that the cycle circuit (8) comprises at least one conduit putting the cycle fluid into heat exchange in series with several trays (4, 5, 6, 7) and / or plates (24, 25, 26, 27) distinct from the same enclosure (2) and / or from several separate enclosures (2).

12. An installation according to any one of claims 1 to 11, characterized in that the cycle circuit (8) is configured to subject the cycle fluid to a thermodynamic cycle bringing the cycle fluid to several distinct cold temperatures at the respective cold ends of the cycle circuit, the cycle circuit (8) of the refrigerator (70) comprising several distinct pipes (208) putting in parallel heat exchange different cycles of fluid at different temperatures with respective distinct trays (4, 5, 6, 7) and / or plates (24, 25, 26, 27).

13. A refrigeration method using an installation according to any one of the preceding claims, the method comprising a step of producing a determined cooling power by the refrigerator (70), using a portion of this produced cooling power to cool a set of tray(s) (4, 5, 6, 7) and / or plate(s) (24, 25, 26, 27) by heat exchange with a cycle fluid stream, a step of recovering this cycle fluid stream after heat exchange and a step of expanding a fraction of this recovered cycle fluid stream to the first storage pot (17) to constitute a cold reserve, the method comprising a step of cooling the cycle fluid stream with the cycle fluid from the first storage pot (17).

14. A method according to claim 13, comprising a step of cooling the cycle fluid by heat exchange with the liquefied cycle fluid contained in the first storage pot (17), a step of cooling at least a portion of trays (4, 5, 6) and / or plates (24, 25, 26) to a first temperature with a first fraction of this cooled cycle fluid, the method comprising a step of expanding, in the enclosure (2), a second fraction of this cooled cycle fluid, this second fraction of cycle fluid being used for cooling at least one tray (7) and / or plates (27) to a second temperature lower than the first temperature.

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