Cryogenic refrigeration method and device

Abstract

Cryogenic refrigeration device comprising a first refrigerator with a refrigeration cycle for a cycle fluid and at least one cold source, the first refrigerator comprising a compression mechanism for the cycle fluid, a first cooling portion for the cycle fluid, a first expansion mechanism for the cycle fluid, a heating portion for the cycle fluid, the device further comprising a first refrigeration portion configured to allow the cooling of a first user, and comprising a first heat exchange system, a second heat exchange system, a refrigeration assembly configured to make the first user exchange heat with the cycle fluid, the set of pipes and the set of valves being configured so as to be able to switch the device between a first operating configuration and a second operating configuration.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 (a) and (b) to French patent application No. FR2500561, filed Jan. 20, 2025, which is herein incorporated by reference in its entirety.FIELD OF THE INVENTION

[0002] The present invention relates to a variable-power cryogenic refrigeration device and method.BACKGROUND OF THE INVENTION

[0003] In numerous cryogenic refrigeration applications, it is necessary to supply a cooling power at various temperature levels. There is often a need to cool one load down to a low temperature, which is the lowest temperature attained by the refrigerator, and one load down to an intermediate temperature. Typically, the low temperature may be between 2 K and 5 K, and the intermediate temperature may be between 50 K and 100 K.

[0004] One example of an application with these needs is the cooling of heat shields in superconducting installations.

[0005] The cooling power at the intermediate temperature is usually supplied by a cold source separate from the main refrigerator. When the intermediate temperature is close to 80 K, it is known practice for the cold source used to be a bath of liquid nitrogen, which is an inexpensive solution that ensures a stable temperature with ease. As an alternative, or in other cases, a second refrigerator can be provided.

[0006] It is often preferred to use a cycle fluid of the main refrigerator for exchanging heat with the load that is to be cooled. The aim is generally to attain the highest possible operating pressure in order to minimize the size of the pipes of the refrigeration device. It is also desirable to keep the flow rate of the cycle fluid constant.

[0007] One specific constraint arises when the thermal load is variable, i.e. when the demand for cooling power at the low or intermediate temperature varies over time. In the case of heat shields, or other superconducting applications which use a degassing or cleaning operating mode, often referred to as “baking”, the need for cooling power can vary from the basic cooling power to twice the cooling power in certain operating cases, and often for limited periods of time.

[0008] One known solution for being able to occasionally supply a greater cooling power consists in increasing the refrigeration capacity that is in place. Refrigeration capacity is understood as meaning the maximum cooling power that can be delivered by the refrigerator at the temperature of the user. The main refrigerator is then sized to supply, for example, twice as much power. The main compression station and all of the equipment upstream of the load that is to be cooled must be sized for the maximum load case, and this is costly and can adversely affect the performance of the assembly during nominal operation with a lesser load.

[0009] Another solution consists in providing an intermediate-temperature closed circuit separate from the main refrigerator. In this case, the cycle fluid of the main refrigerator is not used for exchanging heat with the load that is to be cooled. A dedicated circulator pump is then provided in a closed circuit. The flow rate and the pressure in this closed circuit are decoupled from the constraints on the main refrigerator. If the load on the shields increases, the speed of the circulator pump can be adapted. However, the use of cold circulator pumps is not always desirable or feasible, or it would simply not be economically viable.

[0010] The present invention aims to effectively overcome all or some of these drawbacks.SUMMARY OF THE INVENTION

[0011] According to a first aspect, the invention provides a cryogenic refrigeration device comprising a first refrigerator with a refrigeration cycle for a cycle fluid and at least one cold source.

[0012] The first refrigerator comprises, in series in a cycle circuit and connected by a set of pipes and a set of valves: a compression mechanism for the cycle fluid, a first cooling portion for the cycle fluid, a first expansion mechanism for the cycle fluid, a heating portion for the cycle fluid.

[0013] The device further comprises a first refrigeration portion configured to allow a first user to be cooled, and comprising:

[0014] a first heat exchange system configured to make the cycle fluid exchange heat with the cold source,

[0015] a second heat exchange system configured to make the cycle fluid exchange heat with the cold source,

[0016] a refrigeration assembly configured to make the first user exchange heat with the cycle fluid.

[0017] The set of pipes and the set of valves are configured so as to be able to switch the device between

[0018] a first operating configuration, in which at least some of the cycle fluid is directed to the first heat exchange system, then from the first heat exchange system to the refrigeration assembly, and then away from the first refrigeration portion to the cycle circuit;

[0019] a second operating configuration, in which at least some of the cycle fluid is directed to the first heat exchange system, then from the first heat exchange system to the refrigeration assembly, then from the refrigeration assembly to the second heat exchange system, and then from the second heat exchange system to the refrigeration assembly.

[0020] This makes it possible to supply a variable power to the first user. For a first refrigerator having the same capacity as in the prior art, it is possible to supply a greater cooling power to the user.

[0021] This solution also offers a simple way of adapting an existing installation so as to be able to supply more cooling power to the user.

[0022] In one embodiment, the device comprises a controller configured to switch the device to the first configuration in response to information about a decrease or predicted decrease in the cooling power required by the first user, or to the second configuration in response to information about an increase or predicted increase in the cooling power required by the first user.

[0023] In one embodiment, the refrigeration assembly comprises a third heat exchange system configured to make the first user exchange heat with the cycle fluid, and a fourth heat exchange system configured to make the first user exchange heat with the cycle fluid.

[0024] The third heat exchange system and the fourth heat exchange system are positioned in series and / or in parallel in the cycle circuit.

[0025] In one embodiment, in the second operating configuration, the set of pipes and the set of valves are configured to direct the cycle fluid that has passed through the first heat exchange system from the first heat exchange system to the third heat exchange system, then from the third heat exchange system to the second heat exchange system, and then from the second heat exchange system to the fourth heat exchange system.

[0026] In one embodiment, in the first operating configuration, the set of pipes and the set of valves are configured to direct the cycle fluid that has passed through the first heat exchange system to the third heat exchange system, or to the fourth heat exchange system, or simultaneously to the third heat exchange system and the fourth heat exchange system.

[0027] In one embodiment, the cold source is separate from the first refrigerator; the first refrigerator comprises a second cooling portion located, in the cycle circuit, downstream of the first cooling portion and upstream of the first expansion mechanism, and a second refrigeration portion which is configured to allow a second user to be cooled and is located, in the cycle circuit, downstream of the first expansion mechanism.

[0028] The first refrigeration portion is located, in the cycle circuit, between the first cooling portion and the second cooling portion.

[0029] In one embodiment, the first refrigeration portion comprises a fifth heat exchange system configured to make the cycle fluid exchange heat with the cold source, and the set of pipes is configured to connect the fourth heat exchange system to the fifth heat exchange system in series, and to connect the fifth heat exchange system to the second cooling portion for the cycle fluid in series.

[0030] In one embodiment, the set of pipes comprises a first bypass pipe configured to take at least some of the cycle fluid that has passed through the third heat exchange system and direct it directly to the second cooling portion for the cycle fluid, i.e. without going through the second heat exchange system or through the fourth heat exchange system.

[0031] In one embodiment, the set of pipes comprises a second bypass pipe configured to take at least some of the cycle fluid that has passed through the second heat exchange system and direct it directly to the second cooling portion for the cycle fluid, i.e. without going through the fourth heat exchange system.

[0032] In one embodiment, the cold source is a part of the cycle circuit of the first refrigerator, and the first refrigeration portion is located, in the cycle circuit, downstream of the first expansion mechanism.

[0033] In one embodiment, the set of pipes comprises a third bypass pipe configured to take at least some of the cycle fluid that has passed through the third heat exchange system and direct it to the heating portion for the cycle fluid.

[0034] According to a second aspect, the invention provides a method for cryogenic refrigeration using a device as described above or below for cooling a first user connected to the first refrigeration portion, the method comprising a step of switching the device from the first configuration to the second configuration, or from the second configuration to the first configuration, in particular in response to information about a change or predicted change in the cooling power required by the first user.

[0035] In one embodiment, the flow rate of cycle fluid through the compression mechanism is constant.

[0036] In one embodiment, the cooling power supplied to the user in the second configuration is comprised between 100% and 200%, in particular between 150% and 200%, of the cooling power supplied to the user in the first configuration.

[0037] In one embodiment, the cold source supplies a cooling power at a temperature comprised between 50 K and 100 K.

[0038] In one embodiment, the cold source supplies a cooling power at a temperature comprised between 2 K and 5 K.

[0039] The invention may also relate to any alternative device or method comprising any combination of the features above or below, notably within the scope of the claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The invention will be understood better from reading the following description and from studying the accompanying figures. These figures are given only by way of illustration and do not in any way limit the invention.

[0041] FIG. 1 is a schematic and partial illustration of a device according to a first embodiment of the invention;

[0042] FIG. 2 is a schematic and partial illustration of a device according to a second embodiment of the invention;

[0043] FIG. 3 is a schematic and partial illustration of an implementation detail of the embodiment in FIG. 1 and FIG. 2;

[0044] FIG. 4 is a schematic and partial illustration of an implementation detail of the embodiment in FIG. 1;

[0045] FIG. 5 is a schematic and partial illustration of an implementation detail of the embodiment in FIG. 1;

[0046] FIG. 6 is a schematic and partial illustration of an implementation detail of the embodiment in FIG. 2.DETAILED DESCRIPTION OF THE INVENTION

[0047] According to a first aspect, the invention relates to a refrigeration device. With reference to FIG. 1, FIG. 2 and FIG. 3, a refrigeration device 1 according to the invention has been illustrated. The device 1 comprises a first refrigerator 2 with a refrigeration cycle for a cycle fluid and at least one cold source 4. The cold source may in particular be a store of cryogenic liquid produced by the refrigerator 2, a store of cryogenic liquid separate from the refrigerator 2, a second refrigerator with a refrigeration cycle. The cold source 4 may also be formed by two or more of these elements.

[0048] The first refrigerator 2 comprises, in series in a cycle circuit and connected by a set of pipes and a set of valves, a compression mechanism 21 for the cycle fluid, a first cooling portion 22 for the cycle fluid, a first expansion mechanism 24 for the cycle fluid and a heating portion 25 for the cycle fluid.

[0049] The compression mechanism 21 may comprise one or more compression stages and one or more post-cooling exchangers. They can be positive-displacement or centrifugal compressors.

[0050] Typically, the heating portion 25 and the first cooling portion 22 comprise one or more common exchangers in which the cycle fluid flows in a countercurrent arrangement depending on whether it is cooled or heated.

[0051] The first cooling portion 22 for the cycle fluid may also be configured to make the cycle fluid exchange heat with a fluid of the cold source 4. For example, when the cold source 4 is a store of cryogenic liquid, the boil-off gases of this reserve can be made to exchange heat with the cycle fluid in order to cool the cycle fluid and heat the boil-off gases.

[0052] The device 1 also comprises a first refrigeration portion 3 configured to allow the cooling of a first user 300. The first refrigeration portion 3 comprises a first heat exchange system 31 configured to make the cycle fluid exchange heat with the cold source 4, a second heat exchange system 32 configured to make the cycle fluid exchange heat with the cold source 4, and a refrigeration assembly 33, 34 configured to make the first user 300 exchange heat with the cycle fluid.

[0053] The first heat exchange system 31 and / or the second heat exchange system 32 may for example be a pipe immersed in a reserve of cryogenic liquid, or an exchanger with a passage for the cycle fluid and a passage for a heat-transfer fluid connected to the cold source 4.

[0054] In addition, the first heat exchange system 31 and second heat exchange system 32 may be separate or part of a single heat exchange device. For example, they can be part of an exchanger with a dedicated passage for the first exchange and a dedicated passage for the second exchange. As an alternative, they can be formed by a single passage of one same heat exchanger, in which the stream for the first exchange and the stream for the second exchange are mixed. As another alternative, the first heat exchange system 31 is formed by a first exchanger, and the second heat exchange system 32 is formed by a second exchanger, separate from the first.

[0055] The set of pipes and the set of valves are configured so as to be able to switch the device 1 between:

[0056] a first operating configuration, in which at least some of the cycle fluid is directed to the first heat exchange system 31, then from the first heat exchange system 31 to the refrigeration assembly 33, 34, and then away from the first refrigeration portion 3 to the cycle circuit;

[0057] a second operating configuration, in which at least some of the cycle fluid is directed to the first heat exchange system 31, then from the first heat exchange system 31 to the refrigeration assembly 33, 34, then from the refrigeration assembly 33, 34 to the second heat exchange system 32, and then from the second heat exchange system 32 to the refrigeration assembly 33, 34.

[0058] This means that, in the first configuration, the cycle fluid passes through the heat exchange assembly 33, 34 only once. As the cycle fluid passes through, the user is cooled and the cycle fluid is heated. Then, the cycle fluid returns to the circuit so as to be cooled or heated, while bypassing the heat exchange assembly 33, 34. Thus, in this configuration, the cycle fluid which has passed through the heat exchange assembly 33, 34 a first time is directed directly to the compression mechanism 21, possibly by going through the expansion mechanism 24 beforehand.

[0059] In the second configuration, the cycle fluid passes through the heat exchange assembly 33, 34 twice in succession. Each time the cycle fluid passes through the heat exchange assembly 33, 34, the user 300 is cooled and the cycle fluid is heated. Between these two passes, the cycle fluid is cooled in the second heat exchange system 32.

[0060] This makes it possible to supply a variable power to the first user 300 and to increase the cooling power supplied in relation to a prior-art system.

[0061] In particular, for the same installation cost, i.e. for the same number of compressors of the same capacity, it is possible to supply more cooling power to the first user 300. This is true whether the cold source 4 is separate, or whether the cooling power of the cold source 4 is generated directly by the first refrigerator 2. By virtue of the invention, it is not necessary to increase the compression capacity.

[0062] In one embodiment, the device 1 comprises a controller configured to switch the device 1 to the first configuration in response to information about a decrease or predicted decrease in the cooling power required by the first user 300, or to the second configuration in response to information about an increase or predicted increase in the cooling power required by the first user 300.

[0063] The first configuration is used when the cooling power required by the first user 300 is relatively low. The second configuration is used when the cooling power required by the first user 300 is relatively high or will become high.

[0064] It is possible to trigger the switch between the two configurations on the basis of information, for example current information, about a required cooling power, or on the basis of a predicted change in such a requirement, or of a scheduling of such a requirement.

[0065] It is possible to trigger the switch between the two configurations in one or more of these ways. An operator can manually activate the controller to trigger the switching operation. It is possible to provide a load schedule and the switching happens automatically based on this schedule. It is possible to generate a trigger signal or information on the basis of a measurement taken by a measuring unit or a sensor, for example a measurement of the temperature of the fluid at the outlet of the heat exchange assembly 33, 34.

[0066] Advantageously, the controller may be an electronic controller, such as a microcontroller, a processor or a computer.

[0067] In one embodiment, the refrigeration assembly 33, 34 comprises a third heat exchange system 33 configured to make the first user 300 exchange heat with the cycle fluid, and a fourth heat exchange system 34 configured to make the first user 300 exchange heat with the cycle fluid.

[0068] The third heat exchange system 33 and the fourth heat exchange system 34 are positioned in series and / or in parallel in the cycle circuit. It is also possible to configure the set of pipes and the set of valves so as to be able to modify, while the device 1 is operating, this arrangement of the third heat exchange system 33 and fourth heat exchange system 34.

[0069] In one embodiment, in the second operating configuration of the device 1, the set of pipes and the set of valves are configured to direct the cycle fluid that has passed through the first heat exchange system 31 from the first heat exchange system 31 to the third heat exchange system 33, then from the third heat exchange system 33 to the second heat exchange system 32, and then from the second heat exchange system 32 to the fourth heat exchange system 34.

[0070] As an alternative, the set of pipes and the set of valves may be configured to direct the cycle fluid that has passed through the first heat exchange system 31 from the first heat exchange system 31 to the fourth heat exchange system 34, then from the fourth heat exchange system 34 to the second heat exchange system 32, and then from the second heat exchange system 32 to the third heat exchange system 33.

[0071] This means that, in the “series” arrangement of the third heat exchange system 33 and fourth heat exchange system 34, the order in which the cycle fluid passes through the third heat exchange system 33 and fourth heat exchange system 34 is not important.

[0072] In one embodiment, in the first operating configuration of the device 1, the set of pipes and the set of valves are configured to direct the cycle fluid that has passed through the first heat exchange system 31 selectively to the third heat exchange system 33, or to the fourth heat exchange system 34, or simultaneously to the third heat exchange system 33 and the fourth heat exchange system 34.

[0073] This means that, in the first configuration, the cycle fluid can pass through only one of the third heat exchange system 33 and fourth heat exchange system 34, or in parallel in both.

[0074] With reference to FIG. 4, in one embodiment, the cold source 4 is separate from the first refrigerator 2. This means for example that the cold source 4 supplies a cooling power independently of the first refrigerator 2. The first refrigerator 2 comprises a second cooling portion 23 located, in the cycle circuit, downstream of the first cooling portion 22 and upstream of the first expansion mechanism 24. The first refrigerator further comprises a second refrigeration portion 5 configured to allow the cooling of a second user and located, in the cycle circuit, downstream of the first expansion mechanism 24. The first refrigeration portion 3 is located, in the cycle circuit, between the first cooling portion 22 and the second cooling portion 23.

[0075] With reference to FIG. 5, in one embodiment, the first refrigeration portion 3 comprises a fifth heat exchange system 35 configured to make the cycle fluid exchange heat with the cold source 4. The set of pipes is configured to connect the fourth heat exchange system 34 to the fifth heat exchange system 35 in series, and the fifth heat exchange system 35 to the second cooling portion 23 for the cycle fluid in series.

[0076] The fifth heat exchange system 35 makes the generation of the cooling power required by the second user 5 more efficient, because the cycle fluid is cooled before it returns to the cycle circuit.

[0077] In one embodiment, the set of pipes comprises a first bypass pipe 6 configured to take at least some of the cycle fluid that has passed through the third heat exchange system 33 and direct it to the second cooling portion 23 for the cycle fluid. This means that this portion of the cycle fluid does not go through the second heat exchange system 32 or through the fourth heat exchange system 34.

[0078] This makes it possible to modulate the cooling power supplied to the first user 300, for example between 100% and 200% of the power supplied by the cold source 4.

[0079] In one embodiment, the set of pipes comprises a second bypass pipe 7 configured to take at least some of the cycle fluid that has passed through the second heat exchange system 32 and direct it directly to the second cooling portion 23 for the cycle fluid. This means that this portion of the cycle fluid does not go through the fourth heat exchange system 34.

[0080] In this case too, it is possible to modulate the cooling power supplied to the first user 300, for example between 100% and 200% of the power supplied by the cold source 4. In addition, the generation of the cooling power required by the second user 5 will be more efficient, because at least some of the cycle fluid is cooled before it returns to the cycle circuit.

[0081] In one embodiment, the set of pipes comprises a third bypass pipe 8 configured to take at least some of the cycle fluid that has passed through the third heat exchange system 33 and direct it to the heating portion 25 for the cycle fluid.

[0082] In this case too, it is possible to modulate the cooling power supplied to the first user 300, for example between 100% and 200% of the power supplied by the cold source 4. In addition, it is also possible to modulate the amount of cycle fluid flowing through the expansion mechanism. The efficiency of the device is improved.

[0083] With reference to FIG. 6, in one embodiment, the cold source 4 is part of the cycle circuit of the first refrigerator 2, and the first refrigeration portion 3 is located, in the cycle circuit, downstream of the first expansion mechanism 24.

[0084] The cold source 4 may in particular be, in this case, a store of liquefied cycle fluid.

[0085] In an alternative embodiment to that in FIG. 6, the cold source 4 is separate from the first refrigerator 2, and the first refrigeration portion 3 is located, in the cycle circuit, downstream of the first expansion mechanism 24.

[0086] According to another aspect, the invention relates to a cryogenic refrigeration method using a refrigeration device 1 as described above.

[0087] In order to generate the required cooling power, the cycle fluid is compressed in the compression mechanism 21, cooled in the first cooling portion 22 and, where appropriate, in the second cooling portion 23, and expanded in the first expansion mechanism 24.

[0088] The first expansion mechanism 24 may comprise one or more expansion turbines or valves configured to bring the cycle fluid to the colder temperature required. Once this temperature has been reached, the cycle fluid is made to exchange heat, directly or indirectly, with a user that is to be cooled, then it is heated in the heating portion 25 and returns to the compression mechanism. At least some of the cycle fluid flows through the first refrigeration portion 3.

[0089] The method according to the invention aims to cool a first user 300 connected to the first refrigeration portion 3. The method comprises a step of switching the device 1 from the first configuration to the second configuration, or from the second configuration to the first configuration.

[0090] The switching takes place in particular in response to information about a change, or predicted change, in a cooling power required by the first user 300. For example, there will be a switch from the first configuration to the second if the change corresponds to an increase in the cooling power required. There will be a switch from the second configuration to the first configuration if the change corresponds to a decrease in the cooling power required.

[0091] In one embodiment of the method, the flow rate of cycle fluid through the compression mechanism 21 may be constant. This makes it possible to maintain a high and / or optimum compression efficiency.

[0092] In one embodiment of the method, the cooling power supplied to the user 300 in the second configuration is comprised between 100% and 200%, in particular between 150% and 200%, of the cooling power supplied to the user 300 in the first configuration.

[0093] In one embodiment of the method, the cold source 4 supplies a cooling power at a temperature comprised between 50 K and 100 K, in particular 80 K.

[0094] The cycle fluid enters the first heat exchange system 31 at a temperature comprised between 55 K and 120 K, in particular between 85 K and 120 K, and leaves the first heat exchange system 31 at a temperature comprised between 50 K and 100 K, in particular 80 K.

[0095] After that, this first stream of cooled cycle fluid enters the heat exchange assembly 33, 34, and in particular the third heat exchange system 33, in order to draw off a first amount of heat from the first user 300. A first stream of cycle fluid heated to a temperature comprised between 55 K and 120 K, in particular between 85 K and 120 K, is obtained at the outlet.

[0096] Then, this first stream of heated cycle fluid is introduced into the second heat exchange system 32 in order to cool it down. A second stream of cycle fluid cooled to a temperature comprised between 50 K and 100 K, in particular 80 K, is obtained at the outlet.

[0097] This second stream of cooled cycle fluid is again directed to the heat exchange assembly 33, 34, and in particular to the fourth heat exchange system 34, in order to draw off a second amount of heat from the first user 300. A second stream of cycle fluid heated to a temperature comprised between 55 K and 120 K, in particular between 85 K and 120 K, is obtained at the outlet.

[0098] The second stream of heated cycle fluid returns to the cycle circuit either to be subsequently cooled there or to be subsequently heated there.

[0099] In one embodiment of the method, the cold source 4 supplies a cooling power at a temperature comprised between 2 K and 5 K.

[0100] The operation is the same as that described for the case above. However, the temperature of the cycle fluid at the inlet of the first heat exchange system 31 is then comprised for example between 4 K and 10 K. The temperature at the outlet is comprised for example between 2 K and 5 K.

[0101] The temperature of the first stream of heated cycle fluid and of the second stream of heated cycle fluid is comprised for example between 4 K and 20 K, in particular between 4 K and 10 K.

[0102] In one implementation of the method, the cycle fluid is chosen from the following: helium, neon, argon, nitrogen, or a mixture of at least two of these gases.

[0103] 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.

[0104] The singular forms “a”, “an” and “the” include plural referents, unless the context clearly dictates otherwise.

[0105] “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.

[0106] “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.

[0107] 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.

[0108] 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.

Claims

1. A cryogenic refrigeration device comprising a first refrigerator with a refrigeration cycle for a cycle fluid and at least one cold source, the first refrigerator comprising, in series in a cycle circuit and connected by a set of pipes and a set of valves:a compression mechanism for the cycle fluid,a first cooling portion for the cycle fluid,a first expansion mechanism for the cycle fluid,a heating portion for the cycle fluid,a first refrigeration portion configured to allow the cooling of a first user, and comprising a first heat exchange system configured to make the cycle fluid exchange heat with the cold source,a second heat exchange system configured to make the cycle fluid exchange heat with the cold source,a refrigeration assembly configured to make the first user exchange heat with the cycle fluid,wherein the set of pipes and the set of valves being configured to switch the device between:a first operating configuration, in which at least some of the cycle fluid is directed to the first heat exchange system, then from the first heat exchange system to the refrigeration assembly, and then away from the first refrigeration portion to the cycle circuit;a second operating configuration, in which at least some of the cycle fluid is directed to the first heat exchange system, then from the first heat exchange system to the refrigeration assembly, then from the refrigeration assembly to the second heat exchange system, and then from the second heat exchange system to the refrigeration assembly.

2. The cryogenic refrigeration device according to claim 1, further comprising a controller configured to switch the device to the first configuration in response to information about a decrease or predicted decrease in the cooling power required by the first user, or to the second configuration in response to information about an increase or predicted increase in the cooling power required by the first user.

3. The cryogenic refrigeration device according to claim 1, wherein the refrigeration assembly comprises a third heat exchange system configured to make the first user exchange heat with the cycle fluid, a fourth heat exchange system configured to make the first user exchange heat with the cycle fluid, the third heat exchange system and the fourth heat exchange system being positioned in series and / or in parallel in the cycle circuit.

4. The cryogenic refrigeration device according to claim 3, wherein, in the second operating configuration, the set of pipes and the set of valves are configured to direct the cycle fluid that has passed through the first heat exchange systemfrom the first heat exchange system to the third heat exchange system, thenfrom the third heat exchange system to the second heat exchange system, and thenfrom the second heat exchange system to the fourth heat exchange system.

5. The cryogenic refrigeration device according to claim 3, wherein, in the first operating configuration, the set of pipes and the set of valves are configured to direct the cycle fluid that has passed through the first heat exchange system to the third heat exchange system, or to the fourth heat exchange system, or simultaneously to the third heat exchange system and the fourth heat exchange system.

6. The cryogenic refrigeration device according to claim 1, wherein the cold source is separate from the first refrigerator, and the first refrigerator comprises a second cooling portion located, in the cycle circuit, downstream of the first cooling portion and upstream of the first expansion mechanism, and a second refrigeration portion configured to allow the cooling of a second user and located, in the cycle circuit, downstream of the first expansion mechanism, and wherein the first refrigeration portion is located, in the cycle circuit, between the first cooling portion and the second cooling portion.

7. The cryogenic refrigeration device according to claim 6, wherein the first refrigeration portion comprises a fifth heat exchange system configured to make the cycle fluid exchange heat with the cold source, and the set of pipes is configured to connect the fourth heat exchange system to the fifth heat exchange system in series, and to connect the fifth heat exchange system to the second cooling portion for the cycle fluid in series.

8. The cryogenic refrigeration device according to claim 6, wherein the set of pipes comprises a first bypass pipe configured to take at least some of the cycle fluid that has passed through the third heat exchange system and direct it directly to the second cooling portion for the cycle fluid, i.e. without going through the second heat exchange system or through the fourth heat exchange system.

9. The cryogenic refrigeration device according to claim 6, wherein the set of pipes comprises a second bypass pipe configured to take at least some of the cycle fluid that has passed through the second heat exchange system and direct it directly to the second cooling portion for the cycle fluid, i.e. without going through the fourth heat exchange system.

10. The cryogenic refrigeration device according to claim 1, wherein the cold source is a part of the cycle circuit of the first refrigerator, and the first refrigeration portion is located, in the cycle circuit, downstream of the first expansion mechanism.

11. A method for cryogenic refrigeration using the cryogenic refrigeration device according to claim 1 for cooling a first user connected to the first refrigeration portion, the method comprising a step of switching the cryogenic refrigeration device from the first configuration to the second configuration, or from the second configuration to the first configuration, wherein the switch is in response to information about a change or predicted change in the cooling power required by the first user.

12. The method according to claim 11, wherein the flow rate of cycle fluid through the compression mechanism is constant.

13. The method according to claim 11, wherein the cooling power supplied to the user in the second configuration is comprised between 100% and 200%, in particular between 150% and 200%, of the cooling power supplied to the user in the first configuration.

14. The method according to claim 11, wherein the cold source supplies a cooling power at a temperature comprised between 50 K and 100 K.

15. The method according to claim 11, wherein the cold source supplies a cooling power at a temperature comprised between 2 K and 5 K.

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