Variable-temperature refrigerator and method for regulating the same

Abstract

The application provides a variable-temperature refrigerator and a regulation method thereof. The variable-temperature refrigerator comprises a dilution refrigerator cold plate, a variable-temperature cold plate, a thermal switch for realizing thermal connection and thermal insulation, a flange and a heater for adjusting and controlling temperature. The application is provided with a separate variable-temperature cold plate, and through the combination of multiple sets of thermal switches and the dilution refrigerator cold plate for thermal connection and thermal insulation, and the assistance of different power heating, the rapid temperature change from the mK temperature zone to the room temperature zone is realized without affecting the normal operation of the dilution refrigeration cycle.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of extremely low temperature physics, and particularly relates to a variable temperature refrigerator and a regulating method thereof. BACKGROUND

[0002] In the research of condensed matter physics, it is usually necessary to create an experimental environment from the mK temperature zone to the room temperature zone based on a refrigerator to create conditions for experiments such as physical property measurement.

[0003] The existing variable temperature technology is mainly based on a dilution refrigerator cycle, and is realized by switching different operating modes and auxiliary heating. That is, 1) in the temperature zone below 1K, auxiliary heating is realized in the dilution refrigeration mode; 2) in the temperature zone of 1-4K, some mixed gas is collected, the liquid level is kept in the mixing chamber, and auxiliary heating is realized in the liquid helium pressure reduction refrigeration mode; and 3) in the temperature zone of 4-300K, gas is collected or a small amount of circulating gas is reserved, and the auxiliary heater mode is realized.

[0004] In the specific implementation process of the above variable temperature technology, there are two common means. One is to use a dilution refrigeration plug rod. The other is to use a combination of a dilution refrigeration cycle and an auxiliary gas cycle without using a plug rod.

[0005] The shortcomings of the existing variable temperature technology are that different operating modes correspond to different gas cycle and refrigeration modes, and it is actually impossible to continuously switch; the processes of temperature rise and temperature drop again need to collect gas and re-liquefy, which consumes time and is inconvenient to operate. SUMMARY

[0006] Therefore, the purpose of the present application is to overcome the shortcomings in the prior art, and to provide a variable temperature refrigerator and a regulating method thereof. Without collecting gas and re-liquefying, the large temperature zone variable temperature between 10mK and 300K can be rapidly and conveniently realized, thereby solving a great demand of the current extremely low temperature physics experiment.

[0007] Before the content of the present application is described, the terms used in the present application are defined as follows:

[0008] The term "variable temperature cold plate" refers to a cold plate that is independent of the original cold plate of the dilution refrigerator, is not directly affected by the dilution refrigeration cycle, and can be constructed into a cold plate with different target temperatures through thermal connection and thermal insulation with the original cold plate of the dilution refrigerator.

[0009] The term "first stage cold plate" refers to a cold plate that is thermally connected with the first stage cold head of the mechanical refrigerator and can realize the temperature of the 40K temperature zone.

[0010] The term "second stage cold plate" refers to a cold plate that is thermally connected with the second stage cold head of the mechanical refrigerator and can realize the temperature of the 3K temperature zone.

[0011] The term "Still cold plate" refers to an evaporation chamber cold plate that can realize the temperature of the 0.7K temperature zone.

[0012] The term "IC cold plate" refers to an intermediate cold plate that can achieve a temperature of 100 mK in the cold stage.

[0013] The term "MC cold plate" refers to a mixed chamber cold plate that can achieve a temperature of 10 mK in the cold stage.

[0014] The term "soft connection" refers to a flexible connection fitting for connecting components of a refrigeration device, which has a heat conduction effect.

[0015] To achieve the above-mentioned purpose, the first aspect of the present application provides a variable-temperature refrigerator, which comprises a dilution refrigerator cold plate, a variable-temperature cold plate, a thermal switch for achieving thermal connection and thermal insulation, a flange, and a heater for adjusting and controlling the temperature; and each stage of the dilution refrigerator cold plate is provided with the variable-temperature cold plate, which is separated from each other and is flush with the dilution refrigerator cold plate of the same stage in height; wherein:

[0016] The dilution refrigerator cold plate and the variable-temperature cold plate are connected through the thermal switch;

[0017] Each stage of the dilution refrigerator cold plate is provided with the heater;

[0018] Preferably, the thermal switch comprises an inter-variable-temperature cold plate thermal switch connecting each stage of the variable-temperature cold plate, a variable-temperature cold plate-dilution refrigerator cold plate thermal switch connecting each stage of the variable-temperature cold plate and each stage of the dilution refrigerator cold plate, and a refrigerator thermal switch for the operation of the dilution refrigerator itself.

[0019] The variable-temperature refrigerator according to the first aspect of the present application, wherein,

[0020] The dilution refrigerator cold plate and the variable-temperature cold plate are connected through the variable-temperature cold plate-dilution refrigerator cold plate thermal switch;

[0021] The surface of the variable-temperature cold plate is a smooth surface; and / or

[0022] The flange is a room temperature flange.

[0023] The variable-temperature refrigerator according to the first aspect of the present application, wherein,

[0024] Each of the thermal switches can be independently controlled in the closed and open states, and can be operated independently or in combination; and / or

[0025] The type of the thermal switch is a mechanical thermal switch or an air gap thermal switch.

[0026] The variable-temperature refrigerator according to the first aspect of the present application, wherein,

[0027] The variable temperature cold stage is thermally connected or thermally insulated with the dilution refrigerator cold stages through the thermal switches; and / or

[0028] The heater provides different orders of magnitude of heating power on each of the dilution refrigerator cold stages.

[0029] The variable temperature refrigerator according to the first aspect of the present application, wherein,

[0030] The dilution refrigerator cold stages comprise a first stage cold stage, a second stage cold stage, an evaporation chamber cold stage, an intermediate stage cold stage and a mixing chamber cold stage;

[0031] The variable temperature cold stages comprise a first stage variable temperature cold stage, a second stage variable temperature cold stage, an evaporation chamber variable temperature cold stage, an intermediate stage variable temperature cold stage and a mixing chamber variable temperature cold stage;

[0032] The heater comprises a first stage heater, a second stage heater, an evaporation chamber heater, an intermediate stage heater and a mixing chamber heater;

[0033] The variable temperature cold stage to cold stage thermal switches comprise a first stage variable temperature cold stage to first stage cold stage thermal switch, a second stage variable temperature cold stage to second stage cold stage thermal switch, an evaporation chamber variable temperature cold stage to evaporation chamber cold stage thermal switch, an intermediate stage variable temperature cold stage to intermediate stage cold stage thermal switch and a mixing chamber variable temperature cold stage to mixing chamber cold stage thermal switch;

[0034] The variable temperature cold stage to cold stage thermal switches comprise a first stage variable temperature cold stage to first stage cold stage thermal switch, a second stage variable temperature cold stage to second stage cold stage thermal switch, an evaporation chamber variable temperature cold stage to evaporation chamber cold stage thermal switch, an intermediate stage variable temperature cold stage to intermediate stage cold stage thermal switch and a mixing chamber variable temperature cold stage to mixing chamber cold stage thermal switch; and / or

[0035] The refrigerator thermal switches comprise an evaporation chamber refrigerator thermal switch, an intermediate stage refrigerator thermal switch and a mixing chamber refrigerator thermal switch.

[0036] The variable temperature refrigerator according to the first aspect of the present application, wherein:

[0037] One end of the first stage variable temperature cold stage to cold stage thermal switch is connected with the flange, and the other end is connected with the first stage variable temperature cold stage;

[0038] One end of the second stage variable temperature cold stage to cold stage thermal switch is connected with the first stage variable temperature cold stage, and the other end is connected with the second stage variable temperature cold stage;

[0039] One end of the evaporation chamber variable temperature cold stage to cold stage thermal switch is connected with the second stage variable temperature cold stage, and the other end is connected with the evaporation chamber variable temperature cold stage;

[0040] One end of the intermediate stage variable temperature cold stage to cold stage thermal switch is connected with the evaporation chamber variable temperature cold stage, and the other end is connected with the intermediate stage variable temperature cold stage; and

[0041] One end of the heat switch between the mixing chamber variable temperature cold plate and the intermediate stage variable temperature cold plate is connected to the intermediate stage variable temperature cold plate, and the other end is connected to the mixing chamber variable temperature cold plate.

[0042] The variable temperature refrigerator according to the first aspect of the present application, wherein the variable temperature refrigerator further comprises a flexible connection and a mechanical refrigerator.

[0043] The variable temperature refrigerator according to the first aspect of the present application, wherein,

[0044] The heater further comprises an additional heater arranged on the first stage variable temperature cold plate; and / or

[0045] The head of the mechanical refrigerator is connected to the first stage cold plate and the second stage cold plate through the flexible connection;

[0046] Preferably, the first stage heater, the second stage heater, the evaporation chamber heater, the intermediate stage heater and the mixing chamber heater are arranged on the first stage cold plate, the second stage cold plate, the evaporation chamber cold plate, the intermediate stage cold plate and the mixing chamber cold plate, respectively.

[0047] The second aspect of the present application provides a variable temperature regulation method, which comprises using the variable temperature refrigerator according to the first aspect;

[0048] Preferably, the method comprises the following steps:

[0049] 1) Stabilize the operation of the dilution refrigerator and ensure that the heat switch between the variable temperature cold plates and the heat switch between the cold plates of the variable temperature cold plate refrigerator are both in the closed state;

[0050] 2) According to the range of the target temperature zone, regulate the connection of the heat switch between the variable temperature cold plates and the heat switch between the cold plates of the variable temperature cold plate refrigerator, so as to realize variable temperature regulation.

[0051] The variable temperature regulation method according to the second aspect of the present application, wherein in step 2), the target temperature zone is selected from one or more of the following: 0.01K-0.1K, 0.1K-0.6K, 0.6K-3K, 3K-40K, 40K-300K; wherein,

[0052] When the target temperature zone is 0.01K-0.1K, the heat switch between the mixing chamber variable temperature cold plate and the cold plate of the mixing chamber refrigerator is closed, and the mixing chamber heater is assisted;

[0053] When the target temperature zone is 0.1K-0.6K, the heat switch between the mixing chamber variable temperature cold plate and the cold plate of the mixing chamber refrigerator is opened, the heat switch between the mixing chamber variable temperature cold plate and the intermediate stage variable temperature cold plate is closed, and the heat switch between the intermediate stage variable temperature cold plate and the cold plate of the intermediate stage refrigerator is closed, and the intermediate stage heater is assisted;

[0054] When the target temperature zone is 0.6K-3K, the thermal switches between the mixing chamber variable temperature cold stage and the mixing chamber refrigerator cold stage, the intermediate stage variable temperature cold stage and the intermediate stage refrigerator cold stage, and the evaporation chamber variable temperature cold stage and the evaporation chamber refrigerator cold stage are opened, the thermal switches between the mixing chamber variable temperature cold stage, the intermediate stage variable temperature cold stage, the evaporation chamber variable temperature cold stage, the second stage variable temperature cold stage, and the first stage variable temperature cold stage and the first stage refrigerator cold stage are closed, and the first stage heater or the heater arranged beside the first stage variable temperature cold stage is assisted;

[0055] When the target temperature zone is 3K-40K, the thermal switches between the mixing chamber variable temperature cold stage and the mixing chamber refrigerator cold stage, the intermediate stage variable temperature cold stage and the intermediate stage refrigerator cold stage, and the evaporation chamber variable temperature cold stage and the evaporation chamber refrigerator cold stage are opened, the thermal switches between the mixing chamber variable temperature cold stage, the intermediate stage variable temperature cold stage, the evaporation chamber variable temperature cold stage, the second stage variable temperature cold stage, and the first stage variable temperature cold stage and the first stage refrigerator cold stage are closed, and the second stage heater is assisted; and / or

[0056] When the target temperature zone is 40K-300K:

[0057] In the low temperature zone, the thermal switches between the mixing chamber variable temperature cold stage and the mixing chamber refrigerator cold stage, the intermediate stage variable temperature cold stage and the intermediate stage refrigerator cold stage, the evaporation chamber variable temperature cold stage and the evaporation chamber refrigerator cold stage, and the second stage variable temperature cold stage and the second stage refrigerator cold stage are opened, the thermal switches between the mixing chamber variable temperature cold stage, the intermediate stage variable temperature cold stage, the evaporation chamber variable temperature cold stage, the second stage variable temperature cold stage, and the first stage variable temperature cold stage and the first stage refrigerator cold stage are closed, and the first stage heater or the heater arranged beside the first stage variable temperature cold stage is assisted;

[0058] In the high temperature zone, the thermal switches between the mixing chamber variable temperature cold stage and the mixing chamber refrigerator cold stage, the intermediate stage variable temperature cold stage and the intermediate stage refrigerator cold stage, the evaporation chamber variable temperature cold stage and the evaporation chamber refrigerator cold stage, and the second stage variable temperature cold stage and the second stage refrigerator cold stage are opened, the thermal switches between the mixing chamber variable temperature cold stage, the intermediate stage variable temperature cold stage, the evaporation chamber variable temperature cold stage, the second stage variable temperature cold stage, the first stage variable temperature cold stage and the first stage refrigerator cold stage, and the first stage variable temperature cold stage are closed, and the first stage heater or the heater arranged beside the first stage variable temperature cold stage is assisted; preferably, in the high temperature zone, another mechanical refrigerator is also started to prevent the temperature of the first stage variable temperature cold stage from being too high to affect the dilution refrigerator cold stage;

[0059] Preferably, the temperature of the low temperature zone is 40-80K; and / or

[0060] Preferably, the temperature of the high temperature zone is 80-300K.

[0061] The present application sets up a single variable temperature cold disc, through the combination of multiple groups of thermal switches and dilution refrigerator cold disc heat connection and heat insulation, auxiliary heating of different power, on the premise of not affecting the normal operation of dilution refrigeration cycle, realize the rapid temperature change from mK level temperature zone to room temperature zone. The specific scheme is as follows:

[0062] 1. The existing dilution refrigerator cold disc, each stage has a certain refrigeration capacity in a certain temperature zone, as shown in table 1. The present application proposes to set up a variable temperature cold disc at each stage of the existing dilution refrigerator. After the variable temperature cold disc is connected with the target cold disc, auxiliary heating power is provided to realize temperature change and control. At the same time, as long as the heat load in a certain temperature zone does not exceed the refrigeration power of the original dilution refrigerator cold disc, the variable temperature process can ensure the normal operation of the dilution refrigerator without additional gas handling.

[0063] Table 1. The refrigeration capacity of each stage of the existing medium power dilution refrigerator cold disc

[0064] Temperature stage Approximate cooling power First stage cold plate ~ 40 W @ 45 K Second stage cold plate ~ 1.5 W @ 4.2 K STILL stage cold plate 10-20 mW @ 0.8 K ICP stage cold plate ~ 500 μW @ 200 mK MC stage cold plate ~ 10 μW @ 20 mK

[0065] 2. The variable temperature cold disc is separated from the original dilution refrigerator cold disc in structure and connected only through thermal switches. The variable temperature cold discs of different stages are also connected through thermal switches. At the same time, the variable temperature cold disc of the highest temperature zone is also connected with the dilution refrigerator room temperature flange through thermal switches. In order to reduce the radiation heat leakage of the variable temperature cold disc to the dilution refrigerator cold disc, it is necessary to ensure that the variable temperature cold disc is flush with the dilution refrigerator cold disc of the same stage in height; the surface of the variable temperature cold disc needs to be smooth to reduce its surface emissivity. At the same time, the size of the variable temperature cold disc needs to be calculated and designed according to the heat capacity. In principle, under the premise of ensuring the realization of structural function, the higher the temperature zone, the smaller the area.

[0066] 3. The thermal switch can realize reliable heat connection and heat insulation in the required temperature zone. The optional thermal switch types are: mechanical thermal switch, air gap thermal switch. Each thermal switch can be controlled independently in its closed (ON state) and open (OFF state) state. The thermal switches in the system can operate independently or in combination. Among them, the air gap thermal switch can control its open (OFF state) thermal conductivity through design.

[0067] 4. The large range temperature change of the variable temperature cold disc mainly depends on the heat connection and heat insulation with the original dilution refrigerator cold disc of each stage. At the same time, the more precise adjustment and control of temperature is realized by the heater arranged in the system. The heaters installed on different cold discs can provide different orders of magnitude of heating power.

[0068] 5. In order to prevent the high temperature zone control temperature from causing excessive thermal load on the first and second stage cold plates of the dilution refrigerator, the application proposes that a small mechanical refrigerator cold head can be additionally added on the basis of the original dilution refrigerator configuration, which is used to maintain the temperature of the first and second stage cold plates of the dilution refrigerator.

[0069] The application proposes a new refrigerator variable temperature scheme, that is, based on the existing dilution refrigerator structure and function, a separate variable temperature cold plate is set, a plurality of thermal switches are combined with the dilution refrigerator cold plate for thermal connection and thermal insulation, and different power heating is assisted, so that the rapid variable temperature from the mK temperature zone to the room temperature zone can be realized quickly and conveniently without gas collection and reliquefaction, which can solve the great demand of the current low temperature physical experiment.

[0070] Compared with the prior art, the primer / probe composition and detection method for capillary electrophoresis of the application can have the following beneficial effects, but not limited to:

[0071] 1. The prior art switches, combines and operates through multiple gas circulation and refrigeration modes, and the temperature rising and re-cooling process needs part of the gas collection and reliquefaction, which consumes time and is inconvenient to operate; the scheme of the application can realize large temperature zone temperature change only by switching the thermal switch, without affecting the operation of the dilution refrigeration cycle, without the need for gas collection and reliquefaction, and the operation is simple and convenient.

[0072] 2. The prior art uses helium circulation to change temperature in the high temperature zone (convective heat transfer); the scheme of the application relies on the thermal switch to establish thermal connection (thermal conduction) between the variable temperature cold plate and the stages of the dilution refrigerator, which is expected to achieve higher temperature control accuracy. BRIEF DESCRIPTION OF DRAWINGS

[0073] Hereinafter, the embodiments of the application will be described in detail with reference to the accompanying drawings, in which:

[0074] Figure 1 The internal principle schematic diagram of the large temperature zone variable temperature refrigerator of the application is shown.

[0075] Explanation of reference signs:

[0076] 1. The inner surface temperature of the room temperature flange of the dilution refrigerator is close to room temperature; 2. The first stage cold plate of the dilution refrigerator; 3. The second stage cold plate of the dilution refrigerator; 4. The still cold plate of the dilution refrigerator; 5. The intermediate cold plate (ICP) of the dilution refrigerator; 6. The mixing chamber (MC) cold plate of the dilution refrigerator; 7. The mixing chamber variable temperature cold plate; 8. The intermediate variable temperature cold plate; 9. The still variable temperature cold plate; 10. The second stage variable temperature cold plate; 11. The first stage variable temperature cold plate; 12. The first stage variable temperature cold plate thermal switch; 13. The second stage variable temperature cold plate thermal switch; 14. The still variable temperature cold plate thermal switch; 15. The intermediate variable temperature cold plate thermal switch; 16. The mixing chamber variable temperature cold plate thermal switch; 17. The mixing chamber variable temperature cold plate and the mixing chamber refrigerator cold plate thermal switch; 18. The intermediate variable temperature cold plate and the intermediate refrigerator cold plate thermal switch; 19. The still variable temperature cold plate and the still refrigerator cold plate thermal switch; 20. The second stage variable temperature cold plate and the second stage refrigerator cold plate thermal switch; 21. The first stage variable temperature cold plate and the first stage refrigerator cold plate thermal switch; 22. The copper soft connection connecting the small mechanical refrigerator cold head and the dilution refrigerator first and second stage cold plates; 23. The small mechanical refrigerator; 24. The still refrigerator thermal switch; 25. The intermediate refrigerator thermal switch; 26. The mixing chamber refrigerator thermal switch; 27. The first stage heater; 28. The second stage heater; 29. The still heater; 30. The intermediate heater; 31. The mixing chamber heater; 32. The heater arranged in the first stage variable temperature cold plate. DETAILED DESCRIPTION

[0077] The application will be further described with reference to the drawings, in which specific embodiments are shown. It is understood that these embodiments are merely illustrative of the application and should not be construed as limiting the application in any way.

[0078] This section describes the materials and methods used in the experiments of the application. Although many of the materials and methods used to practice the application are well known in the art, the application will be described in as much detail as is necessary to practice the application. It will be apparent to those skilled in the art that materials and methods known in the art can be used if not specifically mentioned, and that the context will make the appropriate substitutions obvious.

[0079] Example 1

[0080] This example is used to illustrate the variable temperature refrigerator and the control method of the application.

[0081] Figure 1The application can realize large temperature range variable temperature refrigerator internal principle schematic diagram. The variable temperature refrigerator includes: a room temperature flange 1 of a dilution refrigerator, the inner surface temperature of which is close to room temperature; a first stage cold plate 2 of the dilution refrigerator, which can realize a temperature of about 40K; a second stage cold plate 3 of the dilution refrigerator, which can realize a temperature of about 3K; a still cold plate 4 of the dilution refrigerator, which can realize a temperature of about 0.7K; an intermediate stage (ICP) cold plate 5 of the dilution refrigerator, which can realize a temperature of about 100mK; a mixing chamber (MC) cold plate 6 of the dilution refrigerator, which can realize a temperature of about 10mK; a mixing chamber variable temperature cold plate 7; an intermediate stage variable temperature cold plate 8; a still variable temperature cold plate 9; a second stage variable temperature cold plate 10; a first stage variable temperature cold plate 11; a first stage variable temperature cold plate thermal switch 12; a second stage variable temperature cold plate thermal switch 13; a still variable temperature cold plate thermal switch 14; an intermediate stage variable temperature cold plate thermal switch 15; a mixing chamber variable temperature cold plate thermal switch 16; a mixing chamber variable temperature cold plate and mixing chamber refrigerator cold plate thermal switch 17; an intermediate stage variable temperature cold plate and intermediate stage refrigerator cold plate thermal switch 18; a still variable temperature cold plate and still refrigerator cold plate thermal switch 19; a second stage variable temperature cold plate and second stage refrigerator cold plate thermal switch 20; a first stage variable temperature cold plate and first stage refrigerator cold plate thermal switch 21; a copper soft connection 22 connecting a small mechanical refrigerator cold head and the first and second stage cold plates of the dilution refrigerator; a small mechanical refrigerator 23; a still refrigerator thermal switch 24; an intermediate stage refrigerator thermal switch 25; a mixing chamber refrigerator thermal switch 26; a first stage heater 27; a second stage heater 28; a still heater 29; an intermediate stage heater 30; a mixing chamber heater 31; a heater 32 arranged in the first stage variable temperature cold plate.

[0082] 1. The application sets a variable temperature cold plate at each stage of the existing dilution refrigerator. After the variable temperature demand of a given specific temperature range is given, the variable temperature cold plate is connected with the target cold plate which is close to the target temperature, and a certain heating power is used to realize the variable temperature and temperature control. At the same time, as long as the heat load in the specific temperature range does not exceed the refrigeration power of the original dilution refrigerator cold plate, the variable temperature process will not affect the normal operation of the dilution refrigerator, and no additional gas handling is required.

[0083] 2. The variable temperature cold plate is structurally separated from the original dilution refrigerator cold plate and is connected only through a thermal switch. The variable temperature cold plates of different stages are also connected through thermal switches. At the same time, the variable temperature cold plate of the highest temperature zone is also connected with the room temperature flange of the dilution refrigerator through a thermal switch. In order to reduce the radiation heat leakage of the variable temperature cold plate to the dilution refrigerator cold plate, it is necessary to ensure that the variable temperature cold plate is flush with the dilution refrigerator cold plate of the same stage in height; the surface of the variable temperature cold plate needs to be smooth to reduce its surface emissivity. At the same time, the size of the variable temperature cold plate needs to be calculated and designed according to the heat capacity. In principle, under the premise of ensuring the realization of the structure and function, the higher the temperature zone, the smaller the area.

[0084] 3. The thermal switch can achieve reliable thermal connection and thermal insulation in the required temperature range. The optional thermal switch types are mechanical thermal switch and air gap thermal switch. Each thermal switch can be individually controlled in its closed (ON state) and open (OFF state) state. The thermal switches in the system can operate individually or in combination. Among them, the air gap thermal switch can control its OFF state thermal conductivity through design. The air gap thermal switch is used in this embodiment.

[0085] 4. The large-scale temperature change of the variable temperature cold plate mainly relies on the thermal connection and thermal insulation with the original dilution refrigerator cold plate at each stage. At the same time, more precise temperature adjustment and control are achieved by the heaters arranged in the system. The heaters installed on different cold plates can provide different orders of magnitude of heating power.

[0086] 5. In order to prevent the high-temperature zone temperature control from causing excessive thermal load on the first and second cold plates of the dilution refrigerator, the application proposes to additionally increase a small mechanical refrigerator cold head based on the original dilution refrigerator configuration, which is used to maintain the temperature of the first and second cold plates of the dilution refrigerator.

[0087] This embodiment uses a 400-micro-watt medium-power dilution refrigerator. The mixed chamber cold plate can achieve a minimum temperature of 10 mK in steady-state operation. Based on this device, the specific implementation scheme is as follows:

[0088] The steady-state operation of the dilution refrigerator is taken as the initial state. At this time, the thermal switches shown in 12-16 and 17-21 are in ideal OFF state. Based on this, the temperature is changed, and the control strategy is shown in Table 2.

[0089] Table 2. Refrigerator temperature change control strategy

[0090]

[0091] If the temperature is lowered again, only the corresponding switch configuration needs to be restored.

[0092] The application can achieve a large range of temperature change from mK to room temperature without affecting the original dilution refrigeration cycle. As long as the thermal load in a specific temperature range does not exceed the refrigeration power of the original dilution refrigerator cold plate, the temperature change process will not affect the normal operation of the dilution refrigerator, and no additional gas handling is required. At the same time, in order to prevent the high-temperature zone temperature control from causing excessive thermal load on the first and second cold plates of the dilution refrigerator, the application also proposes to additionally increase a small mechanical refrigerator cold head based on the original dilution refrigerator configuration, which is used to maintain the temperature of the first and second cold plates of the dilution refrigerator.

[0093] Although the above only shows the scheme and effect of one specific embodiment, those skilled in the art should understand that according to the concept of the present application, the foregoing other embodiments which do not specifically show the effect or other technical solutions of the present application which are not shown in the embodiments can also achieve the following technical effects declared in the part of the invention content as compared with the embodiments:

[0094] 1. The prior art switches and combines the operation by multiple gas circulation and refrigeration mode, the process of temperature rising and re-cooling needs partial gas collection and re-liquefaction, consumes time, and is inconvenient to operate; the scheme provided in the present application can realize large temperature range temperature variation by only switching the thermal switch, does not affect the operation of the dilution refrigeration cycle, does not need gas collection and re-liquefaction, and is simple and convenient to operate.

[0095] 2. The prior art uses helium circulation to perform temperature variation (convective heat exchange) in the high temperature range; the scheme provided in the present application establishes thermal connection (thermal conduction) between the variable temperature cold plate and the cold plates of each stage of the dilution refrigerator by the thermal switch, and is expected to realize higher temperature control precision.

[0096] Although the present application has been described to a certain extent, obviously, appropriate changes can be made to each condition without departing from the spirit and scope of the present application. It can be understood that the present application is not limited to the described embodiments, but is subject to the scope of the claims, which includes equivalent replacements of each factor described.

Claims

1. A variable-temperature refrigerator, characterized by, The variable-temperature refrigerator comprises: dilution refrigerator cold plates, variable-temperature cold plates, thermal switches for realizing thermal connection and thermal insulation, flanges, and heaters for adjusting and controlling temperature; and each stage of the dilution refrigerator cold plates is provided with the variable-temperature cold plates, which are separated from each other and are flush with the dilution refrigerator cold plates of the same stage in height; wherein: The thermal switches comprise: variable-temperature cold plate inter-thermal switches connecting the variable-temperature cold plates of each stage, variable-temperature cold plate and dilution refrigerator cold plate inter-thermal switches connecting the variable-temperature cold plates of each stage and the dilution refrigerator cold plates of each stage, and refrigerator thermal switches for the operation of the dilution refrigerator itself; The dilution refrigerator cold plates are connected with the variable-temperature cold plates through the variable-temperature cold plate and dilution refrigerator cold plate inter-thermal switches; Each stage of the dilution refrigerator cold plates is provided with the heaters; The variable-temperature refrigerator further comprises: soft connections and mechanical refrigerators, and the soft connections are flexible connecting pieces for connecting refrigeration equipment components and have heat conduction effect; Each of the thermal switches can be independently controlled to be closed and opened, and can be independently or combinedly operated.

2. The temperature-swing refrigerator of claim 1, wherein The type of the thermal switches is mechanical thermal switch or air gap thermal switch.

3. The variable-temperature refrigerator according to claim 1 or 2, characterized in that: The surface of the variable-temperature cold plate is a smooth surface; and / or The flange is a room temperature flange.

4. The variable-temperature refrigerator according to claim 1 or 2, characterized in that: The variable-temperature cold plates are connected with the dilution refrigerator cold plates through the variable-temperature cold plate and dilution refrigerator cold plate inter-thermal switches to realize thermal connection or thermal insulation; and / or The heaters provide different orders of heating power on each stage of the dilution refrigerator cold plates.

5. The variable-temperature refrigerator according to claim 1 or 2, characterized in that: The dilution refrigerator cold plates comprise: first-stage cold plates, second-stage cold plates, evaporation chamber cold plates, intermediate-stage cold plates, and mixing chamber cold plates; The variable-temperature cold plates comprise: first-stage variable-temperature cold plates, second-stage variable-temperature cold plates, evaporation chamber variable-temperature cold plates, intermediate-stage variable-temperature cold plates, and mixing chamber variable-temperature cold plates; The heaters comprise: first-stage heaters, second-stage heaters, evaporation chamber heaters, intermediate-stage heaters, and mixing chamber heaters; The variable-temperature cold plate inter-thermal switches comprise: first-stage variable-temperature cold plate inter-thermal switches, second-stage variable-temperature cold plate inter-thermal switches, evaporation chamber variable-temperature cold plate inter-thermal switches, intermediate-stage variable-temperature cold plate inter-thermal switches, and mixing chamber variable-temperature cold plate inter-thermal switches; The variable-temperature cold plate and dilution refrigerator cold plate inter-thermal switches comprise: first-stage variable-temperature cold plate and first-stage dilution refrigerator cold plate inter-thermal switches, second-stage variable-temperature cold plate and second-stage dilution refrigerator cold plate inter-thermal switches, evaporation chamber variable-temperature cold plate and evaporation chamber dilution refrigerator cold plate inter-thermal switches, intermediate-stage variable-temperature cold plate and intermediate-stage dilution refrigerator cold plate inter-thermal switches, and mixing chamber variable-temperature cold plate and mixing chamber dilution refrigerator cold plate inter-thermal switches; and / or The refrigerator thermal switches comprise: evaporation chamber refrigerator thermal switches, intermediate-stage refrigerator thermal switches, and mixing chamber refrigerator thermal switches.

6. The variable-temperature refrigerator according to claim 5, characterized in that: One end of the first-stage variable-temperature cold plate inter-thermal switch is connected with the flange, and the other end is connected with the first-stage variable-temperature cold plate. One end of the second-stage variable-temperature cold stage inter-heat switch is connected to the first-stage variable-temperature cold stage, and the other end is connected to the second-stage variable-temperature cold stage; One end of the evaporation chamber variable-temperature cold stage inter-heat switch is connected to the second-stage variable-temperature cold stage, and the other end is connected to the evaporation chamber variable-temperature cold stage; One end of the intermediate-stage variable-temperature cold stage inter-heat switch is connected to the evaporation chamber variable-temperature cold stage, and the other end is connected to the intermediate-stage variable-temperature cold stage; and One end of the mixing chamber variable-temperature cold stage inter-heat switch is connected to the intermediate-stage variable-temperature cold stage, and the other end is connected to the mixing chamber variable-temperature cold stage.

7. The variable-temperature refrigerator of claim 5, wherein: The heater further comprises: an additional heater arranged on the first-stage variable-temperature cold stage; and / or The mechanical refrigerator head is connected to the first-stage cold stage and the second-stage cold stage through the soft connection.

8. The variable-temperature refrigerator of claim 7, wherein: The first-stage heater, the second-stage heater, the evaporation chamber heater, the intermediate-stage heater, and the mixing chamber heater are arranged on the first-stage cold stage, the second-stage cold stage, the evaporation chamber cold stage, the intermediate-stage cold stage, and the mixing chamber cold stage, respectively.

9. A method of thermoregulation, comprising, The variable-temperature regulation method comprises using the variable-temperature refrigerator of any one of claims 1 to 8.

10. The method of claim 9, wherein, The method comprises the following steps: 1) Stably operating the dilution refrigerator and ensuring that the variable-temperature cold stage inter-heat switch and the variable-temperature cold stage refrigerator cold stage inter-heat switch are both in a closed state; 2) Regulating the connection of the variable-temperature cold stage inter-heat switch and the variable-temperature cold stage refrigerator cold stage inter-heat switch according to the range of the target temperature zone, so as to realize variable-temperature regulation.

11. The method of claim 10, wherein, In step 2), the target temperature zone is selected from one or more of the following: 0.01K-0.1K, 0.1K-0.6K, 0.6K-3K, 3K-40K, and 40K-300K; wherein: When the target temperature zone is 0.01K-0.1K, the mixing chamber variable-temperature cold stage inter-heat switch and the mixing chamber refrigerator cold stage inter-heat switch are closed, and the mixing chamber heater is assisted; When the target temperature zone is 0.1K-0.6K, the mixing chamber variable-temperature cold stage inter-heat switch and the mixing chamber refrigerator cold stage inter-heat switch are opened, the mixing chamber variable-temperature cold stage inter-heat switch and the intermediate-stage variable-temperature cold stage and the intermediate-stage refrigerator cold stage inter-heat switch are closed, and the intermediate-stage heater is assisted; When the target temperature zone is 0.6K-3K, the mixing chamber variable-temperature cold stage inter-heat switch and the mixing chamber refrigerator cold stage inter-heat switch and the intermediate-stage variable-temperature cold stage and the intermediate-stage refrigerator cold stage inter-heat switch are opened, the mixing chamber variable-temperature cold stage inter-heat switch, the intermediate-stage variable-temperature cold stage inter-heat switch, and the evaporation chamber variable-temperature cold stage and the evaporation chamber refrigerator cold stage inter-heat switch are closed, and the evaporation chamber heater is assisted; When the target temperature zone is 3K-40K, the thermal switch between the mixing chamber variable temperature cold stage and the mixing chamber refrigerator cold stage, the thermal switch between the intermediate stage variable temperature cold stage and the intermediate stage refrigerator cold stage, and the thermal switch between the evaporation chamber variable temperature cold stage and the evaporation chamber refrigerator cold stage are opened, the thermal switch between the mixing chamber variable temperature cold stage, the thermal switch between the intermediate stage variable temperature cold stage, the thermal switch between the evaporation chamber variable temperature cold stage, the thermal switch between the second stage variable temperature cold stage and the second stage refrigerator cold stage are closed, and the second stage heater is assisted; and / or When the target temperature zone is 40K-300K: In the low temperature zone, the thermal switch between the mixing chamber variable temperature cold stage and the mixing chamber refrigerator cold stage, the thermal switch between the intermediate stage variable temperature cold stage and the intermediate stage refrigerator cold stage, the thermal switch between the evaporation chamber variable temperature cold stage and the evaporation chamber refrigerator cold stage, and the thermal switch between the second stage variable temperature cold stage and the second stage refrigerator cold stage are opened, the thermal switch between the mixing chamber variable temperature cold stage, the thermal switch between the intermediate stage variable temperature cold stage, the thermal switch between the evaporation chamber variable temperature cold stage, the thermal switch between the second stage variable temperature cold stage and the thermal switch between the first stage variable temperature cold stage and the first stage refrigerator cold stage are closed, and the first stage heater or the heater arranged beside the first stage variable temperature cold stage is assisted; In the high temperature zone, the thermal switch between the mixing chamber variable temperature cold stage and the mixing chamber refrigerator cold stage, the thermal switch between the intermediate stage variable temperature cold stage and the intermediate stage refrigerator cold stage, the thermal switch between the evaporation chamber variable temperature cold stage and the evaporation chamber refrigerator cold stage, and the thermal switch between the second stage variable temperature cold stage and the second stage refrigerator cold stage are opened, the thermal switch between the mixing chamber variable temperature cold stage, the thermal switch between the intermediate stage variable temperature cold stage, the thermal switch between the evaporation chamber variable temperature cold stage, the thermal switch between the second stage variable temperature cold stage, the thermal switch between the first stage variable temperature cold stage and the first stage refrigerator cold stage and the thermal switch between the first stage variable temperature cold stage are closed, and the first stage heater or the heater arranged beside the first stage variable temperature cold stage is assisted; preferably, in the high temperature zone, another mechanical refrigerator is also started to prevent the temperature of the first stage variable temperature cold stage from being too high to affect the dilution refrigerator cold stage.

12. The variable temperature regulation method of claim 11, wherein: the temperature of the low temperature zone is 40-80K; and / or the temperature of the high temperature zone is 80-300K.

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