Dilution refrigerating system not limited by gravity

Abstract

The utility model provides a dilution refrigeration system not limited by gravity, and relates to the field of extremely-low-temperature dilution refrigeration. The dilution refrigeration system not limited by gravity comprises a first-stage pre-cooling device, a second-stage pre-cooling device, a capillary type dilution refrigeration device, a liquid pool circulating device, a dilution recovery device and a dilution air inlet device, wherein the first-stage pre-cooling device comprises a vacuum cover, a GM pulse tube refrigerator, a 40K-stage heat exchanger, a 40K-stage cold shield, a transition heat exchanger and a 4K-stage heat exchanger. Compared with a conventional dilution refrigeration system, the dilution refrigeration system not limited by gravity has the advantages that due to the fact that the multistage capillary tube heat exchanger is adopted, surface tension can be used for replacing gravity to fix a concentrated phase interface and a dilute phase interface, and refrigeration temperature is directly transmitted to a hot end component in a capillary tube winding mode and the like; the interference of a zero-gravity or anti-gravity environment on the conventional dilution refrigeration process is avoided from the source, the influence of the vibration of the refrigeration unit on the hot end is favorably reduced, and part of high-precision application occasions with strict requirements on free installation and vibration interference is met.

Description

Technical Field

[0001] This utility model relates to the field of ultra-low temperature dilution refrigeration, and in particular to a dilution refrigeration system that is not limited by gravity. Background Technology

[0002] Dilution refrigerators are a common cooling method in the mK temperature range, widely used in cutting-edge technologies such as quantum computing, condensed matter physics, and deep space exploration due to their significant advantages, including no electromagnetic interference, continuous cooling, and large cooling capacity. Conventional dilution refrigerators rely on gravity to fix the concentrated-reduced phase interface in the mixing chamber to maintain a stable dilution cooling process. This means that conventional dilution refrigerators cannot operate normally in zero gravity or anti-gravity environments. In recent years, high-precision equipment such as deep space superconducting detectors and cryogenic electron microscopes have proposed the requirement for zero gravity or anti-gravity cryogenic operating environments. This necessitates that the development of a new generation of dilution refrigerators must break with convention, find alternative forces to gravity, solve the problem of phase interface fixation, and ensure that their operation and cooling performance are no longer limited by gravity. Utility Model Content

[0003] This invention provides a dilution refrigeration system that is not limited by gravity, thereby solving the problem of existing dilution refrigeration machines being limited by gravity.

[0004] This invention provides a dilution refrigeration system that is not limited by gravity, comprising:

[0005] A primary precooling unit includes a vacuum hood, a GM pulse tube refrigerator, a 40K-stage heat exchanger, a 40K-stage cold shield, a transition heat exchanger, and a 4K-stage heat exchanger. The vacuum hood has a top vacuum flange at its port, through which the GM pulse tube refrigerator passes. The 40K-stage heat exchanger is located inside the vacuum hood and on the outer periphery of the GM pulse tube refrigerator. The 40K-stage cold shield is located inside the vacuum hood, with a 40K-stage flange at its port, through which the GM pulse tube refrigerator passes. Both the transition heat exchanger and the 4K-stage heat exchanger are located inside the 40K-stage cold shield and on the outer periphery of the GM pulse tube refrigerator. The inlet of the transition heat exchanger is connected to the outlet of the 40K-stage heat exchanger, and the outlet of the transition heat exchanger is connected to the inlet of the 4K-stage heat exchanger.

[0006] A secondary precooling device is installed inside the 40K-level cold shield. The secondary heat exchange assembly includes a 4K-level cold shield, a 1K-level heat exchanger, a superfluid helium liquid pool, and a 1K-level cold shield. The port of the 4K-level cold shield is provided with a 4K-level flange, which is connected to the GM pulse tube refrigerator. The 1K-level cold shield, the 1K-level heat exchanger, and the superfluid helium liquid pool are all installed inside the 4K-level cold shield. The port of the 1K-level cold shield is provided with a 1K-level flange. The 1K-level heat exchanger and the superfluid helium liquid pool are both installed on the 1K-level flange. The inlet of the 1K-level heat exchanger is connected to one outlet of the 4K-level heat exchanger, and the inlet of the superfluid helium liquid pool is connected to the other outlet of the 4K-level heat exchanger.

[0007] A capillary dilution refrigeration device is installed inside the 1K-level cold shield. The capillary dilution refrigeration device includes a multi-stage capillary heat exchanger, a mixing chamber, and a cold end platform. The multi-stage capillary heat exchanger and the mixing chamber are connected in series between the outlet of the 1K-level heat exchanger and the inlet of the cold end platform.

[0008] A liquid pool circulation device, wherein the inlet of the liquid pool circulation device is connected to the outlet of the superfluid helium liquid pool through a liquid pool outlet pipe, and the outlet of the liquid pool circulation device is connected to the inlet of the 40K-class heat exchanger;

[0009] A dilution and recovery device, wherein the dilution and recovery device is connected to the cold end platform via a dilution outlet pipe;

[0010] A dilution air inlet device is connected to the inlet of the 40K-class heat exchanger and the dilution recovery device.

[0011] According to the present invention, a dilution refrigeration system not limited by gravity is provided, the dilution refrigeration system further includes:

[0012] A refrigeration unit support frame is provided, which is connected to the GM pulse tube refrigeration unit and is used to support the GM pulse tube refrigeration unit.

[0013] According to the present invention, a dilution refrigeration system not limited by gravity is provided, the dilution refrigeration system further includes:

[0014] A Dewar support frame, which is connected to the top vacuum flange.

[0015] According to the present invention, a dilution refrigeration system that is not limited by gravity is provided, wherein a vibration damping bellows is provided between the GM pulse tube refrigerator and the top vacuum flange, and the vibration damping bellows is used to reduce the vibration between the GM pulse tube refrigerator and the top vacuum flange.

[0016] According to the present invention, a dilution refrigeration system that is not limited by gravity is provided, wherein a heat conduction cable is provided between the GM pulse tube refrigerator and the 40K-grade flange and the 4K-grade flange.

[0017] According to the present invention, a dilution refrigeration system not limited by gravity is provided. The capillary dilution refrigeration device includes a first-stage capillary heat exchanger, a second-stage capillary heat exchanger, and a third-stage capillary heat exchanger. The first-stage capillary heat exchanger, the second-stage capillary heat exchanger, and the third-stage capillary heat exchanger are connected in series between the outlet of the 1K-stage heat exchanger and the inlet of the cold end platform.

[0018] According to the present invention, a dilution refrigeration system not limited by gravity includes a liquid pool circulation device comprising:

[0019] The circulation pipeline has its inlet connected to the outlet of the superfluid helium liquid pool via the liquid pool outlet pipe, and its outlet connected to the inlet of the 40K-class heat exchanger.

[0020] A liquid pool circulation pump is installed in the circulation pipeline;

[0021] The liquid tank is equipped with a gas cylinder, the outlet of which is connected to the circulation pipeline between the liquid tank circulation pump and the 40K-class heat exchanger, and a first control valve is provided at the outlet of the liquid tank.

[0022] According to the present invention, a dilution refrigeration system not limited by gravity is provided, the dilution refrigeration system further includes:

[0023] A Dewar vacuum pump, wherein the inlet of the Dewar vacuum pump is connected to the vacuum hood.

[0024] According to the present invention, a dilution refrigeration system not limited by gravity is provided, wherein the dilution recovery device includes:

[0025] A recovery pipeline is connected to the outlet pipe of the dilution path, and the recovery pipeline is provided with a first vacuum interface, which is used to connect to the inlet of the Dewar vacuum pump.

[0026] A mixed recovery gas tank, which is connected to the recovery pipeline.

[0027] According to the present invention, a dilution refrigeration system that is not limited by gravity is provided, wherein the recovery pipeline is equipped with a dilution circulation pump, and both the outlet and inlet of the dilution circulation pump are equipped with a second control valve.

[0028] The gravity-free dilution refrigeration system provided by this utility model, compared with conventional dilution refrigeration systems, adopts a multi-stage capillary heat exchanger. It can rely on surface tension to fix the concentrated and dilute phase interface instead of gravity, and directly transfer the refrigeration temperature to the hot end component through capillary winding and other methods. It avoids the interference of zero gravity or anti-gravity environment on the conventional dilution refrigeration process from the source, which helps to reduce the impact of refrigeration unit vibration on the hot end and meets the requirements of some high-precision applications with strict requirements for free installation and vibration interference. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the dilution refrigeration system provided by this utility model that is not limited by gravity.

[0031] Figure label:

[0032] 1. GM pulse tube refrigerator; 2. Vibration-damping corrugated pipe; 3. Top vacuum flange; 4. Heat transfer cable; 5. 40K-class cold shield; 6. 4K-class cold shield; 7. 1K-class cold shield; 8. Vacuum enclosure; 9. Dewar support frame; 10. Refrigerator support frame; 11. Superfluid helium liquid pool; 12. 1K-class heat exchanger; 13. First-stage capillary heat exchanger; 14. Second-stage capillary heat exchanger; 15. Third-stage capillary heat exchanger; 16. Mixing chamber; 17. 18. Cold end platform; 19. Liquid pool outlet pipe; 20. 40K class heat exchanger; 21. Dilution path outlet pipe; 22. Transition heat exchanger; 23. 4K class heat exchanger; 24. First flow meter; 25. Second flow meter; 26. 40K class flange; 27. 4K class flange; 28. 1K class flange; 29. ​​Circulation pipeline; 30. Dewar vacuum pump; 31. Liquid pool circulation pump; 32. Dilution circulation pump; 33. Liquid pool gas tank; 3 He gas cylinder; 34. 4 He gas cylinder; 35. 3 36. Main gas tank; 37. Mixed recovery gas tank; 4 38. Main air tank; 39. Recovery pipeline; 40. First control valve; 41. Second control valve; 42. Third control valve; 43. Fourth control valve; 44. Fifth control valve; 45. Sixth control valve; 46. Seventh control valve; 47. Eighth control valve; 48. Ninth control valve; 49. Tenth control valve; 50. First air inlet pipeline; 51. Second air inlet pipeline. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0034] In the description of the embodiments of this utility model, it should be noted that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this utility model. In addition, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0035] In the description of the embodiments of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this utility model based on the specific circumstances.

[0036] In this embodiment of the utility model, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0037] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0038] like Figure 1 As shown, the gravity-free dilution refrigeration system includes a primary precooling unit, a secondary precooling unit, a capillary dilution refrigeration unit, a liquid pool circulation unit, a dilution recovery unit, and a dilution air intake unit. The primary precooling unit includes a vacuum hood 8, a GM pulse tube refrigerator 1, a 40K-level heat exchanger 19, a 40K-level cold shield 5, a transition heat exchanger 21, and a 4K-level heat exchanger 22. The vacuum hood 8 has a top vacuum flange 3 at its port, through which the GM pulse tube refrigerator 1 passes. The 40K-level heat exchanger 19 is located inside the vacuum hood 8. The GM pulse tube refrigerator 1 is located on the outer periphery of the GM pulse tube refrigerator 1. The 40K-level cold shield 5 is located inside the vacuum chamber 8. The port of the 40K-level cold shield 5 is equipped with a 40K-level flange 25. The GM pulse tube refrigerator 1 passes through the 40K-level flange 25. The transition heat exchanger 21 and the 4K-level heat exchanger 22 are both located inside the 40K-level cold shield 5 and on the outer periphery of the GM pulse tube refrigerator 1. The inlet of the transition heat exchanger 21 is connected to the outlet of the 40K-level heat exchanger 19, and the outlet of the transition heat exchanger 21 is connected to the inlet of the 4K-level heat exchanger 22.

[0039] The secondary precooling device is located inside the 40K-level cold shield 5. The secondary heat exchange components include a 4K-level cold shield 6, a 1K-level heat exchanger 12, a superfluid helium liquid pool 11, and a 1K-level cold shield 7. The port of the 4K-level cold shield 6 is equipped with a 4K-level flange 26, which is connected to the GM pulse tube refrigerator 1. The 1K-level cold shield 7, the 1K-level heat exchanger 12, and the superfluid helium liquid pool 11 are all located inside the 4K-level cold shield 6. The port of the 1K-level cold shield 7 is equipped with a 1K-level flange 27. The 1K-level heat exchanger 12 and the superfluid helium liquid pool 11 are both located on the 1K-level flange 27. The inlet of the 1K-level heat exchanger 12 is connected to one outlet of the 4K-level heat exchanger 22, and the inlet of the superfluid helium liquid pool 11 is connected to the other outlet of the 4K-level heat exchanger 22. By adopting a pre-cooling scheme with a 1K superfluid helium liquid pool 11, sufficient pre-cooling capacity is provided for the two dilution working fluids, reducing the interference of heat leakage in the temperature range above 1K on the capillary dilution refrigeration device, which is conducive to obtaining better dilution refrigeration performance, and the structure is simple and reliable.

[0040] The capillary dilution refrigeration device is installed inside the 1K-level cold shield 7. The capillary dilution refrigeration device includes a multi-stage capillary heat exchanger, a mixing chamber 16 and a cold end platform 17. The multi-stage capillary heat exchanger and the mixing chamber 16 are connected in series between the outlet of the 1K-level heat exchanger 12 and the inlet of the cold end platform 17.

[0041] The inlet of the liquid pool circulation device is connected to the outlet of the superfluid helium liquid pool 11 through the liquid pool outlet pipe 18, and the outlet of the liquid pool circulation device is connected to the inlet of the 40K-class heat exchanger 19; the dilution and recovery device is connected to the cold end platform 17 through the dilution outlet pipe 20, and the dilution inlet device is connected to the inlet of the 40K-class heat exchanger 19 and the dilution and recovery device.

[0042] The gravity-free dilution refrigeration system provided by this utility model, compared with conventional dilution refrigeration systems, adopts a multi-stage capillary heat exchanger. It can rely on surface tension to fix the concentrated and dilute phase interface instead of gravity, and directly transfer the refrigeration temperature to the hot end component through capillary winding and other methods. It avoids the interference of zero gravity or anti-gravity environment on the conventional dilution refrigeration process from the source, which helps to reduce the impact of refrigeration unit vibration on the hot end and meets the requirements of some high-precision applications with strict requirements for free installation and vibration interference.

[0043] In one embodiment of this utility model, such as Figure 1 As shown, the dilution refrigeration system also includes a refrigerator support frame 10, which is connected to the GM pulse tube refrigerator 1. The refrigerator support frame 10 is used to support the GM pulse tube refrigerator 1. The refrigerator support frame 10 serves to dampen vibrations, reducing the impact of vibrations generated by the GM pulse tube refrigerator 1 during operation on other components. This is particularly important for high-precision components in the dilution refrigeration system, as these components are highly sensitive to vibration. Reducing vibration can improve the overall performance and reliability of the system.

[0044] In one embodiment of this utility model, such as Figure 1 As shown, the dilution refrigeration system also includes a Dewar support frame 9, which is connected to the top vacuum flange 3. The Dewar support frame 9, through its connection to the top vacuum flange 3, provides stable mechanical support for the entire system. This connection method ensures that the system remains in a fixed position during operation, preventing displacement or shaking caused by external vibrations or internal pressure changes.

[0045] In one embodiment of this utility model, such as Figure 1As shown, a vibration-damping bellows 2 is installed between the GM pulse tube refrigerator 1 and the top vacuum flange 3. The vibration-damping bellows 2 is used to reduce the vibration between the GM pulse tube refrigerator 1 and the top vacuum flange 3. Since the GM pulse tube refrigerator 1 generates vibration during operation, this vibration may be transmitted to the vacuum chamber or other sensitive components through mechanical connections, thereby affecting the system's stability and cooling effect. The vibration-damping bellows 2, as a flexible connector, can effectively isolate and absorb these vibrations, reducing the impact of vibration on the vacuum chamber and other components.

[0046] In one embodiment of this utility model, such as Figure 1 As shown, heat transfer cables 4 are installed between the GM pulse tube chiller 1 and the 40K-class flange 25 and the 4K-class flange 26. The heat transfer cables 4 can efficiently transfer the cooling energy generated by the GM pulse tube chiller 1 to the 40K-class cold shield 5 and the 4K-class cold shield 6. Through the connection of the heat transfer cables 4, the cooling energy can be quickly transferred along the heat conduction path to ensure the cooling efficiency of the system.

[0047] It should be noted that the heat-conducting tape also serves as a flexible connecting material, which can effectively isolate vibration when used with the refrigeration unit support frame 10, and can also form a highly efficient thermal coupling structure to ensure efficient transfer of cold energy and improve refrigeration efficiency.

[0048] In one embodiment of this utility model, such as Figure 1 As shown, the capillary dilution refrigeration device includes a primary capillary heat exchanger 13, a secondary capillary heat exchanger 14, and a tertiary capillary heat exchanger 15. These three stages are connected in series between the outlet of the 1K-stage heat exchanger 12 and the inlet of the cold-end platform 17. Specifically, the inlet of the primary capillary heat exchanger 13 is connected to the outlet of the 1K-stage heat exchanger 12, and the outlet of the tertiary capillary heat exchanger 15 is connected to the inlet of the cold-end platform 17. Of course, the number of multi-stage capillary heat exchangers is not limited to this and can be determined based on actual needs.

[0049] In one embodiment of this utility model, such as Figure 1 As shown, the liquid pool circulation device includes a circulation pipeline 28, a liquid pool circulation pump 30, and a liquid pool gas tank 32. The inlet of the circulation pipeline 28 is connected to the outlet of the superfluid helium liquid pool 11 via a liquid pool gas outlet pipe 18, and the outlet of the circulation pipeline 28 is connected to the inlet of the 40K-class heat exchanger 19. The liquid pool circulation pump 30 is located in the circulation pipeline 28, and the outlet of the liquid pool gas tank 32 is connected to the circulation pipeline 28 between the liquid pool circulation pump 30 and the 40K-class heat exchanger 19. A first control valve 39 is installed at the outlet of the liquid pool gas tank 32.

[0050] It should be noted that the function of the liquid pool circulation pump 30 is not only to provide power for the circulation of the medium, but also to draw a vacuum during the process of evacuating the circulation pipeline 28.

[0051] In one embodiment of this utility model, such as Figure 1 As shown, the dilution refrigeration system also includes a Dewar vacuum pump 29, whose inlet is connected to the vacuum chamber 8. The Dewar vacuum pump 29 is used to evacuate the vacuum chamber 8. Preferably, the inlet of the Dewar vacuum pump 29 is equipped with a third control valve 41. When the third control valve 41 is open, the inlet of the Dewar vacuum pump 29 is connected to the vacuum chamber 8, and the Dewar vacuum pump 29 can be used to evacuate the vacuum chamber 8; when the third control valve 41 is closed, the Dewar vacuum pump 29 is not connected to the vacuum chamber 8.

[0052] In one embodiment of this utility model, such as Figure 1 As shown, the dilution and recovery device includes a recovery pipeline 38 and a mixed recovery gas tank 36. The recovery pipeline 38 is connected to the dilution pipeline outlet pipe 20. The recovery pipeline 38 is provided with a first vacuum interface, which is used to connect to the air inlet of the Dewar vacuum pump 29. The mixed recovery gas tank 36 is connected to the recovery pipeline 38.

[0053] In one embodiment of this utility model, such as Figure 1 As shown, the recovery pipeline 38 is equipped with a dilution circulation pump 31, and both the outlet and inlet of the dilution circulation pump 31 are equipped with second control valves 40. When both second control valves 40 are open, the recovery pipeline 38 is open, and the dilution circulation pump 31 can recover the working fluid in the capillary dilution refrigeration device to the mixed recovery gas tank 36 through the recovery pipeline 38.

[0054] Furthermore, the recovery pipeline 38 between the dilution circulation pump 31 and the mixed recovery gas tank 36 is equipped with two fourth control valves 42, and the first vacuum interface is equipped with a fifth control valve 43. When the two fourth control valves 42 are open, the mixed recovery gas tank 36 is connected to the recovery pipeline 38; when the fifth control valve 43 is connected to the fourth control valve 42 away from the mixed recovery gas tank 36, the first vacuum interface is connected to the recovery pipeline 38. By connecting the first vacuum interface to the air inlet of the Dewar vacuum pump 29, the recovery pipeline 38 can be evacuated.

[0055] In one embodiment of this utility model, such as Figure 1 As shown, the dilution air intake device includes a first air intake pipe 49, a second air intake pipe 50, a first flow meter 23, and a second flow meter 24. 3 He gas cylinder 33, 3 He main gas tank 35, 4 He gas cylinder 34 and 4The main gas tank 37 has one end of the first inlet pipe 49 connected to the inlet of the 40K-class heat exchanger 19, and the other end of the first inlet pipe 49 is connected to... 3 He main gas tank 35 is connected, first flow meter 23 and 3 He gas tank 33 is connected in series with the first inlet pipe 49. One end of the second inlet pipe 50 is connected to the inlet of the 40K-class heat exchanger 19, and the other end of the second inlet pipe 50 is connected to... 4 He main gas tank 37 is connected, second flow meter 24 and 4 He gas cylinder 34 is connected in series with the second air intake pipe 50.

[0056] Furthermore, the first flow meter 23 and 3 Two sixth control valves 44 are provided on the first air inlet pipe 49 between the He gas tank 33 and the gas tank 33. 3 He gas tank 33 and 3 Two sixth control valves 44 are provided on the first air inlet pipe 49 between the main air tank 35 and the main air tank 35.

[0057] Furthermore, the second intake pipe 50 is connected to the first intake pipe 49 and the recovery pipe 38 via the first air passage, and the first air passage is equipped with three seventh control valves 45. Preferably, the first air passage is connected to the first intake pipe 49 via three connecting pipes, and the first air passage is equipped with an eighth control valve 46.

[0058] Furthermore, the second intake pipe 50 is provided with four ninth control valves 47. Preferably, the second intake pipe 50 is provided with a second vacuum interface, and the second vacuum interface is provided with three tenth control valves 48.

[0059] Because it has two air intakes, a first air intake pipe 49 and a second air intake pipe 50, it replaces the conventional... 3 He's single-path air intake design avoids... 4 He working fluid cannot be adjusted when it is stationary or 3 The problem of difficult control in heating and distillation can be solved by directly controlling the flow rate parameters of the working fluid in dilution refrigeration from the ambient temperature side, thereby achieving precise and effective control over the cooling capacity and temperature of dilution refrigeration.

[0060] The working principle of this utility model's dilution refrigeration system, which is not limited by gravity:

[0061] S1. Turn on the Dewar vacuum pump 29 to evacuate the vacuum hood 8, and then connect the air inlet of the Dewar vacuum pump 29 to the first vacuum interface and the second vacuum interface to evacuate the superfluid helium liquid pool 11 and the capillary dilution refrigeration device.

[0062] S2. Turn on the GM pulse tube chiller 1 to reduce the temperature of the 4K-level cold shield 6 and the 4K-level flange 26 to 4K.

[0063] S3. Open the liquid tank gas tank 32 and the liquid tank circulation pump 30 to form a superfluid helium liquid tank 11 circulation, so that the temperature of the superfluid helium liquid tank 11, the 1K-class flange 27 and the 1K-class cold shield 7 drops to below 1.5K;

[0064] S4, Open 3 He gas cylinder 33 and 4 The control valve at the outlet of the gas tank 34 is used to connect the first inlet pipe 49 and the second inlet pipe 50 to the 40K-level heat exchanger 19, so that the dilution working fluid begins to liquefy. After the temperature of the capillary dilution refrigeration device drops to 1.5K, the dilution circulation pump 31 is controlled to work, and the dilution refrigeration process that is not limited by gravity is started, so that the temperature of the mixing chamber 16 drops to 100mK.

[0065] S5. Open the second control valve 40 and the fourth control valve 42 so that the mixed recovery gas tank 36 can recover the diluted working fluid.

[0066] The recovered working fluid is separated by a specially designed helium separation system to prepare raw materials for the next dilution operation.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model.

Claims

1. A dilution refrigeration system not limited by gravity, characterized in that, The application relates to a GM pulse tube cryogenic cooling device, which comprises a primary pre-cooling device, a secondary pre-cooling device, a capillary type dilution refrigeration device, a liquid pool circulating device, a dilution recovery device and a dilution gas inlet device. The primary pre-cooling device comprises a vacuum cover (8), a GM pulse tube refrigerator (1), a 40K-stage heat exchanger (19), a 40K-stage cold shield (5), a transition heat exchanger (21) and a 4K-stage heat exchanger (22), the port of the vacuum cover (8) is provided with a top vacuum flange (3), the GM pulse tube refrigerator (1) penetrates through the top vacuum flange (3), the 40K-stage heat exchanger (19) is located inside the vacuum cover (8) and at the outer periphery of the GM pulse tube refrigerator (1); the 40K-stage cold shield (5) is arranged inside the vacuum cover (8), the port of the 40K-stage cold shield (5) is provided with a 40K-stage flange (25), the GM pulse tube refrigerator (1) penetrates through the 40K-stage flange (25), the transition heat exchanger (21) and the 4K-stage heat exchanger (22) are both arranged inside the 40K-stage cold shield (5) and at the outer periphery of the GM pulse tube refrigerator (1), the inlet of the transition heat exchanger (21) is communicated with the outlet of the 40K-stage heat exchanger (19), and the outlet of the transition heat exchanger (21) is communicated with the inlet of the 4K-stage heat exchanger (22); The secondary pre-cooling device is arranged inside the 40K-stage cold shield (5) and comprises a 4K-stage cold shield (6), a 1K-stage heat exchanger (12), a superfluid helium liquid pool (11) and a 1K-stage cold shield (7), the port of the 4K-stage cold shield (6) is provided with a 4K-stage flange (26), the 4K-stage flange (26) is connected with the GM pulse tube refrigerator (1), the 1K-stage cold shield (7), the 1K-stage heat exchanger (12) and the superfluid helium liquid pool (11) are all arranged inside the 4K-stage cold shield (6), the port of the 1K-stage cold shield (7) is provided with a 1K-stage flange (27), the 1K-stage heat exchanger (12) and the superfluid helium liquid pool (11) are both arranged in the 1K-stage flange (27), the inlet of the 1K-stage heat exchanger (12) is communicated with one outlet of the 4K-stage heat exchanger (22), and the inlet of the superfluid helium liquid pool (11) is communicated with the other outlet of the 4K-stage heat exchanger (22); The capillary type dilution refrigeration device is arranged inside the 1K-stage cold shield (7) and comprises a multi-stage capillary heat exchanger, a mixing chamber (16) and a cold end platform (17), the multi-stage capillary heat exchanger and the mixing chamber (16) are sequentially connected between the outlet of the 1K-stage heat exchanger (12) and the inlet of the cold end platform (17); The liquid pool circulating device is communicated with the outlet of the superfluid helium liquid pool (11) through a liquid pool gas outlet pipe (18), and the outlet of the liquid pool circulating device is communicated with the inlet of the 40K-stage heat exchanger (19); The dilution recovery device is communicated with the cold end platform (17) through a dilution path gas outlet pipe (20); The dilution gas inlet device is communicated with the inlet of the 40K-stage heat exchanger (19) and the dilution recovery device.

2. The gravity-unbounded dilution refrigerator system of claim 1, wherein, The dilution refrigeration system further comprises: A cryocooler support frame (10) connected with the GM pulse tube cryocooler (1), the cryocooler support frame (10) being used for supporting the GM pulse tube cryocooler (1).

3. The gravity-unbounded dilution refrigerator system of claim 1, wherein, The dilution refrigeration system further comprises: A dewar support frame (9) connected with the top-end vacuum flange (3).

4. The gravity-unbounded dilution refrigerator system of claim 1, wherein, A damping bellows (2) is arranged between the GM pulse tube cryocooler (1) and the top-end vacuum flange (3), the damping bellows (2) being used for reducing vibration between the GM pulse tube cryocooler (1) and the top-end vacuum flange (3).

5. The gravity-unbounded dilution refrigerator system of any one of claims 1 to 4, wherein, A heat-conducting band (4) is arranged between the GM pulse tube cryocooler (1) and the 40K-stage flange (25) and the 4K-stage flange (26).

6. The gravity-unbounded dilution refrigerator system of any one of claims 1 to 4, wherein, The capillary dilution refrigeration device comprises a first-stage capillary heat exchanger, a second-stage capillary heat exchanger (14) and a third-stage capillary heat exchanger (15), which are sequentially connected between the outlet of the 1K-stage heat exchanger (12) and the inlet of the cold-end platform (17).

7. The gravity-unbounded dilution refrigerator system of any one of claims 1 to 4, wherein, The liquid pool circulation device comprises: A liquid pool circulation pipeline (28), the inlet of the circulation pipeline (28) being communicated with the outlet of the superfluid helium liquid pool (11) through the liquid pool gas outlet pipeline (18), and the outlet of the circulation pipeline (28) being communicated with the inlet of the 40K-stage heat exchanger (19); A liquid pool circulation pump (30) arranged in the circulation pipeline (28); A liquid pool gas tank (32), the outlet of the liquid pool gas tank (32) being communicated with the circulation pipeline (28) between the liquid pool circulation pump (30) and the 40K-stage heat exchanger (19), and the outlet of the liquid pool gas tank (32) being provided with a first control valve.

8. The gravity-unbounded dilution refrigerator system of any one of claims 1 to 4, wherein, The dilution refrigeration system further comprises: A dewar vacuum pump (29), the gas inlet of the dewar vacuum pump (29) being communicated with the vacuum cover (8).

9. The gravity-unbounded dilution refrigerator system of claim 8, wherein, The dilution recycling device comprises: A recycling pipeline (38) communicated with the dilution gas outlet pipeline (20), the recycling pipeline (38) being provided with a first vacuum interface for being communicated with the gas inlet of the dewar vacuum pump (29); A mixed recycling gas tank (36) communicated with the recycling pipeline (38).

10. The gravity-unbounded dilution refrigerator system of claim 9, wherein, The recycling pipeline (38) is provided with a dilution circulation pump (31), and the outlet and the inlet of the dilution circulation pump (31) are both provided with a second control valve.

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