Dilution refrigerating system not limited by gravity

Abstract

The invention 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] The invention relates to the field of ultra-low temperature dilution refrigeration, and in particular to a dilution refrigeration system not restricted by gravity. Background Art

[0002] Dilution refrigerator is a commonly used refrigeration method in the mK temperature range. It is widely used in cutting-edge scientific and technological fields such as quantum computing, condensed matter physics and deep space exploration due to its significant advantages such as no electromagnetic interference, continuous refrigeration and large refrigeration capacity. Conventional dilution refrigerators rely on gravity to fix the concentrated and dilute phase interfaces in the mixing chamber to maintain a stable dilution refrigeration process, which also results in the inability of conventional dilution refrigerators to operate normally in zero gravity or anti-gravity environments. In recent years, high-precision equipment such as deep space superconducting detectors and ultra-low temperature electron microscopes have proposed requirements for extremely low-temperature working environments with zero gravity or anti-gravity. This requires that the development of a new generation of dilution refrigerators must break through conventions, find alternatives to gravity, and solve the problem of phase interface fixation. Their operating processes and refrigeration performance are no longer limited by gravity. Summary of the invention

[0003] The invention provides a dilution refrigeration system which is not limited by gravity, so as to solve the problem that the existing dilution refrigerator is limited by gravity.

[0004] The present invention provides a dilution refrigeration system not limited by gravity, comprising: A primary precooling device, comprising a vacuum hood, a GM pulse tube refrigerator, a 40K-class heat exchanger, a 40K-class cold shield, a transition heat exchanger and a 4K-class heat exchanger, wherein the port of the vacuum hood is provided with a top vacuum flange, the GM pulse tube refrigerator penetrates the top vacuum flange, the 40K-class heat exchanger is located inside the vacuum hood and located at the periphery of the GM pulse tube refrigerator; the 40K-class cold shield is provided inside the vacuum hood, the port of the 40K-class cold shield is provided with a 40K-class flange, the GM pulse tube refrigerator penetrates the 40K-class flange, the transition heat exchanger and the 4K-class heat exchanger are both provided inside the 40K-class cold shield and located at the periphery of the GM pulse tube refrigerator, the inlet of the transition heat exchanger is communicated with the outlet of the 40K-class heat exchanger, and the outlet of the transition heat exchanger is communicated with the inlet of the 4K-class heat exchanger; A secondary precooling device is arranged inside the 40K-class cold screen, the secondary heat exchange assembly includes a 4K-class cold screen, a 1K-class heat exchanger, a superfluid helium liquid pool and a 1K-class cold screen, the port of the 4K-class cold screen is provided with a 4K-class flange, the 4K-class flange is connected to the GM pulse tube refrigerator, the 1K-class cold screen, the 1K-class heat exchanger and the superfluid helium liquid pool are all arranged inside the 4K-class cold screen, the port of the 1K-class cold screen is provided with a 1K-class flange, the 1K-class heat exchanger and the superfluid helium liquid pool are both arranged on the 1K-class flange, the inlet of the 1K-class heat exchanger is communicated with one outlet of the 4K-class heat exchanger, and the inlet of the superfluid helium liquid pool is communicated with another outlet of the 4K-class heat exchanger; A capillary dilution refrigeration device is arranged inside the 1K-level cold screen, and the capillary dilution refrigeration device comprises a multi-stage capillary heat exchanger, a mixing chamber and a cold end platform, and the multi-stage capillary heat exchanger and the mixing chamber are sequentially connected in series between the outlet of the 1K-level heat exchanger and the inlet of the cold end platform; 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; A dilution recovery device, the dilution recovery device is connected to the cold end platform through a dilution path outlet pipe; A dilution air intake device is connected to the inlet of the 40K-level heat exchanger and the dilution recovery device.

[0005] According to a dilution refrigeration system not limited by gravity provided by the present invention, the dilution refrigeration system further comprises: A refrigerator support frame, wherein the refrigerator support frame is connected to the GM pulse tube refrigerator, and the refrigerator support frame is used to support the GM pulse tube refrigerator.

[0006] According to a dilution refrigeration system not limited by gravity provided by the present invention, the dilution refrigeration system further comprises: A Dewar support frame is connected to the top vacuum flange.

[0007] According to a dilution refrigeration system not restricted by gravity provided by the present invention, a vibration-damping bellows is arranged 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.

[0008] According to a dilution refrigeration system not limited by gravity provided by the present invention, heat conducting belts are arranged between the GM pulse tube refrigerator and the 40K grade flange and the 4K grade flange.

[0009] According to a dilution refrigeration system not restricted by gravity provided by the present invention, 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, and the first-stage capillary heat exchanger, the second-stage capillary heat exchanger and the third-stage capillary heat exchanger are connected in series in sequence between the outlet of the 1K-stage heat exchanger and the inlet of the cold end platform.

[0010] According to a dilution refrigeration system not limited by gravity provided by the present invention, the liquid pool circulation device comprises: A circulation pipeline, wherein the inlet of the circulation pipeline is connected to the outlet of the superfluid helium liquid pool through the liquid pool outlet pipe, and the outlet of the circulation pipeline is connected to the inlet of the 40K-class heat exchanger; A liquid pool circulation pump, wherein the liquid pool circulation pump is arranged in the circulation pipeline; A liquid pool gas tank, the outlet of which is connected to the circulation pipeline between the liquid pool circulation pump and the 40K-grade heat exchanger, and the outlet of the liquid pool gas tank is provided with a first control valve.

[0011] According to a dilution refrigeration system not limited by gravity provided by the present invention, the dilution refrigeration system further comprises: A Dewar vacuum pump, wherein the air inlet of the Dewar vacuum pump is communicated with the vacuum cover.

[0012] According to a dilution refrigeration system not limited by gravity provided by the present invention, the dilution recovery device comprises: A recovery pipeline, the recovery pipeline is connected to the dilution line outlet pipe, the recovery pipeline is provided with a first vacuum interface, and the first vacuum interface is used to communicate with the air inlet of the Dewar vacuum pump; A mixed recovery gas tank is connected to the recovery pipeline.

[0013] According to a dilution refrigeration system not restricted by gravity provided by the present invention, the recovery pipeline is provided with a dilution circulation pump, and the outlet and the inlet of the dilution circulation pump are both provided with a second control valve.

[0014] The dilution refrigeration system not restricted by gravity provided by the present invention is compared with the conventional dilution refrigeration system. The dilution refrigeration system not restricted by gravity provided by the present invention adopts a multi-stage capillary heat exchanger, which can rely on surface tension instead of gravity to fix the concentrated and dilute phase interfaces, and directly transmit the refrigeration temperature to the hot end components by means of capillary winding, etc., thereby avoiding the interference of zero gravity or anti-gravity environment to the conventional dilution refrigeration process from the source, which is beneficial to reducing the impact of the vibration of the refrigeration unit on the hot end, and meeting some high-precision applications with strict requirements on free installation and vibration interference. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a structural schematic diagram of a dilution refrigeration system not restricted by gravity provided by the present invention.

[0017] Reference numerals: 1. GM pulse tube refrigerator; 2. Vibration-damping bellows; 3. Top vacuum flange; 4. Conductive belt; 5. 40K-class cold shield; 6. 4K-class cold shield; 7. 1K-class cold shield; 8. Vacuum cover; 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 , cold end platform; 18, liquid pool outlet pipe; 19, 40K class heat exchanger; 20, dilution line outlet pipe; 21, transition heat exchanger; 22, 4K class heat exchanger; 23, first flow meter; 24, second flow meter; 25, 40K class flange; 26, 4K class flange; 27, 1K class flange; 28, circulation pipeline; 29, Dewar vacuum pump; 30, liquid pool circulation pump; 31, dilution circulation pump; 32, liquid pool gas tank; 33, 3 He gas tank; 34. 4 He gas tank; 35. 3 He total gas tank; 36, mixed recovery gas tank; 37, 4 He main gas tank; 38, recovery pipeline; 39, first control valve; 40, second control valve; 41, third control valve; 42, fourth control valve; 43, fifth control valve; 44, sixth control valve; 45, seventh control valve; 46, eighth control valve; 47, ninth control valve; 48, tenth control valve; 49, first intake pipeline; 50, second intake pipeline. DETAILED DESCRIPTION

[0018] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0019] In the description of the embodiments of the present invention, it should be noted that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limitations on the embodiments of the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0020] In the description of the embodiments of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "connected" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the embodiments of the present invention can be understood according to specific circumstances.

[0021] In the embodiments of the present invention, unless otherwise clearly specified and limited, the first feature being "above" or "below" the second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature being "above", "above" and "above" the second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. The first feature being "below", "below" and "below" the second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0022] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiment of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0023] like Figure 1As shown, the dilution refrigeration system not limited by gravity includes a primary precooling device, a secondary precooling device, a capillary dilution refrigeration device, a liquid pool circulation device, a dilution recovery device and a dilution air intake device. The primary precooling device includes a vacuum cover 8, a GM pulse tube refrigerator 1, a 40K-class heat exchanger 19, a 40K-class cold screen 5, a transition heat exchanger 21 and a 4K-class heat exchanger 22. The port of the vacuum cover 8 is provided with a top vacuum flange 3. The GM pulse tube refrigerator 1 passes through the top vacuum flange 3. The 40K-class heat exchanger 19 is located inside the vacuum cover 8. The 40K-class cold shield 5 is arranged inside the vacuum cover 8, and the port of the 40K-class cold shield 5 is provided with a 40K-class flange 25, and the GM pulse tube refrigerator 1 passes through the 40K-class flange 25. The transition heat exchanger 21 and the 4K-class heat exchanger 22 are both arranged inside the 40K-class cold shield 5 and located on the periphery of the GM pulse tube refrigerator 1, and the inlet of the transition heat exchanger 21 is connected with the outlet of the 40K-class heat exchanger 19, and the outlet of the transition heat exchanger 21 is connected with the inlet of the 4K-class heat exchanger 22.

[0024] The secondary precooling device is arranged inside the 40K-level cold shield 5, and the secondary heat exchange component includes 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 provided with a 4K-level flange 26, and the 4K-level flange 26 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 arranged inside the 4K-level cold shield 6. The port of the 1K-level cold shield 7 is provided with a 1K-level flange 27. The 1K-level heat exchanger 12 and the superfluid helium liquid pool 11 are both arranged 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 the precooling scheme of the 1K superfluid helium liquid pool 11, sufficient precooling capacity is provided for the two-way dilution working fluid, reducing the interference of heat leakage in the temperature zone above 1K on the capillary dilution refrigeration device, which is conducive to obtaining better dilution refrigeration performance and has a simple and reliable structure.

[0025] The capillary dilution refrigeration device is arranged inside the 1K-class cold shield 7, and the capillary dilution refrigeration device comprises a multi-stage capillary heat exchanger, a mixing chamber 16 and a cold end platform 17, and the multi-stage capillary heat exchanger and the mixing chamber 16 are sequentially connected in series between the outlet of the 1K-class heat exchanger 12 and the inlet of the cold end platform 17; 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 recovery device is connected to the cold end platform 17 through the dilution path outlet pipe 20, and the dilution air intake device is connected to the inlet of the 40K-class heat exchanger 19 and the dilution recovery device.

[0026] The dilution refrigeration system not restricted by gravity provided by the present invention is compared with the conventional dilution refrigeration system. The dilution refrigeration system not restricted by gravity provided by the present invention adopts a multi-stage capillary heat exchanger, which can rely on surface tension instead of gravity to fix the concentrated and dilute phase interfaces, and directly transmit the refrigeration temperature to the hot end components by means of capillary winding, etc., thereby avoiding the interference of zero gravity or anti-gravity environment to the conventional dilution refrigeration process from the source, which is beneficial to reducing the impact of the vibration of the refrigeration unit on the hot end, and meeting some high-precision applications with strict requirements on free installation and vibration interference.

[0027] In one embodiment of the present invention, Figure 1 As shown, the dilution refrigeration system further includes a refrigerator support frame 10, which is connected to the GM pulse tube refrigerator 1 and is used to support the GM pulse tube refrigerator 1. The refrigerator support frame 10 can play a shock-absorbing role, reducing the impact of the vibration generated by the GM pulse tube refrigerator 1 during operation on other components, which is particularly important for high-precision components in the dilution refrigeration system because these components are very sensitive to vibration. By reducing vibration, the overall performance and reliability of the system can be improved.

[0028] In one embodiment of the present invention, Figure 1 As shown, the dilution refrigeration system further includes a Dewar support frame 9, which is connected to the top vacuum flange 3. The Dewar support frame 9 provides stable mechanical support for the entire system by being connected to the top vacuum flange 3. This connection method can ensure that the system remains in a fixed position during operation to prevent displacement or shaking caused by external vibration or internal pressure changes.

[0029] In one embodiment of the present invention, Figure 1 As shown, a vibration-damping bellows 2 is provided between the GM pulse tube refrigerator 1 and the top vacuum flange 3, and 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 vibrations during operation, such vibrations may be transmitted to the vacuum chamber or other sensitive components through mechanical connections, thereby affecting the stability and refrigeration effect of the system. As a flexible connector, the vibration-damping bellows 2 can effectively isolate and absorb these vibrations and reduce the impact of vibrations on the vacuum chamber and other components.

[0030] In one embodiment of the present invention, Figure 1 As shown, a heat conducting belt 4 is provided between the GM pulse tube refrigerator 1 and the 40K grade flange 25 and the 4K grade flange 26. The heat conducting belt 4 can efficiently conduct the cold energy generated by the GM pulse tube refrigerator 1 to the 40K grade cold shield 5 and the 4K grade cold shield 6. Through the connection of the heat conducting belt 4, the cold energy can be quickly transferred along the heat conduction path, thereby ensuring the cooling efficiency of the system.

[0031] It should be noted here that the heat conductive tape also serves as a flexible connecting material, which can cooperate with the refrigerator support frame 10 to effectively isolate vibration and form an efficient thermal coupling structure to ensure efficient transmission of cold and improve refrigeration efficiency.

[0032] In one embodiment of the present invention, Figure 1 As shown, the capillary dilution refrigeration device includes a first-stage capillary heat exchanger 13, a second-stage capillary heat exchanger 14 and a third-stage capillary heat exchanger 15, which are sequentially connected in series between the outlet of the 1K-stage heat exchanger 12 and the inlet of the cold end platform 17, that is, the inlet of the first-stage capillary heat exchanger 13 is connected to the outlet of the 1K-stage heat exchanger 12, and the outlet of the third-stage 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 thereto, and is determined according to actual needs.

[0033] In one embodiment of the present invention, 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 through the 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 arranged on 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. The outlet of the liquid pool gas tank 32 is arranged with a first control valve 39.

[0034] 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 perform a vacuuming function during the process of hollowing out the circulation pipeline 28 .

[0035] In one embodiment of the present invention, Figure 1 As shown, the dilution refrigeration system further includes a Dewar vacuum pump 29, the air inlet of the Dewar vacuum pump 29 is connected to the vacuum cover 8, and the Dewar vacuum pump 29 is used to evacuate the vacuum cover 8. Preferably, the air inlet of the Dewar vacuum pump 29 is provided with a third control valve 41. When the third control valve 41 is opened, the air inlet of the Dewar vacuum pump 29 is connected to the vacuum cover 8, and the vacuum cover 8 can be evacuated by the Dewar vacuum pump 29; when the third control valve 41 is closed, the Dewar vacuum pump 29 and the vacuum cover 8 are not connected.

[0036] In one embodiment of the present invention, Figure 1As shown, the dilution recovery device includes a recovery pipeline 38 and a mixed recovery gas tank 36. The recovery pipeline 38 is connected to the dilution path outlet pipe 20. The recovery pipeline 38 is provided with a first vacuum interface, which is used to be connected to the air inlet of the Dewar vacuum pump 29. The mixed recovery gas tank 36 is connected to the recovery pipeline 38.

[0037] In one embodiment of the present invention, Figure 1 As shown, the recovery pipeline 38 is provided with a dilution circulation pump 31, and the outlet and inlet of the dilution circulation pump 31 are both provided with a second control valve 40. When the two second control valves 40 are opened, the recovery pipeline 38 is connected, and the dilution circulation pump 31 can recover the working medium in the capillary dilution refrigeration device to the mixed recovery gas tank 36 through the recovery pipeline 38.

[0038] Furthermore, the recovery pipeline 38 between the dilution circulation pump 31 and the mixed recovery gas tank 36 is provided with two fourth control valves 42, and the first vacuum interface is provided with a fifth control valve 43. When the two fourth control valves 42 are opened, 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 far 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.

[0039] In one embodiment of the present invention, Figure 1 As shown, the dilution intake device includes a first intake pipeline 49, a second intake pipeline 50, a first flow meter 23, a second flow meter 24, 3 He gas tank 33, 3 He gas tank 35, 4 He gas tank 34 and 4 He main gas tank 37, one end of the first air intake pipeline 49 is connected to the inlet of the 40K-level heat exchanger 19, and the other end of the first air intake pipeline 49 is connected to the 3 The He main gas tank 35 is connected, and the first flow meter 23 and 3 The He gas tank 33 is connected in series to the first air intake pipeline 49. One end of the second air intake pipeline 50 is connected to the inlet of the 40K-class heat exchanger 19, and the other end of the second air intake pipeline 50 is connected to the 4 The He main gas tank 37 is connected, and the second flow meter 24 and 4 The He gas tank 34 is connected in series to the second air intake pipeline 50 .

[0040] Furthermore, the first flow meter 23 and 3 The first air intake pipeline 49 between the He gas tanks 33 is provided with two sixth control valves 44. 3 He gas tank 33 and 3 The first air intake line 49 between the He main gas tanks 35 is provided with two sixth control valves 44 .

[0041] Further, the second air intake line 50 is connected to the first air intake line 49 and the recovery line 38 through the first air line, and the first air line is provided with three seventh control valves 45. Preferably, the first air line is connected to the first air intake line 49 through three connecting lines, and the first air line is provided with an eighth control valve 46.

[0042] Further, the second air intake pipeline 50 is provided with four ninth control valves 47. Preferably, the second air intake pipeline 50 is provided with a second vacuum interface, and the second vacuum interface is provided with three tenth control valves 48.

[0043] Since the first air intake line 49 and the second air intake line 50 are provided, the conventional 3 He single-channel air intake solution avoids 4 He working fluid is not adjustable or 3 The problem of He heating distillation being difficult to control can be solved by directly controlling the working fluid flow parameters of dilution refrigeration from the room temperature side, thereby achieving precise and effective control of dilution refrigeration cooling capacity, temperature and other performance.

[0044] The working principle of the gravity-free dilution refrigeration system of the present invention is as follows: S1, start the Dewar vacuum pump 29 to evacuate the vacuum cover 8, then connect the air inlet of the Dewar vacuum pump 29 to the first vacuum interface and the second vacuum interface, and evacuate the superfluid helium liquid pool 11 and the capillary dilution refrigeration device; S2, start the GM pulse tube refrigerator 1 to reduce the temperature of the 4K-level cold shield 6 and the 4K-level flange 26 to 4K; S3, opening the liquid pool gas tank 32 and the liquid pool circulation pump 30, forming a circulation of the superfluid helium liquid pool 11, so that the temperature of the superfluid helium liquid pool 11, the 1K-level flange 27 and the 1K-level cold shield 7 drops to below 1.5K; S4. Open 3 He gas tank 33 and 4 The control valve at the gas outlet of the He gas tank 34 is used to connect the first gas inlet pipeline 49 and the second gas inlet pipeline 50 to the 40K-class heat exchanger 19, and the dilution medium begins to liquefy. After the temperature of the capillary dilution refrigeration device drops to 1.5K as a whole, the dilution circulation pump 31 is controlled to work, and the dilution refrigeration process not restricted by gravity is started, and finally the temperature of the mixing chamber 16 drops to 100mK; S5. Open the second control valve 40 and the fourth control valve 42 to allow the mixed recovery gas tank 36 to recover the diluted working fluid.

[0045] The recovered working fluid is sent to a special helium separation system for separation to prepare raw materials for the next dilution operation.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A dilution refrigeration system not limited by gravity, characterized in that: include: A primary precooling device comprises a vacuum cover (8), a GM pulse tube refrigerator (1), a 40K-class heat exchanger (19), a 40K-class cold shield (5), a transition heat exchanger (21) and a 4K-class heat exchanger (22), wherein a top vacuum flange (3) is provided at a port of the vacuum cover (8), the GM pulse tube refrigerator (1) passes through the top vacuum flange (3), the 40K-class heat exchanger (19) is located inside the vacuum cover (8) and at the periphery of the GM pulse tube refrigerator (1); the 40K-class cold shield (5) is provided on the vacuum cover (8) ), the port of the 40K-class cold shield (5) is provided with a 40K-class flange (25), the GM pulse tube refrigerator (1) passes through the 40K-class flange (25), the transition heat exchanger (21) and the 4K-class heat exchanger (22) are both arranged inside the 40K-class cold shield (5) and located on the periphery of the GM pulse tube refrigerator (1), the inlet of the transition heat exchanger (21) is communicated with the outlet of the 40K-class heat exchanger (19), and the outlet of the transition heat exchanger (21) is communicated with the inlet of the 4K-class heat exchanger (22); A secondary precooling device is arranged inside the 40K-class cold shield (5), the secondary heat exchange component comprises a 4K-class cold shield (6), a 1K-class heat exchanger (12), a superfluid helium liquid pool (11) and a 1K-class cold shield (7), the port of the 4K-class cold shield (6) is provided with a 4K-class flange (26), the 4K-class flange (26) is connected to the GM pulse tube refrigerator (1), the 1K-class cold shield (7), the 1K-class heat exchanger (12) and the superfluid helium liquid pool (11) are both arranged inside the 4K-class cold shield (6), the port of the 1K-class cold shield (7) is provided with a 1K-class flange (27), the 1K-class heat exchanger (12) and the superfluid helium liquid pool (11) are both arranged on the 1K-class flange (27), the inlet of the 1K-class heat exchanger (12) is connected to one outlet of the 4K-class heat exchanger (22), and the inlet of the superfluid helium liquid pool (11) is connected to the other outlet of the 4K-class heat exchanger (22); A capillary dilution refrigeration device is arranged inside the 1K-class cold shield (7), the capillary dilution refrigeration device comprising 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) being connected in series between the outlet of the 1K-class heat exchanger (12) and the inlet of the cold end platform (17); 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 (11) through a 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); A dilution recovery device, the dilution recovery device being connected to the cold end platform (17) via a dilution path air outlet pipe (20); A dilution air intake device, the dilution air intake device is connected to the inlet of the 40K-level heat exchanger (19) and the dilution recovery device.

2. The gravity-independent dilution refrigeration system according to claim 1, characterized in that: The dilution refrigeration system further comprises: A refrigerator support frame (10), the refrigerator support frame (10) being connected to the GM pulse tube refrigerator (1), and the refrigerator support frame (10) being used to support the GM pulse tube refrigerator (1).

3. The gravity-independent dilution refrigeration system according to claim 1, characterized in that: The dilution refrigeration system further comprises: A Dewar support frame (9), wherein the Dewar support frame (9) is connected to the top vacuum flange (3).

4. The gravity-independent dilution refrigeration system according to claim 1, characterized in that: A vibration-damping bellows (2) is provided between the GM pulse tube refrigerator (1) and the top vacuum flange (3), and the vibration-damping bellows (2) is used to reduce vibration between the GM pulse tube refrigerator (1) and the top vacuum flange (3).

5. The gravity-independent dilution refrigeration system according to any one of claims 1 to 4, characterized in that: A heat conducting belt (4) is provided between the GM pulse tube refrigerator (1) and the 40K-class flange (25) and the 4K-class flange (26).

6. The gravity-independent dilution refrigeration system according to any one of claims 1 to 4, characterized in that: 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), wherein the first-stage capillary heat exchanger, the second-stage capillary heat exchanger (14) and the third-stage capillary heat exchanger (15) are connected in series in sequence between the outlet of the 1K-stage heat exchanger (12) and the inlet of the cold end platform (17).

7. The gravity-independent dilution refrigeration system according to any one of claims 1 to 4, characterized in that: The liquid pool circulation device comprises: A liquid pool circulation pipeline (28), wherein the inlet of the circulation pipeline (28) is connected to the outlet of the superfluid helium liquid pool (11) through the 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); A liquid pool circulation pump (30), the liquid pool circulation pump (30) being arranged in the circulation pipeline (28); A liquid pool gas tank (32), wherein an 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), and a first control valve is provided at the outlet of the liquid pool gas tank (32).

8. The gravity-independent dilution refrigeration system according to any one of claims 1 to 4, characterized in that: The dilution refrigeration system further comprises: A Dewar vacuum pump (29), wherein an air inlet of the Dewar vacuum pump (29) is in communication with the vacuum cover (8).

9. The gravity-independent dilution refrigeration system according to claim 8, characterized in that: The dilution recovery device comprises: A recovery pipeline (38), the recovery pipeline (38) being in communication with the dilution path air outlet pipe (20), the recovery pipeline (38) being provided with a first vacuum interface, the first vacuum interface being used to communicate with an air inlet of the Dewar vacuum pump (29); A mixed recovery gas tank (36), the mixed recovery gas tank (36) being in communication with the recovery pipeline (38).

10. The gravity-independent dilution refrigeration system according to claim 8, characterized in that: The recovery pipeline (38) is provided with a dilution circulation pump (31), and the outlet and inlet of the dilution circulation pump (31) are both provided with a second control valve.

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