Gas heat sink and dilution refrigerator

Abstract

The present invention provides a gas heat sink and a dilution refrigerator, relating to the technical fields of heat exchange and dilution refrigerators. The gas heat sink includes a housing, a plurality of flow guide plates and a plurality of partition plates. Opposite ends of the housing are provided with an input port and an output port communicating with the outside. The plurality of flow guide plates are arranged in the housing at intervals along the height direction of the housing, and a plurality of through grooves extending along the length direction of the housing are formed in the flow guide plates. Each flow guide plate is clamped between two adjacent partition plates, and is adapted to enclose the middle part of the through groove to form a first flow channel. The side wall of the partition plate facing the input port and the flow guide plate define a second flow channel communicating with the input port, and the first flow channel and the second flow channel are communicated. Wherein, the second flow channel is configured to guide the gas input from the input port to enter the plurality of first flow channels through multiple diffusions along the height direction of the housing, and the housing is configured to exchange heat with the gas through the flow guide plates and the partition plates and transfer the heat to an external cold source.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchange and dilution refrigerators, and more specifically, to a gas heat sink and a dilution refrigerator. Background Art

[0002] A dilution refrigerator is a refrigeration device that utilizes the phase separation characteristics of a helium-3 and helium-4 mixture to achieve extremely low temperatures (usually below 100 mK). Its core principle is based on the property that the solubility of helium-3 ( 3 ³He) in helium-4 ( 4 ⁴He) decreases as the temperature decreases. In a dilution refrigerator, 3 ³He- 4 ⁴He mixture is placed in a closed circulation system. The system generally includes key components such as a mixing chamber, a still, a condenser, a heat exchanger, etc. When the temperature of the mixture drops below about 0.87 K, 3 ³He and 4 ⁴He will undergo phase separation to form a concentrated phase with a higher ³He concentration and a dilute phase with a lower ³He concentration. Since the chemical potential of ³He atoms in the dilute phase is higher than that in the concentrated phase, ³He atoms will cross the phase interface from the concentrated phase into the dilute phase, and this process requires heat absorption, thereby achieving a refrigeration effect.

[0003] To maintain continuous refrigeration, the dilution refrigerator extracts the 3 ³He atoms that enter the dilute phase through distillation and other means, and recycles them back to the mixing chamber to form a continuous refrigeration cycle. By optimizing the design and operating conditions, the dilution refrigerator can achieve an extremely low temperature environment as low as a few millikelvins. Due to its advantages such as high efficiency, stability, and no vibration, the dilution refrigerator is widely used in cryogenic experimental research in fields such as condensed matter physics, quantum computing, and astrophysics. In recent years, with the rapid development of quantum information science, the dilution refrigerator, as a key device for achieving and maintaining the extremely low temperature environment required for superconducting circuits of quantum bits, has received increasing attention and research.

[0004] However, the performance of the dilution refrigerator is affected by many factors, and heat leakage is one of the main factors. Heat leakage mainly comes from solid conduction, gas conduction, and thermal radiation, etc. During the operation of the dilution refrigerator, 3 ³He vapor is pumped out and is in a room temperature environment. Even after throttling and cooling, it will have a significant impact on the temperature of the mixing chamber. In related technologies, usually after 3 ³He vapor is liquefied, multi-stage continuous heat exchange is performed on this part of the 3 ³He solution. However, currently, the amount of heat leakage reduced by this method is limited by the heat exchanger structure and the heat exchange position, and it is difficult to continue to increase. Therefore, how to further reduce the heat leakage of the dilution refrigerator has become an urgent technical problem to be solved. Summary of the Invention

[0005] In view of this, the present invention provides a gas heat sink and a dilution refrigerator, which can expand the internal gas diffusion range, reduce the cross-sectional area of the flow channel, improve the heat exchange efficiency, and reduce the heat leakage during the operation of the dilution refrigerator.

[0006] To achieve the above object, the present invention provides a gas heat sink, including a housing having an input port and an output port communicated with the outside at opposite ends; a plurality of flow guiding plates spaced along the height direction of the housing inside the housing, and a plurality of through grooves extending along the length direction of the housing are formed on the flow guiding plates; a plurality of partition plates, each of the flow guiding plates is clamped between two adjacent partition plates, and is adapted to block the middle part of the through grooves to form a first flow channel, and the side wall of the partition plate facing the input port and the flow guiding plate define a second flow channel communicated with the input port, and the first flow channel and the second flow channel are communicated; the second flow channel is configured to guide the gas input from the input port to enter the plurality of first flow channels along the height direction of the housing through multiple diffusions, and the housing is configured to exchange heat with the gas through the flow guiding plates and the partition plates and transfer the heat to an external cold source.

[0007] According to an embodiment of the present invention, the flow guiding plate has a first main body portion forming the through groove, and a flaring portion extending from the first main body portion to both sides along the length direction of the housing to form gas diffusion or convergence along the width direction of the housing.

[0008] According to an embodiment of the present invention, the flaring portion is configured to extend from both sides of the first main body portion facing each other in the width direction of the housing along the length direction of the housing and approach each other to form a flaring structure at the end.

[0009] According to an embodiment of the present invention, the partition plate has a second main body portion for blocking the through groove, and a partition portion extending from the second main body portion to both sides along the length direction of the housing for blocking the flaring portion to form a flaring flow channel.

[0010] According to an embodiment of the present invention, an avoidance notch is formed on the partition portion and is arranged opposite to the input port in the width direction of the housing, and is adapted to reduce the resistance when the gas is input.

[0011] According to an embodiment of the present invention, the input port is arranged opposite to the flaring portion in the width direction of the housing.

[0012] According to an embodiment of the present invention, the plurality of through grooves are spaced along the width direction of the housing.

[0013] According to an embodiment of the present invention, the above-mentioned housing includes: a main body, which forms a receiving cavity, and the above-mentioned deflector and the above-mentioned partition are arranged in the above-mentioned receiving cavity; a cover body, which is buckled on the above-mentioned main body to close the above-mentioned receiving cavity.

[0014] According to an embodiment of the present invention, a sealing member is clamped between the above-mentioned main body and the above-mentioned cover body. The sealing member is made of indium metal and is adapted to deform under the extrusion of the above-mentioned cover body and the above-mentioned main body to seal the gap between the above-mentioned cover body and the above-mentioned main body.

[0015] The present invention also provides a dilution refrigerator, which includes: a mixing chamber, in which a 3 He enriched phase located in the upper layer and a 3 He dilution phase located in the lower layer are stored. The above-mentioned 3 He enriched phase is configured to respond to the above-mentioned 3 decrease in the concentration of He in the above-mentioned 3 He dilution phase, compensate He in the above-mentioned 3 He dilution phase and absorb the surrounding heat to perform refrigeration; an evaporation chamber, which is communicated with the 3 He dilution phase in the above-mentioned mixing chamber and is adapted to separate 3 He in the form of vapor from the 3 He dilution phase; a transfer pump group, which is adapted to pump 3 He vapor out of the above-mentioned evaporation chamber; a gas heat sink as in any of the above embodiments, which is used to receive 3 He vapor from the above-mentioned transfer pump group and pre-cool 3 He vapor; a throttling device, which is configured to adiabatically throttle the pre-cooled 3 He vapor so that 3 He vapor is liquefied and flows back to the above-mentioned mixing chamber.

[0016] In the gas heat sink and dilution refrigerator provided by the present invention, the deflector and the partition are alternately stacked along the height direction of the housing in the housing. A plurality of through grooves are opened on the deflector, and the middle part of the through grooves is blocked by two adjacent partitions to form a first flow channel; at the same time, the side wall of the partition facing the input port and the deflector define a second flow channel communicating with the input port, which is used to guide the input gas to enter a plurality of first flow channels through the unblocked ends of the through grooves after multiple diffusions along the height direction of the housing, while realizing microchannel heat exchange, making the gas diffuse to as many microchannels as possible, effectively increasing the heat exchange area, improving the heat exchange efficiency, and reducing the heat leakage during the operation of the dilution refrigerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is an overall schematic diagram of the gas heat sink provided by the present invention;

[0018] Figure 2 It is a schematic diagram of the gas heat sink plane provided by the present invention, with the cover removed;

[0019] Figure 3 It is a schematic sectional view of the gas heat sink provided by the present invention;

[0020] Figure 4 It is Figure 3 an enlarged view of part A in;

[0021] Figure 5 It is a schematic sectional view of the gas heat sink from another angle provided by the present invention;

[0022] Figure 6 It is a simplified schematic diagram of the internal gas flow of the gas heat sink provided by the present invention;

[0023] Figure 7 It is an exploded view of the gas heat sink provided by the present invention, mainly showing the flow guide plate and the partition plate;

[0024] Figure 8 It is a schematic diagram of the working principle of the dilution refrigerator provided by the present invention;

[0025] Figure 9 It is a first perspective three-dimensional view of the throttling device provided by the present invention;

[0026] Figure 10 It is a second perspective three-dimensional view of the throttling device provided by the present invention;

[0027] Figure 11 It is a side view of the throttling device according to an embodiment of the present invention;

[0028] Figure 12 It is Figure 11 a sectional view taken along the B-B direction.

[0029] In the said drawings, the meanings of the reference numerals are specifically as follows:

[0030] 1. Housing;

[0031] 11. Input port;

[0032] 12. Output port;

[0033] 13. Main body;

[0034] 14. Cover;

[0035] 15. Seal;

[0036] 2. Flow guide plate;

[0037] 21. First main body part;

[0038] 211. Through slot;

[0039] 22. Flared portion;

[0040] 3. Partition;

[0041] 31. Second main body portion;

[0042] 32. Partition portion;

[0043] 321. Avoidance notch;

[0044] 4. First flow channel;

[0045] 5. Second flow channel;

[0046] 6. Mixing chamber;

[0047] 7. Evaporation chamber;

[0048] 8. Transfer pump group;

[0049] 9. Gas heat sink;

[0050] 10. Throttling device;

[0051] 101. Support body;

[0052] 102. Gas pipeline;

[0053] 103. First rod portion;

[0054] 104. Second rod portion;

[0055] 105. First limiting member;

[0056] 106. Second limiting member. Detailed implementation manners

[0057] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present invention. In the following detailed description, for the sake of explanation, many specific details are set forth to provide a comprehensive understanding of the embodiments of the present invention. However, obviously, one or more embodiments can also be implemented without these specific details. In addition, in the following description, descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0058] The terms used herein are merely for describing specific embodiments and are not intended to limit the present invention. The terms "including", "comprising", etc. used herein indicate the presence of the described features, steps, operations, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, or components.

[0059] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those of ordinary skill in the art, unless otherwise defined. It should be noted that the terms used herein should be interpreted as having a meaning consistent with the context of this specification, and should not be interpreted in an idealized or overly rigid manner.

[0060] In cases where expressions similar to "at least one of A, B, and C, etc." are used, generally, it should be interpreted according to the meaning that those of ordinary skill in the art usually understand such expressions (for example, "a system having at least one of A, B, and C" should include, but not be limited to, a system having only A, only B, only C, having A and B, having A and C, having B and C, and / or having A, B, and C, etc.).

[0061] Figure 1 is a schematic overall view of the gas heat sink provided by the present invention, Figure 2 is a schematic plan view of the gas heat sink provided by the present invention, with the cover removed, Figure 3 is a schematic sectional view of the gas heat sink provided by the present invention, Figure 4 is Figure 3 an enlarged view of part A in Figure 5 is a schematic sectional view of the gas heat sink provided by the present invention from another angle, Figure 6 is a simplified schematic diagram of the internal gas flow of the gas heat sink provided by the present invention.

[0062] An exemplary embodiment of the present invention provides a gas heat sink, as Figures 1 to 6 shown, including a housing 1, a plurality of flow guiding plates 2, and a plurality of partition plates 3. The opposite ends of the housing 1 are provided with an input port 11 and an output port 12 communicating with the outside. The plurality of flow guiding plates 2 are arranged at intervals in the housing 1 along the height direction of the housing 1, and a plurality of through grooves 211 extending along the length direction of the housing 1 are formed in the flow guiding plates 2. Each flow guiding plate 2 is clamped between two adjacent partition plates 3 and is adapted to enclose the middle part of the through groove 211 to form a first flow channel 4. The side wall of the partition plate 3 facing the input port 11 and the flow guiding plate 2 define a second flow channel 5 communicating with the input port 11 and connect the first flow channel 4 and the second flow channel 5. Among them, the second flow channel 5 is configured to guide the gas input from the input port 11 to enter the plurality of first flow channels 4 along the height direction of the housing 1 through multiple diffusions, and the housing 1 is configured to exchange heat with the gas through the flow guiding plates 2 and the partition plates 3 and transfer the heat to an external cold source.

[0063] In such an embodiment, the housing 1 is a sealed housing. The gas carrying more heat enters from the input port 11, exchanges heat with the flow guide plate 2 and the partition plate 3, and then outputs the cooled gas through the output port 12. The heat of the flow guide plate 2 and the partition plate 3 is transferred to the external cold source through heat exchange with the housing 1 to continuously cool the gas. Specifically, inside the housing 1, the flow guide plate 2 and the partition plate 3 are alternately stacked along the height direction of the housing 1. A plurality of through grooves 211 are formed on the flow guide plate 2, and the middle part of the through grooves 211 is blocked by two adjacent partition plates 3 to form the first flow channel 4. At the same time, the side wall of the partition plate 3 facing the input port 11 and the flow guide plate 2 define an irregular-shaped second flow channel 5 communicating with the input port 11, such as Figure 6 as shown, which can guide the input gas to enter the plurality of first flow channels 4 through the unblocked ends of the through grooves 211 after multiple diffusions along the height direction of the housing 1. In this way, not only the cross-sectional area of the flow channel is reduced by using the plurality of first flow channels 4, the boundary layer thickness is reduced, but also the diffusion range of the gas is effectively increased, the heat exchange area is increased, and the heat exchange efficiency is improved.

[0064] Further, in a dilution refrigerator, this gas heat sink is used to 3 pre-cool the He vapor, and at the same time cooperate with other heat exchangers for 3 continuous multi-stage heat exchange of the He solution. In this way, not only the number of heat exchange stages is increased on the original basis, but also the heat exchange efficiency is improved through the optimization of the structure, and further 3 the heat carried by the He solution when it returns to the mixing chamber is reduced.

[0065] Refer to Figures 1 to 3 as shown. The length direction of the housing 1 is parallel to the connection line of the input port 11 and the output port 12. The width direction of the housing 1 is perpendicular to the connection line of the input port 11 and the output port 12, that is, the arrangement direction of the plurality of through grooves 211 on the flow guide plate 2. The height direction of the housing 1 is perpendicular to both the length direction and the width direction of the housing 1 at the same time.

[0066] In the embodiment of the present invention, the materials of the flow guide plate 2, the partition plate 3 and the housing 1 include but are not limited to copper. In cryogenic fields such as dilution refrigerators, oxygen-free copper is preferably used to obtain higher stability and thermal conductivity.

[0067] In some other embodiments, the thickness of the flow guide plate 2 is greater than the thickness of the partition plate 3 to reduce the flow resistance of the gas in the first flow channel 4.

[0068] Figure 7 is the explosion schematic diagram of the gas heat sink provided by the present invention, mainly showing the flow guide plate and the partition plate.

[0069] In an exemplary embodiment, such as Figures 4 to 7As shown in the figure, the flow guide plate 2 has a first main body portion 21 forming a through groove 211, and a flaring portion 22 extending from the first main body portion 21 to both sides along the length direction of the housing 1 to form a gas diffusion or convergence along the width direction of the housing 1.

[0070] In such an embodiment, the first main body portion 21 of the flow guide plate 2 is configured as a rectangular plate, and a plurality of through grooves 211 extending along the length direction of the housing 1 are provided on the rectangular plate. The flaring portion 22 extends from the first main body portion 21 to both sides along the length direction of the housing 1. The side close to the input port 11 is used to guide the input gas to diffuse along the width direction of the housing 1, and the side close to the output port 12 is used to guide the gas to converge along the width direction of the housing 1 towards the output port 12.

[0071] According to an embodiment of the present invention, the flaring portion 22 is configured to extend from the two opposite sides of the first main body portion 21 in the width direction of the housing 1 along the length direction of the housing 1 respectively, and approach each other to form a flaring structure at the end.

[0072] In such an embodiment, taking the side of the first main body portion 21, that is, the rectangular plate, close to the input port 11 as an example, the flaring portion 22 extends from the two opposite sides of the rectangular plate in the width direction of the housing 1, that is, the longer set of side edges, along the length direction of the housing 1 respectively, then approaches each other along the width direction of the housing 1, and cooperates at the end to form a flaring structure, so that the gas can diffuse along the width direction of the housing 1 after entering from the input port 11. Based on the same principle, the flaring portion 22 on the side of the rectangular plate close to the output port 12 has the same structure and is suitable for guiding the heat-exchanged and cooled gas to gradually converge to the output port 12 along the width direction of the housing 1.

[0073] According to an embodiment of the present invention, as Figures 4 to 7 shown, the partition plate 3 has a second main body portion 31 surrounding the through groove 211, and a partition portion 32 extending from the second main body portion 31 to both sides along the length direction of the housing 1 for surrounding the flaring portion 22 to form a flaring flow channel.

[0074] In such an embodiment, the second main body portion 31 of the partition plate 3 is also configured as a rectangular plate, which is a solid structure. Its length in the housing 1 is less than the length of the through groove 211 in the housing 1, and it is located at approximately the middle position of the through groove 211 to leave both ends for the first flow channel 4 and the second flow channel 5 to communicate. After the partition portion 32 extends from the longer set of side edges of the rectangular plate along the length direction of the housing 1 by the same length as the flaring portion 22, it approaches each other and combines along the width direction of the housing 1 to separate the flaring portions 22 of the adjacent flow guide plates 2 in the height direction of the housing 1 to form independent flaring flow channels, which is beneficial to the diffusion of gas along the height direction of the housing 1.

[0075] Further according to an embodiment of the present invention, as Figure 2 and Figure 7 shown, an avoidance notch 321 is formed in the partition portion 32 and is arranged opposite to the input port 11 in the width direction of the housing 1, which is suitable for reducing the resistance when gas is input.

[0076] In such an embodiment, the avoidance notch 321 leaves a distance between the side wall of the partition portion 32 facing the input port 11 and the input port 11, avoiding direct impact of the gas on the side wall, resulting in excessive resistance and accumulation at the input port 11. However, at the same time, the avoidance notch 321 does not disconnect the partition portion 32 and still maintains the formation of a flared flow channel with the flared portion 22.

[0077] In an exemplary embodiment, the input port 11 is arranged opposite to the flared portion 22 in the width direction of the housing 1.

[0078] In such an embodiment, by arranging the input port 11 opposite to the flared portion 22 in the width direction of the housing 1, it is beneficial for gas input. More specifically, as Figure 2 shown, the input port 11 and the flared portion 22 are located on the axis of symmetry of the housing 1 along the length direction of the housing 1.

[0079] In an exemplary embodiment, as Figure 7 shown, a plurality of through grooves 211 are spaced apart along the width direction of the housing 1.

[0080] In such an embodiment, the plurality of through grooves 211 extend along the length direction of the housing 1 and are spaced apart along the width direction of the housing 1 to cooperate with the partition plate 3 to form a densely arranged first flow channel 4. When gas enters the housing 1 from the input port 11, after multiple diffusions, it fully exchanges heat with the guide plate 2 and the partition plate 3 through the plurality of first flow channels 4 and is discharged through the output port 12 after heat exchange. The heat accumulated in the housing 1, the guide plate 2 and the partition plate 3 is taken away by an external cold source, and the choice of the external cold source depends on the application scenario of the gas heat sink. For example, it can be a flowing low-temperature liquid working medium.

[0081] In an exemplary embodiment, as Figure 1 and Figure 2 shown, the housing 1 includes a main body 13 and a cover body 14. A receiving cavity is formed in the main body 13, and the guide plate 2 and the partition plate 3 are arranged in the receiving cavity. The cover body 14 is buckled on the main body 13 to close the receiving cavity.

[0082] In such an embodiment, the guide plates 2 and the partition plates 3 are alternately stacked in the accommodating cavity, and the shape of the accommodating cavity is substantially the same as that of the guide plates 2 and the partition plates 3, so that the guide plates 2 and the partition plates 3 can be stably embedded in the accommodating cavity without the aid of a connecting component. In some optional embodiments, the guide plates 2, the partition plates 3 and the housing 1 are interference fit. After the cover 14 is buckled onto the main body 13, it is fastened by bolts to ensure the sealing performance of the gas heat sink.

[0083] In some other embodiments, a boss is formed on the lower surface of the cover body 14, that is, the surface facing the main body 13 when buckled. When the cover body 14 is buckled to the main body 13, the boss is embedded in the accommodating cavity to further ensure the sealing performance.

[0084] According to an embodiment of the present invention, a seal 15 is sandwiched between the main body 13 and the cover 14 . The seal 15 is made of metal indium and is suitable for deforming under the extrusion of the cover 14 and the main body 13 to seal the gap between the cover 14 and the main body 13 .

[0085] In such an embodiment, the gas heat sink is sealed by using a seal 15 made of metal indium, which improves the sealing performance while also having good corrosion resistance and stability at low temperatures. Since metal indium is soft, sealing can be achieved by extrusion deformation, which is easy to operate.

[0086] In some other embodiments, the sealing member 15 may also be a gasket made of rubber.

[0087] Figure 8 It is a schematic diagram of the working principle of the dilution refrigerator provided by the present invention.

[0088] An exemplary embodiment of the present invention further provides a dilution refrigerator, such as Figure 8 As shown, it includes a mixing chamber 6, an evaporation chamber 7, a transmission pump group 8, a throttling device 10 and a gas heat sink 9 as in any of the above embodiments. The mixing chamber 6 stores the gas located at the upper layer. 3 The He-concentrated phase and the lower 3 He dilution phase, 3 The He-enriched phase is configured to respond to 3 He dilution phase 3 The concentration of He decreases to 3 He dilution phase compensation 3 He also absorbs ambient heat to perform cooling. 3 He dilution connection, suitable for 3 He in the form of vapor 3 He dilution phase separation. Transfer pump group 8 is suitable for 3 He vapor is extracted from the evaporation chamber 7. The gas heat sink 9 is used to receive the gas from the transmission pump group 8.3 He vapor, and 3 the He vapor is pre-cooled. The throttling device 10 is configured to adiabatically throttle the pre-cooled 3 He vapor to liquefy the He vapor and flow it back to the mixing chamber 6 through the Joule-Thomson effect. 3

[0089] In such an embodiment, the mixing chamber 6 stores 3 a He enriched phase (i.e., 3 a He solution) and 3 a He dilute phase (i.e., 3 a mixture of He and 4 He). When the evaporation chamber 7 reaches a preset temperature, about 0.6 - 1 K (Kelvin), generally 0.8 K is selected. At this time, 3 the saturated vapor pressure of He is significantly higher than 4 He, so it is selectively evaporated. The 3 He concentration in the evaporation chamber 7 decreases accordingly, and the 3 He dilute phase in the mixing chamber 6 replenishes 3 He to the evaporation chamber 7, and further causes the 3 He in the 3 He enriched phase in the mixing chamber 6 to dissolve into the 3 He dilute phase. When 3 He passes through the phase interface, it absorbs the surrounding heat, and the temperature of the mixing chamber 6 and the surrounding cold plates decreases, realizing dilution refrigeration. In addition, 3 after He is selectively evaporated, it becomes 3 He vapor, which is pumped out of the evaporation chamber 7 by the transfer pump group 8. To enable continuous and cyclic dilution refrigeration, therefore, the 3 He vapor is throttled and depressurized through the throttling device 10 to be liquefied and then flows back to the 3 He enriched phase in the mixing chamber 6, so as to perform dilution refrigeration cyclically.

[0090] More specifically, since 3 the He vapor is at room temperature after being pumped out, although its temperature is reduced by throttling through the throttling device 10, the heat it carries still has a great impact on the refrigeration of the dilution refrigerator, which is also called heat leakage. Therefore, after the transfer pump group 8 pumps out the 3 He vapor, it is pumped into the gas heat sink 9, and after preliminary heat exchange cooling, it is then introduced into the throttling device 10. The gas heat sink 9 can be cooled by a pulse tube refrigerator to take away at least part of the heat of the 3 He vapor.

[0091] Figure 9 is the first perspective three-dimensional view of the throttling device provided by the present invention, Figure 10 is the second perspective three-dimensional view of the throttling device provided by the present invention.​

[0092] In an exemplary embodiment, as Figure 9 and Figure 10 shown, the throttling device 10 includes a support body 101, a gas pipeline 102, and a pressing assembly. The gas pipeline 102 is configured to be coiled around the outside of the support body 101 in the height direction of the support body 101, and the gas pipeline 102 is used to convey 3 He vapor from the outside to the mixing chamber 6 of the dilution refrigerator. The pressing assembly is arranged outside the gas pipeline 102 and is configured to press the gas pipeline 102 in the width direction of the support body 101 when driven by an external force, so as to reduce the pipe diameter of the gas pipeline 102.

[0093] According to an embodiment of the present invention, during the process that 3 He is drawn out from the dilute phase and passes through the gas pipeline 102, when the pressing assembly is driven by an external force, it presses the gas pipeline 102 in the width direction of the support body 101, the pipe diameter of the gas pipeline 102 decreases, 3 the pressure of 3 He decreases when flowing through the gas pipeline 102, 3 and 3 He undergoes the Joule-Thomson effect. Since the interatomic force of 3 He is close to the ideal gas level, and since the inversion temperature of 3 He is extremely low, approximately 40 K (-233 °C), when the gas expands, the change in the interatomic force causes a change in internal energy, thereby causing a temperature change. When the temperature is greater than 40 K, the Joule-Thomson coefficient is negative, 3 and

[0094] He heats up during throttling. When the temperature is less than 40 K, the Joule-Thomson coefficient is positive, Figure 10 and Figure 10 He cools down during throttling, Figure 10 and

[0095] According to an embodiment of the present invention, the gas pipeline 102 is coiled around the outside of the support body 101 in the Z direction, and the gas pipeline 102 is used to convey 3The He vapor is transported back to the mixing chamber 6 of the dilution refrigerator. The extrusion assembly is arranged outside the gas pipeline 102. When the extrusion assembly is driven by an external force, it extrudes the gas pipeline 102 along the X direction. The throttling device 10 provided by the present invention is applicable to the extremely low temperature working environment of the dilution refrigerator, can flexibly adjust the pipe diameter of the gas pipeline 102, is simple to manufacture, has high use reliability, and a wide adjustable range.

[0096] According to an embodiment of the present invention, two surfaces of the support body 101 close to the extrusion assembly are respectively provided with extrusion surfaces, and the two extrusion surfaces are configured to respectively have recesses, and the two recesses provide space for the extrusion assembly to extrude the gas pipeline 102.

[0097] According to an embodiment of the present invention, the two recesses provide necessary space for the extrusion assembly to extrude the gas pipeline 102, ensure the smooth progress of the extrusion process, avoid direct contact between the extrusion assembly and the support body 101, reduce mechanical interference and wear, extend the service life of the gas pipeline 102, and also facilitate subsequent maintenance and replacement. The two recesses also make the extrusion pressure evenly distributed on the gas pipeline 102 along the Z direction, prevent local stress concentration, provide a protective effect for the gas pipeline 102, and the uniform force improves the stability of the extrusion process, ensuring the consistency of the extrusion effect of the gas pipeline 102 in the Z direction. Moreover, the two extrusion surfaces respectively have recesses, which can adapt to gas pipelines 102 of different sizes, improve flexibility, and also enhance the versatility of the throttling device 10.

[0098] According to an embodiment of the present invention, there are multiple groups of extrusion assemblies, and there are multiple groups of recesses. The multiple groups of recesses respectively provide space for the multiple groups of extrusion assemblies to extrude the gas pipeline 102.

[0099] According to an embodiment of the present invention, multiple groups of extrusion assemblies can be arranged in parallel. Arranging multiple groups of extrusion assemblies and multiple groups of recesses can ensure that the extrusion pressure is evenly distributed on the gas pipeline 102 along the Y direction, prevent local stress concentration, provide a protective effect for the gas pipeline 102, and the uniform force improves the stability of the extrusion process, ensuring the consistency of the extrusion effect of the gas pipeline 102 in the Y direction of the support body 101. The multiple groups of recesses can better limit the position of the gas pipeline 102 and the support body 101, ensuring the accuracy of the extrusion assembly to extrude the gas pipeline 102. Arranging multiple groups of extrusion assemblies and multiple groups of recesses can also achieve load balancing, avoid overloading of a single component, and load balancing can extend the service life of the extrusion assembly and the support body 101.

[0100] According to an embodiment of the present invention, each group of extrusion assemblies includes two first rods 103, two second rods 104, two first stoppers 105 and two second stoppers 106. The two first rods 103 are respectively arranged on the outside of the two recesses, and the two first rods 103 extend along the Z direction. The two second rods 104 pass through the two ends of the two first rods 103 along the X direction to limit the support body 101 between the two first rods 103. The two first stoppers 105 are respectively arranged at one end of the two second rods 104. The two second stoppers 106 are respectively rotatably arranged at the other ends of the two second rods 104 to adjust the positions of the two second rods 104 between the two ends of the two first rods 103.

[0101] According to an embodiment of the present invention, the two second stoppers 106 are driven by external force to adjust the positions of the two second rods 104 between the two ends of the two first rods 103, and a flow detection device can be connected to the gas pipeline 102. 3 The flow rate of He vapor flowing through the gas pipeline 102 is used to obtain the deformation caused by the two first rods 103 exerting a squeezing force on the gas pipeline 102. The applied external force is, for example, 10N, and the pressure of the gas pipeline 102 is 0.2 MPa. 3 The flow rate of He vapor flowing through the gas pipeline 102 is 20 mL / min.

[0102] Figure 11 is a side view of a throttling device according to an embodiment of the present invention, Figure 12 yes Figure 11 Cross-sectional view in the BB direction.

[0103] According to an embodiment of the present invention, Figure 11 and Figure 12 As shown, through holes are formed at opposite ends of the two first rod portions 103 to allow the second rod portion 104 to pass through.

[0104] According to the embodiment of the present invention, one second rod 104 passes through the through holes opened at both ends (on the same side) of the two first rods 103, and the other second rod 104 passes through the through holes opened at both ends of the two first rods 103, which can effectively connect the two first rods 103, improve stability and rigidity, and the two second rods 104 are easy to install and disassemble, which is convenient for subsequent maintenance and replacement. The through holes can ensure the precise alignment of the two first rods 103 and the second rods 104, and improve the installation accuracy.

[0105] According to an embodiment of the present invention, the two second limiting members 106 are nuts, and thread portions are provided on both of the two second rod portions 104. The two nuts are threadedly engaged with the two thread portions respectively. Wherein, when the two nuts are driven by an external force, the two first rod portions 103 are driven to approach each other, so as to squeeze the gas pipeline 102 in the X direction, reducing the diameter of the gas pipeline 102.

[0106] According to an embodiment of the present invention, the two nuts are threadedly engaged with the two thread portions respectively. When the two nuts are driven by an external force, one of the first rod portions 103 is driven to slide on the two second rod portions 104 and approach the other first rod portion 103, so as to squeeze the gas pipeline 102 in the X direction, reducing the diameter of the gas pipeline 102. Thread portions are provided on both of the two second rod portions 104, providing a greater degree of freedom of movement for the sliding of the first rod portion 103 and having a wide adjustable range.

[0107] According to an embodiment of the present invention, by changing the number of turns of the gas pipeline 102 wound around the outside of the support body 101 in the Z direction, the adjustable range of the gas flow rate is further expanded, and the number of turns can be 105 turns.

[0108] According to an embodiment of the present invention, the cross-section of the support body 101 in a plane perpendicular to the Z direction is any one of opposed horseshoe shapes, oval shapes, trapezoid shapes, and square shapes.

[0109] According to an embodiment of the present invention, when the cross-section of the support body 101 in a plane perpendicular to the Z direction is an opposed horseshoe shape or an opposed oval shape, the arc-shaped structure can effectively disperse stress, reduce stress concentration, extend the service life of the support body 101, and can also fit well with the gas pipeline 102, improving the space utilization rate. When the cross-section of the support body 101 in a plane perpendicular to the Z direction is an opposed trapezoid shape or an opposed square shape, the trapezoid and the square are wider than the horseshoe shape or the oval shape, and can provide good support and stability for the gas pipeline 102.

[0110] According to an embodiment of the present invention, the material of the support body 101 is any one of stainless steel, titanium alloy, and nickel alloy.

[0111] According to an embodiment of the present invention, if the material of the support body 101 is made of stainless steel, the stainless steel can maintain good toughness and strength in an extremely low-temperature working environment, and also has good corrosion resistance and low cost. If the material of the support body 101 is made of titanium alloy, the titanium alloy can maintain good toughness and strength in an extremely low-temperature working environment, and the titanium alloy has a low thermal conductivity, which can reduce heat conduction and maintain the ambient temperature. At the same time, the titanium alloy has a low density but high strength, which helps to reduce the overall weight and maintain the structural strength. If the material of the support body 101 is made of nickel alloy, the nickel alloy can maintain excellent toughness and strength in an extremely low-temperature working environment, and the nickel alloy has excellent corrosion resistance.

[0112] In an exemplary embodiment, the transfer pump group 8 includes a vacuum pump and a booster pump, where the vacuum pump is used to extract the 3 He vapor that has been evaporated in the evaporation chamber 7, and after being boosted by the booster pump, it is pumped to the throttling device 10. The throttling device 10 3 throttles the He vapor and then transports it back to the mixing chamber 6.

[0113] According to an embodiment of the present invention, the throttling device 10 is detachably connected between the booster pump and the mixing chamber 6.

[0114] According to an embodiment of the present invention, if it is necessary to adjust the He vapor extracted from the mixing chamber 6 to different flow rates, the throttling device 10 can be removed, and after replacing it with a new throttling device 10, the gas pipeline 102 is re-squeezed along the X direction to adjust the diameter of the gas pipeline 102, so as to adjust the 3 flow rate of the He vapor flowing through the gas pipeline 102. By adjusting the 3 flow rate of the He vapor, it is made to match the dilution refrigerator, expanding its performance limit and laying a foundation for the further development of the dilution refrigerator. 3 3

[0115] In some other embodiments, during the process of the He solution generated after throttling flowing back to the mixing chamber 6, it will also undergo multi-stage heat exchange to further reduce the heat leakage. 3 3

[0116] In such an embodiment, the heat exchange structure includes but is not limited to a disc-shaped radiator, the upper and lower layers of which are separated by oxygen-free copper to transfer heat; or a spiral double-tube radiator, the inner and outer layers of which are separated by the tube wall to transfer heat. The heat exchange object is preferably the 3 He and 4 He mixture from the mixing chamber 6, because 3 He and 4 the temperature of the He and He mixture does not rise significantly after absorbing heat.

[0117] Those skilled in the art can understand that the features described in the various embodiments of the present invention can be combined and / or combined in various ways, even if such combinations or combinations are not explicitly described in the present invention. In particular, without departing from the spirit and teachings of the present invention, the features described in the various embodiments of the present invention can be combined and / or combined in various ways. All such combinations and / or combinations fall within the scope of the present invention.

[0118] The embodiments of the present invention have been described above. However, these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. Although the embodiments have been described separately above, this does not mean that the measures in the various embodiments cannot be used advantageously in combination. Without departing from the scope of the present invention, those skilled in the art can make various substitutions and modifications, and all such substitutions and modifications should fall within the scope of the present invention.

Claims

1. A gas heat sink, characterized in that: include: The shell has an input port and an output port at two opposite ends thereof, which are connected to the outside; A plurality of guide plates are arranged in the shell at intervals along the height direction of the shell, and a plurality of through slots extending along the length direction of the shell are formed on the guide plates; A plurality of baffles, each of the guide plates is sandwiched between two adjacent baffles, and is suitable for enclosing the middle part of the through groove to form a first flow channel, and the side wall of the baffle facing the input port and the guide plate define a second flow channel communicating with the input port, and the first flow channel is communicated with the second flow channel; The second flow channel is configured to guide the gas input from the input port to enter the plurality of first flow channels through multiple diffusions along the height direction of the shell, and the shell is configured to exchange heat with the gas through the guide plate and the partition plate, and transfer the heat to an external cold source.

2. The gas heat sink according to claim 1, characterized in that: The guide plate comprises a first main body portion for forming the through slot, and a flared portion extending from the first main body portion to both sides along the length direction of the shell to form a flared portion for diffusing or converging gas along the width direction of the shell.

3. The gas heat sink according to claim 2, characterized in that: The flared portions are configured to extend from two sides of the first main body portion that are opposite to each other in the width direction of the shell respectively along the length direction of the shell and approach each other to form a flared structure at the ends.

4. The gas heat sink according to claim 2, characterized in that: The partition plate comprises a second main body portion for enclosing the through groove, and a partition portion extending from the second main body portion to both sides along the length direction of the shell and for enclosing the flared portion to form a flared flow channel.

5. The gas heat sink according to claim 4, characterized in that: The partition is provided with an avoidance notch, which is arranged opposite to the input port in the width direction of the shell, and is suitable for reducing the resistance during the input of the gas.

6. The gas heat sink according to claim 2, characterized in that: The input port is disposed opposite to the flared portion in the width direction of the housing.

7. The gas heat sink according to claim 1, characterized in that: The plurality of through slots are distributed at intervals along the width direction of the housing.

8. The gas heat sink according to claim 1, characterized in that: The housing comprises: A main body, formed with a receiving cavity, wherein the guide plate and the partition plate are arranged in the receiving cavity; The cover body is buckled on the main body to close the accommodating cavity.

9. The gas heat sink according to claim 8, characterized in that: A sealing member is sandwiched between the main body and the cover body. The sealing member is made of metal indium and is suitable for deforming under the compression of the cover body and the main body to seal the gap between the cover body and the main body.

10. A dilution refrigerator, characterized in that: include: A mixing chamber is provided in which the upper 3 The He-concentrated phase and the lower 3 He dilution phase, the 3 The He-enriched phase is configured to respond to the 3 He dilution phase 3 The concentration of He decreases to 3 He dilution phase compensation 3 He also absorbs surrounding heat to cool; The evaporation chamber and the mixing chamber 3 He dilution connection, suitable for 3 He in the form of vapor 3 He dilutes phase separation; Transfer pump set, suitable for 3 He vapor is extracted from the evaporation chamber; The gas heat sink according to any one of claims 1 to 9, for receiving gas from the transmission pump group 3 He vapor, and 3 He vapor is pre-cooled; The throttling device is constructed to 3 He vapor is throttled adiabatically to make 3 The He vapor liquefies and flows back into the mixing chamber.

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