A dilution refrigeration system using modular parallel connection

Abstract

The present invention provides a dilution refrigeration system using modular parallel connection, which relates to the technical field of mK-level dilution refrigeration. The system includes a plurality of dilution refrigeration units and a transfer pump group. The plurality of dilution refrigeration units share one transfer pump group. Each dilution refrigeration unit includes: a mixing chamber storing <supgt;3< / supgt;He enriched phase and <supgt;3< / supgt>He diluted phase; an evaporation chamber communicating with the <supgt;3< / supgt>He dilution, and the evaporation chamber separates <supgt;3< / supgt>He vapor from the <supgt;3< / supgt>He diluted phase; a gas flow regulating device connected between the evaporation chamber and the transfer pump group. The transfer pump group extracts at least a part of the <supgt;3< / supgt>He vapor in each evaporation chamber. The gas flow regulating device partially receives the <supgt;3< / supgt>He vapor output from the transfer pump group, and at least partially liquefies the <supgt;3< / supgt>He vapor received from the transfer pump group to form a <supgt;3< / supgt>He fluid flowing back to the mixing chamber. The gas flow regulating devices of the plurality of dilution refrigeration units respectively adjust the diameters of their respective gas pipelines, so that the <supgt;3< / supgt>He fluids flowing back to the mixing chambers of the plurality of dilution refrigeration units are subject to the same resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of mK-class dilution refrigeration, and more specifically, to a modular parallel dilution refrigeration system. Background Art

[0002] A dilution refrigerator is a refrigerator that uses helium-3 ( 3 He) and helium-4 ( 4 He) mixed liquid phase separation characteristics to achieve extremely low temperature refrigeration equipment. In order to maintain continuous refrigeration, the dilution refrigerator separates the dilution phase entering the mixing chamber by distillation and other methods. 3 He atoms are re-extracted and circulated back to the mixing chamber, forming 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 mK. Dilution refrigerators are widely used in extremely low temperature experimental research in the fields of condensed matter physics, quantum computing, astrophysics, etc. due to their advantages such as high efficiency, stability, and vibration-free. In recent years, with the rapid development of quantum information science, dilution refrigerators, as key equipment for realizing and maintaining the extremely low temperature environment required for quantum bit superconducting circuits, have received increasing attention and research.

[0003] At present, the ultra-low temperature refrigeration power of common dilution refrigerators is usually in the order of hundreds of microwatts. However, with the continuous development of use scenarios such as quantum technology, expanding the refrigeration power of dilution refrigerators has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] In order to solve at least one of the technical problems in the prior art, an embodiment of the present invention provides a dilution refrigeration system using modular parallel connection, which can increase the refrigeration power of the dilution refrigeration unit.

[0005] The present invention provides a modular parallel dilution refrigeration system, comprising a plurality of dilution refrigeration units and a transmission pump group, wherein the plurality of dilution refrigeration units are arranged in a vacuum chamber, the plurality of dilution refrigeration units share the transmission pump group, and each of the dilution refrigeration units comprises: a mixing chamber, wherein the mixing chamber stores a liquid located at an upper layer; 3 The He-concentrated phase and the lower 3 He dilution phase; evaporation chamber, and the mixing chamber 3 He dilution is connected, the above evaporation chamber is used to 3 He is separated from the dilute phase 3 He steam; a gas flow regulating device connected between the evaporation chamber and the transmission pump group, the transmission pump group extracts at least a portion of each of the evaporation chambers 3 He steam, the gas flow regulating device partially receives the gas output from the transmission pump group 3He vapor and forming, after at least partially liquefying the He vapor received from the above-mentioned transfer pump group, a He fluid flowing back to the above-mentioned mixing chamber; wherein, the multiple gas flow regulating devices of the multiple above-mentioned dilution refrigeration units respectively adjust the pipe diameters of their respective gas pipelines, such that the resistance received by the He fluids flowing back to the mixing chambers of the multiple above-mentioned dilution refrigeration units is the same. 3 3 3

[0006] Optionally, the multiple evaporation chambers of the multiple above-mentioned dilution refrigeration units and one above-mentioned transfer pump group are all connected through gas transfer pipelines, so as to facilitate the above-mentioned transfer pump group to extract at least a part of the He vapor in each above-mentioned evaporation chamber. 3

[0007] Optionally, the above-mentioned gas flow regulating device is detachably connected between the above-mentioned evaporation chamber and the above-mentioned transfer pump group, so as to facilitate replacing the next gas flow regulating device after adjusting the pipe diameter of the above-mentioned gas pipeline once.

[0008] Optionally, the above-mentioned gas flow regulating device includes: a support body; a gas pipeline configured to be coiled around the outside of the support body in the height direction of the support body, the gas pipeline being used to at least partially throttle and liquefy the He vapor received from the above-mentioned transfer pump group based on the Joule-Thomson effect to form the above-mentioned He fluid; an extrusion assembly disposed outside the gas pipeline, the extrusion assembly being configured to, when driven by an external force, extrude the gas pipeline along the width direction of the support body to reduce the pipe diameter of the gas pipeline, thereby adjusting the resistance received by the He fluid flowing back to the above-mentioned mixing chamber. 3 3 3

[0009] Optionally, two surfaces of the above-mentioned support body close to the above-mentioned extrusion assembly are respectively provided with extrusion surfaces, and the two above-mentioned extrusion surfaces are configured to respectively have recesses, and the two above-mentioned recesses provide space for the above-mentioned extrusion assembly to extrude the gas pipeline.

[0010] Optionally, the above-mentioned extrusion assembly includes: two first rod portions respectively disposed outside the two above-mentioned recesses and extending along the height direction of the support body; two second rod portions respectively passing through both ends of the two above-mentioned first rod portions along the width direction of the support body to limit the support body between the two above-mentioned first rod portions; two first limiting members respectively disposed at one ends of the two above-mentioned second rod portions; and two second limiting members respectively rotatably disposed at the other ends of the two above-mentioned second rod portions to respectively adjust the positions of the two above-mentioned second rod portions between both ends of the two above-mentioned first rod portions.

[0011] ​​​​​​​Optionally, through holes are provided at opposite positions at both ends of the two above-mentioned first rod portions to allow the above-mentioned second rod portion to pass through.

[0012] Optionally, the two above-mentioned second limiting members are nuts, threaded portions are provided on both of the above-mentioned second rod portions, and the two above-mentioned nuts are threadedly engaged with the two above-mentioned threaded portions respectively; wherein, when the two above-mentioned nuts are driven by an external force, the two above-mentioned first rod portions are driven to approach each other to squeeze the above-mentioned gas pipeline in the width direction of the above-mentioned support body, so that the diameter of the above-mentioned gas pipeline is reduced.

[0013] Optionally, the above-mentioned 3 He enriched phase in the mixing chamber is configured to respond to the above-mentioned 3 He dilution phase 3 When the concentration of He decreases, compensate for the above-mentioned 3 He in the He dilution phase 3 while absorbing the surrounding heat for refrigeration.

[0014] Optionally, each of the above-mentioned dilution refrigeration units further includes: a multi-stage heat exchange assembly, each stage of the above-mentioned heat exchange assembly includes a first side and a second side, the first side is used to communicate with the above-mentioned 3 He dilution phase in the mixing chamber and the evaporation chamber, and the second side is used for the above-mentioned 3 He fluid to flow back to the above-mentioned 3 He enriched phase in the mixing chamber for heat exchange with the first side.

[0015] A dilution refrigeration system using modular parallel connection according to an embodiment of the present invention includes a plurality of dilution refrigeration units and a transfer pump group. The dilution refrigeration system using modular parallel connection is arranged in a vacuum chamber. The plurality of dilution refrigeration units share a transfer pump group. Each dilution refrigeration unit includes a mixing chamber, an evaporation chamber and a gas flow regulating device. The mixing chamber stores 3 He enriched phase in the upper layer and 3 He dilution phase in the lower layer. The evaporation chamber is communicated with the 3 He dilution phase in the mixing chamber. The evaporation chamber is used to separate 3 He vapor from the 3 He dilution phase. The gas flow regulating device is connected between the evaporation chamber and the transfer pump group. The transfer pump group extracts at least a part of the 3 He vapor in each evaporation chamber. The gas flow regulating device partially receives the 3 He vapor output from the transfer pump group, and liquefies at least part of the 3 He vapor received from the transfer pump group to form a 3Helium (He) fluid. The gas flow regulating devices of multiple dilution refrigeration units respectively adjust the diameters of their respective gas pipelines, so that the 3 resistance of the He fluid flowing back into the mixing chambers of the multiple dilution refrigeration units is the same, which can increase the refrigeration power of the dilution refrigeration units. Description of the Drawings

[0016] Figure 1 is a side view of two parallel dilution refrigeration units and a transfer pump group according to an embodiment of the present invention;

[0017] Figure 2 is a perspective view of two parallel dilution refrigeration units according to an embodiment of the present invention;

[0018] Figure 3 is a first perspective view of a gas flow regulating device according to an embodiment of the present invention;

[0019] Figure 4 is a second perspective view of a gas flow regulating device according to an embodiment of the present invention;

[0020] Figure 5 is a side view of a gas flow regulating device according to an embodiment of the present invention;

[0021] Figure 6 is Figure 5 a sectional view taken along the A-A direction.

[0022] In the drawings, the meanings of the reference numerals are as follows:

[0023] 1, vacuum chamber;

[0024] 100, dilution refrigeration unit;

[0025] 2, mixing chamber;

[0026] 3, evaporation chamber;

[0027] 4, heat exchange component;

[0028] 5, gas transmission pipeline;

[0029] 6, transfer pump group;

[0030] 7, gas flow regulating device;

[0031] 101, support body;

[0032] 102, gas pipeline;

[0033] 103, first rod portion;

[0034] 104, second rod portion;

[0035] 105, the first limiting member;

[0036] 106, the second limiting member. Detailed implementation manners

[0037] 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.

[0038] 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.

[0039] All terms used herein (including technical and scientific terms) have the meanings commonly understood by those skilled 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.

[0040] In the case of using expressions such as "at least one of A, B, and C, etc.", generally, it should be interpreted according to the meaning commonly understood by those skilled in the art (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.). In the case of using expressions such as "at least one of A, B, or C, etc.", generally, it should be interpreted according to the meaning commonly understood by those skilled in the art (for example, "a system having at least one of A, B, or 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.).

[0041] To solve the problem of low refrigeration power of a single dilution refrigeration unit, according to the inventive concept of one aspect of the present invention, a modular parallel dilution refrigeration system includes a plurality of dilution refrigeration units and a transfer pump group. The plurality of dilution refrigeration units are arranged in a vacuum chamber, and the plurality of dilution refrigeration units share a transfer pump group. Each dilution refrigeration unit includes a mixing chamber, an evaporation chamber, and a gas flow regulating device. The mixing chamber stores3 The He enriched phase and the 3 He diluted phase located in the lower layer. The evaporation chamber is in communication with the 3 He diluted phase in the mixing chamber. The evaporation chamber is used to separate 3 He vapor from the 3 He diluted phase. The gas flow regulating device is connected between the evaporation chamber and the transfer pump group. The transfer pump group extracts at least a part of the 3 He vapor in each evaporation chamber. The gas flow regulating device partially receives the 3 He vapor output from the transfer pump group, and 3 liquefies at least part of the 3 He vapor received from the transfer pump group to form a 3 He fluid that flows back to the mixing chamber. The gas flow regulating devices of multiple dilution refrigeration units adjust the diameters of their respective gas pipelines respectively, so that the

[0042] resistance received by the 3 He fluid flowing back to the mixing chambers of multiple dilution refrigeration units is the same, which can increase the refrigeration power of the dilution refrigeration units.

[0042] The dilution refrigeration system adopting modular parallel connection provided by the embodiment of the present invention includes multiple dilution refrigeration units and a transfer pump group. The multiple dilution refrigeration units are arranged in a vacuum chamber, and the multiple dilution refrigeration units share a transfer pump group. Each dilution refrigeration unit includes a mixing chamber, an evaporation chamber and a gas flow regulating device. The mixing chamber stores the 3 He enriched phase located in the upper layer and the 3 He diluted phase located in the lower layer. The evaporation chamber is in communication with the 3 He diluted phase in the mixing chamber. The evaporation chamber is used to separate 3 He vapor from the 3 He diluted phase. The gas flow regulating device is connected between the evaporation chamber and the transfer pump group. The transfer pump group extracts at least a part of the 3 He vapor in each evaporation chamber. The gas flow regulating device partially receives the 3 He vapor output from the transfer pump group, and 3 liquefies at least part of the 3 He vapor received from the transfer pump group and mixes it with the 3 unliquefied 3 He to form a

[0043] According to the embodiment of the present invention, in the dilution refrigeration unit, mainly 3 He and 4 He mixed working medium is used for refrigeration. When 3 He and4 When the He mixture is below 0.86 K, it will separate into two phases. The upper layer is the concentrated phase, and its main component is 3 He, that is 3 He solution. The lower layer is the dilute phase, and its main component is 3 He and 4 the mixture of He, among which 3 the proportion of He is about 6.4% - 6.6%.

[0044] According to an embodiment of the present invention, the resistance factors of the He fluid flowing back to the mixing chamber of the dilution refrigeration unit include pipeline resistance factors, gravity factors, flow resistance factors inside the heat exchange component, etc. The pipeline resistance is due to the fact that when the 3 He fluid flows back to the mixing chamber, it needs to pass through the pipeline, and the inner wall friction, bending and cross-section change of the pipeline will generate flow resistance. The gravity factor is that when the 3 He fluid flows back from the room temperature environment to the mixing chamber, it needs to overcome gravity (especially when the mixing chamber is in a lower position), and the gravity effect will increase the flow resistance. The flow resistance factor inside the heat exchange component is that when the 3 He fluid flows back to the mixing chamber, it needs to pass through multiple heat exchange components to reduce the temperature, and the internal structure of the heat exchange component will increase the flow resistance. And, when the 3 He vapor flows back to the mixing chamber, partial liquefaction will occur, forming a gas-liquid two-phase flow, and the flow resistance of the gas-liquid two-phase flow will be greater than that of the single-phase flow. 3 He vapor flows back to the mixing chamber, partial liquefaction will occur, forming a gas-liquid two-phase flow, and the flow resistance of the gas-liquid two-phase flow will be greater than that of the single-phase flow.

[0045] Figure 1 is a side view of two parallel dilution refrigeration units and a transfer pump group according to an embodiment of the present invention, Figure 2 is a three-dimensional view of two parallel dilution refrigeration units according to an embodiment of the present invention.

[0046] According to an embodiment of the present invention, the dilution refrigeration system using modular parallel connection includes multiple dilution refrigeration units 100 and a transfer pump group 6. The multiple dilution refrigeration units are arranged in the vacuum chamber 1, and the multiple dilution refrigeration units 100 share a transfer pump group 6. The multiple dilution refrigeration units 100 can be two, three, four, etc. Taking two dilution refrigeration units 100 as an example, as Figure 1 and Figure 2 shown, when connecting two adjacent dilution refrigeration units 100 in parallel, they need to share a transfer pump group 6. In order to make the 3The resistance of the He fluid is the same. A gas flow regulating device 7 is provided between the evaporation chambers 3 of the two dilution refrigeration units 100 and the shared transfer pump group 6. By adjusting the pipe diameters of the two gas flow regulating devices 7 respectively, the flow resistance of the gas pipelines 102 of the fluid flowing through the two gas flow regulating devices 7 is made the same, that is, at least a part of 3 Half of the He vapor is at least partially throttled and liquefied through the gas flow regulating device 7 between the evaporation chamber 3 on one side and the shared transfer pump group 6, and then mixed with the unliquefied 3 He to form 3 He fluid. After that 3 the He fluid flows back to the mixing chamber 2. 3 The other half of the He vapor is at least partially throttled and liquefied through the gas flow regulating device 7 between the evaporation chamber 3 on the other side and the shared transfer pump group 6, and then mixed with the unliquefied 3 He to form 3 He fluid. After that 3 the He fluid flows back to the mixing chamber 2. The 3 He fluids flowing back to the mixing chambers 2 of the two dilution refrigeration units 100 have the same resistance, which can ensure the 3 uniform reflux of the He fluid in the two dilution refrigeration units 100, avoid the flow imbalance caused by uneven resistance, and make the operation more stable. Moreover, the parallel connection enables 3 the total flow rate of He to increase, and more 3 He participates in the refrigeration cycle, saving expensive 3 He and improving the refrigeration power. 3 The increase in the total flow rate of He and the balance of the reflux resistance also improve the heat exchange efficiency and enhance the refrigeration effect. At the same time, connecting the two dilution refrigeration units 100 in parallel reduces the load of a single dilution refrigeration unit 100, reduces the risk of failure, and improves the reliability.

[0047] According to an embodiment of the present invention, in order to further expand the refrigeration power, the dilution refrigeration units 100 can be flexibly increased. Under the condition of meeting the requirements of the refrigeration power, the most reasonable energy efficiency ratio can be achieved, and the increase of ineffective power can be avoided. Multiple dilution refrigeration units 100 can share a transfer pump group 6, which can reduce the number of external transfer pump groups 6, reduce the difficulty of the control system, and further reduce the cost. At the same time, the operator can individually replace or remove a certain dilution refrigeration unit 100 among the multiple dilution refrigeration units 100, which provides great convenience for subsequent maintenance and adjustment of the refrigeration power.

[0048] According to an embodiment of the present invention, the 3 He enriched phase in the mixing chamber 2 is configured to respond to 3 in the 3The concentration of He decreases and compensates to the 3 He dilute phase 3 while He absorbs the surrounding heat for refrigeration.

[0049] According to an embodiment of the present invention, the mixing chamber 2 stores 3 a He concentrated 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 3 reaches a preset temperature, about 0.6K to 1K (Kelvin), generally 0.8K is selected. At this time, 3 the saturated vapor pressure of He is significantly higher than 4 that of He, so it is selectively evaporated. Inside the evaporation chamber 3, 3 the concentration of He decreases accordingly. The 3 He dilute phase in the mixing chamber 2 will supplement 3 He to the evaporation chamber 3, and then the 3 He in the He concentrated phase in the mixing chamber 2 3 dissolves 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 2 and the surrounding cold plates decreases, realizing dilution refrigeration. In addition, 3 after He is selectively evaporated, it becomes 3 He vapor. The transmission pump group 6 (including a vacuum pump, a compressor, etc.) pumps 3 the He vapor out of the evaporation chamber 3, pressurizes it and then returns it. To enable the dilution refrigeration to proceed continuously and cyclically, therefore, 3 the He vapor is at least partially throttled and depressurized through the gas flow regulating device 7 and then liquefied and mixed with the unliquefied 3 He to form 3 a He fluid, and then flows back to the 3 He concentrated phase in the mixing chamber 2, and then passes through the phase interface separating the concentrated phase and the dilute phase, so as to cycle for dilution refrigeration.

[0050] According to an embodiment of the present invention, the multiple evaporation chambers 3 of the multiple dilution refrigeration units 100 are all connected to a transmission pump group 6 through a gas transmission pipeline 5, so that the transmission pump group 6 can extract at least a part of 3 the He vapor in each evaporation chamber 3.

[0051] According to an embodiment of the present invention, the multiple dilution refrigeration units 100 share a transmission pump group 6, which can reduce the number of external transmission pump groups 6, reduce the difficulty of the control system, and further reduce the cost.

[0052] Figure 3The first perspective three-dimensional view of the gas flow regulating device according to an embodiment of the present invention, Figure 4 is the second perspective three-dimensional view of the gas flow regulating device according to an embodiment of the present invention.

[0053] According to an embodiment of the present invention, as Figure 3 and Figure 4 shown, the gas flow regulating device 7 is detachably connected between the evaporation chamber 3 and the transfer pump group 6, so as to facilitate replacing the next gas flow regulating device 7 after adjusting the diameter of the primary gas pipeline 102.

[0054] According to an embodiment of the present invention, if it is necessary to adjust the He vapor output from the transfer pump group 6 to different flow rates, the gas flow device 7 can be removed, and after replacing it with a new gas flow device 7, the gas pipeline 102 is re-squeezed along the width direction of the support body 101 to adjust the diameter of the gas pipeline 102, thereby regulating 3 the flow rate of the He fluid flowing through the gas pipeline 102. By adjusting 3 the flow rate of the He fluid to match the dilution refrigeration unit 100 and expand its performance limit, a foundation is laid for the further development of the dilution refrigeration unit 100. 3 By adjusting the flow rate of the He fluid to match the dilution refrigeration unit 100 and expand its performance limit, a foundation is laid for the further development of the dilution refrigeration unit 100.

[0055] According to an embodiment of the present invention, as Figure 3 and Figure 4 shown, the gas flow regulating device 7 includes a support body 101, a gas pipeline 102, and a squeezing 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. The gas pipeline 102 is used to at least partially throttle and liquefy the He vapor received from the transfer pump group 6 based on the Joule-Thomson effect and then mix with the unliquefied 3 He to form 3 He fluid. The squeezing assembly is arranged on the outside of the gas pipeline 102. The squeezing assembly is configured to squeeze the gas pipeline 102 along the width direction of the support body 101 when driven by an external force, so as to reduce the diameter of the gas pipeline 102, thereby regulating the resistance received by the 3 He fluid flowing back to the mixing chamber 2. 3 He fluid flowing back to the mixing chamber 2.

[0056] According to an embodiment of the present invention, during the process of the He vapor received from the transfer pump group 6 passing through the gas pipeline 102, when the squeezing assembly is driven by an external force, it squeezes the gas pipeline 102 along the width direction of the support body 101, the diameter of the gas pipeline 102 decreases, 3 the pressure of the He vapor decreases when flowing through the gas pipeline 102, 3 the He vapor undergoes the Joule-Thomson effect, due to 3 the He vapor undergoes the Joule-Thomson effect, due to 3The interatomic force between He atoms approaches the ideal gas level. Also, since 3 the inversion temperature of 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, which in turn causes a temperature change. When the temperature is greater than 40 K, the Joule-Thomson coefficient is negative, 3 and He heats up during throttling. When the temperature is less than 40 K, the Joule-Thomson coefficient is positive, 3 and He cools down during throttling. 3 At least part of the He vapor liquefies and then mixes with the unliquefied 3 He to form 3 He fluid.

[0057] According to an embodiment of the present invention, the height direction of the support body 101 is the Figure 4 Z direction shown in [reference], the width direction of the support body 101 is the Figure 4 X direction shown in [reference], and the length direction of the support body 101 is the Figure 4 Y direction shown in [reference].

[0058] According to an embodiment of the present invention, the gas pipeline 102 is wound around the outside of the support body 101 in the height direction of the support body 101. The gas pipeline 102 is used to throttle and liquefy at least part of the He vapor received from the transfer pump group 6 based on the Joule-Thomson effect and then mix it with the unliquefied 3 He to form 3 He fluid. 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 in the width direction of the support body 101. The gas flow regulating device 7 is suitable for the extremely low temperature working environment of the dilution refrigeration unit 100 and can flexibly adjust the pipe diameter of the gas pipeline 102, thereby regulating the 3 resistance of the He fluid flowing back to the mixing chamber 2, and it is simple to manufacture, has high use reliability, and a wide adjustable range. 3 He fluid is received, and the manufacturing is simple, the use reliability is high, and the adjustable range is wide.

[0059] 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 respectively configured to have recesses, and the two recesses provide space for the extrusion assembly to extrude the gas pipeline 102.

[0060] According to an embodiment of the present invention, the two concave portions provide necessary space for the extrusion assembly to extrude the gas pipeline 102, ensuring the smooth progress of the extrusion process, avoiding direct contact between the extrusion assembly and the support body 101, reducing mechanical interference and wear, prolonging the service life of the gas pipeline 102, and also facilitating subsequent maintenance and replacement. The two concave portions also make the extrusion pressure evenly distributed on the gas pipeline 102 along the height direction of the support body 101, preventing local stress concentration, providing a protective effect for the gas pipeline 102, and the uniform force application improves the stability of the extrusion process, ensuring the consistency of the extrusion effect of the gas pipeline 102 in the height direction of the support body 101. Moreover, the two extrusion surfaces respectively have concave portions, which can adapt to gas pipelines 102 of different sizes, improving flexibility and also enhancing the versatility of the gas flow regulating device 7.

[0061] According to an embodiment of the present invention, the extrusion assembly includes two first rod portions 103, two second rod portions 104, two first limiting members 105 and two second limiting members 106. The two first rod portions 103 are respectively arranged outside the two concave portions, and the two first rod portions 103 extend along the height direction of the support body 101. The two second rod portions 104 respectively pass through the two ends of the two first rod portions 103 along the width direction of the support body 101 to limit the support body 101 between the two first rod portions 103. The two first limiting members 105 are respectively arranged at one end of the two second rod portions 104. The two second limiting members 106 are respectively rotatably arranged at the other end of the two second rod portions 104 to respectively adjust the positions of the two second rod portions 104 between the two ends of the two first rod portions 103.

[0062] According to an embodiment of the present invention, when the two second limiting members 106 are driven by an external force to respectively adjust the positions of the two second rod portions 104 between the two ends of the two first rod portions 103, a device for detecting the flow rate can be externally connected to the gas pipeline 102, and by detecting 3 the flow rate of He steam flowing through the gas pipeline 102, the deformation caused by the extrusion force applied by the two first rod portions 103 to the gas pipeline 102 can be obtained. The applied external force is, for example, 10 N, the pressure of the gas pipeline 102 is 0.2 MPa, 3 and the flow rate of He steam flowing through the gas pipeline 102 is 20 ml / min.

[0063] Figure 5 is a side view of a gas flow regulating device according to an embodiment of the present invention, Figure 6 is Figure 5 a cross-sectional view in the A-A direction.

[0064] According to an embodiment of the present invention, as Figure 5 and Figure 6As 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.

[0065] 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.

[0066] According to an embodiment of the present invention, the two second stoppers 106 are nuts, and the two second rods 104 are both provided with threaded portions, and the two nuts are respectively threadedly engaged with the two threaded portions. When driven by an external force, the two nuts drive the two first rods 103 to approach each other, so as to squeeze the gas pipeline 102 along the width direction of the support body 101, so that the diameter of the gas pipeline 102 is reduced.

[0067] According to the embodiment of the present invention, two nuts are respectively threadedly engaged with two threaded parts, and when driven by external force, the two nuts drive one first rod part 103 to slide on the two second rod parts 104, and approach the other first rod part 103 to squeeze the gas pipeline 102 along the width direction of the support body 101, so that the diameter of the gas pipeline 102 is reduced. The two second rod parts 104 are both provided with threaded parts, which provide greater freedom of movement for the sliding of the first rod part 103, and a wide adjustable range.

[0068] According to an embodiment of the present invention, by changing the number of turns of the gas pipeline 102 wound around the outer side of the support body 101 in the height direction of the support body 101, the adjustable range of the gas flow is further expanded, and the number of turns can be 5 turns, 6 turns, 7 turns, etc.

[0069] According to an embodiment of the present invention, the cross section of the support body 101 in a plane perpendicular to the height direction is any one of opposing horseshoes, ellipses, trapezoids and squares.

[0070] According to an embodiment of the present invention, if the cross-section of the support body 101 in a plane perpendicular to the height direction is an opposed horseshoe or opposed ellipse, the arc-shaped structure can effectively disperse stress, reduce stress concentration, and extend the life of the support body 101. It can also better fit with the gas pipeline 102 and improve space utilization. If the cross-section of the support body 101 in a plane perpendicular to the height direction is an opposed trapezoid or an opposed square, the trapezoid and the square are wider than the horseshoe or the ellipse, and can provide good support and stability for the gas pipeline 102.

[0071] 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.

[0072] According to an embodiment of the present invention, if the material of the support body 101 is stainless steel, the stainless steel can maintain good toughness and strength in an extremely low-temperature working environment, has good corrosion resistance, and low cost. If the material of the support body 101 is 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 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.

[0073] According to an embodiment of the present invention, each dilution refrigeration unit 100 further includes a multi-stage heat exchange assembly 4. Each stage of the multi-stage heat exchange assembly 4 includes a first side and a second side. The first side is used to communicate with the 3 He dilution phase in the mixing chamber 2 and the evaporation chamber 3, and the second side is used to 3 return the He fluid to the 3 He enrichment phase in the mixing chamber 2 for heat exchange with the first side.

[0074] According to an embodiment of the present invention, the first side (cold side) of each stage of the heat exchange assembly 4 communicates the He dilution phase in the mixing chamber 2 with the evaporation chamber 3 when the evaporation chamber 3 reaches a preset temperature range, about 0.6K to 1K. 3 When the evaporation chamber 3 reaches a preset temperature range, about 0.6K to 1K. 3 The saturated vapor pressure of He is higher than that of 4 He, so it is evaporated and extracted separately. At this time, the 3 He concentration in the evaporation chamber 3 decreases, and the 3 He dilution phase in the mixing chamber 2 will supplement 3 He to the evaporation chamber 3 through the first side flow path. The transfer pump group 6 extracts at least a part of the 3 He vapor from each evaporation chamber 3. Each gas flow regulating device 7 of each dilution refrigeration unit 100 partially receives the 3 He vapor output from the transfer pump group 6, and based on the Joule-Thomson effect, at least partially throttles and condenses the 3 He vapor received from the transfer pump group 6 and mixes it with the unliquefied 3 He to form 3 He fluid, and returns it to the 3 He enrichment phase in the mixing chamber 2 through the second side (hot side) flow path. At this time, the 3 He concentration in the 3 He enrichment phase is greater than3 He concentration in the dilute phase 3 Therefore 3 He concentration in the concentrated phase 3 He will move towards 3 the He dilute phase. When 3 He passes through the phase interface, it absorbs the surrounding heat, causing the temperature of the mixing chamber 2 to drop, and thus the dilution refrigeration cycle proceeds.

[0075] According to an embodiment of the present invention, the heat exchange component 4 includes but is not limited to a disc-shaped radiator, which is separated by oxygen-free copper between its upper and lower layers to transfer heat, or a spiral double-tube radiator, where the inner and outer layers are separated by the tube wall to transfer heat.

[0076] Those skilled in the art can understand that the features described in various embodiments and / or claims of the present invention can be combined 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 various embodiments and / or claims 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.

[0077] It should also be noted that the directional terms mentioned in the embodiments, such as "upper", "lower", "front", "rear", "left", "right", etc., are only references to the directions in the drawings and are not used to limit the protection scope of the present invention. Throughout the drawings, the same elements are represented by the same or similar reference numerals. When it may cause confusion in the understanding of the present invention, the conventional structures or configurations will be omitted, and the shapes and sizes of the components in the drawings do not reflect the actual sizes and proportions, but only illustrate the content of the embodiments of the present invention.

[0078] Unless otherwise known to the contrary, the numerical parameters in this specification and the appended claims are approximate values and can be changed according to the required characteristics obtained through the content of the present invention. Specifically, all the numbers representing the contents of the composition, reaction conditions, etc. used in the specification and claims should be understood to be modified by the term "about" in all cases. Generally, the meaning it expresses is that it includes a change of ±10% in some embodiments, a change of ±5% in some embodiments, a change of ±1% in some embodiments, and a change of ±0.5% in some embodiments for a specific quantity.

[0079] The ordinal numbers such as "first", "second", "third", etc. used in the specification and claims are used to modify the corresponding elements, and they do not themselves mean that the element has any ordinal number, nor do they represent the order of one element and another element or the order in the manufacturing method. The use of these ordinal numbers is only to clearly distinguish one element with a certain name from another element with the same name.

[0080] In addition, unless the steps are specifically described or must occur in sequence, the order of the above steps is not limited to that listed above and can be varied or rearranged according to the required design. Moreover, based on considerations of design and reliability, the above embodiments can be used in combination with each other or with other embodiments, that is, the technical features in different embodiments can be freely combined to form more embodiments.

[0081] The embodiments of the present invention have been described above. However, these embodiments are only for illustrative purposes and not for limiting the scope of the present invention. Although the embodiments have been described separately above, this does not mean that the measures in each embodiment cannot be used advantageously in combination. The scope of the present invention is defined by the appended claims and their equivalents. Without departing from the scope of the present invention, those skilled in the art can make various substitutions and modifications, and these substitutions and modifications should all fall within the scope of the present invention.

Claims

1. A modular parallel dilution refrigeration system, characterized in that: It comprises a plurality of dilution refrigeration units and a transmission pump group, wherein the plurality of dilution refrigeration units are arranged in a vacuum chamber, the plurality of dilution refrigeration units share one transmission pump group, and each of the dilution refrigeration units comprises: A mixing chamber is provided in which the upper 3 The He-concentrated phase and the lower 3 He dilution phase; The evaporation chamber and the mixing chamber 3 He dilution is connected, and the evaporation chamber is used to extract 3 He is separated from the dilute phase 3 He steam; A gas flow regulating device is connected between the evaporation chamber and the transmission pump group, and the transmission pump group extracts at least a portion of each of the evaporation chambers. 3 He steam, the gas flow regulating device partially receives the gas output from the transmission pump group 3 He steam, and receives it from the transfer pump group 3 The He vapor is at least partially liquefied to form a 3 He fluid; The gas flow regulating devices of the plurality of dilution refrigeration units adjust the diameters of their respective gas pipelines so that the gas flowing back to the mixing chambers of the plurality of dilution refrigeration units is 3 The resistance encountered by the fluid is the same.

2. The modular parallel dilution refrigeration system according to claim 1, characterized in that: The plurality of evaporation chambers of the plurality of dilution refrigeration units are connected to a transmission pump group through a gas transmission pipeline, so that the transmission pump group can transfer at least a portion of each evaporation chamber. 3 And steam is extracted.

3. The modular parallel dilution refrigeration system according to claim 1, characterized in that: The gas flow regulating device is detachably connected between the evaporation chamber and the transmission pump group, so as to facilitate replacement of the next gas flow regulating device after adjusting the diameter of the gas pipeline once.

4. The modular parallel dilution refrigeration system according to claim 1, characterized in that: The gas flow regulating device comprises: Supporting the body; The gas pipeline is configured to be wound around the outside of the support body in the height direction of the support body, and the gas pipeline is used to receive the gas from the transmission pump group. 3 He steam is at least partially throttled and liquefied based on the Joule-Thomson effect to form the 3 He fluid; An extrusion assembly is arranged on the outside of the gas pipeline, and the extrusion assembly is configured to squeeze the gas pipeline along the width direction of the support body when driven by an external force to reduce the diameter of the gas pipeline, thereby adjusting the gas flowing back to the mixing chamber. 3 And the resistance of the fluid.

5. The modular parallel dilution refrigeration system according to claim 4, characterized in that: The two surfaces of the support body close to the extrusion assembly are respectively provided with extrusion surfaces, and the two extrusion surfaces are configured to have recesses respectively, and the two recesses provide space for the extrusion assembly to extrude the gas pipeline.

6. The modular parallel dilution refrigeration system according to claim 5, characterized in that: The extrusion assembly comprises: Two first rod portions are respectively arranged at the outer sides of the two recessed portions, and the two first rod portions extend along the height direction of the support body; Two second rod portions, respectively passing through two ends of the two first rod portions along the width direction of the support body, so as to restrict the support body between the two first rod portions; Two first limit members are respectively arranged at one end of the two second rod parts; The two second position-limiting members are rotatably disposed at the other ends of the two second rod portions, respectively, so as to respectively adjust the positions of the two second rod portions between the two ends of the two first rod portions.

7. The modular parallel dilution refrigeration system according to claim 6, characterized in that: Through holes are provided at opposite ends of the two first rod portions to allow the second rod portion to pass through.

8. The modular parallel dilution refrigeration system according to claim 6, characterized in that: The two second position-limiting members are nuts, the two second rod portions are both provided with threaded portions, and the two nuts are respectively threadedly coupled with the two threaded portions; Wherein, when driven by an external force, the two nuts drive the two first rod portions to approach each other, so as to squeeze the gas pipeline along the width direction of the support body, so that the diameter of the gas pipeline is reduced.

9. The modular parallel dilution refrigeration system according to claim 1, characterized in that: The mixing chamber 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 At the same time, it absorbs the surrounding heat to perform cooling.

10. The modular parallel dilution refrigeration system according to claim 1, characterized in that: Each of the dilution refrigeration units further comprises: A multi-stage heat exchange component, each stage of the heat exchange component includes a first side and a second side, the first side is used to communicate with the 3 He dilution phase and the evaporation chamber, the second side is used for the 3 He fluid flows back into the mixing chamber 3 The He concentrated phase is heat exchanged with the first side.

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