Integrated jet throttling ultra-low temperature cold head device

Abstract

The present application relates to the field of refrigeration and cryogenic engineering, and discloses an integrated jet throttling ultra-low temperature cold head device, comprising: a main jet, a limit clamp, a secondary jet, a low-pressure joint, a small orifice plate, a throttling joint, and an evaporator. The present invention utilizes the main jet to accelerate the high-pressure fluid, while maintaining the pressure difference between the fluid in the evaporator and the low-pressure channel through throttling by the small orifice plate. The secondary jet is used to mix and accelerate the high-pressure fluid and the fluid in the evaporator, causing the fluid in the evaporator to form a secondary pressure reduction, thereby ensuring that the pressure in the evaporator is further lower than that in the low-pressure channel, achieving a lower refrigeration temperature and reducing the low-pressure requirement of the low-pressure channel. In addition, the integrally welded sealing method ensures the compactness and integration of the jet and evaporator, which has a very positive significance for the practical application of ultra-low temperature throttling refrigerators.

Description

Technical Field

[0001] The present application relates to the field of refrigeration and cryogenic engineering, and in particular to the technology of throttling refrigerators in the extremely low temperature zone. Background Art

[0002] Cryogenic throttling refrigerators in the cryogenic zone utilize the isenthalpic expansion refrigeration effect of throttling helium fluid to achieve temperatures below 2K. These refrigerators have no moving parts at the cryogenic end and offer advantages such as long life, zero vibration, and high reliability. They have become a hot topic in recent research on small cryogenic refrigerators and hold broad application prospects in low-temperature superconductivity, quantum communications, and deep space exploration.

[0003] It should be pointed out that for the ultra-low temperature cold head, it is an important device that generates temperatures below 2K and exchanges heat with the actual heat load.

[0004] However, the overall performance of the current ultra-low temperature cold head still needs to be improved due to problems such as the low pressure in the evaporator is not low enough and the cold head structure is not compact enough. Summary of the Invention

[0005] The purpose of the present invention is to provide an integrated jet throttling cryogenic cold head device, which can more reasonably add jet drainage components, more effectively reduce the pressure in the evaporator, and ensure the compactness of the cold head structure, thereby significantly improving the overall performance of the cryogenic cold head.

[0006] The present application discloses an integrated injection throttling cryogenic cold head device, comprising: a main injector, a limit clamp, a secondary injector, a low-pressure joint, a small orifice plate, a throttling joint and an evaporator; wherein,

[0007] The evaporator is connected and sealed with the limit clamp and the throttling joint for heat exchange with an external load; wherein the lower part of the evaporator stores liquid helium, and the upper part stores gaseous helium flowing from right to left;

[0008] The main injector is connected and sealed to the limit clamp to increase the flow rate of the internal high-pressure fluid at its outlet;

[0009] The secondary injector is respectively connected and sealed with the limit clamp and the low-pressure joint, and is used to mix and reduce the pressure of the fluid from the primary injector and the evaporator;

[0010] The orifice plate is connected to the low-pressure joint, and the throttling joint is respectively connected and sealed to the low-pressure joint and the evaporator. The orifice plate is used to allow the fluid in the low-pressure joint to enter the throttling joint through throttling to form a fluid with lower pressure and lower temperature, thereby achieving ultra-low temperature refrigeration.

[0011] In a preferred embodiment, the main injector, the limit clamp, the secondary injector, the low-pressure joint, the orifice plate and the throttling joint are made of oxygen-free copper or stainless steel, and the evaporator is made of oxygen-free copper; and

[0012] The evaporator is connected and sealed with the limit clamp and the throttling joint by welding;

[0013] The main injector and the limit clamp are connected and sealed by welding;

[0014] The secondary injector is respectively connected and sealed to the limit clamp and the low-pressure joint by welding;

[0015] The orifice plate and the low-pressure joint are connected by welding; and

[0016] The throttling joint is respectively connected and sealed with the low-pressure joint and the evaporator by welding.

[0017] In a preferred embodiment, the feature is that the left side of the main injector comprises a cylindrical tube, and the outer diameter of the cylindrical tube is the same as the diameter of the through hole at the lower part of the limiting clamp.

[0018] In a preferred example, it is characterized in that: the right side of the main injector includes a cone with a smooth and tapered outer surface, the interior of the cone includes a high-pressure channel, a main injector throat and a main injector outlet, wherein the ratio of the diameter of the high-pressure channel to the main injector throat is 5:1 to 10:1, and the ratio of the diameter of the main injector outlet to the main injector throat is 2:1 to 4:1.

[0019] In a preferred example, it is characterized in that the upper portion and the side portion of the limiting clamp respectively include a groove for limiting the secondary ejector and the evaporator.

[0020] In a preferred embodiment, it is characterized in that:

[0021] The secondary injector is cylindrical in shape, and its interior is a channel that first gradually contracts and then gradually expands, wherein the secondary injector comprises three positions arranged in sequence: a secondary injector inlet, a secondary injector throat, and a secondary injector outlet; and

[0022] The ratio of the diameter of the secondary injector inlet to the secondary injector throat is the same as the ratio of the diameter of the secondary injector outlet to the secondary injector throat;

[0023] The ratio of the diameter of the secondary injector inlet to the diameter of the secondary injector throat is 1.5:1 to 3:1, and the ratio of the diameter of the secondary injector outlet to the diameter of the secondary injector throat is also 1.5:1 to 3:1; and

[0024] The ratio of the distance from the secondary injector inlet to the secondary injector throat to the distance from the secondary injector outlet to the secondary injector throat is 1:2 to 1:4.

[0025] In a preferred example, it is characterized in that: the upper part of the low-pressure joint includes a boss for guiding the low-pressure fluid; the side part includes a groove for limiting the secondary injector; and the lower part includes a groove for limiting the orifice plate and the throttling joint.

[0026] In a preferred embodiment, the feature is that the center of the pinhole plate comprises a pinhole channel with an inner diameter of 10 to 50 μm, and the ratio of the aperture of the pinhole channel to the thickness of the pinhole plate is 1:10 to 1:20.

[0027] In a preferred example, it is characterized in that the upper portion of the throttling joint includes a boss for limiting the low-pressure joint, and the lower portion of the throttling joint includes a boss for limiting the evaporator.

[0028] In a preferred example, it is characterized in that: the evaporator has a rectangular shape, the side surface of which is used to contact the load to provide low temperature and cooling capacity, and the upper part of the evaporator includes a boss for connecting and positioning with the limit clamp, and the right end of the evaporator includes a groove for connecting and positioning with the throttling joint.

[0029] In an embodiment of the present invention, first, a compact ejector is arranged before a conventional cold head evaporator, wherein the main ejector sharply increases the velocity of the incoming high-pressure fluid through an internal tapering and expanding structure, forming a negative pressure area at its outlet where the pressure is lower than the pressure inside the evaporator, thereby driving the gaseous fluid in the upper part of the evaporator to move toward this area; subsequently, the fluids from the main ejector and the evaporator are mixed at the throat position of the secondary ejector and accelerated to reduce the pressure again, and enter the low-pressure joint area, where the pressure is controlled by the pump group or compressor of the ultra-low temperature refrigerator.

[0030] Secondly, the cooperation between the ejector and the orifice plate further reduces the saturated vapor pressure inside the evaporator. In conventional ultra-low temperature cold heads, the evaporator is directly connected to the low-pressure channel. Therefore, the pressure of the low-pressure channel determines the temperature of the fluid in the evaporator, that is, the cooling temperature of the cold head. In this embodiment, the orifice plate isolates the pressure in the low-pressure channel from the pressure in the evaporator, making the pressure of the former higher than the latter. On the other hand, the ejector further reduces the pressure in the evaporator by diverting and accelerating the gaseous fluid.

[0031] Thus, the primary injector, the secondary injector and the orifice plate cooperate with each other in the above-mentioned specific manner to jointly form a stable pressure difference before and after throttling.

[0032] Third, the cold head achieves a compact structure. The primary ejector is tightly coupled to the secondary ejector via a stopcock, resulting in an overall size comparable to the evaporator. The rational design of the low-pressure connector, orifice plate, and throttling connector ensures close connection of all components. The integrated assembly method ensures the cold head can be sealed with a single, integral weld, eliminating the drawbacks of conventional throttling components and the loose layout of the evaporator.

[0033] In other words, on the one hand, the present invention utilizes the drainage effect of the ejector and the throttling effect of the orifice plate to jointly achieve a reduction in the saturated vapor pressure inside the evaporator, thereby further reducing the refrigeration temperature and alleviating the low-pressure demand of the low-pressure channel; on the other hand, through the reasonable design of each component, the cold head can be sealed through a one-time assembly and welding, ensuring the integration and compactness of the cold head.

[0034] Therefore, the integrated jet throttling cryogenic cold head device of the present invention can more reasonably add jet drainage components, more effectively reduce the pressure in the evaporator, and ensure the compactness of the cold head structure, thereby significantly improving the overall performance of the cryogenic cold head.

[0035] The various technical features disclosed in the above invention content, the various technical features disclosed in the various embodiments and examples below, and the various technical features disclosed in the accompanying drawings can be freely combined with each other to form various new technical solutions (all of which should be deemed to have been recorded in this specification), unless such a combination of technical features is technically infeasible. For example, in one example, feature A+B+C is disclosed, and in another example, feature A+B+D+E is disclosed. Features C and D are equivalent technical means that play the same role. Technically, only one of them needs to be used, and it is impossible to use them at the same time. Feature E can be technically combined with feature C. In this case, the solution of A+B+C+D should not be deemed to have been recorded because it is technically infeasible, while the solution of A+B+C+E should be deemed to have been recorded. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is an overall three-dimensional schematic diagram of an integrated jet throttling cryogenic cold head device according to a first embodiment of the present invention;

[0037] Figure 2 is an overall cross-sectional view of an integrated jet throttling cryogenic cold head device according to a first embodiment of the present invention;

[0038] Figure 3 3D schematic diagram of a main injector of an integrated injection-throttling cryogenic cold head device according to a first embodiment of the present invention;

[0039] Figure 4: is a structural diagram of a limit clamp of an integrated jet throttling cryogenic cold head device according to a first embodiment of the present invention, wherein: Figure 4 (a) is a three-dimensional schematic diagram of the limit clamp. Figure 4 (b) is a cross-sectional view of the limit clamp;

[0040] Figure 5 3D schematic diagram of a secondary injector of an integrated injection-throttling cryogenic cold head device according to a first embodiment of the present invention;

[0041] Figure 6 : is a structural diagram of a low-pressure joint of an integrated jet-throttling cryogenic cold head device according to a first embodiment of the present invention, wherein: Figure 6 (a) is a three-dimensional schematic diagram of the low-pressure joint. Figure 6 (b) is a cross-sectional view of the low-pressure connector;

[0042] Figure 7 : is a structural diagram of a throttling joint of an integrated jet throttling cryogenic cold head device according to a first embodiment of the present invention, wherein: Figure 7 (a) is a three-dimensional schematic diagram of the throttling joint. Figure 7 (b) is a cross-sectional view of the throttle joint;

[0043] Figure 8 : is a structural diagram of an evaporator of an integrated injection throttling cryogenic cold head device according to a first embodiment of the present invention, wherein: Figure 8 (a) is a three-dimensional schematic diagram of the evaporator. Figure 8 (b) is a cross-sectional view of the evaporator;

[0044] 1: Main injector

[0045] 2: Limiting card

[0046] 3: Secondary injector

[0047] 4: Low pressure connector

[0048] 5: Pinhole plate

[0049] 6: Throttle joint

[0050] 7: Evaporator

[0051] 8: High-voltage channel

[0052] 9: Main injector throat

[0053] 10: Main injector outlet

[0054] 11: Secondary injector inlet

[0055] 12: Secondary injector throat

[0056] 13: Secondary injector outlet DETAILED DESCRIPTION

[0057] In the following description, many technical details are provided to help readers better understand this application. However, those skilled in the art will understand that even without these technical details and various changes and modifications based on the following embodiments, the technical solutions claimed in this application can be implemented.

[0058] Description of some concepts:

[0059] A low-pressure joint refers to a joint whose internal cavity pressure is in the range of 5kPa to 10kPa, which corresponds to the saturated vapor pressure of helium fluid of 2K to 2.5K.

[0060] The high-pressure channel refers to the channel through which the helium fluid flows in the initial stage of entering the main injector, and the helium fluid pressure inside the channel is higher than 100kPa.

[0061] The low-pressure channel refers to the channel through which the fluid inside the low-pressure joint flows. The pressure of the fluid in this channel is in the range of 5kPa to 10kPa.

[0062] High-pressure fluid refers to helium fluid with a pressure higher than 100kPa.

[0063] Low-pressure fluid refers to helium fluid with a pressure ranging from 5kPa to 10kPa.

[0064] The following is a summary of some innovative features of the embodiments of the present invention:

[0065] After long-term and in-depth research, the inventors of the present invention found that the technical problems existing in the prior art, such as the lack of a jet drainage structure, high pressure in the evaporator, and a loose cold head structure, are inherently related to the following reasons.

[0066] First, existing cryogenic cold head devices lack an ejector, a crucial flow-guiding component. Ejectors are an effective means of reducing fluid pressure. They also create a negative pressure zone through a single jet flow, lowering the saturated vapor pressure within the evaporator. This plays a crucial role in lowering the cold head's cooling temperature and reducing the low-pressure demand on the low-pressure channel. Therefore, it's essential to rationally install an ejector, a flow-guiding component, before conventional orifice throttling.

[0067] Second, existing cryogenic cold head devices are relatively loosely structured. A complete throttling process includes high-pressure flow, throttling, evaporation, and low-pressure reflux, typically performed in separate components. Adding an ejector structure creates significant spacing between the components of a conventional cold head device, making it difficult to assemble and miniaturize cryogenic refrigerators. Therefore, it is necessary to design the cold head device in an integrated and compact manner.

[0068] Therefore, the inventors of the present invention creatively proposed an integrated jet throttling cryogenic cold head device, the main technical concepts of which include:

[0069] First, a compact ejector is set before the conventional cold head evaporator, in which the main ejector sharply increases the velocity of the incoming high-pressure fluid through the internal tapering and expanding structure, forming a negative pressure area at its outlet with a pressure lower than the pressure inside the evaporator, thereby driving the gaseous fluid in the upper part of the evaporator to move to this area; then, the fluids from the main ejector and the evaporator are mixed at the throat position of the secondary ejector and accelerated to reduce the pressure again, and enter the low-pressure joint area. The pressure of this part is controlled by the pump group or compressor of the ultra-low temperature refrigerator.

[0070] Second, the combined effect of the ejector and orifice plate further reduces the saturated vapor pressure within the evaporator. In conventional cryogenic cold heads, the evaporator is directly connected to the low-pressure channel. Therefore, the pressure in this low-pressure channel determines the temperature of the fluid within the evaporator, and therefore the cooling temperature of the cold head. In this embodiment, the orifice plate isolates the pressure within the low-pressure channel from the pressure within the evaporator, making the pressure in the low-pressure channel higher than the pressure in the evaporator. Furthermore, the ejector further reduces the pressure within the evaporator by directing and accelerating the gaseous fluid.

[0071] Thus, the primary injector, the secondary injector and the orifice plate cooperate with each other in the above-mentioned specific manner to jointly form a stable pressure difference before and after throttling.

[0072] Third, the cold head achieves a compact structure. The primary ejector is tightly coupled to the secondary ejector via a stopcock, resulting in an overall size comparable to the evaporator. The rational design of the low-pressure connector, orifice plate, and throttling connector ensures close connection of all components. The integrated assembly method ensures the cold head can be sealed with a single, integral weld, eliminating the drawbacks of conventional throttling components and the loose layout of the evaporator.

[0073] In summary, the present invention, on the one hand, utilizes the drainage effect of the ejector and the throttling effect of the orifice plate to jointly achieve the reduction of the saturated vapor pressure inside the evaporator, thereby further reducing the refrigeration temperature and alleviating the low-pressure demand of the low-pressure channel; on the other hand, through the reasonable design of each component, the cold head can be sealed through one-time assembly and welding, ensuring the integration and compactness of the cold head.

[0074] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0075] A first embodiment of the present invention relates to an integrated jet throttling cryogenic cold head device.

[0076] Preferably, the extremely low temperature cold head device refers to a cold head device operating at, for example, 2K (ie, -271.15° C.) or below.

[0077] like Figure 1 and Figure 2 As shown, the integrated injection throttling cryogenic cold head device 100 includes: a main injector 1, a limit clamp 2, a secondary injector 3, a low-pressure joint 4, a small orifice plate 5, a throttling joint 6 and an evaporator 7.

[0078] Specifically, the evaporator 7 is a component for performing heat exchange with an external load, and is connected and sealed with the limit clamp 2 and the throttle joint 6 by welding.

[0079] The lower part of the evaporator 7 stores liquid helium, and the upper part stores gaseous helium flowing from right to left.

[0080] More specifically, the main injector 1 and the limit clamp 2 are connected and sealed by welding; the main injector 1 is used to increase the flow rate of the internal high-pressure fluid at its outlet; the secondary injector 3 is connected and sealed to the limit clamp 2 and the low-pressure joint 4 by welding; the secondary injector 3 is used to mix and reduce the pressure of the fluids from the main injector 1 and the evaporator 7.

[0081] Furthermore, the orifice plate 5 and the low-pressure joint 4 are connected by welding; the throttling joint 6, the low-pressure joint 4 and the evaporator 7 are connected and sealed by welding; the orifice plate 5 is used to allow the fluid in the low-pressure joint to enter the throttling joint 6 through throttling, becoming a fluid with lower pressure and lower temperature, thereby achieving the purpose of ultra-low temperature refrigeration.

[0082] In one embodiment of the present invention, the main injector 1, the limit clamp 2, the secondary injector 3, the low-pressure joint 4, the orifice plate 5, and the throttling joint 6 are made of oxygen-free copper or stainless steel, and the evaporator 7 is made of oxygen-free copper.

[0083] For example, the main injector 1, the limit clamp 2, the secondary injector 3, the low-pressure joint 4, the orifice plate 5, and the throttling joint 6 are all made of stainless steel, and the evaporator 7 is made of oxygen-free copper. The components are connected and sealed by vacuum brazing.

[0084] In one embodiment of the present invention, the left side of the main injector 1 includes a cylindrical tube, the outer diameter of which is the same as the diameter of the through hole at the bottom of the limiting clamp 2.

[0085] For example, the outer diameter of the cylindrical tube on the left side of the main injector 1 and the diameter of the through hole at the bottom of the limiting clamp 2 are both 3.5 mm.

[0086] like Figure 3As shown, in one embodiment of the present invention, the right side of the main injector 1 includes a cone with a smooth and tapered outer surface, the interior of which includes a high-pressure channel 8, a main injector throat 9 and a main injector outlet 10, wherein the ratio of the diameters of the high-pressure channel 8 to the main injector throat 9 is 5:1 to 10:1, and the ratio of the diameters of the main injector outlet 10 to the main injector throat 9 is 2:1 to 4:1.

[0087] For example, the cross-sectional diameters of the high-pressure passage 8 , the main injector throat 9 , and the main injector outlet 10 inside the main injector 1 are 3 mm, 0.5 mm, and 1 mm, respectively.

[0088] Furthermore, the upper portion and the side portion of the limiting clamp 2 respectively include a groove for limiting the secondary injector 3 and the evaporator 7 .

[0089] like Figure 5 As shown, in one embodiment of the present invention, the secondary injector 3 is cylindrical in shape, and its interior is a channel that first gradually contracts and then gradually expands, including three positions arranged in sequence: a secondary injector inlet 11, a secondary injector throat 12 and a secondary injector outlet 13.

[0090] Preferably, the ratio of the diameter of the secondary injector inlet 11 to the secondary injector throat 12 is 1.5:1 to 3:1, the ratio of the diameter of the secondary injector outlet 13 to the secondary injector throat 12 is also 1.5:1 to 3:1, and the ratio of the distance from the secondary injector inlet 11 to the secondary injector throat 12 to the distance from the secondary injector outlet 13 to the secondary injector throat 12 is 1:2 to 1:4.

[0091] For example, the cross-sectional diameters of the secondary injector inlet 11, the secondary injector throat 12, and the secondary injector outlet are 5 mm, 2.5 mm, and 5 mm, respectively; the distance from the secondary injector inlet 11 to the secondary injector throat 12 is 6 mm, and the distance from the secondary injector outlet 13 to the secondary injector throat 12 is 18 mm.

[0092] Furthermore, the upper portion of the low-pressure joint 4 includes a boss for guiding the low-pressure fluid; the side portion includes a groove for limiting the secondary injector 3; and the lower portion also includes a groove for limiting the orifice plate 5 and the throttling joint 6.

[0093] In one embodiment of the present invention, the center of the orifice plate 5 comprises a small hole channel with an inner diameter of 10 to 50 μm. Preferably, the ratio of the hole diameter of the small hole channel to the thickness of the orifice plate 5 is 1:10 to 1:20.

[0094] For example, the diameter of the pinhole channel at the center of the pinhole plate 5 is 30 μm, and the thickness of the pinhole plate 5 is 0.5 mm.

[0095] The upper portion and the side portion of the throttling joint 6 each include a boss, which is used to limit the low-pressure joint 4 and the evaporator 7 respectively.

[0096] In one embodiment of the present invention, the evaporator 7 has a rectangular shape, and its side surface is used to contact the load to provide low temperature and cooling capacity. Its upper part and right end respectively contain a boss and a groove, which are respectively used to connect and position with the limit clamp 2 and the throttling joint 6.

[0097] Furthermore, the technical effects of the above embodiments include at least:

[0098] First, a compact ejector structure is set before the conventional cold head evaporator, in which the main ejector 1 sharply increases the velocity of the incoming high-pressure fluid through the internal contraction and expansion structure, forming a negative pressure area at its outlet with a pressure lower than the pressure in the evaporator 7, thereby driving the gaseous fluid in the upper part of the evaporator 7 to move to this area; then, the fluids from the main ejector 1 and the evaporator 7 are mixed at the throat 12 of the secondary ejector and accelerated to reduce the pressure again, and enter the low-pressure joint 4 area, and the pressure of this part is controlled by the pump group or compressor of the ultra-low temperature refrigerator.

[0099] Second, the primary ejector 1, secondary ejector 3, and orifice plate 5 work together to further reduce the saturated vapor pressure within the evaporator 7. In this embodiment, the orifice plate 5 isolates the pressure within the low-pressure connector 4 from that within the evaporator 7, making the pressure within the former higher than that within the latter. Furthermore, the primary ejector 1 and secondary ejector 3 further reduce the pressure within the evaporator 7 by directing and accelerating the gaseous fluid.

[0100] Thus, the primary injector 1 , the secondary injector 3 and the orifice plate 5 cooperate with each other in the above-mentioned specific manner to jointly form a stable pressure difference before and after throttling.

[0101] Third, the cold head device achieves a compact structure. The primary injector 1 is tightly coupled to the secondary injector 3 via the stopper 2, and its overall size is comparable to that of the evaporator 7. The rational design of the low-pressure connector 4, orifice plate 5, and throttling connector 6 also ensures the close connection of all components of the cold head device. The integrated assembly method ensures that the cold head device can be sealed through a single integral welding process, achieving the integration and compactness of the cold head device.

[0102] In summary, the embodiments of the present invention, on the one hand, utilize the drainage effect of the main injector 1 and the secondary injector 3 and the throttling effect of the orifice plate 5 to jointly achieve the reduction of the saturated vapor pressure inside the evaporator 7, thereby further reducing the refrigeration temperature and alleviating the demand for low pressure inside the low-pressure joint 4; on the other hand, through the reasonable design of each component, the cold head can be sealed by a one-time assembly and welding, thereby ensuring the integration and compactness of the cold head.

[0103] Therefore, the integrated jet throttling cryogenic cold head device 100 of the embodiment of the present invention can more reasonably add jet drainage components, more effectively reduce the pressure in the evaporator, and ensure the compactness of the cold head structure, thereby significantly improving the overall performance of the cryogenic cold head.

[0104] It should be noted that, in the disclosure, relational terms such as first and second are merely used to distinguish one entity or operation from another, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprise," "include," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article, or device. Without further restriction, an element defined by the phrase "comprising a" does not exclude the presence of other identical elements in the process, method, article, or device comprising the element. In this application, if it is mentioned that an action is performed according to a certain element, it means that the action is performed at least according to that element, including two situations: performing the action only according to that element, and performing the action according to that element and other elements. Expressions such as "multiple," "multiple," and "multiple" include 2, 2 times, 2 kinds, and more than 2, more than 2 times, and more than 2 kinds.

[0105] This specification includes combinations of the various embodiments described herein. Separate references to an embodiment (e.g., "one embodiment" or "some embodiments" or "preferred embodiments") do not necessarily refer to the same embodiment; however, these embodiments are not mutually exclusive unless indicated as such or clear to one skilled in the art. It should be noted that the word "or" is used in this specification in a non-exclusive sense unless the context clearly indicates or requires otherwise.

[0106] All documents mentioned in this application are considered to be included in their entirety in the disclosure of this application so that they can be used as a basis for modification when necessary. In addition, it should be understood that after reading the contents of this application, those skilled in the art may make various changes or modifications to this application, and these equivalent forms also fall within the scope of protection claimed in this application.

Claims

1. An integrated jet throttling cryogenic cold head device (100), characterized in that: include: A main injector (1), a limit clamp (2), a secondary injector (3), a low-pressure joint (4), a small orifice plate (5), a throttling joint (6) and an evaporator (7); wherein, The evaporator (7) is connected and sealed with the limit clamp (2) and the throttling joint (6) for heat exchange with an external load; wherein the lower part of the evaporator (7) stores liquid helium, and the upper part stores gaseous helium flowing from right to left; The main injector (1) is connected and sealed to the limit clamp (2) to increase the flow rate of the internal high-pressure fluid at its outlet; The secondary injector (3) is respectively connected to and sealed with the limit clamp (2) and the low-pressure joint (4), and is used to mix and reduce the pressure of the fluid from the main injector (1) and the evaporator (7); The orifice plate (5) is connected to the low-pressure joint (4), and the throttling joint (6) is respectively connected to and sealed with the low-pressure joint (4) and the evaporator (7). The orifice plate (5) is used to allow the fluid in the low-pressure joint to enter the throttling joint (6) through throttling to form a fluid with lower pressure and lower temperature, thereby achieving ultra-low temperature refrigeration.

2. The integrated jet throttling cryogenic cold head device (100) according to claim 1, characterized in that: The main injector (1), the limit clamp (2), the secondary injector (3), the low-pressure joint (4), the orifice plate (5) and the throttling joint (6) are made of oxygen-free copper or stainless steel, and the evaporator (7) is made of oxygen-free copper; and The evaporator (7) is connected and sealed to the limit clamp (2) and the throttle joint (6) by welding; The main injector (1) and the limit clamp (2) are connected and sealed by welding; The secondary injector (3) is respectively connected and sealed to the limit clamp (2) and the low-pressure joint (4) by welding; The orifice plate (5) and the low-pressure joint (4) are connected by welding; and The throttling joint (6) is respectively connected and sealed to the low-pressure joint (4) and the evaporator (7) by welding.

3. The integrated jet throttling cryogenic cold head device (100) according to claim 1, characterized in that: The left side of the main injector (1) comprises a cylindrical tube, the outer diameter of which is the same as the diameter of the through hole at the bottom of the limiting clamp (2).

4. The integrated jet throttling cryogenic cold head device (100) according to claim 1, characterized in that: The right side of the main injector (1) includes a cone with a smooth and tapered outer surface, and the interior of the cone includes a high-pressure channel (8), a main injector throat (9) and a main injector outlet (10), wherein the ratio of the diameters of the high-pressure channel (8) to the main injector throat (9) is 5:1 to 10:1, and the ratio of the diameters of the main injector outlet (10) to the main injector throat (9) is 2:1 to 4:

1.

5. The integrated jet throttling cryogenic cold head device (100) according to claim 1, characterized in that: The upper portion and the side portion of the limiting clamp (2) respectively comprise a groove for limiting the secondary ejector (3) and the evaporator (7).

6. The integrated jet throttling cryogenic cold head device (100) according to claim 1, characterized in that: The secondary injector (3) is cylindrical in shape, and its interior is a channel that first gradually contracts and then gradually expands, wherein the secondary injector (3) comprises three positions, namely, a secondary injector inlet (11), a secondary injector throat (12), and a secondary injector outlet (13), which are arranged in sequence; and The ratio of the diameter of the secondary injector inlet (11) to the diameter of the secondary injector throat (12) is the same as the ratio of the diameter of the secondary injector outlet (13) to the diameter of the secondary injector throat (12); The ratio of the diameter of the secondary injector inlet (11) to the diameter of the secondary injector throat (12) is 1.5:1 to 3:1, and the ratio of the diameter of the secondary injector outlet (13) to the diameter of the secondary injector throat (12) is also 1.5:1 to 3:1; and The ratio of the distance from the secondary injector inlet (11) to the secondary injector throat (12) to the distance from the secondary injector outlet (13) to the secondary injector throat (12) is 1:2 to 1:

4.

7. The integrated jet throttling cryogenic cold head device (100) according to claim 1, characterized in that: The upper portion of the low-pressure joint (4) includes a boss for guiding the low-pressure fluid; the side portion includes a groove for limiting the position of the secondary injector (3); and the lower portion includes a groove for limiting the orifice plate (5) and the throttling joint (6).

8. The integrated jet throttling cryogenic cold head device (100) according to claim 1, characterized in that: The center of the pinhole plate (5) comprises a pinhole channel with an inner diameter of 10 to 50 μm, and the ratio of the aperture of the pinhole channel to the thickness of the pinhole plate (5) is 1:10 to 1:

20.

9. The integrated jet throttling cryogenic cold head device (100) according to claim 1, characterized in that: The upper portion of the throttling joint (6) includes a boss for limiting the low-pressure joint (4), and the lower portion of the throttling joint (6) includes a boss for limiting the evaporator (7).

10. The integrated jet throttling cryogenic cold head device (100) according to claim 1, characterized in that: The evaporator (7) has a rectangular shape, and its side surface is used to contact the load to provide low temperature and cooling capacity. The upper part of the evaporator (7) includes a boss for connecting and positioning with the limit clamp (2), and the right end of the evaporator (7) includes a groove for connecting and positioning with the throttling joint (6).

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