Low-temperature heat exchanger and sample rod

Abstract

The utility model relates to the technical field of low-temperature testing, and discloses a low-temperature heat exchanger which comprises an inner pipe, an outer pipe, a cold head and a corrugated pipe section. A first refrigerant channel is arranged in the inner pipe; the outer pipe is sleeved outside the inner pipe; the outer surface of the inner pipe and the inner surface of the outer pipe form a second refrigerant channel; the cold head comprises a third refrigerant channel communicating with the first refrigerant channel. The third refrigerant channel is communicated with the second refrigerant channel; and the corrugated pipe section is arranged on the inner pipe and / or the outer pipe. The corrugated pipe section is arranged on the inner pipe and / or the outer pipe, so that the sample rod or other parts can be cooled through the low-temperature heat exchanger, and meanwhile, the transmission of cold source vibration on a refrigerant circulating part of the low-temperature heat exchanger is reduced, so that the influence of the cold source vibration on sample detection in a low-temperature environment is reduced, and the detection accuracy is improved. The reliability of a sample detection result is improved. The utility model further discloses a sample rod.

Description

Technical Field

[0001] This application relates to the technical field of cryogenic testing, for example, to a cryogenic heat exchanger and a sample rod. Background Art

[0002] Currently, a cryogenic heat exchanger is a device that can provide low-temperature heat exchange equipment and is widely used in constant temperature tests or tests on test samples or products in production. However, existing cryogenic heat exchangers have poor heat exchange performance due to excessive heat leakage and large size.

[0003] Related technologies disclose a cryogenic heat exchanger, including: a heat exchanger core, a heat exchanger housing, and a cold head; the heat exchanger core is arranged inside the heat exchanger housing, and the cold head is connected to the heat exchanger housing; the inside of the heat exchanger core includes a first flow channel composed of a plurality of axially extending holes, and the inlet of the first flow channel is used to introduce a cooling fluid; the surface of the heat exchanger core includes a plurality of convex structures, and the surface of the heat exchanger core and the inner surface of the heat exchanger housing form a second flow channel, and the outlet of the second flow channel is used to export the cooling fluid; the heat exchanger core includes a through hole that communicates the outlet of the first flow channel and the inlet of the second flow channel.

[0004] In the process of implementing the embodiments of the present disclosure, it is found that at least the following problems exist in the related technologies:

[0005] To a certain extent, the related technologies improve the heat exchange efficiency of the cryogenic heat exchanger. However, in the actual application process, when the cryogenic heat exchanger cools the cold head by introducing a refrigerant through a cold source, the cold source will vibrate, which causes the components of the cryogenic heat exchanger that circulate the refrigerant to vibrate, and further causes the sample rod that exchanges heat with the cryogenic heat exchanger to vibrate unexpectedly, affecting the sample detection in a low-temperature environment and reducing the reliability of the detection results.

[0006] The above information disclosed in the background art section is only used to enhance the understanding of the background of the present utility model, and therefore may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Utility Model

[0007] To have a basic understanding of some aspects of the disclosed embodiments, a simple summary is given below. The summary is not a general review, nor is it intended to identify key / important constituent elements or delineate the protection scope of these embodiments, but rather serves as a preface to the subsequent detailed description.

[0008] Embodiments of the present disclosure provide a cryogenic heat exchanger and a sample rod to reduce the influence of cold source vibration on sample detection in a low-temperature environment and improve the reliability of sample detection results.

[0009] In some embodiments, the cryogenic heat exchanger includes: an inner tube with a first refrigerant channel disposed therein; an outer tube sleeved outside the inner tube; wherein, the outer surface of the inner tube and the inner surface of the outer tube form a second refrigerant channel; a cold head including a third refrigerant channel communicating with the first refrigerant channel; wherein, the third refrigerant channel communicates with the second refrigerant channel; a corrugated tube section disposed on the inner tube and / or the outer tube.

[0010] Optionally, the corrugated tube section includes: an inner tube corrugated tube section disposed on the inner tube; an outer tube corrugated tube section disposed on the outer tube.

[0011] Optionally, the outer tube corrugated tube section is disposed on both sides of the inner tube corrugated tube section.

[0012] Optionally, the cryogenic heat exchanger further includes: a secondary heat exchanger respectively connected to the second refrigerant channel and the outer surface of the outer tube; wherein, a fourth refrigerant channel communicating with the second refrigerant channel is disposed inside the secondary heat exchanger.

[0013] Optionally, the second refrigerant channel includes: a plurality of axial diversion channels disposed at the inlet of the fourth refrigerant channel.

[0014] Optionally, the plurality of axial diversion channels are disposed between the corrugated tube section and the secondary heat exchanger.

[0015] Optionally, the axial diversion channels extend axially along the outer surface of the inner tube and are arranged circumferentially on the outer surface of the inner tube.

[0016] Optionally, the axial diversion channels include: a plurality of convex structures extending axially along the outer surface of the inner tube and arranged circumferentially; wherein, adjacent convex structures are connected to the outer surface of the inner tube and the inner surface of the outer tube to form the axial diversion channels.

[0017] Optionally, the axial diversion channels further include: a circumferential diversion channel formed by channel gaps formed by a plurality of convex structures extending axially along the outer surface of the inner tube, and adjacent axial diversion channels communicate through the circumferential diversion channel.

[0018] In some embodiments, the sample rod includes: the above-mentioned cryogenic heat exchanger.

[0019] The cryogenic heat exchanger and the sample rod provided by the embodiments of the present disclosure can achieve the following technical effects:

[0020] The cryogenic heat exchanger includes an inner tube, an outer tube, a cold head, and a corrugated tube section disposed on the inner tube and / or the outer tube. A first refrigerant channel for introducing refrigerant is provided inside the inner tube, and a second refrigerant channel for discharging refrigerant is formed by the inner surface of the outer tube and the outer surface of the inner tube. The cold head includes a third refrigerant channel communicating with the first refrigerant channel for heat exchange between the cold head and the refrigerant introduced into the first refrigerant channel. The third refrigerant channel communicates with the second refrigerant channel, so that the refrigerant heat-exchanged with the cold head in the third refrigerant channel is discharged from the second refrigerant channel. The corrugated tube section is disposed on the inner tube and / or the outer tube. By providing the corrugated tube section on the inner tube and / or the outer tube, while cooling the sample rod or other components through the cryogenic heat exchanger, the transmission of cold source vibration to the components of the circulating refrigerant in the cryogenic heat exchanger can be reduced, thereby reducing the influence of cold source vibration on sample detection in a low-temperature environment and improving the reliability of sample detection results.

[0021] The above general description and the following description are only exemplary and explanatory and are not intended to limit the present application. Brief Description of the Drawings

[0022] One or more embodiments are exemplarily illustrated by corresponding drawings. These exemplary illustrations and the drawings do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements. The drawings do not constitute a scale limitation, and among them:

[0023] Figure 1 is a schematic structural diagram of a cryogenic heat exchanger provided by an embodiment of the present disclosure;

[0024] Figure 2 is a schematic structural diagram of another cryogenic heat exchanger provided by an embodiment of the present disclosure;

[0025] Figure 3 is a schematic structural diagram of another cryogenic heat exchanger provided by an embodiment of the present disclosure;

[0026] Figure 4 is a schematic structural diagram of the surface of an inner tube provided by an embodiment of the present disclosure;

[0027] Figure 5 is a schematic cross-sectional structural diagram of an inner tube provided by an embodiment of the present disclosure;

[0028] Figure 6 is a schematic overall structural diagram of a sample rod provided by an embodiment of the present disclosure;

[0029] Figure 7 is a schematic internal structural diagram of a sample rod provided by an embodiment of the present disclosure.

[0030] Reference Numerals:

[0031] 10: Inner tube; 11: First refrigerant channel; 12: Heat exchanger inlet;

[0032] 20: Outer tube; 21: Second refrigerant channel; 22: Heat exchanger outlet; 23: Protrusion structure; 24: Axial flow guide channel; 25: Channel notch; 26: Circumferential flow guide channel;

[0033] 30: Cold head; 31: Third refrigerant channel; 32: Through hole; 33: Return gap;

[0034] 40: First bellows section; 41: Second bellows section; 42: Third bellows section;

[0035] 50: Secondary heat exchanger; 51: Fourth refrigerant channel;

[0036] 60: Air extraction port; 61: Transparent window; 62: Sample rod; 63: Vacuum chamber; 64: Cold screen; 65: Heat insulation element. Detailed implementation manners

[0037] In order to be able to understand the features and technical content of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure will be described in detail below in conjunction with the accompanying drawings. The accompanying drawings are only for reference and illustration purposes and are not used to limit the embodiments of the present disclosure. In the following technical description, for the sake of explanation, multiple details are provided to provide a full understanding of the disclosed embodiments. However, one or more embodiments can still be implemented without these details. In other cases, well-known structures and devices can be shown in a simplified manner.

[0038] It should be noted that, without conflict, the embodiments in the embodiments of the present disclosure and the features in the embodiments can be combined with each other.

[0039] Combined with Figure 1 As shown, the embodiments of the present disclosure provide a cryogenic heat exchanger, including an inner tube 10, an outer tube 20, a cold head 30 and a bellows section. A first refrigerant channel 11 is provided inside the inner tube 10. The outer tube 20 is sleeved outside the inner tube 10; wherein, the outer surface of the inner tube 10 and the inner surface of the outer tube 20 form a second refrigerant channel 21. The cold head 30 includes a third refrigerant channel 31 communicated with the first refrigerant channel 11; wherein, the third refrigerant channel 31 is communicated with the second refrigerant channel 21. The bellows section is arranged on the inner tube 10 and / or the outer tube 20.

[0040] In the embodiments of the present disclosure, the inner tube 10 and the outer tube 20 are in the form of a sleeve, that is, the inner tube 10 is disposed inside the outer tube 20. Specifically, the first refrigerant channel 11 provided inside the inner tube 10 can be in any form as long as it can send the refrigerant introduced from the heat exchanger inlet 12 into the third refrigerant channel 31 inside the cold head 30. For example, the inner tube 10 can be a cylindrical tube, and the inside of the cylindrical tube is the first refrigerant channel 11 for introducing the refrigerant; or, a plurality of holes extending along the axial direction of the inner tube 10 can be provided inside the inner tube 10, and the plurality of holes extending along the axial direction of the inner tube 10 together form the first refrigerant channel 11.

[0041] In the embodiments of the present disclosure, the cold head 30 is connected to the outer tube 20, and the cold head 30, the inner surface of the outer tube 20 and the outer surface of the inner tube 10 together form a second refrigerant channel 21, and the reflux refrigerant can flow through the second refrigerant channel 21 and flow out from the heat exchanger outlet 22. The cold head 30 and the inner tube 10 can be in any connection manner as long as the third refrigerant channel 31 can be communicated with the second refrigerant channel 21, and the cold head 30 can exchange heat through the refrigerant in the third refrigerant channel 31.

[0042] In some embodiments, the cold head 30 is directly connected to the inner tube 10, and the third refrigerant channel 31 and the second refrigerant channel 21 can be communicated through a through hole 32 provided on the cold head 30. As shown in Figure 1 The cold head 30 can be set as a tubular structure corresponding to the inner tube 10, and the inside of the tubular structure is the third refrigerant channel 31. A tube seat connected to the outer tube 20 is provided on the side of the tubular structure away from the inner tube 10. The tube seat, the outer surface of the tubular structure, the inner surface of the outer tube 20 and the outer surface of the inner tube 10 together form the inlet of the second refrigerant channel 21. A part of the tubular structure corresponding to the third refrigerant channel 31 is inserted into the inner tube 10. For example, the tubular structure part corresponding to the third refrigerant channel 31 is inserted into the first refrigerant channel 11, or the tubular structure part corresponding to the outlet of the first refrigerant channel 11 is inserted into the third refrigerant channel 31. By inserting the tubular structure part corresponding to the third refrigerant channel 31 into the inner tube 10, the communication between the first refrigerant channel 11 and the third refrigerant channel 31 is realized. The through hole 32 can be provided on the tubular structure part of the cold head 30 that is not inserted into the first refrigerant channel 11. Thus, after the refrigerant in the third refrigerant channel 31 exchanges heat, it can flow out through the through hole 32 to the inlet of the second refrigerant channel 21.

[0043] In other embodiments, the cold head 30 and the inner tube 10 may not be connected, forming a channel reflux gap 33, and the third refrigerant channel 31 and the second refrigerant channel 21 are communicated through the reflux gap 33 between the cold head 30 and the inner tube 10. As shown in Figure 2As shown in the figure, the cold head 30 can be set as a tubular structure corresponding to the inner tube 10. Inside the tubular structure is the third refrigerant channel 31. A pipe seat connected to the outer tube 20 is provided on the side of the tubular structure away from the inner tube 10. The pipe seat, the outer surface of the tubular structure, the inner surface of the outer tube 20, and the outer surface of the inner tube 10 together form the inlet of the second refrigerant channel 21. The outlet pipe section of the inner tube 10 corresponding to the outlet of the first refrigerant channel 11 is arranged inside the third refrigerant channel 31. The diameter of the outlet pipe section is smaller than the part of the tubular structure corresponding to the third refrigerant channel 31. Thus, a reflux gap 33 can be formed between the outer surface of the outlet pipe section and the inner surface of the part of the tubular structure corresponding to the third refrigerant channel 31. The refrigerant in the third refrigerant channel 31 can flow from the reflux gap 33 to the second refrigerant channel 21.

[0044] Using the cryogenic heat exchanger provided by the embodiments of the present disclosure, the cryogenic heat exchanger includes an inner tube 10, an outer tube 20, a cold head 30, and a corrugated pipe section arranged on the inner tube 10 and / or the outer tube 20. A first refrigerant channel 11 for introducing refrigerant is arranged inside the inner tube 10. The outer tube 20 is sleeved outside the inner tube 10. The inner surface of the outer tube 20 and the outer surface of the inner tube 10 form a second refrigerant channel 21 for discharging refrigerant. The cold head 30 includes a third refrigerant channel 31 communicated with the first refrigerant channel 11, which is used for the cold head 30 to exchange heat with the refrigerant introduced by the first refrigerant channel 11. Among them, the third refrigerant channel 31 is communicated with the second refrigerant channel 21, so that the refrigerant heat-exchanged with the cold head 30 in the third refrigerant channel 31 flows into the second refrigerant channel 21 and then is discharged. The corrugated pipe section is arranged on the inner tube 10 and / or the outer tube 20. Due to the flexible and elastic corrugated structure of the corrugated pipe section, it can absorb and weaken the transmission of vibration through deformation. Therefore, by arranging the corrugated pipe section on the inner tube 10 and / or the outer tube 20, while cooling the sample rod 62 or other components through the cryogenic heat exchanger, the vibration transmitted by the cold source can be absorbed and weakened through the deformation of the elastic and flexible corrugated structure, thereby reducing the influence of the cold source vibration on the sample detection in the low-temperature environment and improving the reliability of the sample detection result. In addition, by arranging the corrugated pipe section, the flow path of the refrigerant can be increased through the corrugated structure, thereby increasing the heat exchange area of the cryogenic heat exchanger and improving the heat exchange efficiency of the cryogenic heat exchanger. And, the corrugated pipe section can withstand the thermal expansion and contraction caused by temperature change in the low-temperature environment, reduce the structural deformation caused by thermal stress, thereby reducing the thermal drift at the heat exchanger due to the temperature change between the inner and outer tubes, and further increasing the accuracy of the sample detection in the low-temperature environment.

[0045] Optionally, in combination with Figures 1 to 3 As shown in the figure, the corrugated pipe section includes an inner tube corrugated pipe section and an outer tube 20 corrugated pipe section. The inner tube corrugated pipe section is arranged on the inner tube 10. The outer tube 20 corrugated pipe section is arranged on the outer tube 20.

[0046] In the embodiments of the present disclosure, any number of inner tube bellows segments and outer tube 20 bellows segments can be provided. The embodiments of the present disclosure do not limit the number of inner tube bellows segments and outer tube 20 bellows segments, and the number of inner tube bellows segments and outer tube 20 bellows segments can be set according to actual needs. Specifically, one inner tube bellows segment can be provided, and one outer tube 20 bellows segment can be provided; or, one inner tube bellows segment can be provided, and two outer tube 20 bellows segments can be provided.

[0047] In the embodiments of the present disclosure, the inner tube bellows segments and the outer tube 20 bellows segments can be respectively provided at any positions on the inner tube 10 and the outer tube 20. The embodiments of the present disclosure do not limit the installation positions of the inner tube bellows segments and the outer tube 20 bellows segments, and the installation positions of the inner tube bellows segments and the outer tube 20 bellows segments can be set according to actual needs. Specifically, the inner tube bellows segment can be provided in the middle of the inner tube 10, and the outer tube 20 bellows segment can be provided on one side of the inner tube 10 bellows close to the cold head 30 or on the side far from the cold head 30; or, the inner tube bellows segment can be provided in the middle of the inner tube 10, and the outer tube 20 bellows segments can be respectively provided on both sides of the inner tube 10 bellows.

[0048] In this way, by providing the inner tube bellows segments on the inner tube 10 and the outer tube 20 bellows segments on the outer tube 20, the transmission of the cold source vibration on the inner tube 10 and the outer tube 20 can be reduced simultaneously, thereby further improving the reliability of the sample detection result.

[0049] Optionally, as shown in Figures 1 to 3 the outer tube 20 bellows segments are provided on both sides of the inner tube bellows segment.

[0050] In the embodiments of the present disclosure, the number of the outer tube 20 bellows segments provided on both sides of the inner tube bellows segment is not limited. Specifically, one outer tube 20 bellows segment can be respectively provided on both sides of the inner tube bellows segment. As shown in Figures 1 to 3 the first bellows segment 40 is the inner tube bellows segment, the second bellows segment 41 and the third bellows segment 42 are the outer tube 20 bellows segments. The first bellows segment 40 is provided in the middle of the inner tube 10, and the second bellows segment 41 and the third bellows segment 42 are respectively provided on both sides of the first bellows segment 40. One outer tube 20 bellows segment can also be provided on the side of the inner tube bellows segment close to the cold head 30, and two outer tube 20 bellows segments can be provided on the side of the inner tube bellows segment far from the cold head 30.

[0051] In this way, the outer tube corrugated pipe sections are arranged on both sides of the inner tube corrugated pipe section, and both the outer tube corrugated pipe section and the inner tube corrugated pipe section are connected to the vacuum chamber 63 through a vibration isolation connection method. By arranging the outer tube 20 corrugated pipe sections on both sides of the inner tube corrugated pipe section, a structure similar to a "sandwich" is formed. The outer tube 20 corrugated pipe sections on both sides of the inner tube corrugated pipe section play an additional isolation layer role. The vibration transmission path is dispersed, and the vibration energy will be absorbed and dispersed multiple times when passing through multiple corrugated pipe sections, increasing the attenuation of the vibration energy, so that the vibration from the cold source can be more effectively isolated and absorbed. When vibration occurs, the outer tube 20 corrugated pipe section first absorbs a part of the vibration, and the inner tube corrugated pipe section further reduces the vibration transmitted to other parts of the heat exchanger. Finally, an additional blockage is carried out through another outer tube 20 corrugated pipe section, thus more effectively protecting the components for circulating the refrigerant inside and the sample rod 62.

[0052] Optionally, in combination with Figure 3 as shown, the cryogenic heat exchanger further includes a secondary heat exchanger 50. The secondary heat exchanger 50 is respectively connected to the second refrigerant channel 21 and the outer surface of the outer tube 20. Among them, a fourth refrigerant channel 51 communicating with the second refrigerant channel 21 is arranged inside the secondary heat exchanger 50.

[0053] In the embodiment of the present disclosure, the secondary heat exchanger 50 can be connected to the cold shield 64 or other components that need to be cooled. By cooling the cold shield 64 through the secondary heat exchanger 50, the heat radiation loss and heat conduction loss from the cold shield 64 area to the normal temperature environment can be reduced, minimizing the influence of environmental thermal energy on the low-temperature area inside the device, and improving the utilization rate of the reflux refrigerant.

[0054] In some other embodiments, in combination with Figure 6 and Figure 7As shown in the figure, the above-mentioned cryogenic heat exchanger is disposed within a vacuum chamber 63, which includes an air extraction port 60 and a light-transmitting window 61. The air extraction port 60 is used to create a vacuum environment within the vacuum chamber 63, and the light-transmitting window 61 is used to allow detection light and / or observation light to pass through, directing the detection light and / or observation light towards the sample to be measured on the sample rod 62, thereby enabling the observation of the position of the detection light on the sample to be measured and the detection of the sample to be measured. The sample rod 62 is connected to the cold head 30 of the cryogenic heat exchanger and is fixedly connected to the cold shield 64 through a heat insulation element 65. The cold shield 64 is fixed within the vacuum chamber 63 through the heat insulation element 65 and at least sleeves the outside of the cold head 30 and / or the secondary heat exchanger 50 and is connected to the outer tube 20 to isolate the cold head 30 and / or the secondary heat exchanger 50 from the external environment. Among them, the cold shield 64 and the secondary heat exchanger 50 can be directly connected to cool the cold shield 64 through the secondary heat exchanger 50, further reducing the heat exchange between the inside and outside of the cold shield 64. The heat insulation element 65 can either be composed of a heat insulation material with low thermal conductivity to achieve heat insulation or can achieve heat insulation by setting a specific heat insulation structure that can reduce the thermal conductivity. Adopting a central symmetry structure design can reduce the thermal drift caused by temperature changes when the sample to be measured is arranged in the vacuum chamber 63, improving the accuracy of the measurement of the sample to be measured. In this way, the sample rod 62 is fixed within the cold shield 64 using the heat insulation element 65, the cold shield 64 is fixed within the vacuum chamber 63, and the cold quantity of the reflux refrigerant is exported to the cold shield 64 wrapping the sample rod 62 by arranging the secondary heat exchanger 50, which can reduce heat leakage and thus reduce the consumption of the refrigerant.

[0055] In some other embodiments, a bellows section can also be provided in the tubular part of the vacuum chamber 63 and connected to the inner tube 10 and / or the outer tube 20. The outer tube 20 is connected to the secondary heat exchanger 50, the cold head 30, and / or the vacuum chamber 63 through an outer tube bellows section. The inner tube 10 is connected to the cold head 30 and / or the vacuum chamber 63 through an inner bellows section. Among them, in the case where the cold shield 64 is not provided, the outer tube 20 is connected to the secondary heat exchanger 50, the cold head 30, and / or the vacuum chamber 63 through one outer tube bellows section. Correspondingly, in the case where the cold shield 64 is provided, as Figure 7 shown, the outer tube 20 is connected to the secondary heat exchanger 50, the cold head 30, and / or the vacuum chamber 63 through multiple outer tube bellows sections, namely the first bellows section 40 and the third bellows section 42, as well as the bellows section provided at the connection between the outer tube 20 and the secondary heat exchanger 50.

[0056] In some other embodiments, since the sample rod 62 and the vacuum chamber 63 are rigidly connected, vibrations may be transmitted from the vacuum chamber 63 to the sample rod 62. Therefore, a bellows section can also be provided in the tubular part of the vacuum chamber 63 for vibration isolation.

[0057] In some other embodiments, since the corrugated pipe section is a flexible pipe and is greatly affected by the internal fluid pressure, that is, when the pressure of the internal refrigerant changes, one side of the cold head 30 is in a vacuum and not under pressure, and the other side is affected by the refrigerant pressure, which may cause a micron-level displacement at the position of the sample to be measured. To avoid the above situation, a pressure stabilizing device can be correspondingly provided at the heat exchanger inlet 12 and / or at the cold source and / or at other positions to balance the refrigerant pressures on different sides.

[0058] In some other embodiments, when the temperature changes, the position of the sample rod 62 changes relative to the position of the microscope, thus affecting the test effect. To further reduce the influence of thermal drift on the test effect, a temperature sensor and a temperature control heater can also be provided on the outer shell of the vacuum chamber 63. The temperature change of the outer shell of the vacuum chamber 63 is monitored by the temperature sensor, and when the temperature of the outer shell of the vacuum chamber 63 is too low, the outer shell of the vacuum chamber 63 is heated by the temperature control heater to raise the temperature of the outer shell of the vacuum chamber 63, so that the temperature of the outer shell of the vacuum chamber 63 is within the set temperature range, thereby reducing the position change of the sample rod 62 relative to the microscope. Among them, the outer shell of the vacuum chamber 63 can be made of a material with high thermal conductivity to ensure the uniformity of the temperature of the outer shell of the vacuum chamber 63, thereby reducing the influence of the temperature change of the outer shell of the vacuum chamber 63 on the test results.

[0059] In this way, a fourth refrigerant channel 51 communicating with the second refrigerant channel 21 is provided inside the secondary heat exchanger 50. The refrigerant flowing back after exchanging heat with the cold head 30 in the second refrigerant channel 21 will flow through the fourth refrigerant channel 51 to exchange heat with the secondary heat exchanger 50, and then other components can be cooled by the secondary heat exchanger 50. By providing the secondary heat exchanger 50, the cold quantity of the refrigerant flowing back in the second refrigerant channel 21 can be reused, thereby improving the utilization rate of the refrigerant. In addition, the secondary heat exchanger 50 is only connected to the second refrigerant channel 21 and the outer tube 20, and is not connected to the outer surface of the inner tube 10, so that there is only solid contact between the inner tube 10 and the outer tube 20 on one side of the sample rod 62 and one side of the heat exchanger inlet 12. Through the flexibility of the corrugated pipe section, the position where the secondary heat exchanger 50 is connected to the outer tube 20 can be flexibly adjusted relative to the sample rod 62 and the cold head 30, which is convenient for Figure 7The installation support of the middle heat insulation element 65. On the other hand, the secondary heat exchanger 50 has no physical contact with the inner tube 10, which can reduce the thermal stress caused by temperature changes and greatly reduce the impact of thermal cycling on the service life. Accordingly, only one inner tube bellows section can be provided on the inner tube 10. In another case, based on the change of test requirements or the change of structural setting requirements, the secondary heat exchanger 50 can be connected to both the second refrigerant channel 21, the outer surface of the inner tube 10 and the outer tube 20, that is, the secondary heat exchanger 50 physically connects the inner tube 10 and the outer tube 20. Accordingly, inner tube bellows sections can be provided before and after the secondary heat exchanger 50 on the inner tube 10. Through the flexibility of the bellows sections, the position where the secondary heat exchanger 50 is connected to the inner tube 10 can also be flexibly adjusted relative to the sample rod 62 and the cold head 30, which is convenient for the installation support of the heat insulation element 65. And through the two bellows sections provided on the inner tube 10 before and after the secondary heat exchanger 50, the strain caused by the expansion difference between the inner tube 10 and the outer tube 20 is reduced, that is, the thermal stress caused by temperature changes is reduced, and the impact of thermal cycling on the service life is reduced.

[0060] Optionally, in combination with Figure 4 as shown, the second refrigerant channel 21 includes a plurality of axial diversion channels 24. The plurality of axial diversion channels 24 are arranged at the entrance of the fourth refrigerant channel 51.

[0061] In the embodiment of the present disclosure, in combination with Figure 4 as shown, the plurality of axial diversion channels 24 are arranged at the entrance of the fourth refrigerant channel 51, that is, the entrance of the secondary heat exchanger 50. Among them, Figure 4 the fourth refrigerant channel 51 of the secondary heat exchanger 50 in Figure 3 .

[0062] In this way, by arranging a plurality of axial diversion channels 24 at the entrance of the fourth refrigerant channel 51, the refrigerant in the second refrigerant channel 21 can be diverted through the plurality of axial diversion channels 24 before the refrigerant in the second refrigerant channel 21 exchanges heat with the secondary heat exchanger 50, so that the refrigerant flowing into the secondary heat exchanger 50 is more uniform, thereby increasing the heat exchange area and further improving the heat exchange efficiency.

[0063] Optionally, the plurality of axial diversion channels 24 are arranged between the bellows section and the secondary heat exchanger 50.

[0064] In this way, by arranging the plurality of axial diversion channels 24 between the bellows section and the secondary heat exchanger 50, the influence of the bellows section on the diversion is reduced, and the diversion effect is ensured.

[0065] Optionally, in combination with Figure 4 as shown, the axial diversion channels 24 extend axially along the outer surface of the inner tube 10 and are arranged circumferentially along the outer surface of the inner tube 10.

[0066] In the embodiments of the present disclosure, in combination with Figure 5 as shown, the axial diversion channels 24 are uniformly arranged along the circumferential direction of the outer surface of the inner tube 10, and the length and width of each axial diversion channel 24 are the same. In combination with Figure 4 as shown, a plurality of axial diversion channels 24 with the same width and length respectively extend axially from different positions in the circumferential direction of the outer surface of the inner tube 10 towards the inlet of the secondary heat exchanger 50.

[0067] In this way, the axial diversion channels 24 extend axially along the outer surface of the inner tube 10 and are arranged in the circumferential direction on the outer surface of the inner tube 10, enabling the refrigerant in the second refrigerant channel 21 to be uniformly distributed axially and circumferentially along the surface of the inner tube 10, so that the refrigerant entering the secondary heat exchanger 50 is more uniform, improving the heat exchange efficiency.

[0068] Optionally, in combination with Figure 4 as shown, the axial diversion channels 24 include a plurality of convex structures 23. The plurality of convex structures 23 extend axially along the outer surface of the inner tube 10 and are arranged in the circumferential direction. Among them, adjacent convex structures 23 are connected to the outer surface of the inner tube 10 and the inner surface of the outer tube 20 to form the axial diversion channels 24.

[0069] In the embodiments of the present disclosure, the convex structure 23 can be a fin structure, and the top of the fin structure can be connected to the inner surface of the outer tube 20; among them, the bottom of the fin structure can be connected to the outer surface of the inner tube 10 or can be not connected to the outer surface of the inner tube 10.

[0070] In this way, the plurality of convex structures 23 extend axially along the outer surface of the inner tube 10 and are arranged in the circumferential direction, and adjacent convex structures 23 are connected to the outer surface of the inner tube 10 and the inner surface of the outer tube 20 to form the axial diversion channels 24 for guiding the refrigerant in the second refrigerant channel 21.

[0071] Optionally, in combination with Figure 4 as shown, the axial diversion channels 24 further include circumferential diversion channels 26. The circumferential diversion channels 26 are composed of channel gaps 25 formed by disconnecting a plurality of convex structures 23 extending axially along the outer surface of the inner tube 10, and adjacent axial diversion channels 24 are communicated through the circumferential diversion channels 26.

[0072] In this way, by forming the circumferential diversion channels 26 along the circumferential direction of the outer surface of the inner tube 10 through a plurality of channel gaps 25, the refrigerant entering the plurality of axial diversion channels 24 can be further rectified through the circumferential diversion channels 26, so that the refrigerant in each axial diversion channel 24 is more uniform, and further the refrigerant in the fourth refrigerant channel 51 entering the secondary heat exchanger 50 is more uniform, improving the heat exchange efficiency.

[0073] The above description and the accompanying drawings fully illustrate embodiments of the present disclosure so that those skilled in the art can practice them. Other embodiments may include structural and other changes. Embodiments represent only possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Parts and features of some embodiments may be included in or substituted for parts and features of other embodiments. Embodiments of the present disclosure are not limited to the structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A low-temperature heat exchanger, characterized in that, Comprising: An inner tube with a first refrigerant channel provided inside; An outer tube sleeved outside the inner tube; wherein, the outer surface of the inner tube and the inner surface of the outer tube form a second refrigerant channel; A cold head including a third refrigerant channel communicating with the first refrigerant channel; wherein, the third refrigerant channel communicates with the second refrigerant channel; A corrugated pipe section provided on the inner tube and / or the outer tube.

2. The low-temperature heat exchanger according to claim 1, wherein The corrugated pipe section includes: An inner tube corrugated pipe section provided on the inner tube; An outer tube corrugated pipe section provided on the outer tube.

3. The cryogenic heat exchanger according to claim 2, wherein, The outer tube corrugated pipe section is provided on both sides of the inner tube corrugated pipe section.

4. The cryogenic heat exchanger according to any one of claims 1 to 3, characterized in that, Further comprising: A secondary heat exchanger respectively connected to the second refrigerant channel and the outer surface of the outer tube; wherein, a fourth refrigerant channel communicating with the second refrigerant channel is provided inside the secondary heat exchanger.

5. The cryogenic heat exchanger according to claim 4, characterized in that, The second refrigerant channel includes: A plurality of axial flow guiding channels provided at the inlet of the fourth refrigerant channel.

6. The cryogenic heat exchanger according to claim 5, characterized in that, The plurality of axial flow guiding channels are provided between the corrugated pipe section and the secondary heat exchanger.

7. The cryogenic heat exchanger according to claim 4, wherein, The axial flow guiding channels axially extend along the outer surface of the inner tube and are arranged in a circumferential direction on the outer surface of the inner tube.

8. The low-temperature heat exchanger according to claim 4, characterized in that, The axial flow guiding channel includes: A plurality of convex structures axially extending along the outer surface of the inner tube and arranged in a circumferential direction; wherein, adjacent convex structures are connected to the outer surface of the inner tube and the inner surface of the outer tube to form an axial flow guiding channel.

9. The cryogenic heat exchanger according to claim 8, characterized in that, The axial flow guiding channel further includes: A circumferential flow guiding channel formed by channel gaps formed by a plurality of convex structures axially extending along the outer surface of the inner tube, and adjacent axial flow guiding channels are communicated through the circumferential flow guiding channel.

10. A sample rod, characterized in that, Including the cryogenic heat exchanger according to any one of claims 1 to 9.

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