Annular heat exchange unit, multi-stage heat exchanger and dilution refrigerator

Abstract

The invention relates to the technical field of extremely-low-temperature refrigeration equipment, and provides an annular heat exchange unit which comprises a flow channel box, and the two ends of the flow channel box are covered with an upper cover body and a lower cover body correspondingly; a cavity partition plate is arranged in the runner box to form an upper heat exchange cavity and a lower heat exchange cavity; two upper runners which are not communicated with each other are arranged in the upper heat exchange chamber; two lower runners which are not communicated with each other are arranged in the lower heat exchange chamber; the adjacent flow channel partition plates in the two cavities are arranged in a staggered mode to form a transition flow channel. The annular heat exchange unit further comprises two circulating pipe sets. Therefore, the two heat exchange channels which are not communicated with each other and are arranged up and down are formed in the runner box; media in the two heat exchange channels do not make contact with each other, and heat exchange is achieved through the flow channel partition plate in the flowing process. On the premise that the overall size of the runner box is not increased, two heat exchange channels which are arranged in an up-down staggered mode are formed in the runner box. The heat exchange efficiency is improved, and the space is saved. The invention provides a multi-stage heat exchanger and a dilution refrigerator.

Description

Technical Field

[0001] The present invention belongs to the technical field of extremely low temperature refrigeration equipment, and in particular relates to an annular heat exchange unit, a multi-stage heat exchanger and a dilution refrigerator. Background Art

[0002] Dilution refrigerator can provide ultra-low temperature environment and is an important equipment in scientific research fields such as astronomical observation, quantum computing, high energy physics, superconductivity, and condensed matter physics.

[0003] The heat exchanger is the core component of the dilution refrigerator, which uses a mixture of 3He (dense phase) and 3He-4He (dilute phase) to obtain extremely low temperatures. However, in an extremely low temperature environment, the influence of the Kapitza thermal resistance between the liquid and the solid surface will increase exponentially, which will seriously affect the heat exchange effect. At present, there is no effective solution to improve the heat exchange effect.

[0004] In summary, the prior art obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the invention

[0005] In view of the above-mentioned defects, the present invention mainly provides an annular heat exchange unit to solve the technical problem that the heat exchange effect of the heat exchanger is not high.

[0006] In order to solve the above problems, the present invention provides an annular heat exchange unit, comprising a flow channel box, wherein the two ends of the flow channel box are respectively covered with an upper cover body and a lower cover body; a chamber partition is provided in the flow channel box; an upper heat exchange chamber is formed between the chamber partition and the upper cover body, and a lower heat exchange chamber is formed between the chamber partition and the lower cover body;

[0007] Two flow channel partitions are provided in the upper heat exchange chamber, and the two flow channel partitions divide the upper heat exchange chamber into two upper flow channels that are not connected to each other;

[0008] Two flow channel partitions are provided in the lower heat exchange chamber, and the two flow channel partitions divide the lower heat exchange chamber into two lower flow channels that are not connected to each other;

[0009] The flow channel baffle in the upper heat exchange chamber is staggered with the flow channel baffle in the adjacent lower heat exchange chamber to form a transition flow channel on the chamber baffle; the transition flow channel is configured to: connect the upper flow channel and the lower flow channel that are obliquely opposite to each other to form a heat exchange channel;

[0010] The annular heat exchange unit also includes two groups of circulation tube groups; each circulation tube group includes two medium tubes respectively arranged on the upper cover body and the lower cover body, and the two medium tubes are respectively connected to the upper flow channel and the lower flow channel belonging to the same heat exchange channel.

[0011] According to the annular heat exchange unit of the present invention, the two flow channel partitions in the upper heat exchange chamber and the lower heat exchange chamber are distributed at 180 degrees in their respective chambers.

[0012] According to the annular heat exchange unit of the present invention, the chamber partition and the flow channel partition are both made of copper.

[0013] According to the annular heat exchange unit of the present invention, the upper heat exchange chamber and the lower heat exchange chamber are both provided with a heat exchange layer attached to the surface of the chamber partition.

[0014] According to the annular heat exchange unit of the present invention, the heat exchange layer is a powder sintered layer.

[0015] According to the annular heat exchange unit of the present invention, the powder sintered layer is sintered with silver powder.

[0016] A multi-stage heat exchanger comprises multiple layers of the annular heat exchange unit; the circulation tube groups of the annular heat exchange units of each layer located on the same side are sequentially connected in series from top to bottom, thereby forming two medium passages;

[0017] Specific:

[0018] The medium pipe of the upper cover body of each circulation pipe group on the same side is connected to the medium pipe of the lower cover body of the upper circulation pipe group, and the medium pipe of the lower cover body is connected to the medium pipe of the upper cover body of the lower circulation pipe group.

[0019] According to the multi-stage heat exchanger of the present invention, the number of the annular heat exchange units is no less than 5 layers.

[0020] According to the multi-stage heat exchanger of the present invention, the medium flow directions in the two medium passages are opposite.

[0021] A dilution refrigerator comprises the multi-stage heat exchanger.

[0022] In summary, the annular heat exchange unit of the present invention forms two heat exchange channels that are not connected to each other and are arranged up and down in the flow channel box; the media in the two heat exchange channels do not contact each other, and heat exchange is achieved through the flow channel baffle during the flow process. The medium in each heat exchange channel can flow through the upper flow channel, the transition flow channel and the lower flow channel, and the flow path covers the circumference of the flow channel box, thereby ensuring the heat exchange time. The flow channel box forms two heat exchange channels that are staggered up and down inside without increasing the overall volume. The heat exchange efficiency is improved and space is saved. The present invention provides a multi-stage heat exchanger, which realizes multi-stage heat exchange by sequentially connecting multiple layers of annular heat exchange units, greatly prolongs the flow path of the medium in a limited space, increases the heat exchange contact time and contact area, improves the heat exchange efficiency, and achieves a better heat exchange effect. The present invention provides a dilution refrigerator. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a schematic structural diagram of an annular heat exchange unit of the present invention;

[0024] Figure 2 yes Figure 1 Schematic diagram of the explosion structure of the medium annular heat exchange unit;

[0025] Figure 3 It is a schematic structural diagram of the flow channel box of the annular heat exchange unit of the present invention;

[0026] Figure 4 It is a partial cross-sectional structural schematic diagram of the annular heat exchange unit of the present invention;

[0027] Figure 5 It is a schematic structural diagram of a multi-stage heat exchanger of the present invention;

[0028] In the figure: 1-flow channel box, 11-heat exchange layer, 12-chamber partition, 13-flow channel partition, 14-upper flow channel, 15-lower flow channel, 16-transition flow channel; 2-upper cover body, 21-lower cover body; 3-medium pipe. DETAILED DESCRIPTION

[0029] See also Figure 1-4 The present invention provides an annular heat exchange unit, comprising a flow channel box 1, wherein the two ends of the flow channel box 1 are respectively covered with an upper cover body 2 and a lower cover body 21; Figure 3 , a chamber partition 12 is provided in the flow channel box 1; an upper heat exchange chamber is formed between the chamber partition 12 and the upper cover 2, and a lower heat exchange chamber is formed between the chamber partition 12 and the lower cover 21;

[0030] Recombination Figure 4 The upper heat exchange chamber is provided with two flow channel partitions 13, and the two flow channel partitions 13 divide the upper heat exchange chamber into two upper flow channels 14 that are not connected to each other;

[0031] Two flow channel partitions 13 are provided in the lower heat exchange chamber, and the two flow channel partitions 13 divide the lower heat exchange chamber into two lower flow channels 15 that are not connected to each other;

[0032] The flow channel baffle 13 in the upper heat exchange chamber is staggered with the flow channel baffle 13 in the adjacent lower heat exchange chamber, forming a transition flow channel 16 on the chamber baffle 12; the transition flow channel 16 is configured to connect the upper flow channel 14 and the lower flow channel 15 which are obliquely opposite to each other, forming a heat exchange channel;

[0033] The two transition channels 16 of the present invention form two heat exchange channels that are not connected to each other and are arranged up and down in the channel box 1; the media in the two heat exchange channels do not contact each other, and heat exchange is achieved through the channel partition 13 during the flow process.

[0034] The medium in each heat exchange channel can flow through the upper flow channel 14, the transition flow channel 16 and the lower flow channel 15. The flow path covers the circumference of the flow channel box 1, ensuring the heat exchange time. The flow channel box 1 forms two heat exchange channels arranged in an upper and lower staggered manner inside without increasing the overall volume. The heat exchange efficiency is improved and space is saved.

[0035] Optionally, the media in the two heat exchange channels flow in opposite directions, which can achieve countercurrent heat exchange and improve the heat exchange effect.

[0036] The annular heat exchange unit further includes two groups of circulation pipe groups; each circulation pipe group includes two medium pipes 3 respectively arranged on the upper cover body 2 and the lower cover body 21, and the two medium pipes 3 are respectively connected to the upper flow channel 14 and the lower flow channel 15 belonging to the same heat exchange channel;

[0037] The two medium pipes 3 of the circulation pipe group can be used as the inlet and outlet pipes of the medium respectively, so as to realize the flow of the medium in the annular heat exchange unit. The medium is introduced into the flow channel box 1 through the two circulation pipe groups respectively, and the two mediums exchange heat through the chamber partition 12 during the flow in their respective heat exchange channels.

[0038] As an embodiment, the two flow channel partitions 13 in the upper heat exchange chamber and the lower heat exchange chamber are distributed at 180° in their respective chambers; the two circulation pipe groups are respectively arranged on both sides of the annular heat exchange unit, which is convenient for connection with other pipelines of the equipment and facilitating the passage of the medium.

[0039] Preferably, the chamber partition 12 and the flow channel partition 13 of the present invention are both made of copper, and have good heat exchange performance.

[0040] As an embodiment, the upper heat exchange chamber and the lower heat exchange chamber are both provided with a heat exchange layer 11 attached to the surface of the chamber partition 12 to improve the heat exchange efficiency.

[0041] Furthermore, the heat exchange layer 11 is a powder sintered layer, and the fine porous structure of the powder sintered material is used to form a huge contact area between the medium and the powder sintered layer, thereby enhancing the heat exchange effect. Preferably, the powder sintered layer is sintered with silver powder, which has a good heat exchange effect.

[0042] Preferably, the flow channel box 1 of the present invention is annular, and the resistance to medium flow is low. Those skilled in the art can also adaptably design the flow channel box 1 into other annular structures according to actual application scenarios, including but not limited to triangular annular, rectangular annular, pentagonal annular, hexagonal annular, etc.

[0043] See also Figure 5 The present invention also provides a multi-stage heat exchanger, comprising multiple layers of the annular heat exchange unit; the circulation tube groups of each layer of the annular heat exchange unit located on the same side are sequentially connected in series from top to bottom, thereby forming two medium passages;

[0044] Specific:

[0045] The medium pipe 3 of the upper cover body 2 of each circulation pipe group on the same side is connected to the medium pipe 3 of the lower cover body 21 of the upper layer circulation pipe group, and the medium pipe 3 of the lower cover body 21 is connected to the medium pipe 3 of the upper cover body 2 of the lower layer circulation pipe group;

[0046] The circulation pipe groups on the same side of each layer are connected in sequence, and the heat exchange channels in the flow channel boxes 1 of each layer are connected in series in sequence to form a medium passage, which prolongs the flow path of the medium. Different media are introduced into the two medium passages respectively, and the two media exchange heat in each layer of the annular heat exchange unit, realizing multi-stage heat exchange, greatly prolonging the flow path of the medium in a limited space, increasing the heat exchange contact time and contact area, improving the heat exchange efficiency, and achieving a better heat exchange effect.

[0047] Optionally, the flow directions of the two medium passages are opposite to each other, so as to realize countercurrent heat exchange and improve the heat exchange effect.

[0048] As an implementation mode, the number of the annular heat exchange units of the present invention can be adaptively set according to the actual refrigeration and heat exchange requirements. Preferably, the number of the annular heat exchange units is not less than 5 layers, such as 5-15 layers.

[0049] The present invention also provides a dilution refrigerator having the multi-stage heat exchanger.

[0050] In summary, the present invention provides an annular heat exchange unit, which forms two heat exchange channels that are not connected to each other and are arranged up and down in the flow channel box; the media in the two heat exchange channels do not contact each other, and heat exchange is achieved through the flow channel partition during the flow process. The medium in each heat exchange channel can flow through the upper flow channel, the transition flow channel and the lower flow channel, and the flow path covers the circumference of the flow channel box, thereby ensuring the heat exchange time. The flow channel box forms two heat exchange channels that are staggered up and down inside without increasing the overall volume. The heat exchange efficiency is improved and space is saved. The present invention provides a multi-stage heat exchanger, which realizes multi-stage heat exchange by sequentially connecting multiple layers of annular heat exchange units, greatly prolongs the flow path of the medium in a limited space, increases the heat exchange contact time and contact area, improves the heat exchange efficiency, and achieves a better heat exchange effect. The present invention provides a dilution refrigerator.

[0051] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. An annular heat exchange unit, characterized in that: It comprises a flow channel box, wherein the two ends of the flow channel box are respectively covered with an upper cover body and a lower cover body; a chamber partition is arranged inside the flow channel box; an upper heat exchange chamber is formed between the chamber partition and the upper cover body, and a lower heat exchange chamber is formed between the chamber partition and the lower cover body; Two flow channel partitions are provided in the upper heat exchange chamber, and the two flow channel partitions divide the upper heat exchange chamber into two upper flow channels that are not connected to each other; Two flow channel partitions are provided in the lower heat exchange chamber, and the two flow channel partitions divide the lower heat exchange chamber into two lower flow channels that are not connected to each other; The flow channel baffle in the upper heat exchange chamber is staggered with the flow channel baffle in the adjacent lower heat exchange chamber to form a transition flow channel on the chamber baffle; the transition flow channel is configured to: connect the upper flow channel and the lower flow channel that are obliquely opposite to each other to form a heat exchange channel; The annular heat exchange unit also includes two groups of circulation tube groups; each circulation tube group includes two medium tubes respectively arranged on the upper cover body and the lower cover body, and the two medium tubes are respectively connected to the upper flow channel and the lower flow channel belonging to the same heat exchange channel.

2. The annular heat exchange unit according to claim 1, characterized in that: The two flow channel partitions in the upper heat exchange chamber and the lower heat exchange chamber are distributed at 180 degrees in their respective chambers.

3. The annular heat exchange unit according to claim 1, characterized in that: The chamber partition and the flow channel partition are both made of copper.

4. The annular heat exchange unit according to claim 1, characterized in that: The upper heat exchange chamber and the lower heat exchange chamber are both provided with a heat exchange layer attached to the surface of the chamber partition.

5. The annular heat exchange unit according to claim 4, characterized in that: The heat exchange layer is a powder sintered layer.

6. The annular heat exchange unit according to claim 5, characterized in that: The powder sintering layer is sintered by silver powder.

7. A multi-stage heat exchanger, characterized in that: It comprises multiple layers of annular heat exchange units according to any one of claims 1 to 6; the circulation tube groups of each layer of annular heat exchange units located on the same side are sequentially connected in series from top to bottom, thereby forming two medium passages; Specific: The medium pipe of the upper cover body of each circulation pipe group on the same side is connected to the medium pipe of the lower cover body of the upper circulation pipe group, and the medium pipe of the lower cover body is connected to the medium pipe of the upper cover body of the lower circulation pipe group.

8. The multi-stage heat exchanger according to claim 7, characterized in that: The number of the annular heat exchange units is no less than 5 layers.

9. The multi-stage heat exchanger according to claim 7, characterized in that: The medium flow directions in the two medium passages are opposite.

10. A dilution refrigerator, characterized in that: A multi-stage heat exchanger as claimed in claim 7.

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