Ring-in-ring multi-stage powder sintering heat exchanger for dilution refrigerator

Abstract

The invention discloses a ring-in-ring multi-stage powder sintering heat exchanger for a dilution refrigerator, and relates to an extremely low temperature refrigeration technology. The ring-in-ring multi-stage powder sintering heat exchanger comprises a plurality of heat exchange sets, each heat exchange set comprises a plurality of annular heat exchange units, and the heat exchange units are coaxially arranged and communicate with one another through dense-phase pipes and dilute-phase pipes; each heat exchange unit is hollow and provided with a partition plate, and the partition plate divides the inner space of each heat exchange unit into a first heat exchange cavity and a second heat exchange cavity. The first heat exchange cavity comprises a first upper flow channel and a first lower flow channel which are communicated with each other and are both communicated with concentrated phase pipes; the second heat exchange cavity comprises a second upper flow channel and a second lower flow channel which are communicated with each other and communicated with dilute phase pipes. By adopting the ring-in-ring structural arrangement, the space utilization rate can be effectively improved, and the heat exchange effect can be effectively improved by utilizing the contact area generated by the micro porous medium in the powder sintering material.

Description

Technical Field

[0001] The invention relates to an extremely low temperature refrigeration technology, in particular to a ring-in-ring multi-stage powder sintering heat exchanger for a dilution refrigerator. Background Art

[0002] Dilution refrigeration (DR) is a refrigeration method that uses the properties of 3He (dense phase) and 3He-4He (dilute phase) mixtures at extremely low temperatures to obtain extremely low temperatures. It has a large cooling capacity in the mK temperature range and has been vigorously developed and applied in the fields of quantum computing, superconductivity, and condensed matter physics. For the core component of the dilution refrigerator, the powder sintering heat exchanger, in an extremely low temperature environment, the thermal resistance between the liquid and the solid surface will increase exponentially due to the influence of the Kapitza thermal resistance, which will seriously affect the heat exchange effect of the heat exchanger.

[0003] At present, specific metal powders are usually sintered on the heat exchanger baffles to increase the heat exchange area and achieve good heat exchange effects. If it is necessary to continuously impact extremely low temperatures, a multi-stage powder sintered heat exchanger is required to achieve this goal by cooling down the stage by stage. However, due to the limitations of installation space, the sintered powder heat exchanger in the dilution refrigerator has the disadvantages of limited heat exchanger shape, complex concentrated and dilute phase pipeline directions, and difficult installation. The huge contact heat exchange area generated by the fine porous medium in the powder sintered material cannot be reasonably utilized, resulting in poor heat exchange effects. At the same time, the structure also has disadvantages such as unstable support and complex processing technology. In addition, for some demonstration projects, the traditional sintered powder heat exchanger is not aesthetically pleasing and has a poor appearance. Summary of the invention

[0004] In view of the problem that the existing sintered powder heat exchanger has complex pipeline layout and cannot fully utilize the heat exchange area, resulting in poor heat exchange effect, the present invention provides a ring-in-ring multi-stage powder sintered heat exchanger for a dilution refrigerator.

[0005] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A ring-in-ring multi-stage powder sintering heat exchanger for a dilution refrigerator includes a plurality of heat exchange groups, and adjacent heat exchange groups are connected through dense phase tubes and dilute phase tubes. Each of the heat exchange groups includes a plurality of annular heat exchange units, which are coaxially arranged and connected through dense phase tubes and dilute phase tubes; each of the heat exchange units is hollow inside and has a partition, which divides the internal space of the heat exchange unit into a first heat exchange chamber and a second heat exchange chamber. The first heat exchange chamber is divided into a first upper flow channel and a first lower flow channel, the first upper flow channel is connected to the first lower flow channel, and the first upper flow channel and the first lower flow channel are both connected to a dense phase tube; the second heat exchange chamber is divided into a second upper flow channel and a second lower flow channel, the second upper flow channel is connected to the second lower flow channel, and the two upper flow channels and the second lower flow channel are both connected to a dilute phase tube.

[0007] Further, one end of the first upper flow channel is connected to one end of the first lower flow channel through a connecting port, and the first upper flow channel and the first lower flow channel are in a stepped shape; one end of the second upper flow channel is connected to one end of the second lower flow channel through a connecting port, and the second upper flow channel and the second lower flow channel are in a stepped shape.

[0008] Further, the first upper flow channel is located at the upper left side of the heat exchange unit, the second upper flow channel is located at the upper right side of the heat exchange unit, the first lower flow channel is located at the lower right side of the heat exchange unit, and the second lower flow channel is located at the lower left side of the heat exchange unit.

[0009] Further, the dense phase tube is far away from the communication port between the first upper flow channel and the first lower flow channel, and the dilute phase tube is far away from the communication port between the second upper flow channel and the second lower flow channel.

[0010] Furthermore, the heat exchange group includes a first heat exchange unit, a second heat exchange unit and a third heat exchange unit, and the first heat exchange unit, the second heat exchange unit and the third heat exchange unit are arranged from inside to outside.

[0011] Furthermore, a dense phase tube and a dilute phase tube are respectively provided on the top wall of the first heat exchange unit, and the lower part of the outer wall of the first heat exchange unit is connected to the lower part of the inner wall of the second heat exchange unit through the dense phase tube and the dilute phase tube respectively.

[0012] Furthermore, the upper portion of the outer side wall of the second heat exchange unit is connected to the upper portion of the inner side wall of the third heat exchange unit through a dense phase tube and a dilute phase tube, and a dense phase tube and a dilute phase tube are respectively provided on the bottom wall of the third heat exchange unit.

[0013] Furthermore, the plurality of heat exchange groups are divided into a first heat exchange group and a second heat exchange group, and the first heat exchange group and the second heat exchange group are symmetrically arranged.

[0014] Furthermore, a layer of nano metal powder is sintered on the upper and lower surfaces of the partition.

[0015] The beneficial effects of the present invention are as follows: the present invention adopts a ring-in-ring structural arrangement, which can effectively improve the space utilization rate, and utilizes the contact area generated by the fine porous medium in the powder sintered material to effectively improve the heat exchange effect. The component structure in the present invention is simple, easy to process and install, and the components are symmetrically distributed, with good support, ensuring the stability of the overall structure. The present invention connects multiple ring-in-ring sintered powder heat exchangers in series to form a stepped heat exchanger, which can further increase the heat exchange area, thereby further improving the heat exchange effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Shown is a schematic diagram of the structural principle of an embodiment of the present invention.

[0017] Figure 2 Shown Figure 1 Front view of .

[0018] Figure 3 for Figure 1 A partial structural schematic diagram shows the structure of the heat exchange group.

[0019] Figure 4 Shown Figure 3 Top view of the .

[0020] Figure 5 Shown Figure 4 Cross-sectional view at point A.

[0021] Figure 6 Shown Figure 5 Side view of .

[0022] Figure 7 Shown Figure 3 Front view of .

[0023] Figure 8 Shown Figure 7 Cross-sectional view at point B. DETAILED DESCRIPTION

[0024] The present invention discloses a ring-in-ring multi-stage powder sintering heat exchanger for a dilution refrigerator. An embodiment of the present invention is described in detail below in conjunction with the accompanying drawings.

[0025] Combination Figure 1 and Figure 2 As shown, a ring-in-ring multi-stage powder sintering heat exchanger for a dilution refrigerator includes a plurality of heat exchange groups, and adjacent heat exchange groups are connected through dense phase tubes 4 and dilute phase tubes 5. Figure 3 and Figure 4As shown, each heat exchange group includes a plurality of annular heat exchange units, and the heat exchange units include a first heat exchange unit 1, a second heat exchange unit 2 and a third heat exchange unit 3. The first heat exchange unit 1, the second heat exchange unit 2 and the third heat exchange unit 3 are arranged concentrically from the inside to the outside. The diameter of the second heat exchange unit 2 is larger than the diameter of the first heat exchange unit 1 and smaller than the diameter of the third heat exchange unit 3. The interior of each heat exchange unit is hollow and has a partition 6. The partition 6 divides the internal space of the heat exchange unit into a first heat exchange chamber and a second heat exchange chamber. The first heat exchanger and the second heat exchange chamber are isolated from each other and are not connected. The partition 6 is sintered with nano metal powder 12 of suitable thickness on the upper and lower surface fluid flow areas to increase the heat exchange area between the dense phase fluid and the dilute phase fluid, thereby improving the heat exchange effect.

[0026] Combination Figure 7 and Figure 8 As shown, the first heat exchange chamber is divided into a first upper flow channel 7 and a first lower flow channel 9. One end of the first upper flow channel 7 is connected to one end of the first lower flow channel 9 through a connecting port 8. The other ends of the first upper flow channel 7 and the first lower flow channel 9 are both connected to a dense phase pipe 4. The dense phase pipe 4 is far away from the connecting port 8 between the first upper flow channel 7 and the first lower flow channel 9. Figure 5 and Figure 6 As shown, the first upper flow channel 7 and the first lower flow channel 9 are stepped, which can effectively increase the heat exchange area and further improve the heat exchange effect. The second heat exchange chamber is divided into a second upper flow channel 10 and a second lower flow channel 11. One end of the second upper flow channel 10 is connected to one end of the second lower flow channel 11 through a connecting port 8. The other end of the second upper flow channel 10 and the other end of the second lower flow channel 11 are both connected to a dilute phase pipe 5, and the dilute phase pipe 5 is far away from the connecting port 8 between the second upper flow channel 10 and the second upper flow channel 10. The second upper flow channel 10 and the second lower flow channel 11 are stepped, which can effectively increase the heat exchange area and further improve the heat exchange effect. The top wall of the first heat exchange unit 1 is respectively provided with a dense phase pipe 4 and a dilute phase pipe 5. The lower part of the outer wall of the first heat exchange unit 1 is connected to the lower part of the inner wall of the second heat exchange unit 2 through the dense phase pipe 4 and the dilute phase pipe 5 respectively. The upper part of the outer wall of the second heat exchange unit 2 is connected to the upper part of the wall of the third heat exchange unit 3 through the dense phase tube 4 and the dilute phase tube 5 respectively. The bottom wall of the third heat exchange unit 3 is provided with a dense phase tube 4 and a dilute phase tube 5 respectively.

[0027] In this embodiment, the heat exchange group is divided into a first heat exchange group, a second heat exchange group, a third heat exchange group and a fourth heat exchange group. The first heat exchange group and the second heat exchange group are symmetrically arranged, and the third heat exchange group and the fourth heat exchange group are symmetrically arranged. The first heat exchange group and the second heat exchange group form a first heat exchange assembly, and the third heat exchange group and the fourth heat exchange group form a second heat exchange assembly. The first heat exchange assembly and the second heat exchange assembly are symmetrically arranged.

[0028] When in use, the fluid realizes countercurrent heat exchange between the first heat exchange chamber and the second heat exchange chamber. The dense phase fluid enters the semi-circular first upper flow channel 7 of the first heat exchange unit 1 from the dense phase tube 4, then enters the first lower flow channel 9 through the connecting port 8 between the first upper flow channel 7 and the first lower flow channel 9, and flows out of the first heat exchange unit 1 from the dense phase tube 4 connected to the first lower flow channel 9. The dilute phase fluid enters the semi-circular second lower flow channel 11 of the first heat exchange unit 1 from the dilute phase tube 5, then enters the second upper flow channel 10 through the connecting port 8 between the second lower flow channel 11 and the second upper flow channel 10, and flows out from the dilute phase tube 5 connected to the second upper flow channel 10.

[0029] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A ring-in-ring multi-stage powder sintered heat exchanger for a dilution refrigerator, characterized in that: The invention comprises a plurality of heat exchange groups, wherein adjacent heat exchange groups are connected via a concentrated phase tube (4) and a dilute phase tube (5); each of the heat exchange groups comprises a plurality of annular heat exchange units, wherein the plurality of heat exchange units are coaxially arranged and connected via a concentrated phase tube (4) and a dilute phase tube (5); each of the heat exchange units is hollow inside and has a partition (6), wherein the partition (6) divides the internal space of the heat exchange unit into a first heat exchange chamber and a second heat exchange chamber; the first heat exchange chamber is divided into a first upper flow channel (7) and a first lower flow channel (9), wherein the first upper flow channel (7) and the first lower flow channel (9) are connected, and the first upper flow channel (7) and the first lower flow channel (9) are both connected via a concentrated phase tube (4); the second heat exchange chamber is divided into a second upper flow channel (10) and a second lower flow channel (11), wherein the second upper flow channel (10) and the second lower flow channel (11) are connected, and the two upper flow channels and the second lower flow channel (11) are both connected via a dilute phase tube (5).

2. The ring-in-ring multi-stage powder sintered heat exchanger for a dilution refrigerator according to claim 1, characterized in that: One end of the first upper flow channel (7) is connected to one end of the first lower flow channel (9) through a connecting port (8), and the first upper flow channel (7) and the first lower flow channel (9) are in a stepped shape; One end of the second upper flow channel (10) is connected to one end of the second lower flow channel (11) via a connecting port (8), and the second upper flow channel (10) and the second lower flow channel (11) are in a stepped shape.

3. The ring-in-ring multi-stage powder sintered heat exchanger for a dilution refrigerator according to claim 2, characterized in that: The first upper flow channel (7) is located at the upper left side of the heat exchange unit, the second upper flow channel (10) is located at the upper right side of the heat exchange unit, the first lower flow channel (9) is located at the lower right side of the heat exchange unit, and the second lower flow channel (11) is located at the lower left side of the heat exchange unit.

4. The ring-in-ring multi-stage powder sintered heat exchanger for a dilution refrigerator according to claim 2, characterized in that: The concentrated phase tube (4) is away from the communication port (8) between the first upper flow channel (7) and the first lower flow channel (9), and the dilute phase tube (5) is away from the communication port (8) between the second upper flow channel (10) and the second lower flow channel (11).

5. The ring-in-ring multi-stage powder sintered heat exchanger for a dilution refrigerator according to claim 1, characterized in that: The heat exchange group comprises a first heat exchange unit (1), a second heat exchange unit (2) and a third heat exchange unit (3), wherein the first heat exchange unit (1), the second heat exchange unit (2) and the third heat exchange unit (3) are arranged from inside to outside.

6. The ring-in-ring multi-stage powder sintered heat exchanger for a dilution refrigerator according to claim 5, characterized in that: A concentrated phase tube (4) and a dilute phase tube (5) are respectively arranged on the top wall of the first heat exchange unit (1), and the lower part of the outer wall of the first heat exchange unit (1) is connected to the lower part of the inner wall of the second heat exchange unit (2) through the concentrated phase tube (4) and the dilute phase tube (5).

7. The ring-in-ring multi-stage powder sintered heat exchanger for a dilution refrigerator according to claim 6, characterized in that: The upper portion of the outer wall of the second heat exchange unit (2) is connected to the upper portion of the inner wall of the third heat exchange unit (3) via a concentrated phase tube (4) and a dilute phase tube (5), respectively, and a concentrated phase tube (4) and a dilute phase tube (5) are respectively provided on the bottom wall of the third heat exchange unit (3).

8. The ring-in-ring multi-stage powder sintered heat exchanger for a dilution refrigerator according to claim 5, characterized in that: The plurality of heat exchange groups are divided into a first heat exchange group and a second heat exchange group, and the first heat exchange group and the second heat exchange group are symmetrically arranged.

9. The ring-in-ring multi-stage powder sintered heat exchanger for a dilution refrigerator according to claim 1, characterized in that: A layer of nano metal powder (12) is sintered on both the upper and lower surfaces of the partition (6).

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