A heat transfer structure and method of manufacture

Abstract

The heat transfer structure and the preparation method provided by the application, the heat bus (32) is arranged in the positioning member (31), the welding hole (33) is arranged on the heat transfer copper rod (35), the heat bus (32) is inserted into the welding hole (33), the heat bus (32) and the heat transfer copper rod (35) are pressed, the component after pressing is welded, the heat transfer between the heat bus (32) and the heat transfer copper rod (35) is strengthened, the additional thermal resistance between the heat bus and the magnetic heat material due to the existence of the solder is avoided, and the heat transfer structure after being manufactured still has high flexibility.

Description

Technical Field

[0001] This application relates to the field of cryogenic refrigeration technology, and in particular to a heat transfer structure and its preparation method. Background Technology

[0002] Cryogenic cooling technology is an important scientific technology widely used in cutting-edge fields such as space exploration and quantum technology. In astronomical observation, condensed matter physics experiments, and industrial applications, high-resolution detectors must be cooled to extremely low temperatures (<0.3K) to achieve the required sensitivity, such as infrared calorimeters, superconducting TES sensors, and superconducting tunnel junction detectors. Among several cryogenic cooling methods, adiabatic demagnetization refrigeration (ADR) is based on the magnetocaloric effect of solid materials, that is, the thermal effect generated by the magnetocaloric material in response to changes in an external magnetic field. It features high efficiency, independence from gravity, no moving parts, and operation not dependent on scarce resources. 3 His strengths.

[0003] A typical ADR consists of a superconducting magnet, a thermal switch, a heat transfer structure (30), a high-temperature heat sink, and a low-temperature cold head. The refrigeration cycle is completed by the heat transfer structure (30) releasing / absorbing heat in a changing magnetic field, in conjunction with the opening and closing of the thermal switch.

[0004] The existing method for manufacturing heat transfer structures involves threading high-purity copper or gold wires through perforated positioning sheets (stainless steel, brass) to ensure even distribution of the heat transfer lines; drilling welding holes at the ends of the copper rods, filling them with solder, and then inserting the ends of the heat transfer lines into the welding holes for welding. Common welding methods include flame welding, argon arc welding, and vacuum brazing.

[0005] In existing technologies, during welding, the capillary force of the hot bus on the solder causes most of the solder to climb along the hot bus, leading to several problems: First, the solder flows out between the copper rod and the hot bus due to capillary action, resulting in insufficient filling of the welding material at that location and poor heat transfer. Second, due to capillary action, the solder flows from the end of the hot bus to the middle section, covering the surface of the hot bus and increasing the thermal resistance between the magnetocaloric material and the hot bus, further worsening heat transfer. Third, during the process of the solder flowing from the end of the hot bus to the middle section due to capillary action, multiple metal wires are welded together, reducing flexibility and hindering the final positioning and fit with the outer casing. Summary of the Invention

[0006] In view of this, it is necessary to provide a heat transfer structure component and test method to solve the heat transfer problem between the heat bus and the heat transfer copper rod and to enhance the heat transfer of the heat transfer structure (30) in order to address the defects in the existing technology.

[0007] To solve the above problems, this application adopts the following technical solution:

[0008] This application provides a heat transfer structure, including: a magnetocaloric material (10), a shell (20), and a heat transfer structure (30), wherein the heat transfer structure (30) includes a heat transfer bus (32) and a heat transfer copper rod (35); wherein:

[0009] The magnetocaloric material (10) is disposed inside the outer shell (20). One end of the heat bus (32) passes through the positioning member (31) and is distributed inside the magnetocaloric material (10). The heat transfer copper rod (35) extends into the outer shell (20) and has a welding hole (33) at one end. The other end of the heat bus (32) is pressed together with the heat transfer copper rod (35) and welded into the welding hole (33).

[0010] In some embodiments, the magnetothermal material (10) comprises a hydrated paramagnetic salt in the lower temperature range, the hydrated paramagnetic salt comprising ferric ammonium alum or chromium potassium alum.

[0011] In some embodiments, the thermal bus (32) is a plurality of uniformly arranged high thermal conductivity metal wires, the high thermal conductivity metal wires comprising copper or gold.

[0012] In some embodiments, the positioning element (31) is a positioning sheet made of stainless steel or brass, and one end of the hot bus (32) passes through the positioning sheet to make the hot bus (32) evenly distributed.

[0013] In some embodiments, the diameter of the welding hole (33) is preferably just large enough to fit the hot bus (32), and the length of the welding hole (33) is slightly longer than the end of the hot bus (32).

[0014] In some embodiments, solder (34) is also provided at the bottom of the welding hole (33), and the amount of solder (34) should be slightly more than the volume of the welding hole (33) minus the volume of the hot bus (32).

[0015] In addition, this application also provides a method for manufacturing the aforementioned heat transfer structure, comprising the following steps:

[0016] The hot bus (32) is passed through the positioning member (31);

[0017] Welding holes (33) are made on the heat transfer copper rod (35);

[0018] Insert the hot bus (32) into the welding hole (33);

[0019] The heat transfer bus (32) and the heat transfer copper rod (35) are pressed together;

[0020] Welding is then performed on the pressed components.

[0021] In some embodiments, the pressing includes cold pressing and hot pressing, wherein the cold pressing may be performed using hydraulic clamps with electrical terminals or a hydraulic press, and the hot pressing is performed using a hot press.

[0022] In some embodiments, most of the solder (34) accumulates in the gap below the small hole of the heat transfer copper rod (35) and the heat transfer copper rod (35), and a small portion of the solder (34) rises upward during welding, just filling the gap between the heat transfer copper rod (35) and the heat transfer copper rod (32).

[0023] In some embodiments, the welding includes flame welding, argon arc welding, electron beam welding, ion beam welding, or laser welding.

[0024] The present application adopts the above technical solution, and its beneficial effects are as follows:

[0025] The heat transfer structure and its preparation method provided in this application involve passing a heat bus (32) through the positioning member (31), opening a welding hole (33) on the heat transfer copper rod (35), inserting the heat bus (32) into the welding hole (33), pressing the heat bus (32) and the heat transfer copper rod (35) together, and welding the pressed components to enhance the heat transfer between the heat bus (32) and the heat transfer copper rod (35), avoiding additional thermal resistance between the heat bus and the magnetocaloric material due to the presence of solder, and ensuring that the heat transfer structure still has high flexibility after it is made. Attached Figure Description

[0026] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the heat transfer structure provided in Embodiment 1 of this application.

[0028] Figure 2 This is a flowchart of the method steps for the heat transfer structure provided in Embodiment 2 of this application. Detailed Implementation

[0029] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this application, and should not be construed as limiting this application.

[0030] In the description of this application, it should be understood that the terms "upper", "lower", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0032] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments.

[0033] Example 1

[0034] Please see Figure 1 This is a schematic diagram of a heat transfer structure provided in Embodiment 1, including: a magnetocaloric material (10), a shell (20), and a heat transfer structure (30). The connection relationship and implementation of each component are described in detail below.

[0035] In this embodiment, the magnetocaloric material (10) is disposed inside the outer casing (20).

[0036] In some embodiments, the magnetocaloric material (10) comprises a hydrated paramagnetic salt in the lower temperature range (below 1K), which includes ferric ammonium alum or chromium potassium alum.

[0037] In some embodiments, the housing (20) is used to encapsulate the magnetocaloric material (10), particularly the hydrated paramagnetic salt of the low-temperature heat transfer structure (30), to prevent dehydration failure.

[0038] In this embodiment, the heat transfer structure (30) includes a heat transfer bus (32) and a heat transfer copper rod (35). One end of the heat transfer bus (32) passes through the positioning member (31) and is distributed within the magnetocaloric material (10).

[0039] In some embodiments, the thermal bus (32) is a plurality of uniformly arranged high thermal conductivity metal wires, the high thermal conductivity metal wires comprising copper or gold.

[0040] In some embodiments, the positioning element (31) is a positioning sheet made of stainless steel or brass, and one end of the hot bus (32) passes through the positioning sheet to make the hot bus (32) evenly distributed.

[0041] In some embodiments, the heat transfer structure (30) may also be a copper rod provided at each of the upper and lower ends of the heat bus (32).

[0042] In this embodiment, a welding hole (33) is provided at one end of the heat transfer copper rod (35) extending into the outer shell (20), and the other end of the heat transfer bus (32) is pressed together with the heat transfer copper rod (35) and welded into the welding hole (33).

[0043] It can be understood that the heat bus (32) consists of multiple uniformly arranged high thermal conductivity metal wires (copper, gold), the ends of which are connected to the heat transfer copper rod (35). The magnetocaloric material (10) grows into crystals on the heat bus (32), and the heat generated is first transferred to the heat bus (32), then to the heat transfer copper rod (35), and finally to the heat sink or load through the heat transfer copper rod (35).

[0044] In some embodiments, the diameter of the welding hole (33) is preferably just large enough to fit the hot bus (32), and the length of the welding hole (33) is slightly longer than the end of the hot bus (32).

[0045] In some embodiments, solder (34) is also provided at the bottom of the welding hole (33), and the amount of solder (34) should be slightly more than the volume of the welding hole (33) minus the volume of the hot bus (32).

[0046] It is understood that most of the solder (34) accumulates in the gap between the heat transfer bus (35) and the small hole of the heat transfer copper rod (35), and a small portion of the solder (34) climbs upward and just fills the gap between the heat transfer copper rod (35) and the heat transfer bus (32), further enhancing the heat transfer effect.

[0047] In addition, another advantage of welding is that the heat transfer structure (30) undergoes multiple thermal expansion and contraction cycles between low and high temperatures, which may cause the pressed parts to loosen; and since copper itself is relatively soft, the force generated by pressing is small at low temperatures. The above factors may lead to poor thermal contact caused by insufficient pressing force, while welding can avoid the above problems.

[0048] The heat transfer structure provided in the above embodiments of this application has a heat bus (32) passing through the positioning member (31), a welding hole (33) opened on the heat transfer copper rod (35), the heat bus (32) inserted into the welding hole (33), the heat bus (32) and the heat transfer copper rod (35) pressed together, and the pressed component is welded together to enhance the heat transfer between the heat bus (32) and the heat transfer copper rod (35), avoid the additional thermal resistance between the heat bus and the magnetocaloric material due to the presence of solder, and ensure that the heat transfer structure can still have high flexibility after the heat transfer structure is manufactured.

[0049] Example 2

[0050] Please see Figure 2 This application also provides a method for manufacturing the aforementioned heat transfer structure, comprising the following steps:

[0051] Step S110: Pass the hot bus (32) through the positioning member (31).

[0052] Furthermore, the thermal bus (32) consists of multiple uniformly arranged high thermal conductivity metal wires, the high thermal conductivity metal wires including copper or gold.

[0053] Furthermore, the positioning element (31) is a positioning sheet, which is made of stainless steel or brass. One end of the hot bus (32) is inserted through the positioning sheet so that the hot bus (32) is evenly distributed.

[0054] Step S120: Open welding holes (33) on the heat transfer copper rod (35).

[0055] Specifically, the heat transfer copper rod (35) has a welding hole (33) at one end extending into the outer shell (20), and the other end of the heat transfer bus (32) is pressed together with the heat transfer copper rod (35) and welded into the welding hole (33).

[0056] It can be understood that the heat bus (32) consists of multiple uniformly arranged high thermal conductivity metal wires (copper, gold), the ends of which are connected to the heat transfer copper rod (35). The magnetocaloric material (10) grows into crystals on the heat bus (32), and the heat generated is first transferred to the heat bus (32), then to the heat transfer copper rod (35), and finally to the heat sink or load through the heat transfer copper rod (35).

[0057] Step S130: Insert the hot bus (32) into the welding hole (33).

[0058] In some embodiments, the diameter of the welding hole (33) is preferably just large enough to fit the hot bus (32), and the length of the welding hole (33) is slightly longer than the end of the hot bus (32).

[0059] Step S140: Press the heat transfer bus (32) and the heat transfer copper rod (35) together.

[0060] In some embodiments, the pressing includes cold pressing and hot pressing, wherein the cold pressing may be performed using hydraulic clamps with electrical terminals or a hydraulic press, and the hot pressing is performed using a hot press.

[0061] Step S150: Weld the pressed components.

[0062] In some embodiments, solder (34) is also provided at the bottom of the welding hole (33), and the amount of solder (34) should be slightly more than the volume of the welding hole (33) minus the volume of the hot bus (32).

[0063] In some embodiments, the pressed structure is sent into a vacuum brazing furnace. At this time, since the distance between the heat transfer copper rod (35) and the heat bus (35) and between the metal wires of the heat bus (35) has been compressed to a very small size, the solder (34) is difficult to continue to climb under the action of capillary force. Most of the solder (34) accumulates in the gap below the small hole of the heat bus (35) and the heat transfer copper rod (35), and a small part of the solder (34) climbs upward and just fills the gap between the heat transfer copper rod (35) and the heat bus (32), which further enhances the heat transfer effect.

[0064] In addition, another advantage of welding is that the heat transfer structure (30) undergoes multiple thermal expansion and contraction cycles between low and high temperatures, which may cause the pressed parts to loosen; and since copper itself is relatively soft, the force generated by pressing is small at low temperatures. The above factors may lead to poor thermal contact caused by insufficient pressing force, while welding can avoid the above problems.

[0065] In some embodiments, the welding includes flame welding, argon arc welding, electron beam welding, ion beam welding, or laser welding.

[0066] It is understandable that when using flame welding, argon arc welding, electron beam welding, ion beam welding, laser welding or other processes that can perform local welding, filler metal can be omitted, and the heat transfer copper rod (35) and heat transfer bus (32) can be locally softened by high temperature to achieve the same purpose.

[0067] The method for preparing the heat transfer structure provided in the above embodiments of this application involves passing a heat bus (32) through the positioning member (31), opening a welding hole (33) on the heat transfer copper rod (35), inserting the heat bus (32) into the welding hole (33), pressing the heat bus (32) and the heat transfer copper rod (35) together, and welding the pressed component to enhance the heat transfer between the heat bus (32) and the heat transfer copper rod (35), avoiding additional thermal resistance between the heat bus and the magnetocaloric material due to the presence of solder, and ensuring that the heat transfer structure still has high flexibility after it is made.

[0068] It is understood that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] The above are merely preferred embodiments of this application, and only specifically describe the technical principles of this application. These descriptions are only for explaining the principles of this application and should not be construed as limiting the scope of protection of this application in any way. Based on this explanation, any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application, as well as other specific embodiments of this application that can be conceived by those skilled in the art without creative effort, should be included within the scope of protection of this application.

Claims

1. A heat transfer structural component, characterized in that, include: The system comprises a magnetocaloric material (10), a shell (20), and a heat transfer structure (30), wherein the heat transfer structure (30) includes a heat transfer bus (32) and a heat transfer copper rod (35); wherein: The magnetocaloric material (10) is disposed inside the outer shell (20). One end of the heat bus (32) passes through the positioning member (31) and is distributed inside the magnetocaloric material (10). The heat transfer copper rod (35) extends into the outer shell (20) and has a welding hole (33) at one end. The other end of the heat bus (32) is pressed together with the heat transfer copper rod (35) and welded into the welding hole (33). The diameter of the welding hole (33) is preferably just large enough to fit the hot bus (32), and the length of the welding hole (33) is slightly longer than the end of the hot bus (32). The bottom of the welding hole (33) is also provided with solder (34), and the amount of solder (34) should be slightly more than the volume of the welding hole (33) minus the volume of the hot bus (32).

2. The heat transfer structure as described in claim 1, characterized in that, The magnetothermal material (10) comprises hydrated paramagnetic salts in the lower temperature range, and the hydrated paramagnetic salts include ferric ammonium alum or chromium potassium alum.

3. The heat transfer structure as described in claim 1, characterized in that, The heat bus (32) consists of multiple uniformly arranged high thermal conductivity metal wires, including copper or gold.

4. The heat transfer structure as described in claim 3, characterized in that, The positioning element (31) is a positioning sheet, which is made of stainless steel or brass. One end of the hot bus (32) is inserted through the positioning sheet so that the hot bus (32) is evenly distributed.

5. A method for preparing a heat transfer structural component as described in any one of claims 1 to 4, characterized in that, Includes the following steps: The hot bus (32) is passed through the positioning member (31); Welding holes (33) are made on the heat transfer copper rod (35); Insert the hot bus (32) into the welding hole (33); The heat transfer bus (32) and the heat transfer copper rod (35) are pressed together; Welding is then performed on the pressed components.

6. The method for preparing the heat transfer structure as described in claim 5, characterized in that, The pressing includes cold pressing and hot pressing. The cold pressing uses a hydraulic clamp or hydraulic press with electrical terminals, and the hot pressing uses a hot press.

7. The method for preparing the heat transfer structure as described in claim 6, characterized in that, Most of the solder (34) accumulates in the gap between the heat transfer bus (32) and the small hole of the heat transfer copper rod (35). During the soldering process, a small portion of the solder (34) rises upward and just fills the gap between the heat transfer copper rod (35) and the heat transfer bus (32).

8. The method for preparing the heat transfer structure as described in claim 6, characterized in that, The welding includes flame welding, argon arc welding, electron beam welding, ion beam welding, laser welding, or vacuum brazing.

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