Process for forming microchannel heat exchangers, second bends connecting between heat exchange units, and headers

Abstract

The present application relates to a kind of microchannel heat exchanger, the forming process of second bending piece and header connected between heat exchange unit, the heat exchange pipe section in heat exchange unit in the microchannel heat exchanger is flat tube, each heat exchange pipe section in each heat exchange unit can form passage by first bending piece in series, and further form passage between the heat exchange unit of adjacent layer by second bending piece, that is, each heat exchange unit is serpentine structure, at least two layers of serpentine structure in series are provided in microchannel heat exchanger, under the condition that the heat exchange medium with same flow, the heat exchange area of flat tube is larger, and the internal flow channel of flat tube is very close to outer wall, greatly improve the utilization of refrigerant in flat tube, so as to greatly improve heat exchange efficiency, that is, if the same refrigerating capacity is needed, the total amount of refrigerant required by the microchannel heat exchanger provided by the present application is less, the volume of microchannel heat exchanger is reduced accordingly, and the overall volume of the evaporator can be effectively reduced, facilitate space arrangement, and can reduce air side resistance, ensure system reliability.

Description

Technical Field

[0001] This invention relates to the field of heat exchange technology, specifically to a microchannel heat exchanger, a second bending member connecting heat exchange units, and a forming process for a manifold. Background Technology

[0002] Microchannel heat exchangers are widely used in the refrigeration field. For example, in the field of refrigerator refrigeration, microchannel evaporators are a typical type of microchannel heat exchanger.

[0003] Currently, the heat exchange tubes of microchannel evaporators used in refrigerators are in the form of circular tubes. However, these circular tubes are filled with a relatively large amount of refrigerant. During heat exchange, energy exchange mainly relies on the refrigerant near the periphery of the tube, while the refrigerant in the center of the tube exchanges relatively little heat, resulting in low heat exchange efficiency. When the heat exchange capacity is large, the diameter of the circular tube also needs to be larger, which leads to a larger volume of microchannel evaporators, occupying a larger space and significantly reducing the usable volume of the refrigerator.

[0004] In addition, the larger the volume of the microchannel evaporator, the greater its air resistance, and the lower the reliability of the refrigeration system will be. Summary of the Invention

[0005] The purpose of this invention is to provide a microchannel heat exchanger with high heat exchange efficiency and small overall size. Another purpose of this invention is to provide a forming process for a second bent component and a manifold connecting the heat exchange units.

[0006] This invention provides a microchannel heat exchanger, comprising at least two heat exchange units. Each heat exchange unit includes a first bending element and at least two heat exchange tube segments. Each heat exchange tube segment is a flat tube. All heat exchange tube segments in the heat exchange unit are arranged along the thickness direction of the heat exchange tube segments. The first bending element is provided between adjacent openings of adjacent heat exchange tube segments in the heat exchange unit. All heat exchange tube segments in the same heat exchange unit are connected in series through each of the first bending elements to form a passage with an inlet and an outlet.

[0007] It also includes a second bending member with an internal channel. Each heat exchange unit is arranged along the width direction of the heat exchange tube segment. The second bending member is connected and fixed between adjacent heat exchange units. The outlet of the heat exchange unit in the previous layer is connected to the inlet of the adjacent heat exchange unit in the next layer through the internal channel of the second bending member.

[0008] Additionally, a forming process for a second bent component connected between heat exchange units includes the following steps:

[0009] The first groove mandrel is placed between two aluminum plates and the aluminum plates are pressed to form an initial model groove. Then the first groove mandrel is taken out from the first opening, wherein the initial model groove includes an inner cavity with a first opening, and the inner cavity is adapted to the first groove mandrel.

[0010] Two second grooved core rods are inserted into the inner cavity in parallel from the first opening, and the side wall portions of the initial model groove located between the two second grooved core rods are squeezed to isolate the first opening to form a first socket and a second socket, and the first socket and the second socket can communicate through the inner cavity; wherein the outer contour of the second grooved core rod is the same as the outer contour of the end of the heat exchange tube section that is fitted into the corresponding socket.

[0011] Furthermore, a forming process for a second bent component connected between heat exchange units, the forming process comprising the following steps:

[0012] The first groove mandrel is placed between two aluminum plates and the aluminum plates are pressed to form an initial model groove. Then the first groove mandrel is taken out from the first opening, wherein the initial model groove includes an inner cavity with a first opening, and the inner cavity is adapted to the first groove mandrel.

[0013] The segment is inserted into the inner cavity through the first opening and fixed to the side wall of the inner cavity so that a first socket and a second socket are formed on both sides of the segment to be inserted into the corresponding heat exchange tube section, and the first socket and the second socket can communicate through the inner cavity.

[0014] In addition, a forming process for a manifold includes the following steps:

[0015] The first groove mandrel is placed between two aluminum plates and the aluminum plates are pressed to form a first mold groove. Then the first groove mandrel is taken out from the first opening. The initial mold groove includes an inner cavity with a first opening, and the inner cavity is adapted to the first groove mandrel.

[0016] Along a direction perpendicular to the end face of the first opening, one end of the first model groove is cut to form an intermediate model groove, wherein the intermediate model groove has a second opening at the cut end;

[0017] One end of the second grooved mandrel is inserted into the inner cavity through the first opening, and one end of the tube mandrel is inserted into the inner cavity through the second opening. The two ends are pressed together to form partial sidewalls of the first and second openings, such that the first opening is formed as a first connecting end adapted to the second grooved mandrel, and the second opening is formed as a second connecting end adapted to the tube mandrel. The first connecting end and the second connecting end are connected through the inner cavity. The second grooved mandrel and the tube mandrel are then removed, wherein the outer contour of the cross-section of the second grooved mandrel is the same as the outer contour of the end cross-section of the flat tube.

[0018] In this invention, the heat exchange tubes in the heat exchange units of the microchannel heat exchanger are flat tubes with a flat cross-section. Each heat exchange tube in each heat exchange unit can be connected in series to form a passage through a first bending element, and adjacent heat exchange units can be further connected through a second bending element. That is, each heat exchange unit is a serpentine structure. The microchannel heat exchanger has at least two layers of serpentine structures connected in series. Compared with round tubes, flat tubes are flat and, under the condition of the same flow rate of heat exchange medium, the heat exchange area of ​​flat tubes is larger. Moreover, the distance between the internal flow channel and the outer wall of the flat tube is very close, which improves the utilization rate of the refrigerant in the flat tube, thereby greatly improving the heat exchange efficiency. In other words, if the same cooling capacity is required, the total amount of refrigerant required by the microchannel heat exchanger provided by this invention is less, and the volume of the microchannel heat exchanger is correspondingly reduced. In addition, flat tubes are easier to arrange between rows and columns, thereby effectively reducing the overall volume of the evaporator, facilitating spatial arrangement, reducing air-side resistance, and improving system reliability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the microchannel heat exchanger provided in an embodiment of the present invention;

[0020] Figure 2 yes Figure 1 Enlarged view of point A in the middle;

[0021] Figure 3 yes Figure 1 A schematic diagram of the decomposition process;

[0022] Figure 4 This is a schematic diagram of the manifold structure provided in an embodiment of the present invention;

[0023] Figure 5 This is a schematic diagram of the structure of the second bending member provided in one embodiment of the present invention;

[0024] Figure 6 yes Figure 5 The forming process diagram of the second bent part is shown below;

[0025] Figure 7This is a schematic diagram of the structure of the first grooved core rod provided in one embodiment of the present invention;

[0026] Figure 8 This is a schematic diagram of a structure provided in one embodiment of the present invention;

[0027] Figure 9 This is a schematic diagram of the structure of the second bending member provided in another embodiment of the present invention;

[0028] Figure 10 yes Figure 9 The forming process diagram of the second bent part is shown below;

[0029] Figure 11 yes Figure 10 A schematic diagram of the structure of the partition used in the process;

[0030] Figure 12 This is a flowchart illustrating the forming process of a manifold according to an embodiment of the present invention;

[0031] Figure 13 This is a schematic diagram of the intermediate model groove structure according to an embodiment of the present invention;

[0032] Figure 14 This is a schematic diagram of the structure of a tube mandrel according to an embodiment of the present invention.

[0033] Appendix Figures 1-14 The reference numerals in the attached figures are explained as follows:

[0034] 1-First heat exchange unit; 11-Heat exchange tube section; 12-First bending element;

[0035] 2-Second heat exchange unit;

[0036] 3-Third heat exchange unit;

[0037] 4-Second bending component; 41-First insertion port; 42-Second insertion port; 43-Inner cavity; 4a-Partial side wall area; 4-1-Aluminum plate; 4-2-Initial model groove; 4-3-First groove core rod; 4-4-Second groove core rod;

[0038] 5-Heat dissipation fins; 51-Fin segment; 52-Connecting section;

[0039] 6-Manifold, 61-First connecting end, 62-Second connecting end, 63-Arc-shaped segment, 6a-Compressed sidewall area;

[0040] 6-1-Aluminum plate, 6-2-First model groove, 6-3-Intermediate model groove, 6a-Partial sidewall; 6a1-First opening; 6a2-Second opening; 7-Tube mandrel. Detailed Implementation

[0041] This article takes the application of a microchannel heat exchanger as an evaporator in a refrigerator refrigeration system as an example to introduce the technical solution and technical effects. Of course, those skilled in the art should understand that the microchannel heat exchanger provided in this article is not limited to refrigerator refrigeration systems, but can also be applied to other fields.

[0042] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0043] Please refer to Figures 1 to 5 This invention provides a microchannel heat exchanger, which includes at least two heat exchange units. Each heat exchange unit includes a first bending element 12 and at least two heat exchange tube segments 11. Each heat exchange tube segment 11 can be a flat tube, a straight tube segment, or a tube segment of other shapes. It should be noted that the cross-section of the flat tube includes a long side and a short side, with the length of the long side being greater than the length of the short side. For ease of description, the thickness direction, length direction, and width direction of the heat exchange tube segment 11 mentioned herein are referred to in [reference needed]. Figure 3 As shown in the image.

[0044] Each heat exchange tube segment 11 in the heat exchange unit is arranged at intervals along the thickness direction of the heat exchange tube segment 11. A first bending element 12 is provided between adjacent pipe openings of adjacent heat exchange tube segments 11 in the heat exchange unit. All heat exchange tube segments 11 in the same heat exchange unit are connected in series through the first bending elements 12 to form a passage with an inlet and an outlet. That is, the first bending element connects adjacent heat exchange tube segments 11 to achieve communication between two heat exchange tube segments 11, forming a serpentine structure. The number of heat exchange tube segments 11 in a heat exchange unit can be determined according to the specific application environment, and is not limited in this paper. Figure 1 The figure shows a specific implementation of a heat exchange unit consisting of four heat exchange tube segments 11 connected in series.

[0045] The first bending member 12 can be inserted and fixed to the heat exchange tube section 11, or it can be fixed by welding.

[0046] The first bending element 12 can be an arc-shaped flat tube, with the openings at both ends of the arc-shaped flat tube sealingly connected to the adjacent heat exchange tube section 11.

[0047] Of course, in order to improve the heat exchange efficiency of the heat exchange unit, heat dissipation fins 5 can also be provided on the outer wall of the adjacent heat exchange tube section 11. The heat dissipation fins 5 can take many forms, and two specific implementation methods are given later.

[0048] The microchannel heat exchanger further includes a second bend 4 with an internal channel. Each heat exchange unit is arranged along the width of the heat exchange tube segment 11. The second bend 4 is fixed between adjacent heat exchange units, and the outlet of the preceding heat exchange unit is connected to the inlet of the adjacent following heat exchange unit through the internal channel of the second bend 4. In other words, the second bend 4 enables the series connection of adjacent heat exchange units. Specifically, the outlet of the upstream heat exchange unit is connected to the inlet of the downstream heat exchange unit through the internal channel of the second bend 4. This allows the cold medium to flow from the upstream layer to the downstream heat exchange unit.

[0049] The number of heat exchange units is not limited in this article. Figure 1 The paper provides a specific implementation with three heat exchange units. For the sake of brevity in the following description, the three heat exchange units are defined as the first heat exchange unit 1, the second heat exchange unit 2, and the third heat exchange unit 3, respectively.

[0050] In this invention, the heat exchange tube segment 11 in the heat exchange unit of the microchannel heat exchanger is a flat tube with a flat cross-section. Each heat exchange tube segment 11 in each heat exchange unit can be connected in series to form a passage through the first bending member 12, and the heat exchange units in adjacent layers can be further connected through the second bending member 4. That is, each heat exchange unit is a serpentine structure. The microchannel heat exchanger is provided with at least two layers of serpentine structures connected in series. Compared with round tubes, flat tubes are flat. Under the condition of the same flow rate of heat exchange medium, the heat exchange area of ​​flat tubes is larger, and the distance between the internal flow channel and the outer wall of the flat tube is very close, which greatly improves the utilization rate of the refrigerant in the flat tube, thereby greatly improving the heat exchange efficiency. In other words, if the same cooling capacity is required, the total amount of refrigerant required by the microchannel heat exchanger provided by this invention is relatively small, and the volume of the microchannel heat exchanger is correspondingly reduced. In addition, flat tubes are easier to arrange between rows and columns, thereby effectively reducing the overall volume of the evaporator, facilitating spatial arrangement, reducing air-side resistance, and ensuring system reliability.

[0051] like Figure 1 As shown, the connection ports of adjacent heat exchange units are located on the same side, which minimizes the volume of the second bending member 4 and simplifies its structure. Each heat exchange unit in the first, second, and third layers has four heat exchange tube segments 11. The inlet end of the rightmost heat exchange tube segment 11 of the first layer is connected to a manifold 6. The outlet end of the leftmost heat exchange tube segment 11 of the first layer is connected to the inlet end of the leftmost heat exchange tube segment 11 of the second layer via the second bending member 4. The outlet end of the rightmost heat exchange tube segment 11 of the second layer is connected to the inlet end of the rightmost heat exchange tube segment 11 of the third layer via another second bending member 4.

[0052] From the above description, those skilled in the art will clearly understand the microchannel heat exchanger structure of other numbers of heat exchange units.

[0053] In one specific embodiment, the second bending member 4 includes a first socket 41 and a second socket 42 that are connected. The first socket 41 and the second socket 42 are respectively sealed and plugged into the outlet of the preceding heat exchange unit and the inlet of the following heat exchange unit. The first socket 41 and the second socket 42 can be formed by machining or by extrusion molding. The two forming processes of the second bending member 4 will be described in detail later. The shapes of the first socket 41 and the second socket 42 are adapted to the end fitting section type of the heat exchange tube section 11 that they mate with.

[0054] The plug-in connection structure is simple and has high reliability.

[0055] The heat exchange tube section 11 includes relatively independent flow channels, each extending along the length of the heat exchange tube section 11. Typically, the flow channels are arranged at predetermined intervals along the width of the heat exchange tube section 11. Extensive experiments have revealed that when there are too many flow channels in the heat exchange tube section 11, the refrigerant only enters a few of these channels, resulting in only a portion of the refrigerant participating in heat exchange while the rest does not, leading to relatively low heat exchange efficiency.

[0056] Based on the above findings, this paper makes the following improvements to overcome the aforementioned shortcomings.

[0057] In one specific embodiment, the number of flow channels in the heat exchange tube segment 11 of at least the upstream heat exchange unit is less than or equal to three. For Figure 1 In the first heat exchange unit 1, the number of flow channels in the heat exchange tube section 11 is less than or equal to 3.

[0058] For microchannel evaporators, the initial cold medium flowing in is liquid cold medium. In this paper, the number of flow channels in the uppermost heat exchange tube section 11 is controlled to be 3 or less. This is conducive to the uniform distribution of liquid cold medium, avoids the phenomenon of uneven distribution of cold medium in the flat tube, and improves the heat exchange efficiency of microchannel heat exchanger.

[0059] As the cold medium flows in the microchannel heat exchanger, it gradually vaporizes and expands in volume as it flows downstream, resulting in better uniformity of distribution. Therefore, the number of flow channels inside the heat exchange tube section 11 in the subsequent heat exchange unit can be appropriately increased, for example, to more than 3. The specific number can be determined according to the operating environment of the microchannel heat exchanger.

[0060] In one specific embodiment, the heat exchange tube segments 11 in the same heat exchange unit have the same width, and the width of the heat exchange tube segments 11 gradually increases along the width direction to meet the needs of gas refrigerant flow. Figure 1 The width of the heat exchange tubes in the first heat exchange unit 1, the second heat exchange unit 2, and the third heat exchange unit 3 increases layer by layer.

[0061] As mentioned above, the microchannel heat exchanger also includes heat dissipation fins 5 disposed on the outer wall of the heat exchange tube section 11 to increase the heat exchange area of ​​the heat exchange tube section 11 and improve the heat exchange efficiency.

[0062] In one specific structure, the heat dissipation fins 5 include aluminum foil plate fins, which are fitted onto each heat exchange tube section 11.

[0063] In another specific embodiment, the heat dissipation fins 5 include multiple fin segments 51 and multiple connecting segments 52. The multiple fin segments 51 are disposed between adjacent heat exchange tube segments 11 of the heat exchange unit and are spaced apart along the length direction of the heat exchange tube segments 11. A connecting segment 52 connects adjacent fin segments 51 and is fixedly connected to the outer wall of the heat exchange tube segment 11. That is, the heat dissipation fins 5 have a corrugated sheet structure, and the crests and troughs of the corrugated sheet structure are the connecting segments 52, which can be fixedly connected to the opposite outer walls of two adjacent heat exchange tube segments 11. Of course, in this embodiment, the specific structure of the heat dissipation fins 5 is not limited to that described herein. For example, it can also be set as a fixed protrusion along the outer wall of the heat exchange tube segment 11.

[0064] The heat dissipation fins 5, with their sheet-like or corrugated structures, can increase the heat exchange area and ensure heat exchange efficiency.

[0065] In the above embodiment, no heat dissipation fins 5 are provided at the first bending member 12 and the second bending member 4. This arrangement facilitates the bending process and avoids the heat dissipation fins 5 affecting the bending.

[0066] When the microchannel heat exchanger is in use, the heat exchange units are arranged vertically, and the gap between the five heat dissipation fins gradually increases from top to bottom. In other words, the upper fins are arranged more densely, while the lower fins are arranged more sparsely. This facilitates the rapid drainage of water accumulated in the upper layer, thereby improving the heat exchange efficiency.

[0067] In each of the above embodiments, the microchannel heat exchanger further includes two manifolds 6, which are respectively installed at the inlet of the first heat exchange unit and the outlet of the last heat exchange unit. The manifold 6 includes a first connecting end 61 and a second connecting end 62 connected through its inner cavity. The first connecting end 61 is used to connect and fix to the end of the corresponding heat exchange tube segment 11, and the second connecting end 62 is used to connect and fix to an external pipe, so that the external pipe can allow the cooling medium to flow into or out of the heat exchange tube segment 11 along the manifold 6.

[0068] The two manifolds 6 can be located at the same end of the microchannel heat exchanger. This arrangement makes the two manifolds 6 located on the same side of the heat exchange unit, which facilitates connection and operation.

[0069] Similarly, the second bending element 4 and the manifold 6 can both be located at the same end of the microchannel heat exchanger.

[0070] Furthermore, a limiting structure is also provided inside the manifold 6. The end of the heat exchange tube section 11 is connected to the first connecting end 61 via a plug-in connection. Specifically, when the end of the heat exchange tube section 11 is inserted into the first connecting end 61 and abuts against the limiting structure, it indicates that the two are properly fitted. Then, they can be fixed by welding, bonding, or other methods, or the heat exchange tube section 11 and the first connecting end 61 can be fixed by an interference fit. No specific limitation is made here. The setting of this limiting structure facilitates the installation between the heat exchange tube section 11 and the manifold 6, improving installation efficiency.

[0071] Furthermore, an arc-shaped segment is provided between the first connecting end 61 and the second connecting end 62. During installation, the end of the heat exchange tube segment 11 is inserted into the first connecting end 61 and abuts against the inner wall of the arc-shaped segment. The inner wall of the arc-shaped segment can form a limiting structure. Alternatively, a protrusion can be provided in the inner cavity. During installation, the end of the heat exchange tube segment 11 is inserted into the first connecting end 61 and abuts against the protrusion. No specific restrictions are made here. However, the limiting structure formed by the inner wall of the arc-shaped segment can simplify the overall structure and the manufacturing process.

[0072] In the above embodiments, the heat exchange tube section 11, the manifold 6 and the heat dissipation fins 5 can all be made of aluminum, which is lightweight and soft, making it easy to form.

[0073] Furthermore, the manifold 6, the first bending component 12, and the second bending component 4 are all integrally formed from metal plates using a progressive die.

[0074] Please refer to Figures 6 to 8 Furthermore, the present invention also provides a forming process for a second bent member 4 connected between heat exchange units, the forming process comprising the following steps:

[0075] S21. Place the first grooved core rod 4-2 between two aluminum plates 4-1 and press the aluminum plates so that the two aluminum plates are pressed to form an initial model groove 4-2. Then take out the first grooved core rod 4-2 from the first opening. The initial model groove 4-2 includes an inner cavity 43 with a first opening, and the inner cavity is adapted to the first grooved core rod 4-2.

[0076] S22. Two second groove core rods 4-4 are inserted into the inner cavity in parallel from the first opening, and the side wall portions 4a of the initial model groove located between the two second groove core rods 4-4 are squeezed to isolate the first opening to form a first socket 41 and a second socket 42, and the first socket 41 and the second socket 42 can be connected through the inner cavity 43; wherein the outer contour of the second groove core rod 4-4 is the same as the outer contour of the end of the heat exchange tube section that is fitted into the corresponding socket.

[0077] Please refer to Figure 9 and Figure 10 In another specific embodiment, the forming process of a second bent member connected between heat exchange units according to the present invention includes the following steps:

[0078] S31. Place the first grooved core rod 4-3 between two aluminum plates 4-1 and press the aluminum plates so that the two aluminum plates are pressed to form an initial model groove 4-2. Then take out the first grooved core rod 4-3 from the first opening. The initial model groove 4-2 includes an inner cavity with a first opening, and the inner cavity is adapted to the first grooved core rod 4-3.

[0079] Step S31 is basically the same as the molding step S21 in the above embodiment.

[0080] S32. Insert the segment 4-5 into the inner cavity from the first opening and fix it to the side wall of the inner cavity so that a first socket 41' and a second socket 42' are formed on both sides of the segment to be inserted into the corresponding heat exchange tube section, and the first socket 41' and the second socket 42' can be connected through the inner cavity.

[0081] Unlike step S22, the first and second insertion ports of the second bent part 4' formed by S32 are formed by the segment 4-5.

[0082] Additionally, please refer to Figures 12 to 14 The present invention also provides a forming process for a manifold, the forming process comprising the following steps:

[0083] S11. Place the first grooved core rod between two aluminum plates 6-1 and press the aluminum plates 6-1 so that the two aluminum plates 6-1 are pressed to form the first molded groove 6-2. Then take out the first grooved core rod from the first opening. The first molded groove 6-2 includes an inner cavity with a first opening, and the inner cavity is adapted to the first grooved core rod.

[0084] The first grooved core rod is mainly used to form the inner cavity. The first grooved core rod is preferably flat, and the cross-section of the first opening after forming is similar to the outer contour of the cross-section of the heat exchange tube section. Please refer to the following for the shape of the first grooved core rod. Figure 7The first model groove 6-2 can have the same structure as the initial model groove 4-2 in steps S21 and S32 above. That is to say, steps S11, 21, and 31 can also be the same process steps.

[0085] S12. Along the direction perpendicular to the end face of the first opening 6a1, one side end of the initial model groove is cut to form an intermediate model groove 6-3, wherein the intermediate model groove 6-3 has a second opening 6a2 at the cut end.

[0086] That is, the orientation of the first opening 6a1 is approximately perpendicular to the orientation of the second opening 6a2.

[0087] S13. Insert one end of the second grooved core rod into the inner cavity through the first opening, and insert one end of the tube core rod 7 into the inner cavity through the second opening 6a2. Press them together to form partial sidewalls of the first opening 6a1 and the second opening 6a2, such that the first opening 6a1 is formed as a first connecting end 61 adapted to the second grooved core rod, and the second opening 6a2 is formed as a second connecting end 62 adapted to the tube core rod 7. The first connecting end 61 and the second connecting end 62 are connected through the inner cavity 63. Remove the second grooved core rod and the tube core rod 7. The outer contour of the cross-section of the second grooved core rod is the same as the outer contour of the end cross-section of the flat tube. Please refer to [reference needed]. Figure 8 .

[0088] In the above embodiments, the manifold 6 is manufactured using a progressive die, which is a fully automated die production process that is highly efficient and simple to manufacture.

[0089] In this paper, the forming process of the manifold 6 and the second bending component is to realize a microchannel heat exchanger with the above structure. Therefore, the forming process of the manifold and the second bending component also has the above-mentioned technical effects of the microchannel heat exchanger.

[0090] Of course, in this embodiment, the specific structure of the manifold is not limited. For example, it can be configured as any two interconnecting ends, wherein the first connecting end can be sealed and connected to the end of the heat exchange tube section, and the second connecting end can be connected to the external pipe. Alternatively, the manifold can be machined to have a through hole inside, with one end of the through hole forming the first connecting end and the other end forming the second connecting end. When the manifold is fabricated using a progressive die integral molding structure, the fabrication process is relatively simple and the manufacturing efficiency is high.

[0091] Furthermore, the terms "first" and "second" in this article are used only to name them in order to distinguish between two components with the same structure or function; there is no order between them.

[0092] The above are merely preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A microchannel heat exchanger, characterized in that, It includes at least two heat exchange units, each heat exchange unit including a first bending element and at least two heat exchange tube segments, each heat exchange tube segment being a flat tube, all heat exchange tube segments in the heat exchange unit being arranged along the thickness direction of the heat exchange tube segments, and the first bending element being provided between adjacent tube openings of adjacent heat exchange tube segments in the heat exchange unit, and all heat exchange tube segments of the same heat exchange unit being connected in series through each of the first bending elements to form a passage with an inlet and an outlet; It also includes a second bending member with an internal channel. Each heat exchange unit is arranged along the width direction of the heat exchange tube segment. The second bending member is connected and fixed between adjacent heat exchange units. The outlet of the heat exchange unit in the previous layer is connected to the inlet of the adjacent heat exchange unit in the next layer through the internal channel of the second bending member. The heat exchange tube segment, the first bending member, and the second bending member are all formed separately. The heat exchange tube segment is sealed and plugged into the first bending member, the heat exchange tube segment, and the second bending member. When the microchannel heat exchanger is in use, the heat exchange units are arranged vertically, and the cold medium flows from the upstream layer to the downstream layer of the heat exchange unit.

2. The microchannel heat exchanger according to claim 1, characterized in that, The connection ports of two adjacent heat exchange units are located on the same side. The second bending member includes a first socket and a second socket that are connected. The first socket and the second socket are respectively sealed and plugged into the outlet of the heat exchange unit of the previous layer and the inlet of the heat exchange unit of the next layer.

3. The microchannel heat exchanger according to claim 2, characterized in that, The heat exchange tube section includes relatively independent flow channels, each of which extends along the length of the heat exchange tube section. The number of flow channels in the heat exchange tube section of at least the upstream heat exchange unit is less than or equal to 3.

4. The microchannel heat exchanger according to claim 2, characterized in that, The heat exchange tube segments in the same heat exchange unit have the same width, and the width of the heat exchange tube segment gradually increases along the width direction of the heat exchange tube segment.

5. The microchannel heat exchanger according to claim 2, characterized in that, It also includes heat dissipation fins, which include aluminum foil plate fins, fitted onto each of the heat exchange tube sections; Alternatively, the heat dissipation fins include multiple fin segments and multiple connecting segments. The multiple fin segments are disposed between adjacent heat exchange tube segments of the heat exchange unit and are spaced apart along the length of the heat exchange tube segment. A connecting segment connects adjacent fin segments and the connecting segment is fixedly connected to the outer wall of the heat exchange tube segment.

6. The microchannel heat exchanger according to claim 5, characterized in that, When the microchannel heat exchanger is in use, the heat exchange units are arranged vertically, and the gap between the fin segments gradually increases from top to bottom.

7. The microchannel heat exchanger according to any one of claims 1 to 6, characterized in that, It also includes two manifolds, which are respectively installed at the inlet of the first heat exchange unit and the outlet of the last heat exchange unit. Each manifold includes a first connecting end and a second connecting end that are connected through its inner cavity. The first connecting end is used to connect and fix to the end of the corresponding heat exchange tube segment, and the second connecting end is used to connect and fix to an external pipe.

8. The microchannel heat exchanger according to claim 7, characterized in that, An arc-shaped section is provided between the first connecting end and the second connecting end. During installation, the end of the heat exchange tube section is inserted into the first connecting end and abuts against the inner wall of the arc-shaped section. Alternatively, the inner cavity may be provided with a protrusion, and during installation, the end of the heat exchange tube section is inserted into the first connection end and abuts against the protrusion.

9. The microchannel heat exchanger according to claim 7, characterized in that, The manifold, the first bent component, and the second bent component are all integrally formed from metal plates using a progressive die. Alternatively, both manifolds and all the second bends are located at the same end of the heat exchange tube section.

10. A forming process for a second bent member connected between heat exchange units in a microchannel heat exchanger according to any one of claims 1 to 9, characterized in that, The molding process includes the following steps: The first groove mandrel is placed between two aluminum plates and the aluminum plates are pressed to form an initial model groove. Then the first groove mandrel is taken out from the first opening, wherein the initial model groove includes an inner cavity with a first opening, and the inner cavity is adapted to the first groove mandrel. Two second grooved core rods are inserted into the inner cavity in parallel from the first opening, and the side wall portions of the initial model groove located between the two second grooved core rods are squeezed to isolate the first opening to form a first socket and a second socket, and the first socket and the second socket can communicate through the inner cavity; wherein the outer contour of the second grooved core rod is the same as the outer contour of the end of the heat exchange tube section that is fitted into the corresponding socket.

11. A forming process for a second bent member connected between heat exchange units in a microchannel heat exchanger according to any one of claims 1 to 9, characterized in that, The molding process includes the following steps: The first groove mandrel is placed between two aluminum plates and the aluminum plates are pressed to form an initial model groove. Then the first groove mandrel is taken out from the first opening, wherein the initial model groove includes an inner cavity with a first opening, and the inner cavity is adapted to the first groove mandrel. The segment is inserted into the inner cavity through the first opening and fixed to the side wall of the inner cavity so that a first socket and a second socket are formed on both sides of the segment to be inserted into the corresponding heat exchange tube section, and the first socket and the second socket can communicate through the inner cavity.

12. A forming process for the manifold in a microchannel heat exchanger as described in any one of claims 7 to 9, characterized in that, The molding process includes the following steps: The first grooved core is placed between two aluminum plates and the aluminum plates are pressed to form a first molded groove. Then the first grooved core is taken out from the first opening. The first molded groove includes an inner cavity with a first opening, and the inner cavity is adapted to the first grooved core. Along a direction perpendicular to the end face of the first opening, one end of the first model groove is cut to form an intermediate model groove, wherein the intermediate model groove has a second opening at the cut end; One end of the second grooved mandrel is inserted into the inner cavity through the first opening, and one end of the tube mandrel is inserted into the inner cavity through the second opening. The two ends are pressed together to form partial sidewalls of the first and second openings, such that the first opening is formed as a first connecting end adapted to the second grooved mandrel, and the second opening is formed as a second connecting end adapted to the tube mandrel. The first connecting end and the second connecting end are connected through the inner cavity. The second grooved mandrel and the tube mandrel are then removed, wherein the outer contour of the cross-section of the second grooved mandrel is the same as the outer contour of the end cross-section of the flat tube.

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