A heat exchanger

Abstract

The application discloses a heat exchanger, comprising a heat exchange tube and a fin, the fin having a through hole, the heat exchange tube being arranged in the through hole, the heat exchange tube being welded to the fin, the fin comprising a plurality of bending sections, the bending sections extending along the length direction of the fin, the plurality of bending sections being arranged along the width direction of the fin, the adjacent two bending sections having a preset included angle, the adjacent two bending sections forming a bending area, and the through hole being located on the intersection line of the two bending sections forming the bending area in the width direction of the fin. The heat exchanger has the bending area at the position of the through hole of the fin, and the through hole is located on the intersection line of the two bending sections forming the bending area, so that the stress is released along the bending sections of the fin, the stress is effectively reduced, the cracking problem caused by the stress at the welding position of the heat exchange tube and the fin is reduced, the welding reliability of the heat exchange tube and the fin is improved, and the reliability and service life of the heat exchanger are improved.

Description

Technical Field

[0001] This application relates to the field of heat exchanger technology, and more specifically, to a heat exchanger. Background Technology

[0002] Fins, as a common heat transfer enhancement element, are widely used in various heat exchangers. To reduce the contact thermal resistance between the heat exchange tubes and fins and improve the heat exchange efficiency, the fins and heat exchange tubes are fixed by welding. However, when the fins and heat exchange tubes are made of different metal materials, due to the difference in their coefficients of thermal expansion, large thermal stress can easily be generated between the fins and heat exchange tubes under high temperature or large temperature gradient conditions, leading to failure problems such as fin cracking, which affects the reliability and service life of the heat exchanger. Utility Model Content

[0003] The purpose of this application is to provide a heat exchanger that reduces the problem of stress cracking after welding of heat exchange tubes and fins, thereby improving the reliability and service life of the heat exchanger.

[0004] This application provides a heat exchanger, including a heat exchange tube and fins. The fins have through holes, the heat exchange tube passes through the through holes, and the heat exchange tube is welded to the fins. The fins include multiple bent segments that extend along the length direction of the fins and are arranged along the width direction of the fins. There is a preset angle between two adjacent bent segments, and two adjacent bent segments form a bending area. In the width direction of the fins, the through hole is located on the intersection line of the two bent segments forming the bending area.

[0005] The heat exchanger of this application has a bending zone at the through hole position, and the through hole is located on the intersection line of the two bending segments forming the bending zone. This allows stress to be released along the bending segment direction of the fin, which can effectively reduce stress, reduce stress-induced cracking at the welding position of the heat exchange tube and fin, improve the welding reliability of the heat exchange tube and fin, and thus improve the reliability and service life of the heat exchanger. Attached Figure Description

[0006] Figure 1 This is a partial perspective view of the heat exchanger provided in an embodiment of this application; Figure 2 This is a perspective view of one of the fins provided in the embodiments of this application; Figure 3 This is a three-dimensional schematic diagram of the fins provided in an embodiment of this application from another perspective; Figure 4 This is a schematic diagram of the structure of the fins provided in Embodiment 1 of this application; Figure 5 yes Figure 4 A magnified view of part C in the middle; Figure 6 This is a schematic diagram of the fin structure provided in Embodiment 2 of this application; Figure 7 yes Figure 6 A magnified view of part D in the middle; Figure 8 This is a schematic diagram of the fin structure provided in Embodiment 3 of this application; Figure 9 This is a schematic diagram of the fin structure provided in Embodiment 4 of this application; Figure 10 This is a schematic diagram of the fin structure provided in Embodiment 5 of this application; Figure 11 yes Figure 1 A magnified view of part A in the middle; Figure 12 yes Figure 3 A magnified view of part B in the middle.

[0007] Explanation of reference numerals in the attached figures: 10-Heat exchange tube; 20-Fin, 21-Through hole, 22-Bent section, 23-Bent area, 24-Straight section, 25-Concave part, 26-Flange, 27-Protrusion, 28-Abutting part; 30 - First tube. Detailed Implementation

[0008] To better understand the technical solution of this application, the embodiments of this application are described below with reference to the accompanying drawings.

[0009] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms “a,” “the,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise.

[0010] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.

[0011] This application provides a heat exchanger for use in a heat exchange system. The description uses an air conditioning system as an example; however, the application of the heat exchanger in this application is not limited to air conditioning systems, and can also be used in other heat exchange systems, such as water heaters, automobiles, and heat pumps.

[0012] When the air conditioning system is in cooling mode, the outdoor unit heat exchanger acts as the condenser, and the indoor unit heat exchanger acts as the evaporator. The working process in cooling mode mainly includes: the compressor compresses and pressurizes the low-temperature, low-pressure gas from the evaporator into a high-temperature, high-pressure liquid (consuming electrical energy during compression). The high-temperature, high-pressure liquid from the compressor enters the condenser, where it releases heat and liquefies into a medium-temperature, high-pressure liquid (releasing heat to the outside during liquefaction). The medium-temperature, high-pressure liquid from the condenser enters the throttling device, where it is throttled and depressurized into a low-temperature, low-pressure liquid. This low-temperature, low-pressure liquid from the throttling device enters the evaporator, where it absorbs heat and vaporizes into a low-temperature, low-pressure gas. During this heat absorption process, it absorbs heat from the room, thus cooling the room. The low-temperature, low-pressure gas from the evaporator then re-enters the compressor to begin the next cooling cycle.

[0013] When the air conditioning system switches from cooling mode to heating mode, the reversing valve switches the direction of refrigerant flow within the system, causing the outdoor unit heat exchanger to function as an evaporator and the indoor unit heat exchanger to function as a condenser. The heating mode operation mainly includes: the compressor compresses and increases the pressure of the low-temperature, low-pressure refrigerant from the evaporator, transforming it into a high-temperature, high-pressure refrigerant (consuming electrical energy during compression). The high-temperature, high-pressure refrigerant from the compressor enters the condenser, where it releases heat and becomes a medium-temperature, high-pressure refrigerant. During liquefaction, it releases heat to the room where the condenser is located, thus heating the room. The medium-temperature, high-pressure liquid from the condenser enters the throttling device, where it is throttled and depressurized, becoming a low-temperature, low-pressure refrigerant. This low-temperature, low-pressure refrigerant from the throttling device enters the evaporator, where it absorbs heat and vaporizes into a low-temperature, low-pressure refrigerant (absorbing heat from the outdoor environment during the heat absorption process). The low-temperature, low-pressure refrigerant in the evaporator then re-enters the compressor, starting the next heating cycle.

[0014] Reference Figures 1 to 3 As shown, this application provides a heat exchanger, including heat exchange tubes 10 and fins 20, wherein: The fin 20 has a through hole 21 through which a heat exchange tube 10 passes. The heat exchange tube 10 is welded to the fin 20. The fin 20 includes multiple bent sections 22, which extend along the length direction of the fin 20 and are arranged along the width direction of the fin 20. Figures 1 to 3 In the diagram, direction D1 is the length direction of fin 20, direction D2 is the width direction of fin 20, and direction D3 is the thickness direction of fin 20, which is also the length direction of heat exchange tube 10. The length direction, width direction, and thickness direction of fin 20 are generally perpendicular to each other. Two adjacent bending segments 22 have a predetermined included angle, forming a bending region 23. In the width direction of fin 20, the through hole 21 is located on the intersection line of the two bending segments 22 forming the bending region 23.

[0015] The bending section 22 extends along the length of the fin 20, and there is a preset angle between two adjacent bending sections 22. Thus, a bending area 23 is a generally V-shaped structure formed by two adjacent bending sections 22 extending along the length of the fin 20. Furthermore, along the width of the fin 20, multiple bending areas 23 constitute a fin 20 with a corrugated structure, thereby forming a periodic zigzag stress dispersion path, which can effectively disperse thermal stress.

[0016] In related technologies, when the heat exchange tube 10 passes through the through hole 21 and is welded to the fin 20, if the fin 20 is a flat fin, the welding position between the fin 20 and the heat exchange tube 10 is prone to large stresses F1 and F2, causing cracks at the welding position between the heat exchange tube 10 and the fin 20. When the fin 20 and the heat exchange tube 10 are designed to be made of different metal materials due to performance requirements, for example, since water, refrigerant, and other heat exchange media flow in the inner cavity of the heat exchange tube 10 of the heat exchanger, in order to prevent the heat exchange media from leaking and improve the service life of the heat exchanger, the heat exchange tube 10 can be made of stainless steel or copper with high corrosion resistance. However, the fin 20 usually needs to have a large heat exchange efficiency, and aluminum has better thermal conductivity than stainless steel. Therefore, using aluminum fins 20 can improve the heat exchange effect of the heat exchanger. However, since different types of metal materials have different coefficients of thermal expansion, welding will further increase the risk of cracking at the welding position between the heat exchange tube 10 and the fin 20, reducing the reliability and service life of the heat exchanger.

[0017] In this application, such as Figure 6 and Figure 7 As shown, since the fin 20 includes multiple bent sections 22, the circumferential stress is dispersed along the extension direction of the bent sections 22. That is, stresses F3 and F4 are generated in the two bent sections 22 along the bending region 23 where the fin 20 is connected to the heat exchange tube 10, where F3 = F1 / cosθ, θ = (180° - α) / 2, and α is the preset angle between two adjacent bent sections. Similarly, F4 = F2 / cosθ. Two adjacent bent sections 22 on the fin 20 form a bending region 2. 3. Expansion stress F5 is generated on the adjacent bend section 22 of the bend area 23 at the connection position between the fin 20 and the heat exchange tube 10. F5 is in the opposite direction to F3 and can offset the stress at the F3 position. Similarly, F6 can offset the stress at the F4 position. Thus, during the welding process of the heat exchange tube 10 and the fin 20, the cracking phenomenon caused by stress at the welding position is reduced, making the welding of the heat exchange tube 10 and the fin 20 more reliable, thereby improving the welding reliability and service life of the heat exchanger.

[0018] The heat exchange tube 10 is inserted into the through hole 21, which is located on the intersection line of the two bending segments 22 forming the bending area 23. This allows the circumferential stress to be dispersed along the extension direction of the bending segment 22, reducing the cracking phenomenon caused by stress at the welding position, improving the welding reliability of the heat exchange tube 10 and the fins 20, and thus improving the welding reliability and service life of the heat exchanger.

[0019] Furthermore, the center of the through hole 21 is located on the intersection line of the two bending segments 22 forming the bending area 23, that is, the heat exchange tube 10 is located on the axis of symmetry of the two bending segments 22. Therefore, the gap between the outer peripheral surface of the heat exchange tube 10 and the inner wall surface of the through hole 21 is uniform, and the stress release at the connection position of the heat exchange tube 10 and the fin 20 will be more uniform, which will better reduce the risk of cracking at the welding position of the heat exchange tube 10 and the fin 20. Moreover, during welding, the thickness of the welding position of the heat exchange tube 10 and the fin 20 is uniform, which can further improve the welding rate and welding reliability.

[0020] After the heat exchange tube 10 and fins 20 are combined to form a heat exchanger, the corrugated structure of the fins 20, including multiple bends 22, increases the surface area of ​​the fins 20, which can promote the turbulent flow of the fluid in the heat exchanger and thus improve the heat exchange efficiency.

[0021] In one feasible implementation, the fins 20 are made of a first material, and the heat exchange tube 10 is made of a second material. The coefficient of thermal expansion of the first material is M1, and the coefficient of thermal expansion of the second material is M2, satisfying M1 ≥ 1.2. M2, for example, M1 can be 1.25 M2, 1.3 M2, 1.35 M2, 1.4 M2, etc.

[0022] When the heat exchange tube 10 is welded to the fin 20, the thermal expansion coefficient of the fin 20 is more than 20% greater than that of the heat exchange tube 10. During the welding process, the expansion and contraction of the fin 20 side are greater than those of the heat exchange tube 10 side. This will generate circumferential stress along the circumference of the heat exchange tube 10 at the welding position, increasing the risk of cracking at the welding position between the heat exchange tube 10 and the fin 20.

[0023] However, since the fin 20 includes multiple bent sections 22, the circumferential stress is dispersed along the extension direction of the bent sections 22. That is, stresses F3 and F4 are generated along the two bent sections 22 of the bending region 23 where the fin 20 connects to the heat exchange tube 10. An expansion stress F5 is generated on the other bent section 22 of the bending region 23 where the fin 20 connects to the heat exchange tube 10. F5 is in the opposite direction to F3. Furthermore, since the expansion coefficient of the fin 20 is greater than that of the heat exchange tube 10, M1 ≥ 1.2. M2 causes the stress F5 generated by the adjacent bending section 22 on the fin 20 to be greater than the stress F3 at the connection position between the heat exchange tube 10 and the fin 20. This releases the stress at position F3. Similarly, F6 is greater than F4, which can release the stress at position F4. In this way, during the welding process of heat exchange tubes 10 and fins 20 made of different materials, cracking caused by thermal stress at the welding position is better reduced, making the welding of heat exchange tubes 10 and fins 20 more reliable, thereby improving the welding reliability and service life of the heat exchanger.

[0024] The first material can be aluminum, including pure aluminum or aluminum alloys, and the second material can be stainless steel or copper. Using stainless steel or copper for the heat exchange tube 10 reduces leakage of the heat exchange medium flowing within the tube during operation, improves the heat exchanger's corrosion resistance, and extends its service life. The fins 20 are made of aluminum, which has better thermal conductivity than stainless steel, thus improving the heat exchanger's heat exchange performance. The multiple bends 22 in the fins 10 reduce cracking at weld points due to thermal stress, improving the welding reliability of the heat exchange tube 10 and fins 20.

[0025] Reference Figure 1 As shown, the heat exchanger also includes a first tube 30, which is connected to the heat exchange tube 10. The end of the heat exchange tube 10 is directly or indirectly connected to the first tube 30. When the heat exchanger is in operation, heat exchange media such as water and refrigerant flow through the first tube 30 and the heat exchange tube 10 to achieve heat exchange.

[0026] The first tube 30 can be used as Figure 1 The U-shaped connecting pipe in the middle, multiple U-shaped connecting pipes connect adjacent heat exchange tubes 10. The first pipe 30 can also be a manifold extending along the length direction (direction D1) of the fin 20, and multiple heat exchange tubes 10 are connected through the manifold. There is no limitation here.

[0027] In the embodiments provided in this application, reference is made to Figure 4 , Figure 6 as well as Figure 8 As shown, α is the preset included angle between two adjacent bending segments 22, and at least part of the preset included angle is 120°-160°, for example, it can be 120°, 125°, 130°, 140°, 150°, 158°, 160°, etc. On the one hand, the preset included angle of 120°-160° makes the corrugated structure of the fin 20 obtuse-angle corrugation. After the heat exchange tube 10 is installed in the through hole 21, the obtuse-angle corrugation can increase the contact size between the outer peripheral surface of the heat exchange tube 10 and the fin 20, thereby increasing the welding area between the heat exchange tube 10 and the fin 20, which is beneficial to improving the welding rate.

[0028] On the other hand, when the preset angle is less than 120°, the wind resistance is large, which will reduce the heat exchanger's heat exchange performance and make it difficult to install the heat exchange tube 10 into the through hole 21; when the preset angle is greater than 160°, it will weaken the distribution of stress. Therefore, setting the preset angle between 120° and 160° allows the heat exchanger to maintain the wind resistance within a suitable range to ensure heat exchange performance, while also allowing thermal stress to be effectively released along the direction of the bending section 22 of the fin 20, reducing the impact of thermal stress, improving the reliability of the welding position between the heat exchange tube 10 and the fin 20, and improving the reliability of the heat exchanger.

[0029] At least some of the preset included angles are 120°-160°. That is, the preset included angle between two adjacent bends 22 can both be 120°-160°, or some of the preset included angles can be 120°-160°. For example, the preset included angle between two adjacent bends 22 can be 120°-160° only at the position where the heat exchange tube 10 is placed in the through hole 21. This allows the connection position between the fins 20 and the heat exchange tube 10 to better balance heat exchange performance and reduce the impact of thermal stress, thereby improving the reliability of the heat exchanger.

[0030] To ensure effective dispersion of thermal stress and reliability of welding, in one feasible implementation, refer to Figure 5 As shown, the maximum dimension of the through hole 21 in the width direction of the fin 20 is D, and the width of the bent section 22 is W, where 1 / 6D ≤ W ≤ D. For example, W can be 1 / 6D, 0.25D, 0.5D, 0.7D, 0.92D, D, etc. When W < 1 / 6D, the number of bent sections 22 increases due to their narrowness, which increases the processing difficulty. When W is greater than or equal to 1 / 6D, the bent section 22 has sufficient length to deform and absorb thermal stress. Under the premise that the width of the fin 20 is constant, the larger W is, the fewer the number of bent sections 22. When the number of bent sections 22 is too small, it is impossible to guarantee the effective release of stress at the welding position between each heat exchange tube 10 and the fin 20. Setting W to be less than or equal to D can ensure the dispersion effect of the bent area 23, reduce the influence of thermal stress, and improve the welding reliability between the heat exchange tube 10 and the fin 20.

[0031] Therefore, setting 1 / 6D≤W≤D makes processing easier, and under the premise of ensuring that the width of the fin 20 meets the requirements, the number of bending areas 23 is reasonably set to ensure that the dispersion effect of the bending areas 23 is improved, so as to improve the reliability of the welding between the fin 20 and the heat exchange tube 10.

[0032] It should be noted that the heat exchange tube 10 of this application can be a circular tube or an elliptical tube. When the heat exchange tube 10 is a circular tube, the through hole 21 is a circular hole, and D is the diameter of the through hole 21 through which the circular tube can pass. When the heat exchange tube 10 is an elliptical tube, the through hole 21 is an elliptical hole, and D is the length of the long side of the through hole 21 through which the elliptical tube can pass. The direction of the long side of the elliptical tube is consistent with the width direction of the fins 20, which can better improve the heat exchange effect of the heat exchanger.

[0033] Furthermore, referring to Figure 4 and Figure 6 As shown, since the fin 20 has a corrugated structure, when multiple through holes 21 are provided along the width direction of the fin 20, two adjacent through holes 21 can be located at the crest or trough of the fin 20 bending area. Thus, when two adjacent heat exchange tubes 10 are installed, they can be inserted along the crest or trough of the fin bending area. Regardless of whether the heat exchanger is a single row of heat exchange tubes 10 or multiple rows of heat exchange tubes 10, it is feasible for the heat exchange tubes 10 to be inserted from the crest or trough. That is, the heat exchange tubes 10 can all be inserted along the crest of the fin 20 bending area 23, or all be inserted along the trough of the fin 20 bending area 23, or some heat exchange tubes 10 can be inserted along the crest of the fin 20 bending area 23 and some heat exchange tubes 10 can be inserted along the trough of the fin 20 bending area 23.

[0034] Optionally, the number of bent segments 22 is N1, and the number of through holes 21 is N2, where N1 > 2N2. Since the center of the through hole 21 is located on the intersection line of the two bent segments 22 forming a bent area 23, a bent area 23 can have one through hole 21 or no through hole 21. A bent area 23 is formed by two bent segments 22. When the number of bent segments 22 N1 is determined, in order to ensure the width of the fin 20, the number of bent segments 22 should be more than twice the number of through holes 21.

[0035] The through holes 21 on the fins 20 facilitate the insertion of the heat exchange tubes 10. The number of through holes 21 is the same as the number of heat exchange tubes 10. When the number of heat exchange tubes 10 is fixed, by setting the number of bending sections 22 N1>2N2, each heat exchange tube 10 has a bending section 22 in the circumference to release stress. Thus, the setting of bending sections 22 can better reduce the stress at the connection position between the heat exchange tubes 10 and the fins 20, reduce the cracking problem caused by stress at the welding position of the heat exchange tubes 10 and the fins 20, and improve the welding reliability of the heat exchange tubes 10 and the fins 20.

[0036] Reference Figure 4 and Figure 6As shown in the embodiments provided in this application, the heat exchanger can be configured as a single row of heat exchange tubes 10, that is, there is a row of heat exchange tubes 10 in the width direction of the fins 20; the heat exchanger can also be configured as two or more rows of heat exchange tubes 10, that is, there are two or more rows of heat exchange tubes 10 in the width direction of the fins 20. In the width direction of the fin 20, the fin 20 has at least three bending areas 23 on the outer periphery of a through hole 21. The three bending areas 23 are arranged along the width direction of the fin 20. In some embodiments, four consecutive bending segments 22 can form three bending areas 23. The through hole 21 is located in the middle bending area 23, and the other two bending areas 23 are symmetrically arranged on both sides of the through hole 21. After the heat exchange tube 10 is inserted into the through hole 21, the resulting thermal stress is dispersed along the extension direction of the bending segment 22 of the middle bending area 23 and the stress is released through the bending segments 22 connected on both sides. Thus, the thermal stress generated when the heat exchange tube 10 is installed in the through hole 21 and welded can be evenly dispersed to the bending areas 23 on both sides, reducing the risk of cracking at the welding position of the heat exchange tube 10 and the fin 20 and improving the reliability of the welding position of the heat exchange tube 10 and the fin 20.

[0037] When the heat exchanger is configured with two or more rows of heat exchange tubes 10, that is, there are at least two rows of heat exchange tubes 10 in the width direction of the fins 20. The fins 20 include at least two through holes 21 in the width direction, and at least four bends 22 are provided between adjacent through holes 21. The area between adjacent through holes 21 refers to the part between the centers of two adjacent through holes 21.

[0038] Reference Figure 4 As shown, two adjacent through holes 21 are both located at the troughs of the corrugated structure of the fin 20. There are four bends 22 between the two through holes 21, forming three bend zones 23. (Refer to...) Figure 6 As shown, two adjacent through holes 21 are located at the trough of the corrugated fin 20 and at the crest of the corrugated fin 20. There are five bends 22 between the two through holes 21, and the five bends 22 can form four bend zones 23.

[0039] At least four bends 22 are provided between adjacent through holes 21, so that the thermal stress generated when the heat exchange tube 10 is installed in the through hole 21 for welding can be dispersed along the two bends 22 near the through hole 21, and then released through the two adjacent bends 22, so that there is a sufficient area on both sides of the through hole 21 to disperse the thermal stress, thereby reducing the risk of cracking at the welding position of the heat exchange tube 10 and the fin 20 and improving the reliability of the welding position of the heat exchange tube 10 and the fin 20.

[0040] In one feasible implementation, refer to Figure 8 and Figure 9As shown, the fin 20 also includes a straight segment 24, which is located between adjacent through holes 21, and / or the straight segment 24 is located on the side of the fin 20 in its width direction. Figure 8 In this embodiment, the straight segment 24 between adjacent through holes 21 can improve the bending stiffness of the fin plane 20. When assembling multiple rows of heat exchange tubes 10, it can reduce the collapse or deformation of the fins 20, thereby improving the assembly qualification rate and the reliability of the heat exchanger. In other embodiments, the straight segment 24 can be provided on both the adjacent through holes 21 and the side of the fins 20 in the width direction, or the straight segment 24 can be provided only on the side of the fins 20 in the width direction; there is no limitation here.

[0041] Reference Figure 9 As shown, the straight segment 24 is disposed on at least one side of the fin 20 in the width direction. The straight segment 24 can form the frame of the fin 20. The frame of the straight segment 24 can prevent the edge warping of the corrugated fin 20 when it is assembled with the heat exchange tube 10 or heated, thereby reducing structural damage and deformation of the fin 20.

[0042] When welding the heat exchange tube 10 to the fins 20, solder is required to weld them together. Therefore, a space needs to be left between the heat exchange tube 10 and the fins 20 to fill the solder. In the embodiments provided in this application, refer to... Figure 11 As shown, before the heat exchange tube 10 is welded to the fin 20, there is a gap h between the outer surface of the heat exchange tube 10 and the through hole 21. Setting a certain gap makes it easier for the heat exchange tube 10 to be assembled into the through hole 21 of the fin 20. During welding, the connection between the heat exchange tube 10 and the fin 20 is achieved by melting the solder.

[0043] When the gap h between the outer surface of the heat exchange tube 10 and the through hole 21 is too large, more solder is required to achieve a good weld between the heat exchange tube 10 and the fin 20. This may also cause incomplete or uneven welding between the heat exchange tube 10 and the fin 20, affecting the welding effect. When the heat exchange tube 10 and the fin 20 are made of different metals, if the gap h is too large, the intermetallic compound formed after welding will be too thick, which may also cause cracking at the weld position, reducing the reliability of the weld between the heat exchange tube 10 and the fin 20. When the gap h between the outer surface of the heat exchange tube 10 and the through hole 21 is too small, it is difficult to assemble the heat exchange tube 10 into the through hole of the fin 20, affecting processing efficiency, and assembly may cause deformation of the heat exchange tube 10 or the fin 20.

[0044] Therefore, the gap h between the outer surface of the heat exchange tube 10 and the through hole 21 is set to 20-100μm, for example, it can be 20μm, 30μm, 50μm, 75μm, 100μm, etc. This not only facilitates the insertion of the heat exchange tube 10 into the through hole 21, but also ensures the welding effect of the heat exchange tube 10 and the fin 20, and improves the welding reliability of the heat exchange tube 10 and the fin 20.

[0045] Reference Figure 4 , Figure 6 , Figures 8 to 10 as well as Figure 12 As shown, the fin 20 also includes a recess 25, which is located on the outer periphery of the through hole 21. The recess 25 is arranged along the circumferential direction of the through hole 21, and the recess 25 can be one circumference along the through hole 21. (Refer to...) Figure 3 As shown, the fin 20 also includes a flange 26, which is located at the edge of the through hole 21 and along the thickness direction of the fin 20. Figure 3 or Figure 5 The direction of the recess 25 is set in the middle direction (D3), and the direction of the recess 25 is consistent with the direction of the flange 26.

[0046] During the welding process of the heat exchanger, on the one hand, the recess 25 can further buffer the stress of the fin 20. On the other hand, the direction of the recess 25 is consistent with the direction of the flange 26, so that the recess 25 can accommodate the solder and lock the solder in the recess 25, making the weld between the fin 20 and the heat exchange tube 10 more full, thereby further improving the welding reliability.

[0047] During the assembly of the heat exchange tube 10 into the through hole 21, the flange 26 guides the heat exchange tube 10 to be inserted in the correct direction, limiting the axial and radial displacement of the heat exchange tube 10. When the heat exchange tube 10 passes through the through holes 21 of multiple fins 20, it can accurately pass through multiple through holes 21 under the action of the flange 26, thereby improving the assembly qualification rate. Since the flange 26 is set at the edge of the through hole 21, after the heat exchange tube 10 is inserted into the through hole 21, the contact between the heat exchange tube 10 and the fins 20 is surface contact, thereby increasing the contact area between the heat exchange tube 10 and the fins 20 and improving welding reliability.

[0048] The recess 25 is recessed in the same direction as the flange 26, which also makes it easier to form the recess 25 and flange 26 in one stamping on the fin 20, reducing the formation of burrs or dimensional errors by reverse stamping.

[0049] Furthermore, a certain spacing must be maintained between the multiple fins 20 of the heat exchanger to prevent the heat exchange effect from being affected by the fins being too far apart or too close together. Therefore, referring to... Figures 8 to 10 As shown, an abutment portion 28 is also provided on the fin 20. The abutment portion 28 can be provided on the flange 26 of each through hole 21. The abutment portion 28 is located on the side of the flange 26 away from the fin body 20. The abutment portion on one fin 20 abuts against another adjacent fin 20 so that the adjacent fins 20 maintain a fixed distance. The abutment portion 28 can also be provided between two through holes 21. The abutment portion 28 can be set according to the distance requirement between adjacent fins 20 so that the multiple fins 20 of the heat exchanger are kept within the corresponding distance.

[0050] Reference Figure 10 As shown, the fin 20 also includes a protrusion 27 located at the intersection of two adjacent bends 22, connecting the two adjacent bends 22, and protruding from the surface of the fin 20. The protrusion 27 can be positioned at the crest or trough of the bend 22 of the corrugated structure of the fin 20. Thermal stress can be transferred to the protrusion 27 through the bend 22, further releasing the thermal stress of the bend 22 at the protrusion 27. The protrusion 27 can provide a buffer for thermal stress, reducing the large stress generated by thermal expansion in the fin 20, reducing the risk of cracking at the weld position between the heat exchange tube 10 and the fin 20, and improving welding reliability.

[0051] In some other embodiments, a recessed portion can be provided on the intersection line of two adjacent bending segments 22, that is, the recessed portion is provided at the position of the crest or trough of the corrugated structure of the fin 20. The recessed portion has the same function as the protrusion 27, and will not be described again here.

[0052] The above examples illustrate the principles and implementation methods of this application. The descriptions of the embodiments are merely for the purpose of helping to understand the technical solutions and core ideas of this application. It should be noted that those skilled in the art can make various improvements and modifications to this application without departing from its principles, and these improvements and modifications also fall within the protection scope of this application.

Claims

1. A heat exchanger, characterized in that, The device includes a heat exchange tube and fins. The fins have through holes, and the heat exchange tube passes through the through holes and is welded to the fins. The fins include multiple bent sections that extend along the length of the fins and are arranged along the width of the fins. There is a preset angle between two adjacent bent sections, and two adjacent bent sections form a bending area. In the width direction of the fins, the through hole is located on the intersection line of the two bent sections that form the bending area.

2. The heat exchanger according to claim 1, characterized in that, In the width direction of the fin, the center of the through hole is located on the intersection line of the two bending segments forming the bending area.

3. The heat exchanger according to claim 1, characterized in that, At least part of the preset included angle is 120°-160°.

4. The heat exchanger according to claim 1, characterized in that, The maximum dimension of the through hole in the fin width direction is D, and the width of the bent section is W, wherein 1 / 6D≤W≤D.

5. The heat exchanger according to claim 1, characterized in that, In the width direction of the fin, the number of bent sections is N1, and the number of through holes is N2, wherein N1>2N2.

6. The heat exchanger according to any one of claims 1-5, characterized in that, Along the width direction of the fin, the fin has at least three bending zones around the outer periphery of one of the through holes.

7. The heat exchanger according to claim 6, characterized in that, The fin includes at least two through holes in its width direction, and at least four bends are provided between adjacent through holes.

8. The heat exchanger according to claim 6, characterized in that, The fin further includes a straight segment located between adjacent through holes, and / or the straight segment is located on the side of the fin in its width direction.

9. The heat exchanger according to any one of claims 1-5, characterized in that, There is a gap between the outer surface of the heat exchange tube and the through hole, and the gap is 20-100μm.

10. The heat exchanger according to any one of claims 1-5, characterized in that, The fin further includes a recess located on the outer periphery of the through hole and arranged along the circumferential direction of the through hole. The fin also includes a flange located at the edge of the through hole and arranged along the thickness direction of the fin. The recessed direction of the recess is consistent with the direction of the flange.

11. The heat exchanger according to any one of claims 1-5, characterized in that, The fin also includes a protrusion located at the intersection of two adjacent bent segments, the protrusion protruding from the surface of the fin.

12. The heat exchanger according to any one of claims 1-5, characterized in that, The fins are made of a first material, and the heat exchange tube is made of a second material. The coefficient of thermal expansion of the first material is M1, and the coefficient of thermal expansion of the second material is M2, where M1 ≥ 1.

2. M2.

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