Welding method and welding equipment for heat exchanger
By using multi-point synchronous welding and batch melting methods when welding copper film, the problem of easy warping of copper film welding is solved, and the welding quality and thermal conductivity are improved.
Patent Information
- Application Number
- CN202510137946.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-08
- Publication Date
- 2025-03-28
AI Technical Summary
During the welding process, the copper film is prone to warping and deformation, resulting in a decrease in welding quality.
A heat exchanger welding method is adopted, by providing a thermal sleeve and welding equipment, multiple welding points are calibrated at the joint of the flange and flange, and the first welding points are melted at low temperature, and then the second welding points are melted at high temperature to ensure that the shape becomes fixed during the welding process.
By synchronously welding multiple welding points, the deformation is fixed, and the occurrence of warping is avoided, and the welding quality and thermal conductivity are improved.
Smart Images
Figure CN119703478A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of welding technology, and in particular to a heat exchanger welding method and welding equipment. Background Art
[0002] A heat exchanger is a device that effectively recovers heat energy from exhaust gas. It includes at least one hot channel for industrial exhaust gas to pass through. High-temperature exhaust gas is introduced into the hot channel and a liquid pipe is arranged around the outside of the heat exchanger. Under the action of temperature difference, the heat energy in the high-temperature exhaust gas will be spontaneously transferred to the liquid pipe through the heat exchanger, thereby achieving the effect of waste heat recovery.
[0003] In order to ensure the structural strength of the heat exchanger, the heat exchanger usually has a main body made of aluminum alloy. Considering that the thermal conductivity of aluminum alloy is still insufficient, in the prior art, a layer of copper film is usually welded and coated in the heat channel so that the heat exchanger can better absorb heat from the exhaust gas.
[0004] However, due to the thin thickness of the copper film itself, the copper film is very easy to deform during the welding process, which means that as the welding progresses, each solder joint will accumulate a certain degree of deformation, and the last few solder joints will show more obvious warping deformation. Summary of the invention
[0005] An object of the present invention is to provide a heat exchanger welding method and welding equipment, which aims to solve the technical problem that copper film is prone to warping deformation during welding.
[0006] To achieve the above object, the present invention provides a solution: a heat exchanger welding method, the heat exchanger welding method comprising the following steps: B1. Provide a heat exchange tube, wherein the heat exchange tube comprises a tube body and a flange, wherein the flange is connected to one end of the tube body, and a heat channel penetrating the tube body and the flange is formed on the heat channel; B2. Providing a heat-conducting sleeve, wherein the heat-conducting sleeve comprises a copper film and a flange connected to each other, and the outer size of the copper film corresponds to the inner size of the tube body; B3, the heat-conducting sleeve is assembled on the heat exchange tube, the copper film is passed through the heat channel and fits the inner wall of the tube body, and the flange fits the flange; B4. Marking a plurality of welding points at the joints between the flange and the flange; B5. Simultaneously melt the flanges or flanges at the plurality of welding points so that the flanges are welded and connected to the flanges.
[0007] In some embodiments of the present application, there are at least 10 welding points, and the welding points are evenly distributed around the heat channel.
[0008] To achieve the above object, another solution provided by the present invention is: a heat exchanger welding method, the heat exchanger welding method comprising the following steps: B1. Provide a heat exchange tube, wherein the heat exchange tube comprises a tube body and a flange, wherein the flange is connected to one end of the tube body, and a heat channel penetrating the tube body and the flange is formed on the heat channel; B2. Providing a heat-conducting sleeve, wherein the heat-conducting sleeve comprises a copper film and a flange connected to each other, and the outer size of the copper film corresponds to the inner size of the tube body; B3, the heat-conducting sleeve is assembled on the heat exchange tube, the copper film is passed through the heat channel and fits the inner wall of the tube body, and the flange fits the flange; B4, marking a plurality of first welding points and a plurality of second welding points at the joint between the flange and the flange; B5. Simultaneously melting the flanges or flanges at the plurality of first welding points so that the flanges are welded to the flanges; B6. Simultaneously melt the flanges or flanges at the plurality of second welding points so that the flanges are welded and connected to the flanges.
[0009] In some embodiments of the present application, the step B5 includes: at a temperature T1, simultaneously melting the flanges or flanges at multiple first welding points so that the flanges are welded to the flanges; the step B6 includes: at a temperature T2, simultaneously melting the flanges or flanges at multiple second welding points so that the flanges are welded to the flanges, T1<T2.
[0010] In some embodiments of the present application, the heat exchange tube provided in step B1 is made of aluminum, and the flange provided in step B2 is made of copper; the step B5 includes: at a temperature T1, simultaneously melting the flanges at multiple first welding points so that the flanges are welded to the flanges; the step B6 includes: at a temperature T2, simultaneously melting the flanges at multiple second welding points so that the flanges are welded to the flanges, T1<T2.
[0011] In some embodiments of the present application, the step B5 includes: at a temperature T1, simultaneously melting the flanges or flanges at multiple first welding points so that the flanges are welded to the flanges, 620℃≤T1≤750℃; the step B6 includes: at a temperature T2, simultaneously melting the flanges or flanges at multiple second welding points so that the flanges are welded to the flanges, 650℃≤T2≤1200℃ and T1<T2.
[0012] In some embodiments of the present application, the step B5 includes: simultaneously melting the flanges at multiple first welding points so that the flanges are welded to the flange, the thickness of the flanges is L1, the thickness of the flanges is L2, L1<L2, and the melting depth at the first welding point is L3, L1=L3; the step B6 includes: at a temperature T2, simultaneously melting the flanges and part of the flange at multiple second welding points so that the flanges are welded to the flange, and the melting depth at the second welding point is L4, L1<L4<L1+L2.
[0013] In some embodiments of the present application, step B5 includes: marking multiple first welding points and multiple second welding points at the joint of the flange and the flange, the distance between the first welding point and the hot run is L5, the distance between the second welding point and the hot run is L6, and L5<L6.
[0014] In some embodiments of the present application, step B2 includes: B2.1. Provide a heat-conducting sleeve, wherein the heat-conducting sleeve comprises a copper film and a flange connected to each other, and the outer size of the copper film corresponds to the inner size of the tube body; B2.2. Provide nail buckles, which are made of the same material as the flange; B2.3, riveting or clamping the button to the flange; The welding point, the first welding point or the second welding point in step B4 is marked at the button position.
[0015] To achieve the above object, another solution provided by the present invention is: a welding device, the welding device comprises a plurality of welding heads, and the welding heads are used to perform any one of the above heat exchanger welding methods.
[0016] The beneficial effects of the present invention include but are not limited to: 1. Welding multiple welding points at the same time, the deformation caused by welding is fixed when it occurs and evenly distributed over the entire flange, without accumulating obvious warping; 2. The melting temperature used for welding the first welding point is lower than the melting temperature used for welding the second welding point. When the second welding point is melted at high temperature, the flange and the flange have been fixed by the first welding point. At this time, even if the welding temperature is high, it is difficult to cause warping; 3. The depth of the molten pool used for welding the first weld is smaller than that used for welding the second weld. Specifically, the molten pool at the first weld only covers the flange, and the flange is not melted. The molten pool at the second weld penetrates the flange and extends into the flange. Under the premise that the relative position of the flange and the flange has been pre-fixed at the first weld, the second weld with a deep molten pool can achieve stable welding without obvious warping. BRIEF DESCRIPTION OF THE DRAWINGS
[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.
[0018] Figure 1 is a schematic diagram of the overall structure of a heat exchanger provided by an embodiment of the present invention; Figure 2 is a schematic flow chart of a heat exchanger welding method provided by an embodiment of the present invention; Figure 3 is a schematic diagram of the overall structure of a heat exchanger provided by another embodiment of the present invention; Figure 4 is a schematic flow chart of a heat exchanger welding method provided by another embodiment of the present invention; Figure 5 is along Figure 3 Schematic diagram of the local section along the AA line; Figure 6 is along Figure 3 Schematic diagram of the local section along line BB. Description of Figure Numbers: 10. heat exchange tube; 11. tube body; 12. flange; 20. heat transfer sleeve; 21. copper film; 22. flange; 30. welding point; 31. first welding point; 32. second welding point. DETAILED DESCRIPTION
[0019] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0020] See also Figure 1-2 As shown, Figure 1 is a schematic diagram of the overall structure of a heat exchanger provided by an embodiment of the present invention; Figure 2 It is a schematic flow chart of a heat exchanger welding method provided in an embodiment of the present invention.
[0021] In the first aspect, in order to solve the technical problem in the prior art that the copper film 21 is easily warped when being welded in the hot channel, the present invention discloses a heat exchanger welding method, which comprises the following steps: B1. Provide a heat exchange tube 10, which includes a tube body 11 and a flange 12. The flange 12 is connected to one end of the tube body 11, and a heat channel is formed on the heat channel, which runs through the tube body 11 and the flange 12. Exemplarily, the material of the heat exchange tube 10 can be aluminum alloy, steel or cast iron, etc., the tube body 11 can be a cylinder, a square cylinder, an elliptical cylinder, etc., the distance between the inner and outer edges of the flange 12 is preferably kept constant, and the flange 12 can be provided with an assembly hole for other components to cooperate with, or it can not be provided with an assembly hole.
[0022] B2. Provide a heat-conducting sleeve 20, which includes a copper film 21 and a flange 22 connected to each other, and the outer size of the copper film 21 corresponds to the inner size of the tube body 11; the size correspondence defined here should be understood as: the copper film 21 is used to be inserted into the tube body 11, and when the heat exchanger is completed, the outer surface of the copper film 21 fits with the inner surface of the tube body 11, and according to the difference in processing technology and materials, the copper film 21 and the tube body 11 can be any one of a clearance fit, a transition fit or an interference fit.
[0023] B3. Assemble the heat-conducting sleeve 20 on the heat exchange tube 10 , the copper film 21 penetrates the heat channel and fits the inner wall of the tube body 11 , and the flange 22 fits the flange 12 .
[0024] B4. Mark a plurality of welding points 30 at the joints between the flange 22 and the flange 12.
[0025] B5. Simultaneously melt the flanges 22 or flanges 12 at a plurality of welding points 30 , so that the flanges 22 are welded to the flanges 12 .
[0026] In the prior art, an important reason why the deformation of the copper film 21 accumulates and forms obvious warping is that the copper film 21 is thin but has a large thermal conductivity, and is heated and cooled quickly. When the next solder joint 30 is soldered, the deformation generated at the previous solder joint 30 has been completely released and evenly distributed on the unsoldered part of the copper film 21. When multiple solder joints 30 are soldered one by one, the deformation will be enriched at the last few solder joints 30 and eventually manifest as warping visible to the naked eye.
[0027] In this embodiment, the welding points 30 are welded synchronously, and the deformation generated by the welding points 30 is released synchronously and evenly distributed on the entire flange 22. There is no prerequisite for deformation accumulation. Therefore, the welding effect is better, the flange 22 fits the flange 12, the copper film 21 has good conformity with the tube body 11, and the thermal conductivity effect is excellent.
[0028] It should be pointed out that the heat exchanger in the prior art may not have the flange 22 part, and a considerable portion of the copper film 21 is directly welded to the heat exchange tube 10. Therefore, the copper film 21 referred to in the description of the prior art in this application is not equivalent to the copper film 21 of this application, but should be equivalent to the heat conductive sleeve 20 of this application.
[0029] In some embodiments of the present application, there are at least 10 welding points 30, and the welding points 30 are evenly distributed around the heat channel.
[0030] It has been verified by simulation tests that when the central angle of adjacent welding points 30 relative to the center of the hot runner is less than or equal to 40°, the heat exchanger welding method of multi-point synchronous welding has a better effect in suppressing warping. Therefore, the welding points 30 are configured to be 10 or more. The heat exchanger produced by the heat exchanger welding method of this embodiment has better product quality.
[0031] See also Figure 3-6 As shown, Figure 3 is a schematic diagram of the overall structure of a heat exchanger provided by another embodiment of the present invention; Figure 4 is a schematic flow chart of a heat exchanger welding method provided by another embodiment of the present invention; Figure 5 is along Figure 3 Schematic diagram of the local section along the AA line; Figure 6 is along Figure 3 Schematic diagram of the local section along line BB.
[0032] In a second aspect, the present invention further discloses a heat exchanger welding method, the heat exchanger welding method comprising the following steps: B1. Provide a heat exchange tube 10, which includes a tube body 11 and a flange 12. The flange 12 is connected to one end of the tube body 11, and a heat channel is formed on the heat channel, which runs through the tube body 11 and the flange 12. Exemplarily, the material of the heat exchange tube 10 can be aluminum alloy, steel or cast iron, etc., the tube body 11 can be a cylinder, a square cylinder, an elliptical cylinder, etc., the distance between the inner and outer edges of the flange 12 is preferably kept constant, and the flange 12 can be provided with an assembly hole for other components to cooperate with, or it can not be provided with an assembly hole.
[0033] B2. Provide a heat-conducting sleeve 20, which includes a copper film 21 and a flange 22 connected to each other, and the outer size of the copper film 21 corresponds to the inner size of the tube body 11; the size correspondence defined here should be understood as: the copper film 21 is used to be inserted into the tube body 11, and when the heat exchanger is completed, the outer surface of the copper film 21 fits with the inner surface of the tube body 11, and according to the difference in processing technology and materials, the copper film 21 and the tube body 11 can be any one of a clearance fit, a transition fit or an interference fit.
[0034] B3. Assemble the heat-conducting sleeve 20 on the heat exchange tube 10 , the copper film 21 penetrates the heat channel and fits the inner wall of the tube body 11 , and the flange 22 fits the flange 12 .
[0035] B4. Mark a plurality of first welding points 31 and a plurality of second welding points 32 at the joint between the flange 22 and the flange 12.
[0036] B5. Simultaneously melt the flanges 22 or flanges 12 at the plurality of first welding points 31 , so that the flanges 22 are welded to the flanges 12 .
[0037] B6. Simultaneously melt the flanges 22 or flanges 12 at a plurality of the second welding points 32 so that the flanges 22 are welded to the flanges 12 .
[0038] In this embodiment, the first welding points 31 and the second welding points 32 are welded in two batches. Under the premise that the total number of welding points 30 remains unchanged, the number of welding heads required for single welding of the heat exchanger welding method of this embodiment is reduced, which reduces the equipment configuration cost and makes the heat exchanger welding method easier to implement. When the first welding points 31 and the second welding points 32 are kept evenly distributed, the welding effect is similar to that of the heat exchanger welding method of the first aspect.
[0039] In some embodiments of the present application, the step B5 includes: at a temperature T1, simultaneously melting the flanges 22 or flanges 12 at multiple first welding points 31, so that the flanges 22 are welded to the flange 12; the step B6 includes: at a temperature T2, simultaneously melting the flanges 22 or flanges 12 at multiple second welding points 32, so that the flanges 22 are welded to the flange 12, T1<T2.
[0040] Another important factor that limits deformation is the degree of constraint of the welding parent material. In addition to the design of the fixture, the formed weld 30 itself is also an important factor. During the welding process of the heat exchanger, the weld 30 to be welded later will be constrained by the formed weld 30 and show a smaller deformation. In this embodiment, when the first weld 31 is welded, a lower welding temperature is adopted to avoid excessive deformation; when the second weld 32 is welded, because the first weld 31 has largely constrained the relative position of the flange 22 and the flange 12, the deformation caused by the second weld 32 is constrained between the two adjacent first welds 31, so a higher welding temperature can be selected to achieve better penetration.
[0041] Furthermore, the heat exchange tube 10 provided in step B1 is made of aluminum, and the flange 22 provided in step B2 is made of copper; the step B5 includes: at a temperature T1, simultaneously melting the flanges 12 at multiple first welding points 31, so that the flanges 22 are welded and connected to the flanges 12; the step B6 includes: at a temperature T2, simultaneously melting the flanges 22 at multiple second welding points 32, so that the flanges 22 are welded and connected to the flanges 12, T1<T2.
[0042] In this embodiment, the heat exchange tube 10 is made of aluminum and the flange 22 is made of copper, and there is a melting point difference of about 400°C between the two. Therefore, the first welding point 31 is welded by melting the flange 12 under the condition of weak constraint, which can avoid excessive deformation. The second welding point 32 is welded by melting the flange 22 under the condition of the constraint of the first welding point 31, and the two sides are welded at the same time, which achieves better welding effect and is not easy to cause warping.
[0043] Exemplarily, the step B5 includes: at a temperature T1, simultaneously melting the flanges 22 or flanges 12 at multiple first welding points 31, so that the flanges 22 are welded to the flange 12, 620℃≤T1≤750℃; the step B6 includes: at a temperature T2, simultaneously melting the flanges 22 or flanges 12 at multiple second welding points 32, so that the flanges 22 are welded to the flange 12, 650℃≤T2≤1200℃ and T1<T2.
[0044] This embodiment provides reference values for the first solder joint 31 and the second solder joint 32. At this temperature, the welding of the first solder joint 31 and the second solder joint 32 is relatively stable and not prone to significant deformation. In addition, it should be pointed out that although T1 is much lower than the melting point of copper, under the premise that the specific material of the flange 22 is adjustable and the welding method is controllable, there is a situation where the welding of the first solder joint 31 is achieved by melting the flange 22 with T1, and the protection scope of this application cannot be limited by this.
[0045] In some embodiments of the present application, the step B5 includes: simultaneously melting the flanges 22 at multiple first welding points 31 so that the flanges 22 are welded to the flange 12, the thickness of the flanges 22 is L1, the thickness of the flange 12 is L2, L1<L2, and the melting depth at the first welding point 31 is L3, L1=L3; the step B6 includes: at a temperature T2, simultaneously melting the flanges 22 and part of the flange 12 at multiple second welding points 32 so that the flanges 22 are welded to the flange 12, and the melting depth at the second welding point 32 is L4, L1<L4<L1+L2.
[0046] Within a certain range, the penetration depth is positively correlated with the stability of welding. However, as the penetration depth increases, the volume of the molten pool increases accordingly, and the deformation of the welding increases accordingly. In this embodiment, the first welding point 31 only melts the flange 22, and the melted flange 22 is clad on the surface of the flange 12 to achieve welding connection. The flange 12 without obvious deformation positions the flange 22 and the first welding point 31; when the second welding point 32 is welded, because it is already limited by the first welding point 31, the penetration depth can be appropriately increased, and in addition to the flange 22, part of the flange 12 is also melted to optimize the welding stability.
[0047] In some embodiments of the present application, the step B5 includes: marking a plurality of first welding points 31 and a plurality of second welding points 32 at the joint between the flange 22 and the flange 12, the distance between the first welding point 31 and the hot run is L5, the distance between the second welding point 32 and the hot run is L6, and L5<L6.
[0048] Because there is an angle between the flange 22 and the copper film 21, deformation is not easy to occur. Therefore, the closer the welding point 30 is to the hot runner, the smaller the welding deformation is. However, due to the influence of the lever principle, the welding strength is also low. In this embodiment, the first welding point 31 is closer to the hot runner. Therefore, the deformation is small when the first welding point 31 is welded, and when the second welding point 32 is welded, it is difficult to warp due to the limitation of the first welding point 31.
[0049] In some embodiments of the present application, step B2 includes: B2.1. Provide a heat-conducting sleeve 20, wherein the heat-conducting sleeve 20 comprises a copper film 21 and a flange 22 connected to each other, and the outer dimension of the copper film 21 corresponds to the inner dimension of the tube body 11; B2.2, providing nail buckles, wherein the nail buckles and the flange 12 are made of the same material; B2.3, riveting or clamping the button to the flange 22; The welding point 30, the first welding point 31 or the second welding point 32 in the step B4 is marked at the button position.
[0050] There is a big difference between the melting point and welding temperature of copper and aluminum materials. When the copper parent material melts normally, the aluminum parent material is prone to overburning. When the aluminum parent material melts normally, it is difficult to form a molten pool on the side of the copper parent material. In this embodiment, the nail buckle made of the same material as the flange 12 is fixed to the flange 22 by riveting or clamping, and the welding of the heat-conducting sleeve 20 and the heat exchange tube 10 becomes welding of the same material, and the weld penetration and weld stability are good.
[0051] In a third aspect, the present invention further discloses a welding device, which includes a plurality of welding heads, and the welding heads are used to perform any of the above-mentioned heat exchanger welding methods.
[0052] Because the welding device can perform any of the above-mentioned heat exchanger welding methods, the welding device also has the technical effects of the above-mentioned heat exchanger welding methods, that is, the heat exchange tube 10 and the heat-conducting sleeve 20 are stably connected, the copper film 21 and the tube body 11 have good conformity, and the heat exchanger has excellent thermal conductivity. It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative position relationship, movement, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.
[0053] It should also be noted that when an element is referred to as being "fixed on" or "disposed on" another element, it may be directly on the other element or there may be an intermediate element at the same time. When an element is referred to as being "connected to" another element, it may be directly connected to the other element or may be indirectly connected to the other element through an intermediate element.
[0054] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.
[0055] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the design concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.
Claims
1. A heat exchanger welding method, characterized in that: The following steps are involved: B1. Provide a heat exchange tube, wherein the heat exchange tube comprises a tube body and a flange, wherein the flange is connected to one end of the tube body, and a heat channel penetrating the tube body and the flange is formed on the heat channel; B2. Providing a heat-conducting sleeve, wherein the heat-conducting sleeve comprises a copper film and a flange connected to each other, and the outer size of the copper film corresponds to the inner size of the tube body; B3, the heat-conducting sleeve is assembled on the heat exchange tube, the copper film is passed through the heat channel and fits the inner wall of the tube body, and the flange fits the flange; B4. Marking a plurality of welding points at the joints between the flange and the flange; B5. Simultaneously melt the flanges or flanges at the plurality of welding points so that the flanges are welded and connected to the flanges.
2. The heat exchanger welding method according to claim 1, characterized in that: There are at least 10 welding points, and the welding points are evenly distributed around the heat channel.
3. A heat exchanger welding method, characterized in that: The following steps are involved: B1. Provide a heat exchange tube, wherein the heat exchange tube comprises a tube body and a flange, wherein the flange is connected to one end of the tube body, and a heat channel penetrating the tube body and the flange is formed on the heat channel; B2. Providing a heat-conducting sleeve, wherein the heat-conducting sleeve comprises a copper film and a flange connected to each other, and the outer size of the copper film corresponds to the inner size of the tube body; B3, the heat-conducting sleeve is assembled on the heat exchange tube, the copper film is passed through the heat channel and fits the inner wall of the tube body, and the flange fits the flange; B4, marking a plurality of first welding points and a plurality of second welding points at the joint between the flange and the flange; B5. Simultaneously melting the flanges or flanges at the plurality of first welding points so that the flanges are welded to the flanges; B6. Simultaneously melt the flanges or flanges at the plurality of second welding points so that the flanges are welded and connected to the flanges.
4. The heat exchanger welding method according to claim 3, characterized in that: The step B5 comprises: at a temperature T1, simultaneously melting the flanges or flanges at a plurality of the first welding points, so that the flanges are welded to the flanges; The step B6 includes: at a temperature T2, simultaneously melting the flanges or flanges at a plurality of the second welding points, so that the flanges are welded to the flanges, T1<T2.
5. The heat exchanger welding method according to claim 4, characterized in that: The heat exchange tube provided in step B1 is made of aluminum, and the flange provided in step B2 is made of copper; The step B5 comprises: at a temperature T1, simultaneously melting the flanges at a plurality of the first welding points, so that the flanges are welded to the flanges; The step B6 includes: at a temperature T2, simultaneously melting the flanges at a plurality of the second welding points, so that the flanges are welded to the flanges, T1<T2.
6. The heat exchanger welding method according to claim 4, characterized in that: The step B5 comprises: at a temperature T1, simultaneously melting the flanges or flanges at a plurality of the first welding points, so that the flanges are welded to the flanges, 620°C≤T1≤750°C; The step B6 comprises: at a temperature T2, simultaneously melting the flanges or flanges at a plurality of the second welding points, so that the flanges are welded to the flanges, 650°C≤T2≤1200°C and T1<T2.
7. The heat exchanger welding method according to claim 3, characterized in that: The step B5 comprises: simultaneously melting the flanges at the plurality of the first welding points, so that the flanges are welded to the flanges, the thickness of the flanges is L1, the thickness of the flanges is L2, L1<L2, the melting depth at the first welding points is L3, L1=L3; The step B6 includes: at a temperature T2, simultaneously melting the flanges and part of the flange at a plurality of the second welding points, so that the flanges are welded and connected to the flanges, and the melting depth at the second welding points is L4, L1<L4<L1+L2.
8. The heat exchanger welding method according to claim 3, characterized in that: The step B5 includes: marking a plurality of first welding points and a plurality of second welding points at the joint of the flange and the flange, the distance between the first welding point and the hot run is L5, the distance between the second welding point and the hot run is L6, and L5<L6.
9. The heat exchanger welding method according to any one of claims 1 to 8, characterized in that: The step B2 comprises: B2.
1. Provide a heat-conducting sleeve, wherein the heat-conducting sleeve comprises a copper film and a flange connected to each other, and the outer size of the copper film corresponds to the inner size of the tube body; B2.
2. Provide nail buckles, which are made of the same material as the flange; B2.3, riveting or clamping the button to the flange; The welding point, the first welding point or the second welding point in step B4 is marked at the button position.
10. A welding device, characterized in that: The invention comprises a plurality of welding heads, wherein the welding heads are used to perform the heat exchanger welding method according to any one of claims 1 to 9.