Heat exchanger processing technology and heat exchanger

Abstract

The invention discloses a heat exchanger machining process and a heat exchanger. The heat exchanger machining process comprises the following steps that B1, a heat channel is provided, and the heat channel is in a barrel shape with at least two openings; b2, a clamp and a heat pipe are provided, the clamp comprises a clamp body, a clamp groove and a pipe groove, the clamp groove and the pipe groove are formed in the clamp body, and the clamp groove is communicated with the pipe groove; b3, the heat pipe is partially clamped in the pipe groove; b4, the clamp and the heat pipe are assembled in the heat channel, so that the cylinder wall of the heat channel is embedded into the clamping groove, and the heat pipe is wound on the outer wall of the heat channel; b5, a welding wire is placed between the heat pipe and the heat channel; b6, the whole is heated till the welding wire is molten; b7, cooling the whole; and B8, the clamp is dismantled. Compared with the prior art, pre-fixed spot welding is omitted, and the formed heat exchanger is uniform in structure, longer in service life and higher in structural strength.

Description

Technical Field

[0001] The invention relates to the technical field of material forming, and in particular to a heat exchanger processing technology and a heat exchanger. Background Art

[0002] Heat exchangers are devices that recover waste heat from industrial exhaust gas to improve energy utilization and are widely used in various thermal processing procedures. Optimizing the design of heat exchangers has great practical value in reducing energy waste and mitigating the greenhouse effect. Common heat exchangers include a heat channel and a heat pipe. The heat pipe is placed through or around the heat channel. High-temperature exhaust gas is passed through the heat channel, and low-temperature energy storage liquid is passed through the heat pipe. When the high-temperature exhaust gas flows through the heat channel, the low-temperature energy storage liquid heats up, extracting and storing the energy in the exhaust gas.

[0003] In the production of heat exchangers, in order to make the heat transfer efficiency of heat pipes and heat channels higher, a welding process is usually used to connect the heat channels and heat pipes into one, which includes a pre-fixing step of spot welding and a connection step of brazing.

[0004] However, in the pre-fixing process, even if the material is not easily oxidized under gas protection, the formation of the molten pool itself will cause certain damage to the structure of the material, resulting in structural weaknesses in the heat channels and heat pipes of the finished heat exchanger, which are more prone to damage in subsequent use, shortening the service life of the heat exchanger to a certain extent. Summary of the invention

[0005] An object of the present invention is to provide a heat exchanger processing technology, which aims to solve the technical problem that the pre-fixing step will destroy the structural strength during the heat exchanger processing.

[0006] In order to achieve the above object, the present invention provides a solution: a heat exchanger processing technology, the heat exchanger processing technology comprises the following steps: B1. Provide a heat channel, which is cylindrical with at least two openings; B2. Provide a clamp and a heat pipe. The clamp includes a clamp body and a clamp groove and a pipe groove opened in the clamp body. The clamp groove and the pipe groove are in conduction. B3. Install the heat pipe part in the pipe groove; B4. Assemble the fixture and the heat pipe to the heat runner so that the wall of the heat runner is embedded in the clamping groove and the heat pipe is wound around the outer wall of the heat runner; B5. Place welding wire between the heat pipe and the heat channel; B6. Heat the whole until the welding wire melts; B7, cooling the whole; B8. Remove the clamp.

[0007] In some embodiments, the axis of the welding wire placed in step B5 extends in the horizontal direction.

[0008] In some embodiments, the shape of the heat channel is a prism, and the heat exchanger processing technology further includes step B9, and looping steps B5 to B7 until all sides of the heat channel are welded to the heat pipe.

[0009] In some embodiments, the clamp provided in step B2 includes a first section and a second section, the first section and the second section are detachably connected, the first section and the second section are combined to form a clamping groove, and the tube groove is opened in the second section.

[0010] In some embodiments, the heat channel provided in step B1 is a straight tube; after the assembly in step B4 is completed, the upper edge of the heat channel abuts against the bottom of the clamping groove.

[0011] In some embodiments, the heat channel provided in step B1 includes a cylinder and a flange, wherein the flange is disposed on an upper edge of the cylinder and sleeved on an outer wall of the cylinder.

[0012] In some embodiments, after the assembly of step B4 is completed, there is a gap between the heat pipe and the heat channel, and the width of the gap is in the range of 2.5 mm to 4.0 mm.

[0013] In some embodiments, the clamp provided in step B2 has one and only one.

[0014] In some embodiments, there are multiple clamps provided in step B2; and / or, the heat pipe provided in step B2 is in a multi-turn coiled shape.

[0015] To achieve the above object, the present invention provides a solution: a heat exchanger, which is produced using any of the above heat exchanger processing technologies, and the heat pipe and the heat channel are connected only by strip welds, and there are no welding points.

[0016] The present invention has at least one of the following beneficial effects: 1. The heat exchanger processing technology of the present application uses a fixture to pre-fix the heat pipe and the heat channel. Before the heat pipe and the heat channel are welded, the structure of the heat pipe and the heat channel is complete, and the welding of the heat pipe and the heat channel is completed by melting the welding wire. The weld formed is a strip weld, and it will not cause obvious stress concentration or thin-wall weakness. Compared with the existing heat exchanger production process that achieves pre-fixation by spot welding, the heat exchanger produced by the heat exchanger production process proposed in this application has higher structural strength and longer service life.

[0017] 2. When the welding wire is melted, there is a gap of 2.5mm to 4.0mm between the heat pipe and the heat runner. This gap allows the gravity of the molten metal to break through the surface tension of the metal liquid in the area between the heat pipe and the heat runner, allowing part of the metal liquid to infiltrate the other side of the surface between the heat pipe and the heat runner where the welding wire is not placed, thereby increasing the connection area and heat conduction area between the heat pipe and the heat runner.

[0018] 3. In step B4, only one clamp is used to connect the heat pipe and the heat runner. Under the action of gravity, the heat pipe and the clamp as a whole will rotate relative to the fulcrum of the clamp and the heat runner, or the heat pipe will rotate relative to the clamp until the heat pipe and the heat runner are in contact, which effectively reduces the gap between the heat pipe and the heat runner caused by limited processing accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 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.

[0020] Figure 1 is a schematic diagram of the structure of the heat channel provided in step B1 in an embodiment of the present invention; Figure 2 is a diagram showing the matching relationship between the heat pipe and the clamp in step B3 of an embodiment of the present invention; Figure 3 is an overall assembly schematic diagram of step B4 in an embodiment of the present invention; Figure 4 is along Figure 3 Schematic diagram of the cross section along the AA line; Figure 5 is an overall assembly schematic diagram of step B5 in an embodiment of the present invention; Figure 6 is an overall cross-sectional schematic diagram of step B6 in an embodiment of the present invention; Figure 7 yes Figure 6 A partial enlarged view of the middle B area; Figure 8 It is a schematic structural diagram of a clamp in another embodiment of the present invention.

[0021] Description of Figure Numbers: 10. heat channel; 11. cylinder; 12. flange; 20. clamp; 21. clamp groove; 22. pipe groove; 23. first section; 24. second section; 30. heat pipe; 40. welding wire; 50. welding seam. DETAILED DESCRIPTION

[0022] 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.

[0023] The present invention provides a heat exchanger processing technology, please refer to Figure 1-7 , Figure 1 is a schematic diagram of the structure of the heat channel 10 provided in step B1 in an embodiment of the present invention; Figure 2 is a diagram showing the matching relationship between the heat pipe 30 and the fixture 20 in step B3 of the embodiment of the present invention; Figure 3 is an overall assembly schematic diagram of step B4 in an embodiment of the present invention; Figure 4 is along Figure 3 Schematic diagram of the cross section along the AA line; Figure 5 is an overall assembly schematic diagram of step B5 in an embodiment of the present invention; Figure 6 is an overall cross-sectional schematic diagram of step B6 in an embodiment of the present invention; Figure 7 yes Figure 6 A partial enlarged view of area B in the middle. The heat exchanger processing technology includes the following steps: B1. Provide a heat channel 10, which is in a cylindrical shape with at least two openings.

[0024] For example, the figure shows a straight-sided cylinder with a rectangular bottom surface, and the four edges of the straight-sided cylinder are provided with fillets to relieve stress concentration. The heat channel 10 can be a straight cylinder with the same upper and lower edge shapes, such as any one of a cylinder, an elliptical cylinder or a straight-sided cylinder. The heat channel 10 can also be set to a conical cylinder or a spiral shape for fluid mechanics considerations such as wind pressure control.

[0025] B2. Provide a clamp 20 and a heat pipe 30 . The clamp 20 includes a clamp body and a clamp groove 21 and a pipe groove 22 opened in the clamp body. The clamp groove 21 and the pipe groove 22 are conductively connected.

[0026] The heat pipe 30 and the heat channel 10 are preferably made of copper, and the shape of the pipe groove 22 can be a semicircular groove or an arcuate groove arranged corresponding to the heat pipe 30, or can be a V-shaped groove.

[0027] B3. Part of the heat pipe 30 is clamped in the pipe groove 22.

[0028] The outer diameter of the heat pipe 30 is preferably equal to the inner diameter of the tube groove 22. However, when the inner diameter of the heat pipe 30 is larger or smaller than the inner diameter of the tube groove 22, the fixture 20 can still achieve the function of abutting the heat pipe 30 against the heat channel 10 during the subsequent assembly process, and the protection scope of this application shall not be limited by this. For the technical solution in which the tube groove 22 is a V-shaped groove, when the diameter of the heat pipe 30 is adjusted within a certain range, the tube groove 22 has two planes that are tangent to the outer wall of the heat pipe 30, so that the same style of fixture 20 can be universally matched with heat pipes 30 of various sizes.

[0029] B4. Assemble the clamp 20 and the heat pipe 30 on the heat runner 10 so that the wall of the heat runner 10 is embedded in the clamp groove 21 and the heat pipe 30 is wound around the outer wall of the heat runner 10 .

[0030] It should be noted that the winding here can be multiple turns of winding as shown in the figure. For the straight heat pipe 30 in extreme cases, the heat pipe 30 and the surface of the heat channel 10 are fitted at a certain distance, which should also be understood as winding in this shape.

[0031] B5. Place welding wire 40 between heat pipe 30 and heat channel 10.

[0032] Specifically, the shape of the welding wire 40 matches the subsequent working environment. For welding under a protective atmosphere, the welding wire 40 may only include a solder for filling the weld 50. For welding under an atmospheric environment, the welding wire 40 may include a solder and a coating, and preferably, the coating only covers a portion of the circumference of the solder. When the welding wire 40 is placed, the exposed solder should be facing between the heat pipe 30 and the heat channel 10.

[0033] B6. Heat the entire structure until the welding wire 40 melts.

[0034] B7, cooling the whole.

[0035] B8. Remove the fixture 20.

[0036] In this embodiment, the fixture 20 is used to replace the existing spot welding to pre-fix the heat pipe 30. The entire pre-fixing process will not cause any changes to the structure or physical and chemical properties of the heat pipe 30 and the heat runner 10. After the welding wire 40 melts, it infiltrates between the complete heat pipe 30 and the complete heat runner 10 to form a uniform strip weld 50. Compared with the prior art, the heat exchanger produced by the technical solution of this embodiment has a more uniform structural strength, no obvious structural weaknesses, and can carry a larger airflow and liquid flow rate without collapse, which increases the theoretical power upper limit and expected service life of the heat exchanger.

[0037] In some embodiments, the axis of the welding wire 40 placed in step B5 extends in the horizontal direction.

[0038] The molten metal has a certain fluidity. If the groove carrying the metal liquid, that is, the gap between the heat pipe 30 and the heat channel 10, is in a non-horizontal state, the metal liquid will tend to flow to one end, resulting in different thicknesses on both sides of the weld 50. In this embodiment, the axis of the welding wire 40 extends in the horizontal direction, which makes the weld 50 formed in this embodiment more uniform.

[0039] Furthermore, the shape of the heat runner 10 is a prism, and the heat exchanger processing technology further includes step B9, and looping steps B5 to B7 until all side surfaces of the heat runner 10 are welded to the heat pipe 30 .

[0040] As shown in the figure, the outer contour of the heat runner 10 is configured as a quadrangular prism, in which the heat pipes 30 wound around two opposite sides are parallel to the bottom surface of the heat runner 10. The connection between these two sides and the heat pipe 30 can be welded synchronously in one cycle, and then the welding of the remaining two sides and their corresponding heat pipe 30 sections is completed in sequence. With this arrangement, on the one hand, each side of the heat runner 10 is connected to the heat pipe 30 through a weld 50 with good thermal conductivity, so that the heat exchange efficiency of the heat exchanger is better. On the other hand, each welding process can adjust the overall angle according to the specific inclination angle of the heat runner 10, and the welding wire 40 is extended in the horizontal direction by means of pads or clamping, and the forming quality of the weld 50 is better.

[0041] Please refer to Figure 8 In some embodiments, the clamp 20 provided in step B2 includes a first section 23 and a second section 24 , the first section 23 and the second section 24 are detachably connected, the first section 23 and the second section 24 are combined to form a clamping groove 21 , and the tube groove 22 is opened in the second section 24 .

[0042] The detachably connected first section 23 and second section 24 allow the assembly of the heat pipe 30, the heat runner 10 and the clamp 20 to be refined as follows in practical applications: the heat pipe 30 is clamped in the second section 24, and then the second section 24 and the heat pipe 30 are arranged on the outer surface of the heat runner 10, and then the first section 23 and the second section 24 are assembled together to complete the fixation.

[0043] It should be noted that even if the clamp 20 is not detachably connected, there are other technical solutions to achieve the assembly of the heat pipe 30, the heat runner 10 and the clamp 20, for example, the part of the clamp 20 located at the bottom of the clamping groove 21 is an elastic structure, etc. This embodiment only provides a preferred solution that can make the clamp 20 clamp the heat runner 10 tighter and make the contact between the heat pipe 30 and the heat runner 10 more closely, and the protection scope of this application cannot be limited by this.

[0044] In some embodiments, the heat runner 10 provided in step B1 is a straight tube; after the assembly in step B4 is completed, the upper edge of the heat runner 10 abuts against the bottom of the clamping groove 21 .

[0045] Since the upper edge of the heat runner 10 abuts against the bottom of the clamping groove 21, after the assembly in step B4 is completed, during the placement of the welding wire 40 in step B5, the heating in step B6, and the cooling in step B7, the clamp 20 and the heat pipe 30 tend to sink due to gravity, and the clamp 20 and the heat pipe 30 are hung on the upper edge of the heat runner 10 without the need for additional fixation. For the processing of the heat exchanger, there is no subsequent additional load requirement. The hanging form can meet the fixing requirements of the welding process, and the slight yielding ability brought by the non-fixed connection can also meet the stress release requirements during the welding forming process, which can alleviate the residual stress of the weld 50 after forming and the internal stress of the structure to a certain extent.

[0046] Furthermore, the hot runner 10 provided in step B1 includes a cylinder 11 and a flange 12 , wherein the flange 12 is disposed on the upper edge of the cylinder 11 and sleeved on the outer wall of the cylinder 11 .

[0047] The provision of the flange 12 increases the force-bearing area of ​​the hot run 10 that carries the clamp 20 , greatly reduces the pressure at the bottom of the clamp groove 21 , and prolongs the service life of the clamp 20 .

[0048] Furthermore, there is only one clamp 20 provided in step B2. Alternatively, in the case of clamping by multiple clamps 20, the axes of the clamped sections of all the heat pipes 30 are collinear.

[0049] In the above case, because only the part of the heat pipe 30 located on one side of the hot runner 10 is clamped, and the clamp 20 is hung on the upper edge of the hot runner 10, the heat pipe 30 is deformed under the action of gravity, or the heat pipe 30 is rotated relative to the pipe groove 22, until the heat pipe 30 located on the side of the hot runner 10 away from the clamp 20 abuts against the outer wall of the hot runner 10. Even if there is a certain gap when the heat pipe 30 is wound around the hot runner 10, the spontaneous rotation or deformation process of the heat pipe 30 can also achieve the fit between the heat pipe 30 and the hot runner 10. In the case of a single-layer heat pipe 30 wound around the hot runner 10, the rotation or deformation of the heat pipe 30 can achieve a good adaptive effect. In the case of a multi-layer heat pipe 30 wound around the hot runner 10, the adaptive effect achieved by the deformation of the heat pipe 30 is better than the rotation of the heat pipe 30.

[0050] In some embodiments, after the assembly of step B4 is completed, there is a gap between the heat pipe 30 and the heat channel 10 , and the width of the gap is in the range of 2.5 mm to 4.0 mm.

[0051] "Scope" disclosed in the present application is defined in the form of lower limit and upper limit, and a given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of a particular range. The scope defined in this way can be inclusive or exclusive of end values, and can be arbitrarily combined, i.e., any lower limit can be combined with any upper limit to form a range. For example, if a range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that a range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3, 4 and 5 are listed, the following range can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In the present application, unless otherwise specified, the numerical range "a to b" represents the abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, the numerical range "2.5-4.0" means that all real numbers between 2.5 and 4.0 have been listed in this article, and "2.5-4.0" is just an abbreviation of these numerical combinations.

[0052] When the heat pipe 30 and the heat runner 10 fit perfectly, the weld 50 is formed above the tangent of the heat pipe 30 and the heat runner 10, and its shape is similar to a V-shaped groove; and when there is a gap between the heat pipe 30 and the heat runner 10 for the molten metal to penetrate, the weld 50 is simultaneously formed on both sides of a busbar closest to the heat pipe 30 and the heat runner 10, and its shape is similar to an X-shaped groove or a double-sided V-shaped groove. When the volume of the welding wire 40 and the length of the weld 50 are fixed, the X-shaped groove can form a deeper weld 50 compared to the V-shaped groove, that is, the cross-sectional area of ​​the connection surface between the heat pipe 30 and the heat runner 10 is expanded, the heat conduction area is increased, and the heat conduction efficiency is improved. Moreover, the average heat conduction distance from the heat runner 10 to the heat pipe 30 is also reduced, reducing the heat dissipated to the environment. For example, under ideal conditions, when the welds 50 on both sides of a busbar closest to the heat pipe 30 and the heat runner 10 are of the same V-shaped weld 50, compared to the single-sided V-shaped weld 50, the effective heat conduction area between the heat pipe 30 and the heat runner 10 is increased by nearly half, while the average heat conduction distance is reduced by about one third.

[0053] The gap range of 2.5mm to 4.0mm is adapted to most commonly used welding wire 40 components, so that on the one hand, the molten metal liquid can overcome the surface tension between the heat pipe 30 and the heat channel 10 and flow to the opposite side of the gap, but will not completely flow to the opposite side of the gap or even drip.

[0054] In some embodiments, there are multiple clamps 20 provided in step B2; and / or, the heat pipe 30 provided in step B2 is in a multi-turn coiled shape. The fixing of multiple clamps 20 and the multi-turn coiling both increase the stability of the structure, and the multi-turn coiled heat pipe 30 can significantly increase the recovery efficiency of the waste gas heat in the heat channel 10.

[0055] An embodiment of the present invention provides a heat exchanger, which is manufactured using any of the above-mentioned heat exchanger processing technologies. Therefore, the heat exchanger has the advantages of the above-mentioned heat exchanger processing technologies.

[0056] Since the pre-fixation of the heat pipe 30 and the heat runner 10 is achieved by using the clamp 20, there is no spot welding process. Therefore, there is only a uniform strip weld 50 between the heat pipe 30 and the heat runner 10, but no welding spot, and the structural strength and service life of the heat exchanger are greatly improved.

[0057] 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 status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0058] 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.

[0059] 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.

[0060] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0061] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0062] 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 processing technology, characterized in that: The following steps are involved: B1. Providing a heat channel, wherein the heat channel is cylindrical and has at least two openings; B2. Provide a clamp and a heat pipe, wherein the clamp comprises a clamp body and a clamp groove and a tube groove provided in the clamp body, wherein the clamp groove is in conduction with the tube groove; B3, clamping the heat pipe part in the pipe groove; B4, assembling the clamp and the heat pipe to the heat runner, so that the tube wall of the heat runner is embedded in the clamping groove, and the heat pipe is wound around the outer wall of the heat runner; B5. placing welding wire between the heat pipe and the heat channel; B6. Heat the whole until the welding wire melts; B7, cooling the entire body; B8. Remove the clamp.

2. A heat exchanger processing technology according to claim 1, characterized in that: The axis of the welding wire placed in step B5 extends in the horizontal direction.

3. A heat exchanger processing technology according to claim 2, characterized in that: The shape of the heat channel is a prism, and the heat exchanger processing technology further includes step B9, and looping steps B5 to B7 until all sides of the heat channel are welded to the heat pipe.

4. A heat exchanger processing technology according to claim 1, characterized in that: The clamp provided in step B2 includes a first section and a second section, the first section and the second section are detachably connected, the first section and the second section are combined to form the clamping groove, and the tube groove is opened in the second section.

5. The heat exchanger processing technology according to claim 1, characterized in that: The heat channel provided in step B1 is a straight tube; After the assembly of step B4 is completed, the upper edge of the heat channel abuts against the bottom of the clamping groove.

6. A heat exchanger processing technology according to claim 5, characterized in that: The hot channel provided in step B1 includes a cylinder and a flange, wherein the flange is arranged on the upper edge of the cylinder and sleeved on the outer wall of the cylinder.

7. A heat exchanger processing technology according to claim 5, characterized in that: The clamp provided in step B2 has one and only one.

8. The heat exchanger processing technology according to claim 1, characterized in that: After the assembly of step B4 is completed, there is a gap between the heat pipe and the heat channel, and the width of the gap is in the range of 2.5 mm to 4.0 mm.

9. The heat exchanger processing technology according to claim 1, characterized in that: There are multiple clamps provided in step B2; and / or The heat pipe provided in step B2 is in a multi-turn coiled shape.

10. A heat exchanger, characterized in that: The heat exchanger is produced using the heat exchanger processing technology described in any one of claims 1 to 9, and the heat pipe and the heat channel are connected only by strip welds without any welding spots.

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