Tubular heat exchanger and preparation method thereof

Abstract

The present invention provides a tubular heat exchanger and a preparation method thereof, the preparation method comprising: 3D printing a tube sheet additive on the second plate surface of a tube sheet support plate, so that the tube sheet additive is integrated with the tube sheet support plate and one end of the heat exchange tube passing through the second plate surface. The present invention improves the connection strength and high temperature resistance between the tube sheet and the heat exchange tube by 3D printing the tube sheet additive, and is suitable for applications with high temperature, high pressure and thinner heat exchange tubes; at the same time, by 3D printing the tube sheet additive, additional processing of the tube sheet, custom high temperature brazing furnace and other processes are omitted, the influence of high temperature processing on the heat exchange tube is reduced, the preparation cost is reduced, and the production cycle is shortened; in addition, the tube mouth of the heat exchange tube and the second plate surface of the tube sheet support plate are roughened before 3D printing, the adhesion contact area of ​​the tube sheet additive and the heat exchange tube and the tube sheet support plate is increased, and the integrated connection strength is improved; finally, a plug is set at the tube mouth of the heat exchange tube before 3D printing to prevent the 3D printed powder from entering the heat exchange tube and causing the pipeline to be blocked, thereby improving the yield and service life of the heat exchanger.

Description

Technical Field

[0001] The invention belongs to the technical field of heat exchange equipment, and in particular relates to a tubular heat exchanger and a preparation method thereof. Background Art

[0002] In the existing tubular heat exchanger, the connection method between the tube sheet and the heat exchange tube requires first processing the tube sheet, and then assembling the processed tube sheet and the heat exchange tube and then performing expansion or welding.

[0003] In the fields of aerospace and nuclear energy, there are higher requirements for the compactness and efficiency of tubular heat exchangers, which leads to the small diameter of heat exchange tubes, which may even need to reach an outer diameter of 1 mm and a wall thickness of 0.05 mm. However, since small-diameter heat exchange tubes and tube sheets welded by traditional expansion welding, sealing welding and strength welding often cannot meet the requirements for welding strength in the high temperature and high pressure environment in the fields of aerospace and nuclear energy, the nickel-based vacuum brazing process is currently commonly used.

[0004] However, since the furnace temperature of the brazing process reaches about 2000℃, the heat exchange tubes of the heat exchanger are easily deformed by heat during the overall brazing. At the same time, welding materials that can adapt to the high-temperature brazing process also need to be independently selected, resulting in a long overall cycle, high risk, high investment cost, and a serious impact on the quality of the heat exchange tubes.

[0005] Therefore, there is an urgent need for a new tube sheet-heat exchange tube connection method that can adapt to small diameter heat exchange tubes while meeting the connection strength requirements under high temperature and high pressure.

[0006] It should be noted that the above introduction to the technical background is only for the convenience of providing a clear and complete description of the technical solutions of the present application and for the convenience of understanding by those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because these solutions are described in the background technology part of the present application. Summary of the invention

[0007] In view of the above shortcomings of the prior art, the purpose of the present invention is to provide a tubular heat exchanger and a preparation method thereof, which are used to solve the problems of poor connection strength and high cost between small-diameter heat exchange tubes and tube sheets of tubular heat exchangers in the prior art.

[0008] To achieve the above object, the present invention provides a method for preparing a tubular heat exchanger, the method comprising:

[0009] A heat exchanger core is provided, the heat exchanger core comprising a heat exchange tube and a tube sheet support plate; the tube sheet support plate comprises a first plate surface and a second plate surface which are relatively parallel, and the tube sheet support plate is provided with more than two first through holes, the first through holes penetrate the first plate surface and the second plate surface; the heat exchange tube passes through the first through holes from the first plate surface to the second plate surface and exceeds the second plate surface by a preset distance;

[0010] 3D printing of tube sheet additives is performed on the second plate surface of the tube sheet support plate, so that the tube sheet additives, the tube sheet support plate, and one end of the heat exchange tube passing through the second plate surface are integrally formed.

[0011] Optionally, the preparation method further comprises: after 3D printing the tube sheet additive material, annealing, turning, reaming and / or polishing the tube sheet additive material.

[0012] Optionally, the preparation method further comprises: after 3D printing the tube sheet additive, continuing 3D printing a head, a partition plate, an inlet pipe and / or an outlet pipe integrally formed with the tube sheet additive.

[0013] Optionally, the tube openings of the heat exchange tubes face the same direction, and the tube openings of the heat exchange tubes all pass through the first through hole of the same tube sheet support plate, and the tube sheet additive material is 3D printed on the second board surface of the same tube sheet support plate; or the tube openings of the heat exchange tubes are not all facing the same direction, and the heat exchange tubes facing different tube openings each pass through a different first through hole of the tube sheet support plate, and the tube sheet additive material is 3D printed on the second board surfaces of two different tube sheet support plates.

[0014] Optionally, when the tube openings of the heat exchange tube face the same direction, the heat exchange tube is a U-shaped tube; when the tube openings of the heat exchange tube do not all face the same direction, the heat exchange tube is a straight tube, a serpentine tube or an arc tube.

[0015] Optionally, the heat exchange tube is obtained by drawing or extrusion.

[0016] Optionally, the preparation method further comprises: before 3D printing, providing a high temperature resistant plug at the tube opening of the heat exchange tube.

[0017] Optionally, the preparation method further comprises: before 3D printing, performing surface roughening treatment on the tube mouth of the heat exchange tube and / or the second plate surface of the tube sheet support plate.

[0018] Optionally, the material of the tube sheet additive is a high temperature resistant material.

[0019] The present invention also provides a tubular heat exchanger, which is obtained by using any one of the above methods for preparing a tubular heat exchanger.

[0020] As described above, the tubular heat exchanger and the preparation method thereof of the present invention have the following beneficial effects:

[0021] The present invention integrates tube sheet additives, tube sheet support plates, and heat exchange tubes by 3D printing tube sheet additives, thereby improving the connection strength and high temperature resistance between the tube sheet and the heat exchange tubes, improving the structural reliability, and being conducive to the application in the fields of nuclear power, aerospace, etc. where high temperature and high pressure and thinner heat exchange tube walls are required;

[0022] The present invention uses 3D printing to add material to the tube sheet, eliminating the need for additional tube sheet processing, custom high-temperature brazing furnaces and other processes, reducing the impact of high-temperature processing on the overall heat exchange tube, reducing preparation costs, and shortening production cycles;

[0023] The present invention can increase the adhesion contact area between the tube sheet additive material and the heat exchange tube and the tube sheet support plate by roughening the tube mouth of the heat exchange tube and the second plate surface of the tube sheet support plate before 3D printing, thereby improving the integrated connection strength;

[0024] The present invention provides a plug at the pipe opening of the heat exchange pipe before 3D printing, thereby preventing powder from entering the heat exchange pipe during 3D printing and causing pipe blockage, which is beneficial to improving the yield and service life of the heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It shows a schematic diagram of the structure of the heat exchanger core provided in step 1 of the method for preparing a tubular heat exchanger according to the first embodiment of the present invention.

[0026] Figure 2 It shows a schematic diagram of the structure presented during the assembly of the heat exchanger core in step 1 of an example of the method for preparing a tubular heat exchanger in embodiment 1 of the present invention.

[0027] Figure 3 Shown is a schematic diagram of the structure presented by the 3D printed tube sheet additive in step 2 of the method for preparing a tubular heat exchanger according to the first embodiment of the present invention.

[0028] Figure 4 It shows a schematic diagram of the structure in which the heat exchange tube is an arc tube in an example of step 2 of the preparation method of the tubular heat exchanger of the first embodiment of the present invention.

[0029] Figure 5 It shows a schematic diagram of the structure in which the heat exchange tube is a U-shaped tube in an example of a method for preparing a tubular heat exchanger according to the second embodiment of the present invention.

[0030] Component number description

[0031] 10. Heat exchanger core; 11. Heat exchange tube; 12. Tube sheet support plate; 121. First plate surface; 122. Second plate surface; 13. Positioning rod; 14. Positioning tube; 15. Baffle; 21. Tube sheet material addition. DETAILED DESCRIPTION

[0032] The following describes the embodiments of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention.

[0033] For example, when describing the embodiments of the present invention in detail, for the sake of convenience, the schematic diagrams showing the device structure will not be partially enlarged according to the general scale, and the schematic diagrams are only examples, which should not limit the scope of protection of the present invention. In addition, in actual production, the three-dimensional dimensions of length, width and depth should be included.

[0034] For convenience of description, spatially relative terms such as "under", "below", "below", "below", "above", "on", etc. may be used herein to describe the relationship of one element or feature shown in the drawings to other elements or features. It will be understood that these spatially relative terms are intended to encompass other orientations of the device in use or operation in addition to the orientation depicted in the drawings.

[0035] In the context of the present application, a structure in which a first feature is described as being "above" a second feature may include embodiments in which the first and second features are in direct contact, and may also include embodiments in which additional features are formed between the first and second features, such that the first and second features may not be in direct contact.

[0036] It should be noted that the illustrations provided in this embodiment are only used to illustrate the basic concept of the present invention in a schematic manner, and therefore the illustrations only show components related to the present invention rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated. Embodiment 1:

[0037] This embodiment provides a method for preparing a tubular heat exchanger, the preparation method comprising:

[0038] Step 1: providing a heat exchanger core, the heat exchanger core comprising a heat exchange tube and a tube sheet support plate; the tube sheet support plate comprising a first plate surface and a second plate surface that are relatively parallel, the tube sheet support plate being provided with more than two first through holes, the first through holes penetrating the first plate surface and the second plate surface; the heat exchange tube passing through the first through holes from the first plate surface to the second plate surface and exceeding the second plate surface by a preset distance;

[0039] Step 2: 3D printing tube sheet additives is performed on the second plate surface of the tube sheet support plate, so that the tube sheet additives, the tube sheet support plate, and one end of the heat exchange tube passing through the second plate surface are integrally formed.

[0040] The preparation method of the tubular heat exchanger of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that the above sequence does not strictly represent the sequence of the preparation method of the tubular heat exchanger protected by the present invention, and those skilled in the art may change it according to the actual preparation steps.

[0041] First, if Figure 1 As shown, step 1 is performed to provide a heat exchanger core 10, wherein the heat exchanger core 10 includes a heat exchange tube 11 and a tube sheet support plate 12; the tube sheet support plate 12 includes a relatively parallel first plate surface 121 and a second plate surface 122, and more than two first through holes are provided on the tube sheet support plate 12, wherein the first through holes penetrate the first plate surface 121 and the second plate surface 122; the heat exchange tube 11 passes through the first through hole from the first plate surface 121 to the second plate surface 122 and exceeds the second plate surface 122 by a preset distance.

[0042] In one embodiment, the heat exchange tube 11 is obtained by drawing or extrusion.

[0043] In one embodiment, the heat exchange tube 11 may also be produced by 3D printing followed by drawing or extrusion.

[0044] Specifically, the heat exchange tube 11 cannot be obtained directly through 3D printing, and needs to be subjected to processes such as drawing and extrusion to obtain a heat exchange tube 11 with a thin tube diameter and a thin tube wall that meets the requirements of aviation, nuclear power and other fields.

[0045] Specifically, the heat exchanger core 10 may include a plurality of heat exchange tubes 11 to form a heat exchange tube bundle.

[0046] Specifically, the preset distance can be adjusted as needed to meet the connection strength between the tube sheet augmentation material 21 and the heat exchange tube 11 when the tube sheet augmentation material 21 is subsequently set.

[0047] In one embodiment, Figure 1-Figure 2As shown, the heat exchanger core 10 also includes a positioning rod 13 and a baffle 15; the positioning rod 13 passes through the first through hole of the tube sheet support plate 12 from the first plate surface 121 of the tube sheet support plate 12 and is fixedly connected to the tube sheet support plate 12; the baffle 15 includes more than two second through holes, and the second through holes of the baffle 15 pass through the positioning rod 13 at the corresponding position from the side of the tube sheet support plate 12 close to the first plate surface 121.

[0048] In one embodiment, Figure 2 As shown, each positioning rod 13 is sleeved in a positioning tube 14 .

[0049] In one embodiment, the heat exchange tube 11 is a round tube, a flat tube or a polygonal tube. Specifically, the heat exchange tube 11 can be a tube bundle in various suitable forms, and other structures of the tubular heat exchanger can be adaptively adjusted according to the form of the heat exchange tube 11 and the requirements of heat transfer efficiency, all of which are within the protection scope of the present invention.

[0050] In one embodiment, before preparing the heat exchanger core 10 , the components in the heat exchanger core 10 are cleaned to improve the product surface quality of the heat exchanger core 10 obtained and to improve the connection quality of the 3D printed tube sheet additive material 21 .

[0051] In one embodiment, the method for assembling the heat exchanger core 10 is as follows: first, the components of the heat exchanger core 10 are cleaned as required; Figure 2 As shown, one end of the required positioning rod 13 is welded and fixed on the tube sheet support plate 12, and the positioning tube 14 is sleeved on the positioning rod 13, and then the second through hole of the baffle plate 15 is installed to pass through the positioning tube 14 (if two tube sheet support plates 12 are included, the tube sheet support plate 12 at the other end is installed and fixed after the baffle plate 15 is set), and a complete heat exchanger core frame is obtained; as shown Figure 1 As shown, a heat exchange tube bundle including a plurality of heat exchange tubes 11 is assembled on the heat exchanger core frame, and the heat exchange tube 11 at each end extends out of the second plate surface 122 of the tube sheet support plate 12 by a certain distance, thereby completing the assembly of the heat exchanger core 10.

[0052] Then, if Figure 3 As shown, step 2 is performed to 3D print the tube sheet additive material 21 on the second plate surface 122 of the tube sheet support plate 12, so that the tube sheet additive material 21 and the tube sheet support plate 12 and the heat exchange tube 11 are integrally formed at one end of the second plate surface 122.

[0053] In the prior art, the connection method between the tube sheet and the heat exchange tube 11 in the tubular heat exchanger is to first process the tube sheet, and then assemble the processed tube sheet and the heat exchange tube 11 for expansion or welding. In the fields of aerospace and nuclear energy, there are higher requirements for the compactness and efficiency of the tubular heat exchanger, resulting in the small diameter of the heat exchange tube 11. The small diameter heat exchange tube 11 and the tube sheet welded by traditional expansion, sealing welding and strength welding processes often cannot meet the requirements for welding strength under high temperature and high pressure environments in the fields of aerospace and nuclear energy. Therefore, the nickel-based vacuum brazing process is currently generally used in these fields. However, since the furnace temperature of the brazing process reaches about 2000°C, the heat exchange tube 11 of the heat exchanger is easily deformed by heat during the overall brazing. At the same time, the welding materials that can adapt to the high temperature brazing process also need to be independently selected, resulting in a long overall cycle, high risk, high investment cost, and a serious impact on the quality of the heat exchange tube 11.

[0054] The present invention performs 3D printing of the tube sheet additive material 21 on the tube sheet support plate 12, so that the tube sheet additive material 21, the tube sheet support plate 12, and the heat exchange tube 11 are integrated into one, thereby improving the connection strength between the tube sheet and the heat exchange tube 11, and improving the safety, reliability, and high temperature resistance of the connection between the heat exchange tube 11 with a small diameter and the tube sheet, which is conducive to adapting to the application in the fields of nuclear power, aerospace, etc. where the heat exchange tube 11 needs to have a thinner wall and a thinner diameter due to high temperature and high pressure; at the same time, the method of 3D printing the tube sheet additive material 21 eliminates the processes of additional tube sheet processing, customizing a high-temperature brazing furnace, etc. in the prior art, shortens the production cycle, and also extends the tube sheet The optional range of materials; in addition, since the 3D printed tube sheet additive 21 adopts local additive technology, the local molten metal additive has little effect on the quality of the heat exchange tube 11, and the deformation of the heat exchange tube 11 can be ignored, thereby reducing the impact of high-temperature processing on the overall heat exchange tube 11 and reducing the preparation cost; finally, since 3D printing cannot directly print out a heat exchange tube 11 structure with a smaller diameter in an integrated manner, the present invention uses the setting of the tube sheet support plate 12 as a 3D printing recipient and constitutes a part of the tube sheet, so that the heat exchange tube 11 with a smaller diameter can be obtained while improving the connection strength between the heat exchange tube 11 and the tube sheet.

[0055] In one embodiment, the preparation method further comprises: before 3D printing, a high temperature resistant plug is provided at the tube opening of the heat exchange tube 11 .

[0056] The present invention arranges a high temperature resistant plug at the tube mouth of the heat exchange tube 11 before 3D printing, thereby preventing powder from entering the heat exchange tube 11 during 3D printing or ordinary plugs from melting under the local high temperature of 3D printing to cause pipeline blockage, which is beneficial to improving the yield and service life of the heat exchanger.

[0057] In one embodiment, the high temperature resistant plug is a carbon rod or a high temperature resistant ceramic.

[0058] Specifically, the high temperature resistant plug may also be made of other suitable materials or forms.

[0059] In one embodiment, the preparation method further comprises: before 3D printing, performing surface roughening treatment on the tube mouth of the heat exchange tube 11 and / or the second plate surface 122 of the tube sheet support plate 12 .

[0060] The present invention can increase the adhesion contact area between the melted tube sheet additive material 21 and the heat exchange tube 11 and the tube sheet support plate 12 during 3D printing by roughening the tube mouth of the heat exchange tube 11 and / or the second plate surface 122 of the tube sheet support plate 12 before 3D printing, thereby improving the integrated connection strength between the tube sheet additive material 21 and the heat exchange tube 11 and the tube sheet support plate 12.

[0061] In one embodiment, the surface of the tube mouth of the heat exchange tube 11 is roughened by grinding, wire drawing and / or spinning.

[0062] In one embodiment, the second plate surface 122 of the tube sheet support plate 12 is roughened by grinding, wire drawing and / or sand blasting.

[0063] In one embodiment, the preparation method further includes: before 3D printing the tube sheet additive material 21, cleaning and drying the surface of the tube sheet support plate 12.

[0064] The present invention can further improve the connection quality between the 3D printed tube sheet additive 21 and the tube sheet support plate 12 and improve the connection reliability by cleaning and drying the surface of the tube sheet support plate 12 before 3D printing to remove impurities such as grease and floating dust on the surface of the tube sheet support plate 12.

[0065] In one embodiment, the surface of the tube sheet support plate 12 is dried by a drying oven.

[0066] In one embodiment, the material of the tube sheet additive 21 is a high temperature resistant material.

[0067] The present invention can further adapt to the application in the technical fields of high temperature and high pressure aerospace, nuclear power, etc. by setting the material of the tube plate additive 21 to be a high temperature resistant material.

[0068] In one embodiment, the material of the tube sheet additive 21 includes but is not limited to high temperature resistant materials such as high temperature alloys, pure tungsten, pure molybdenum, and pure nickel, and may also be other suitable tube sheet additive 21 materials such as organic or inorganic non-metallic materials.

[0069] In one embodiment, when 3D printing the tube sheet additive material 21, the heat exchanger core 10 is vertically placed on the 3D printing additive material device through the positioning hole of the 3D printing additive material device; if two tube sheet support plates 12 are included, after the tube sheet additive material 21 is set on one tube sheet support plate 12, the upper and lower surfaces of the heat exchanger core 10 are reversed so that the tube sheet support plate 12 without the tube sheet additive material 21 is facing the direction of the 3D printing additive material device, and the tube sheet additive material 21 at the other end is 3D printed.

[0070] In one embodiment, the preparation method further includes: after 3D printing the tube sheet additive material 21 , annealing, turning, reaming and / or polishing the tube sheet additive material 21 .

[0071] The present invention can optimize the surface quality of the tube sheet augmented material 21 by annealing, turning, reaming and / or polishing the tube sheet augmented material 21, so as to improve the appearance and service life of the tubular heat exchanger.

[0072] In one embodiment, the preparation method further includes: after 3D printing the tube sheet additive material 21 , continuing 3D printing a head, a separator plate, an inlet pipe and / or an outlet pipe integrally formed with the tube sheet additive material 21 .

[0073] The present invention further integrates and prints other structures connected to the tube sheet on the basis of the tube sheet additive 21, thereby making the connection strength between the other structures and the tube sheet stronger, further improving the overall structural reliability and yield of the tubular heat exchanger.

[0074] In this embodiment, Figure 3-Figure 4 As shown, the directions of the various pipe openings of the heat exchange tube 11 are not all facing the same direction. The heat exchange tube 11 faces different pipe openings and each passes through a different first through hole of the tube sheet support plate 12. The tube sheet additive material 21 is 3D printed on the second plate surfaces 122 of two different tube sheet support plates 12.

[0075] In one embodiment, when the directions of the various pipe openings of the heat exchange tube 11 are not all facing the same direction, the heat exchange tube 11 is as follows: Figure 3 Straight tube, serpentine tube or Figure 4 The arc-shaped tube shown may also be a heat exchange tube shape with other tube openings having different directions. Embodiment 2:

[0076] This embodiment provides a method for preparing a tubular heat exchanger. Other features of the preparation method are the same as those of the first embodiment, except that:

[0077] In this embodiment, Figure 5As shown, each tube opening of the heat exchange tube 11 faces the same direction, and each tube opening of the heat exchange tube 11 passes through the first through hole of the same tube sheet support plate 12; in step 2, the tube sheet additive material 21 is 3D printed on the second plate surface 122 of the same tube sheet support plate 12.

[0078] In one embodiment, Figure 5 As shown, when the tube openings of the heat exchange tube 11 face the same direction, the heat exchange tube 11 is a U-shaped tube. Specifically, the heat exchange tube may also be a heat exchange tube with other tube openings facing the same direction. Embodiment three:

[0079] This embodiment provides a tubular heat exchanger, and the tubular heat exchanger is obtained by using the preparation method of any one of the tubular heat exchangers in Embodiment 1 or Embodiment 2.

[0080] The tubular heat exchanger prepared by the preparation method in Example 1 or Example 2 of the present invention can achieve better safety and reliability through the stronger connection strength between the heat exchange tube and the tube sheet, and obtains a thin-diameter heat exchange tube whose quality is not affected, which is more suitable for application fields such as aerospace and nuclear power.

[0081] In summary, the tubular heat exchanger and its preparation method of the present invention can integrate the tube sheet additive material, the tube sheet support plate and the heat exchange tube into one by 3D printing the tube sheet additive material, thereby improving the connection strength and high temperature resistance between the tube sheet and the heat exchange tube, improving the structural reliability, and being conducive to adapting to the application of high temperature and high pressure, and the thinner tube wall of the heat exchange tube in the fields of nuclear power, aerospace, etc.; at the same time, by 3D printing the tube sheet additive material, it is possible to save the additional processing of the tube sheet, customize the high temperature brazing furnace and other processes, reduce the impact of high temperature processing on the overall heat exchange tube, reduce the preparation cost, and shorten the production cycle; in addition, by roughening the tube mouth of the heat exchange tube and the second plate surface of the tube sheet support plate before 3D printing, the adhesion contact area between the tube sheet additive material and the heat exchange tube and the tube sheet support plate can be increased, thereby improving the integrated connection strength; finally, a plug is set at the tube mouth of the heat exchange tube before 3D printing to prevent the powder from entering the heat exchange tube during 3D printing and causing the pipeline to be blocked, which is conducive to improving the yield and service life of the heat exchanger.

[0082] Therefore, the present invention effectively overcomes various shortcomings in the prior art and has high industrial utilization value.

[0083] The above embodiments are merely illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Anyone familiar with the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by a person of ordinary skill in the art without departing from the spirit and technical concept disclosed by the present invention shall still be covered by the claims of the present invention.

Claims

1. A method for preparing a tubular heat exchanger, characterized in that: The preparation method comprises: A heat exchanger core is provided, the heat exchanger core comprising a heat exchange tube and a tube sheet support plate; the tube sheet support plate comprises a first plate surface and a second plate surface which are relatively parallel, and the tube sheet support plate is provided with more than two first through holes, the first through holes penetrate the first plate surface and the second plate surface; the heat exchange tube passes through the first through holes from the first plate surface to the second plate surface and exceeds the second plate surface by a preset distance; 3D printing of tube sheet additives is performed on the second plate surface of the tube sheet support plate, so that the tube sheet additives are integrally formed with the tube sheet support plate and one end of the heat exchange tube passing through the second plate surface; the tube sheet additives are not head, partition plate, inlet pipe or outlet pipe, and the 3D printing of tube sheet additives is used to save the process of additional processing of tube sheets and customized high-temperature brazing furnaces, thereby reducing the impact of high-temperature processing on the overall heat exchange tube.

2. The method for preparing a tubular heat exchanger according to claim 1, characterized in that: The preparation method further comprises: after 3D printing the tube sheet additive material, annealing, turning, reaming and / or polishing the tube sheet additive material.

3. The method for preparing a tubular heat exchanger according to claim 1, characterized in that: The preparation method further comprises: after 3D printing the tube sheet additive, continuing 3D printing a head, a partition plate, an inlet pipe and / or an outlet pipe integrally formed with the tube sheet additive.

4. The method for preparing a tubular heat exchanger according to claim 1, characterized in that: The tube openings of the heat exchange tubes face the same direction, and all of the tube openings of the heat exchange tubes pass through the first through hole of the same tube sheet support plate, and the tube sheet additive material is 3D printed on the second board surface of the same tube sheet support plate; or the tube openings of the heat exchange tubes are not all facing the same direction, and the heat exchange tubes facing different tube openings each pass through a different first through hole of the tube sheet support plate, and the tube sheet additive material is 3D printed on the second board surfaces of two different tube sheet support plates.

5. The method for preparing a tubular heat exchanger according to claim 4, characterized in that: When the tube openings of the heat exchange tube face the same direction, the heat exchange tube is a U-shaped tube; when the tube openings of the heat exchange tube do not all face the same direction, the heat exchange tube is a straight tube, a serpentine tube or an arc tube.

6. The method for preparing a tubular heat exchanger according to claim 1, characterized in that: The heat exchange tube is obtained by drawing or extrusion.

7. The method for preparing a tubular heat exchanger according to claim 1, characterized in that: The preparation method further includes: before 3D printing, a high temperature resistant plug is provided at the tube opening of the heat exchange tube.

8. The method for preparing a tubular heat exchanger according to claim 1, characterized in that: The preparation method further comprises: before 3D printing, performing surface roughening treatment on the tube opening of the heat exchange tube and / or the second plate surface of the tube sheet support plate.

9. The method for preparing a tubular heat exchanger according to claim 1, characterized in that: The material of the tube sheet additive is a high temperature resistant material.

10. A tubular heat exchanger, characterized in that: The tubular heat exchanger is obtained by the preparation method described in any one of claims 1 to 9.

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