Welding structure of heat exchange tube and tube plate and heat exchanger

Abstract

The utility model provides a heat exchange tube and tube plate welding structure and a heat exchanger, the tube plate comprises an upper tube plate and a lower tube plate, the bottom surface of the upper tube plate is provided with a convex ring corresponding to the position of a tube plate hole, the convex ring is welded with the upper tube head of the heat exchange tube, and the lower tube head of the heat exchange tube is welded with the lower tube plate. The convex ring is arranged at the position, corresponding to the tube plate hole, of the bottom face of the upper tube plate and welded to the upper tube head, the upper tube head does not need to be inserted into the tube plate hole, liquid cannot be accumulated at the welding position of the upper tube head and the upper tube plate, direct contact between a tube pass medium and the welding position is avoided, and therefore crevice corrosion at the position is avoided. The sealing performance of welding of the upper tube head and the upper tube plate is improved, and the problem that crevice corrosion is likely to be generated at the welding position of the upper tube head and the upper tube plate, and consequently medium leakage is caused is solved.

Description

Technical Field

[0001] The present application relates to the technical field of heat exchanger equipment, and in particular to a welding structure of a heat exchange tube and a tube sheet and a heat exchanger. Background Art

[0002] Crevice corrosion refers to localized corrosion that occurs in crevices and other hidden areas on metal surfaces in corrosive media. Holes, gasket contact surfaces, lap joints, under sediments, and in fastener crevices are common places where crevice corrosion occurs. Metals that rely on oxide films or passivation layers to resist corrosion are particularly susceptible to this type of corrosion.

[0003] The PVC converter is a vertical fixed tube sheet heat exchanger. The medium in the tube is vinyl chloride, acetylene and other substances. The material contains chloride ions. When the chloride ion content in the medium increases, crevice corrosion is prone to occur. The tube head and tube sheet of the heat exchange tube are welded structures. When crevice corrosion occurs, this structure is the most prone to leakage in the heat exchanger. Therefore, how to solve the problem of crevice corrosion in this area can greatly increase the service life of the PVC converter.

[0004] The welding structures of the upper and lower tube sheets of the existing tube sheet heat exchangers are as follows Figure 1 In the welding structure shown, the end of the tube head extends out of the tube sheet for a certain distance, so that liquid is easily accumulated on the upper part of the upper tube sheet and cannot be drained out. Long-term immersion of the tube head in liquid containing chloride ions will cause crevice corrosion at the welding point between the tube head and the tube sheet, thereby causing medium leakage. Summary of the invention

[0005] The present application provides a heat exchange tube and tube sheet welding structure and a heat exchanger, which solves the problem that the welding points between the tube heads and the tube sheets of the existing tube sheet heat exchangers are prone to crevice corrosion, resulting in medium leakage and the like.

[0006] In a first aspect, the present application provides a welding structure of a heat exchange tube and a tube sheet, wherein the tube sheet comprises an upper tube sheet and a lower tube sheet, a convex ring is provided on the bottom surface of the upper tube sheet at a position corresponding to the tube sheet hole, the convex ring is welded to the upper tube head of the heat exchange tube, and the lower tube head of the heat exchange tube is welded to the lower tube sheet.

[0007] In the technical solution provided by the present application, a convex ring is arranged on the bottom surface of the upper tube plate at a position corresponding to the tube plate hole and welded to the upper tube head. There is no need to insert the upper tube head into the tube plate hole, and liquid will not accumulate at the welding point between the upper tube head and the upper tube plate, thereby avoiding direct contact between the tube medium and the welding part, thereby avoiding the occurrence of crevice corrosion at the welding point, improving the sealing of the welding between the upper tube head and the upper tube plate, and solving the problem that crevice corrosion is prone to occur at the welding point between the upper tube head and the upper tube plate, resulting in medium leakage.

[0008] In some embodiments, an annular positioning groove is provided on the end face of the convex ring, and the inner diameter of the positioning groove matches the outer diameter of the upper tube head of the heat exchange tube; by providing an annular positioning groove on the end face of the convex ring for alignment during welding of the upper tube head, the welding efficiency and welding consistency of the upper tube head are improved.

[0009] In certain embodiments, the convex ring and the upper tube plate are an integrally formed structure, and the convex ring has strong structural stability and a long service life.

[0010] In some embodiments, the outer wall of the convex ring is connected to the bottom surface of the upper tube plate in a circular arc transition, which can further enhance the structural stability of the convex ring and improve the service life of the convex ring.

[0011] In some embodiments, an annular groove is provided on the inner wall of the tube sheet hole of the lower tube sheet, and the side wall of the lower tube head of the heat exchange tube is expanded with the annular groove. The lower tube head and the annular groove on the inner wall of the tube sheet hole of the lower tube sheet are connected by expansion, which can effectively prevent the medium in the shell from seeping through the gap between the outer wall of the lower tube head and the inner wall of the tube sheet hole, thereby playing a role of anti-leakage insurance.

[0012] In some embodiments, there are multiple annular grooves, and the multiple annular grooves are arranged axially at intervals along the tube sheet hole of the lower tube sheet. By providing multiple annular grooves, each annular groove can play a role in preventing leakage, thereby further improving the sealing performance of the heat exchanger.

[0013] In some embodiments, the lower tube head of the heat exchange tube extends out of the bottom surface of the lower tube plate, and the outer wall of the lower tube head extending out of the bottom surface of the lower tube plate is welded to the bottom surface of the lower tube plate. By passing the lower tube head through the outer wall of the bottom surface of the lower tube plate and welding it to the bottom surface of the lower tube plate, the sealing performance of the heat exchanger can be further improved to prevent medium leakage.

[0014] The second aspect of the present application provides a heat exchanger, comprising an upper tube box, an upper tube plate, a shell, a lower tube plate and a lower tube box connected in sequence from top to bottom, wherein a plurality of heat exchange tubes are arranged inside the shell; a tube side inlet is arranged at the top of the upper tube box, and a tube side outlet is arranged at the bottom of the lower tube box; a shell side inlet and a shell side outlet are arranged on the side of the shell; and the heat exchange tubes are welded to the upper tube plate and the lower tube plate using the above-mentioned welding structure.

[0015] The above description is only an overview of the technical solution of the present application. In order to more clearly understand the technical means of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The drawings in this application are used to illustrate preferred embodiments, so that those skilled in the art can clearly understand various other advantages and benefits, and should not be considered as limitations of this application. In addition, the same reference numerals are used throughout the drawings to represent the same or similar components.

[0017] Figure 1 It is a schematic diagram of the welding structure of the upper tube head and the upper tube plate in the prior art;

[0018] Figure 2 This is a schematic diagram of the welding structure of the upper tube head and the upper tube plate in one embodiment of the present application;

[0019] Figure 3 for Figure 2 Enlarged view of part A in the middle;

[0020] Figure 4 This is a schematic diagram of the welding structure of the lower tube head and the lower tube plate in one embodiment of the present application;

[0021] Figure 5 This is a schematic diagram of the structure of a heat exchanger in one embodiment of the present application;

[0022] Icons: 1. Upper tube sheet; 2. Lower tube sheet; 3. Convex ring; 4. Heat exchange tube; 5. Upper tube head; 6. Lower tube head; 7. Positioning groove; 8. Annular groove; 9. Upper tube box; 10. Shell; 11. Lower tube box; 12. Tube side inlet; 13. Tube side outlet; 14. Shell side inlet; 15. Shell side outlet. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

[0024] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0025] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two (including two), unless otherwise clearly and specifically defined.

[0026] In the description of the embodiments of the present application, the term "and / or" is only a description of the association relationship of the associated objects, indicating that there may be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0027] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the embodiments of the present application.

[0028] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the internal connection of two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0029] See also Figure 2-Figure 4 In a first aspect, an embodiment of the present application provides a welding structure of a heat exchange tube 4 and a tube sheet, wherein the tube sheet comprises an upper tube sheet 1 and a lower tube sheet 2, a convex ring 3 is provided on the bottom surface of the upper tube sheet 1 at a position corresponding to the tube sheet hole, the convex ring 3 is welded to an upper tube head 5 of the heat exchange tube 4, and a lower tube head 6 of the heat exchange tube 4 is welded to the lower tube sheet 2.

[0030] In the technical solution provided in the present application, a convex ring 3 is arranged on the bottom surface of the upper tube plate 1 at a position corresponding to the tube plate hole and welded to the upper tube head 5. There is no need to insert the upper tube head 5 into the tube plate hole, and no liquid will accumulate at the welding point between the upper tube head 5 and the upper tube plate 1, thereby avoiding direct contact between the tube medium and the welding part, thereby avoiding the occurrence of crevice corrosion at the welding point, improving the sealing of the welding between the upper tube head 5 and the upper tube plate 1, and solving the problem that crevice corrosion is prone to occur at the welding point between the upper tube head 5 and the upper tube plate 1, resulting in medium leakage.

[0031] like Figure 1 As shown, the heat exchange tubes and tube sheets of the traditional heat exchanger need to be expanded, and then the tube heads extending out of the tube sheets are welded to the tube sheets by fillet welds. The welding of the convex ring and the upper tube head in the present application belongs to a butt welding structure, which has better stress resistance, better load-bearing capacity and stronger welding than fillet welds.

[0032] Please continue reading Figure 2 , Figure 3 In some embodiments, an annular positioning groove 7 is provided on the end face of the convex ring 3, and the inner diameter of the positioning groove 7 matches the outer diameter of the upper tube head 5 of the heat exchange tube 4; by providing the annular positioning groove 7 on the end face of the convex ring 3 for alignment during welding of the upper tube head 5, the welding efficiency and welding consistency of the upper tube head 5 are improved.

[0033] In some embodiments, the convex ring 3 and the upper tube plate 1 are an integrally formed structure, and the convex ring 3 has strong structural stability and a long service life.

[0034] Please continue reading Figure 2 In some embodiments, the outer wall of the convex ring 3 is connected to the bottom surface of the upper tube plate 1 by an arc transition, which can further enhance the structural stability of the convex ring 3 and improve the service life of the convex ring 3.

[0035] Please continue reading Figure 4 In some embodiments, an annular groove 8 is provided on the inner wall of the tube sheet hole of the lower tube sheet 2, and the side wall of the lower tube head 6 of the heat exchange tube 4 is expanded with the annular groove 8. The lower tube head 6 and the annular groove 8 on the inner wall of the tube sheet hole of the lower tube sheet 2 are connected by expansion, which can effectively prevent the medium in the shell from seeping through the gap between the outer wall of the lower tube head 6 and the inner wall of the tube sheet hole, thereby playing a role of anti-leakage insurance.

[0036] Please continue reading Figure 4 In a specific embodiment, two annular grooves 8 are provided, and the two annular grooves 8 are arranged axially spaced apart along the tube sheet hole of the lower tube sheet 2. The two annular grooves 8 can both play a role in preventing leakage, thereby further improving the sealing performance of the heat exchanger.

[0037] Please continue reading Figure 4In some embodiments, the lower tube head 6 of the heat exchange tube 4 extends out of the bottom surface of the lower tube plate 2, and the outer wall of the lower tube head 6 extending out of the bottom surface of the lower tube plate 2 is welded to the bottom surface of the lower tube plate 2. By passing the lower tube head 6 through the outer wall of the bottom surface of the lower tube plate 2 and welding it to the bottom surface of the lower tube plate 2, the sealing performance of the heat exchanger can be further improved to prevent medium leakage.

[0038] See also Figure 5 A second aspect of an embodiment of the present application provides a heat exchanger, comprising an upper tube box 9, an upper tube sheet 1, a shell 10, a lower tube sheet 2 and a lower tube box 11 connected in sequence from top to bottom, wherein a plurality of heat exchange tubes 4 are arranged inside the shell 10; a tube side inlet 12 is arranged at the top of the upper tube box 9, and a tube side outlet 13 is arranged at the bottom of the lower tube box 11; a shell side inlet 14 and a shell side outlet 15 are arranged on the side of the shell 10; the heat exchange tubes 4 are welded to the upper tube sheet 1 and the lower tube sheet 2 using the above-mentioned welding structure.

[0039] The installation method of the heat exchange tube 4 in this embodiment is as follows:

[0040] First, insert the lower tube head 6 of the heat exchange tube 4 into the tube sheet hole of the lower tube sheet 2 so that the lower tube head 6 extends out of the lower tube sheet 2 by a certain distance. Then, align the upper tube head 5 of the heat exchange tube 4 and insert it into the positioning groove 7 on the corresponding convex ring 3 on the bottom surface of the upper tube sheet 1. Weld the upper tube head 5 and the convex ring 3 firmly. Then, use the tube expander to expand the lower tube head 6 and the tube sheet hole of the lower tube sheet 2. Finally, weld the outer wall of the lower tube head 6 extending out of the lower tube sheet 2 firmly to the bottom surface of the lower tube sheet 2.

[0041] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no contradiction or conflict, the various technical features mentioned in the embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A welding structure of a heat exchange tube and a tube sheet, wherein the tube sheet comprises an upper tube sheet (1) and a lower tube sheet (2), characterized in that: A convex ring (3) is provided on the bottom surface of the upper tube plate (1) at a position corresponding to the tube plate hole; the convex ring (3) is welded to the upper tube head (5) of the heat exchange tube (4); and the lower tube head (6) of the heat exchange tube (4) is welded to the lower tube plate (2).

2. A heat exchange tube and tube sheet welding structure according to claim 1, characterized in that: An annular positioning groove (7) is provided on the end surface of the convex ring (3), and the inner diameter of the positioning groove (7) matches the outer diameter of the tube head (5) on the heat exchange tube (4).

3. The welding structure of heat exchange tube and tube sheet according to claim 1, characterized in that: The convex ring (3) and the upper tube plate (1) are an integrally formed structure.

4. The welding structure of heat exchange tube and tube sheet according to claim 1, characterized in that: The outer wall of the convex ring (3) is connected to the bottom surface of the upper tube plate (1) in a circular arc transition.

5. The welding structure of heat exchange tube and tube sheet according to claim 1, characterized in that: An annular groove (8) is provided on the inner wall of the tube plate hole of the lower tube plate (2), and the side wall of the lower tube head (6) of the heat exchange tube (4) is expansion-connected to the annular groove (8).

6. A heat exchange tube and tube sheet welding structure according to claim 5, characterized in that: A plurality of the annular grooves (8) are provided, and the plurality of the annular grooves (8) are arranged at intervals along the axial direction of the tube plate hole of the lower tube plate (2).

7. The welding structure of heat exchange tube and tube sheet according to claim 1, characterized in that: The lower tube head (6) of the heat exchange tube (4) protrudes from the bottom surface of the lower tube plate (2), and the outer wall of the lower tube head (6) that protrudes from the bottom surface of the lower tube plate (2) is welded to the bottom surface of the lower tube plate (2).

8. A heat exchanger, comprising an upper tube box (9), an upper tube sheet (1), a shell (10), a lower tube sheet (2) and a lower tube box (11) connected in sequence from top to bottom, wherein a plurality of heat exchange tubes (4) are arranged inside the shell (10); a tube side inlet (12) is arranged at the top of the upper tube box (9), and a tube side outlet (13) is arranged at the bottom of the lower tube box (11); a shell side inlet (14) and a shell side outlet (15) are arranged on the side of the shell (10); characterized in that: The heat exchange tube (4) is welded to the upper tube plate (1) and the lower tube plate (2) using the welding structure described in any one of claims 1 to 7.

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