Shell and tube heat exchanger with nichrome medium tube stack

Abstract

The utility model provides a shell and tube heat exchanger with a nichrome medium tube stack, which comprises a shell, and an internal component is arranged in the shell and is in welded connection with the shell; a medium pipe group and a baffle plate; the baffle plate comprises abutting ends located on the upper end face and the lower end face of the baffle plate, and when the baffle plate is in a non-welding state, a third brazing filler metal filling layer is arranged between the abutting ends and the shell. The baffle plate further comprises at least one set of baffle plate vertical faces, and when the baffle plate is in a non-welding state, first brazing filler metal filling layers are arranged between the baffle plate vertical faces and the shell. The first brazing filler metal filling layers and the third brazing filler metal filling layers are additionally arranged on the two side end faces, the upper end face and the lower end face of the baffle plate, so that after the baffle plate is placed in a brazing furnace to be welded, the baffle plate and the shell are tightly attached through the first brazing filler metal filling layers and the third brazing filler metal filling layers, sealing connection is formed, and gaps do not need to be reserved; and a circulating medium is prevented from flowing out from a gap between the shell plate and the baffle plate.

Description

Technical Field

[0001] This utility model belongs to the field of heat exchanger manufacturing technology, and specifically relates to a shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly. Background Technology

[0002] A heat exchanger includes a tube sheet, tube bundle, shell, baffles, inlet shroud, and outlet shroud. Baffles are installed inside the heat exchanger shell to increase the flow path. Traditionally, both the shell and baffles are made of non-metallic materials.

[0003] When assembling using the traditional method, the tube sheet and short connecting pipes are first flame-brazed. After this part is welded, it is then welded to the straight pipes and U-joints. Next, the baffles are installed onto the straight pipes to form a single unit. Finally, the entire unit is installed into the shell to complete the heat exchanger assembly. Because the baffles and shell are assembled using an insert method, a certain installation gap exists between them for ease of assembly. During operation, the external circulating medium flows out through the gap between the shell and the baffles, resulting in a certain loss of exchange energy.

[0004] Furthermore, when assembling heat exchangers using traditional methods, the inability to weld the entire heat exchanger results in the need for multi-point welding, which makes the heat exchanger prone to leakage and also presents drawbacks such as greater difficulty and longer processing time. Utility Model Content

[0005] In view of the problems existing in the background art, the present invention provides a shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly, including a shell,

[0006] The internal components are welded using a brazing furnace for integral welding and are housed within the housing, and are welded together.

[0007] Medium tube assembly;

[0008] Baffles through which the medium tube assembly passes;

[0009] The medium tubes of the medium tube assembly pass through the baffle plate and extend into the collector shroud, so that the medium tube assembly is connected to the collector shroud;

[0010] Tube sheet welded to the flow collector;

[0011] The baffle plate includes abutting ends located on its upper and lower end faces.

[0012] When in an unwelded state, a third solder filling layer is provided between the contact end and the housing;

[0013] The baffle plate also includes at least one set of baffle plate facades.

[0014] When in the unwelded state, a first brazing filler layer is provided between the baffle plate and the housing. Optionally, when in the welded state, a third brazing filler layer ensures that the baffle plate and the housing are tightly bonded, forming a sealed connection.

[0015] Optionally, the baffle facades of two adjacent sets of baffles are staggered.

[0016] When in the welding state, the first brazing filler layer makes the two end faces of the baffle plate fit tightly against the shell, forming a sealed connection.

[0017] Optionally, the baffle plate has at least one set of through holes.

[0018] The medium tube of the medium tube assembly is disposed inside the through hole.

[0019] The dielectric tube is a nickel-chromium alloy dielectric tube with a diameter of 3mm-8mm.

[0020] There is a certain gap of 0.1mm-0.2mm between the medium tube and the through hole, and the gap is filled with brazing filler metal.

[0021] Optionally, the media tube assembly includes at least one set of media tubes.

[0022] The diameter of a single medium tube in the medium tube assembly is 3-7 mm;

[0023] The medium tube includes a straight end and a U-shaped end.

[0024] Optionally, a recessed discharge chute is provided on the tube sheet.

[0025] Medium tube solder is provided on the end of the straight pipe located in the sunken discharge trough;

[0026] At least one set of troughs is also provided on the end of the straight pipe located at the position of the sunken discharge trough.

[0027] Optionally, a recessed groove is provided at the junction of the flow collector and the tube sheet, away from the location of the recessed discharge chute.

[0028] The sinking trough is filled with solder, and the flow collector and the tube sheet are connected by the solder placed in the sinking trough.

[0029] In summary, the beneficial effects of this utility model are:

[0030] (1) This utility model makes the product safe and reliable by integrating multiple components, which can reduce the labor intensity of workers, is easy to operate, does not require professional personnel, thereby reducing labor costs and greatly improving work efficiency. At the same time, by reducing the types of welding (argon welding, flame brazing and other welding methods), the production cost is reduced.

[0031] (2) By adding a first brazing filler layer and a third brazing filler layer to the two side end faces and the upper and lower end face faces of the baffle plate, the baffle plate and the shell are tightly attached to each other through the first brazing filler layer and the third brazing filler layer after the baffle plate is placed in the brazing furnace and welded, forming a sealed connection without leaving any gaps; thus preventing the circulating medium from flowing out from the gap between the shell plate and the baffle plate. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of the overall structure of an embodiment of a shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly according to this utility model.

[0033] Figure 2 This is a two-dimensional diagram of an embodiment of a shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly according to this utility model;

[0034] Figure 3 This is a three-dimensional view of a shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly according to this utility model.

[0035] Figure 4 This is an enlarged view of the structure at position B of an embodiment of a shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly according to this utility model;

[0036] Figure 5 This is a two-dimensional structural diagram of a shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly according to an embodiment of the present invention.

[0037] Figure 6 This is an enlarged view of the structure at the connection point between the intermediate manifold and the medium tube assembly in an embodiment of a shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly according to this utility model.

[0038] Figure 7 Exploded view of an embodiment of a shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly according to this utility model;

[0039] Figure 8 This utility model Figure 7 Enlarged view of the middle section structure;

[0040] Figure 9 This utility model discloses an embodiment of a shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly, showing a partial enlarged view of the structure at the assembly position of the baffle and the shell.

[0041] Figure label:

[0042] 100. Heat exchanger;

[0043] 10. Shell;

[0044] 20. Flow collector fairing; 201. First flow collector fairing; 202. Intermediate flow collector fairing; 203. Second flow collector fairing;

[0045] 30. Baffle plate; 301. Baffle plate facade; 302. Through hole; 303. Abutting end; 304. Third brazing filler layer;

[0046] 40. Medium tube assembly; 401. Straight tube end; 4011. Medium tube solder; 402. U-shaped end;

[0047] 50. Tube sheet; 501. Sinking groove; 502. Brazing filler layer A; 503. Sinking discharge groove;

[0048] 60. First brazing filler layer;

[0049] 70. Second weld layer;

[0050] 80. Second brazing filler layer. Detailed Implementation

[0051] This application document is mainly used for heat exchange of fluid media.

[0052] To solve the above technical problems, such as Figure 1-9 As shown, this embodiment provides a shell-and-tube heat exchanger 100 with a nickel-chromium alloy medium tube assembly, including a shell 10 and internal components welded by an integral welding process using a brazing furnace, which are disposed inside the shell 10.

[0053] The internal components include a dielectric tube assembly 40 disposed within the housing 10 for energy exchange.

[0054] The housing 10 is provided with a baffle plate 30 through which the medium tube assembly 40 passes. The medium tube assembly 40 and the baffle plate 30 are fitted with a clearance and are connected by brazing filler metal.

[0055] The medium tubes of the medium tube assembly 40 pass through the baffle plate 30 and extend into the collector shroud 20, so that the medium tube assembly 40 is connected to the collector shroud 20.

[0056] The tube sheet 50 is welded to the manifold 20, and the medium tube group 40 is welded to the tube sheet 50 to form an internal component. The manifold 20 of the internal component is assembled and welded to the shell through the tube sheet 50 to form a heat exchanger 100.

[0057] Furthermore, the internal components are assembled into the shell and placed in a brazing furnace for welding to form the heat exchanger 100 as a whole. The brazing furnace can be a vacuum furnace, a continuous tunnel furnace, or other welding furnaces that can realize the integrated welding scheme of this application. The shell 10, baffle 30, flow collector 20, and tube sheet 50 of the heat exchanger 100 are made of stainless steel, or can be made of carbon steel, copper, or aluminum.

[0058] Furthermore, the baffle plate 30 includes abutting ends 303 located on its upper and lower end faces. The abutting ends 303 include a transverse end and an arc-shaped end, and the transverse end extends continuously toward the arc-shaped end and intersects with the arc-shaped end to form an included angle α, which is 35°-175°.

[0059] When in the unwelded state, a third brazing filler layer 304 is provided between the contact end 303 and the housing 10. When in the welded state, the third brazing filler layer 304 makes the baffle 30 and the housing 10 fit tightly together to form a sealed connection, thereby preventing the medium from flowing out from the gap between the baffle 30 and the housing 10.

[0060] The baffle plate 30 further includes at least one set of baffle plate facades 301, and the baffle plate facades 301 of two adjacent sets of baffle plates 30 are staggered. When in the unwelded state, a first brazing filler layer 60 is provided between the baffle plate facade 301 and the shell 10. The first brazing filler layer 60 is located at the contact point of the shell 10. When in the welded state (that is, the assembled heat exchanger is placed into the brazing chamber for welding), the first brazing filler layer 60 makes the two end faces of the baffle plate 30 fit tightly against the shell, forming a sealed connection.

[0061] In this embodiment, by adding a first brazing filler layer and a third brazing filler layer 304 to both sides and the top and bottom ends of the baffle plate 30, after it is placed in the brazing furnace for welding, the baffle plate 30 and the shell 10 are tightly attached through the first brazing filler layer and the third brazing filler layer 304, forming a sealed connection without leaving any gaps; thus preventing the circulating medium from flowing out from the gap between the shell plate and the baffle plate.

[0062] Furthermore, the baffle plate 30 has multiple sets of through holes 302, and the medium tube of the medium tube group 40 is arranged in the through holes 302. The medium tube is a nickel-chromium alloy medium tube with a diameter of 3mm-8mm, and there is a certain gap of 0.1mm-0.2mm between the medium tube and the through hole 302. The gap is filled with brazing filler metal. By filling the gap with brazing filler metal, the sealing performance is improved, thereby preventing the external circulating medium from flowing out from the gap between the straight pipe and the through hole of the baffle plate. This ensures that the external circulating medium flows completely along the designated route, reducing pressure loss and energy exchange differences.

[0063] In this embodiment, the leakage of the external circulating medium from the gap between the straight pipe and the through hole of the baffle is prevented, so that the external circulating medium flows completely along the designated route. This reduces pressure loss and energy exchange differences, while also meeting the requirements of nickel-chromium alloy medium pipes with diameters of 3mm-8mm, thereby greatly improving practicality.

[0064] Furthermore, the flow collector 20 includes a first flow collector 201, an intermediate flow collector 202, and a third flow collector 203.

[0065] Furthermore, the dielectric tube assembly 40 employs at least one set of dielectric tubes, and the dielectric tube assembly 40 is made of a nickel-chromium alloy material. The nickel-chromium alloy material is preferably martensitic, austenitic, ferritic, or duplex stainless steel, and more preferably 303, 304, 316, or 317 austenitic stainless steel.

[0066] In this embodiment, the heat exchanger using a nickel-chromium alloy medium tube assembly can achieve the required heat exchange performance and greatly extend the overall service life. It also reduces the risk of leakage during later cleaning and maintenance. Furthermore, the product is welded using an integrated welding process in a brazing furnace, making it safe and reliable. This reduces the labor intensity of workers, simplifies operation, eliminates the need for professional personnel, thereby reducing labor costs and significantly improving work efficiency. At the same time, by reducing the types of welding (argon welding, flame brazing, etc.), production costs are reduced.

[0067] Traditional heat exchanger tube assemblies consist of short tubes, straight tubes, and U-joints. During assembly, the U-joints need to be inserted into the tube sheet for mechanical expansion or connected using flame brazing. However, due to the reduction in the diameter of the medium tubes and the increase in the number of medium tubes, expansion connections are no longer feasible. If flame brazing is used, since the internal structure of the heat exchanger is mostly U-shaped loops, multiple points of welding are required between the U-joints and the short and straight tubes. Welding must be done row by row from top to bottom. When welding the first row, residual flame heat is generated during the welding of the second row. Due to the large tube spacing, this residual heat can affect the welding of the first row, creating leak points. Therefore, highly skilled personnel are required for professional welding, resulting in extremely high production costs, and even then, leaks cannot be completely eliminated. This invention aims to solve the above-mentioned technical problems. Please refer to [link to relevant documentation]. Figure 1-9 As shown,

[0068] The flow collector 20 includes a first flow collector 201, an intermediate flow collector 202, and a second flow collector 203. The medium tube group 40 includes at least one set of medium tubes. The diameter of a single medium tube in the medium tube group 40 is 3-7 mm, preferably 5 mm. The heat exchange performance of the heat exchanger is 11-12 kW per square meter.

[0069] Both the first manifold 201 and the third manifold 203 are provided with a medium port. The medium pipe connected to the first manifold 201 is connected to another set of medium pipes adjacent to it through the second manifold 202, and is connected to the third manifold 203 through the other set of medium pipes adjacent to it, forming a loop pipeline.

[0070] Furthermore, the medium tube includes a straight end 401 and a U-shaped end 402.

[0071] In this embodiment, those skilled in the art should understand that traditional heat exchangers using U-shaped joints in the range extender require multi-point welding during connection, resulting in multiple weld points at the tube sheet and U-shaped joint. This makes installation cumbersome, requires highly skilled personnel for professional welding, and leads to extremely high production costs. Even then, leaks cannot be completely avoided. Therefore, this invention replaces the traditional U-shaped joint in the range extender by adding an intermediate manifold 202. This simplifies installation, and during integrated welding in the brazing furnace, all weld points are concentrated on the tube sheet, reducing the number of weld points and significantly lowering the probability of leaks.

[0072] Furthermore, a recessed discharge trough 503 is provided on the tube sheet 50, and a medium tube solder 4011 is provided on the straight tube end 401 located in the recessed discharge trough 503;

[0073] By opening a recessed discharge trough 503 on the tube sheet 50, the solder can be fixed, so that the medium tube of the medium tube assembly and the recessed discharge trough are in close contact. At the same time, when in the welding state, it can be ensured that the liquid solder flows along the designated path and does not flow erratically.

[0074] Furthermore, in practical applications, the depth of the sunken discharge trough 503 can be set according to the value of the medium tube solder 4011, for example:

[0075] If the inner diameter of the solder is 4.9mm and the wire diameter is 0.8mm, then the depth of the sunken discharge trough 503 is 2mm.

[0076] In this embodiment, those skilled in the art should understand that during welding, all solder softens and expands during heating, causing a change in its morphology. Due to the small distance and high density of adjacent medium tube groups, solder easily flows onto adjacent medium tube groups, resulting in less solder on those groups and potential leakage. To address this problem, the present invention provides a recessed discharge trough 503 on the tube sheet 50 to fix the solder, ensuring a tight connection between the medium tube groups and the recessed discharge trough. Furthermore, during welding, this ensures that the liquid solder flows along a designated path without turbulence.

[0077] Furthermore, multiple sets of troughs are provided on the end 401 of the straight pipe located at the position of the sunken material discharge trough 503, and the troughs extend continuously along the longitudinal direction of the straight pipe. By opening the troughs, the liquid solder can be guided when the welding state is in progress.

[0078] Furthermore, a sinking groove is provided at the junction of the flow collector (first flow collector, intermediate flow collector and second flow collector) and the tube sheet 50 at a position away from the sinking discharge trough 503, and the sinking groove is filled with solder. The flow collector and the tube sheet are connected by the solder set in the sinking groove.

[0079] In this embodiment, the present invention adopts an external furnace assembly method. During the assembly process, the welding parts are filled (filled or attached) with brazing flux. The workpieces are connected by spot welding or gap control during the assembly process (no welding operation is performed during assembly). This reduces the time consumed by welding and lowers the processing cost caused by welding. After the assembly is completed, the high-temperature brazing filler metal is melted in the furnace, so that the brazing filler metal has been absorbed (wetting the weld) and slowly fills the gap, realizing the connection between the components, meeting the welding requirements, and satisfying the product design requirements.

[0080] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. Although exemplary embodiments are disclosed in the drawings, it should be understood that the present utility model can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to facilitate a more thorough understanding of the present utility model and to fully convey the concept of the present utility model to those skilled in the art.

[0081] In the description of this specification, the references to terms such as "certain embodiments," "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in a suitable manner in any one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0082] In this utility model, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise explicitly defined. The terms "install," "connect," "join," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "join" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0083] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and are not restrictive. Although this utility model has been described in detail with reference to the embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solution of this utility model do not depart from the spirit and scope of the technical solution of this utility model, and all such modifications or substitutions should be covered within the scope of the claims of this utility model.

Claims

1. A shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly, characterized in that, Including the casing, Internal components, welded using a brazing furnace for integral welding, are assembled inside the housing and connected by welding. Medium tube assembly; Baffles through which the medium tube assembly passes; The medium tubes of the medium tube assembly pass through the baffle plate and extend into the collector shroud, so that the medium tube assembly is connected to the collector shroud; Tube sheet welded to the flow collector; The baffle plate includes abutting ends located on its upper and lower end faces. When in an unwelded state, a third solder filling layer is provided between the contact end and the housing; The baffle plate also includes at least one set of baffle plate facades. When in an unwelded state, a first brazing filler layer is provided between the baffle plate facade and the shell.

2. A shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly according to claim 1, characterized in that, When in the welding state, the baffle plate is tightly attached to the shell through the third brazing filler layer, forming a sealed connection.

3. A shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly according to claim 2, characterized in that, The baffle facades of two adjacent sets of baffles are staggered. When in the welding state, the first brazing filler layer makes the two end faces of the baffle plate fit tightly against the shell, forming a sealed connection.

4. A shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly according to claim 3, characterized in that, The baffle plate has at least one set of through holes. The medium tube of the medium tube assembly is disposed inside the through hole. The dielectric tube is a nickel-chromium alloy dielectric tube with a diameter of 3mm-8mm. There is a certain gap of 0.1mm-0.2mm between the medium tube and the through hole, and the gap is filled with brazing filler metal.

5. A shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly according to claim 1, characterized in that, The media tube assembly includes at least one set of media tubes. The diameter of a single medium tube in the medium tube assembly is 3-7 mm; The medium tube includes a straight end and a U-shaped end.

6. A shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly according to claim 5, characterized in that, The tube sheet is provided with a sunken discharge chute. Medium tube solder is provided on the end of the straight pipe located in the sunken discharge trough; At least one set of troughs is also provided on the end of the straight pipe located at the position of the sunken discharge trough.

7. A shell-and-tube heat exchanger with a nickel-chromium alloy medium tube assembly according to claim 6, characterized in that, A recessed groove is provided at the junction of the flow collector and the tube sheet, away from the location of the recessed discharge chute. The sinking trough is filled with solder, and the flow collector and the tube sheet are connected by the solder placed in the sinking trough.

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