Methods for manufacturing a heat exchanger and heat exchangers
Patent Information
- Authority / Receiving Office
- DE · DE
- Patent Type
- Patents
- Current Assignee / Owner
- AUDI AG
- Filing Date
- 2019-12-09
- Publication Date
- 2026-07-23
AI Technical Summary
The production of microchannel heat exchangers is associated with high manufacturing and component costs due to complex assembly processes.
A method involving a stacked tube arrangement with frames and adhesive bonding, using plastic extrusion and cutting to form layers, followed by adhesive connection and sealing to create a rigid and efficient heat exchanger structure.
Reduces manufacturing effort and component costs while maintaining structural integrity and efficiency in heat transfer.
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Abstract
Description
[0001] The invention relates to a method for manufacturing a heat exchanger according to the preamble of claim 1 and a heat exchanger according to claim 10.
[0002] In vehicle construction, a heat exchanger positioned at the front of the vehicle, functioning as a radiator, is one example. Airflow from the vehicle is allowed to pass through it, thus cooling the refrigerant flowing through the heat exchanger. Alternatively, other applications are conceivable, such as its use as an auxiliary water cooler or as a low-temperature cooler.
[0003] A heat exchanger of this type comprises a tube arrangement with a plurality of heat exchanger tubes arranged parallel to and spaced apart from one another. These extend longitudinally between two manifold housings. Each manifold housing has a tube sheet with pipe passages through which the heat exchanger tubes are fluidically connected to a distribution chamber within the manifold housing.
[0004] For efficient heat transfer, the heat exchanger can be implemented as a microchannel heat exchanger, which, for example, can consist of at least 10,000 heat exchanger tubes. Manufacturing such a microchannel heat exchanger involves significant production effort and high component / unit costs.
[0005] A heat exchanger in a refrigerator and / or freezer is known from DE 10 2011 100 192 A1. A heat transfer device with oscillating flows in counterflow mode is known from DE 103 36 066 A1. A microchannel heat exchanger is known from DE 11 2013 004 284 T2.
[0006] The object of the invention is to provide a method for manufacturing a heat exchanger in which, compared to the prior art, the manufacturing effort and the component effort in the manufacture are reduced.
[0007] The problem is solved by the features of claim 1 or claim 10. Preferred embodiments of the invention are disclosed in the dependent claims.
[0008] According to the characterizing part of claim 1, the heat exchanger tube arrangement is formed as a stacked package in a laying process. In the laying process, a plurality of tube layers are stacked one above the other in a stacking direction. Each of these tube layers has a plurality of heat exchanger tubes that are axially parallel in a tube layer plane. These are arranged side by side at a defined distance in a stack transverse direction oriented perpendicular to the stacking direction.
[0009] In a process-oriented preferred embodiment, continuous tubes are produced using plastic extrusion injection molding. The continuous tubes are wound onto reels. In a unwinding process, the continuous tubes are unwound and subsequently cut to the desired heat exchanger tube length in a cutting process. The laying process according to the invention can then be carried out, in which a plurality of heat exchanger tubes are mechanically grouped into a tube layer and then the respective tube layer is stacked using a suitable handling device.
[0010] Sufficient component rigidity of the stack and correct positioning of the heat exchanger tubes within the stack are crucial for the heat exchanger's functionality. Therefore, the tube stack features an outer heat exchanger frame on each side in the stacking direction, as well as intermediate heat exchanger middle frames. The outer and middle frames can be largely identical in design, incorporating longitudinal and transverse braces. The longitudinal braces extend along both sides of the stack's outer longitudinal edges. The transverse braces extend along both sides of the stack's outer transverse edges. Additionally, the outer and middle frames may include further intermediate transverse braces connecting the two longitudinal braces.
[0011] With regard to a reliable laying process, it is preferred if the middle and / or outer frames each have guide grooves into which the heat exchanger tubes can be placed in a positionally accurate manner during the laying process.
[0012] Against this background, the laying process can be carried out as follows: First, an initial, unassembled outer frame of the heat exchanger is prepared. A first layer of tubes is placed on this frame. During the subsequent laying process, the intermediate frames are laid down, each with an intermediate layer of tubes. At the end of the laying process, the second outer frame of the heat exchanger is laid down, completing the tube stack. After each laying operation, the joining surfaces of the outer and intermediate frames and / or the heat exchanger tubes can be coated with adhesive to achieve a strong bond between the heat exchanger components.
[0013] With a view to a structurally simple and rigid design of the heat exchanger, it is preferred if the respective tube sheet of the distributor housing is built directly from the cross members of the outer and central frames. In this case, the cross members can be aligned with each other at the joining surfaces in the stacking direction, forming a closed tube sheet.
[0014] Similarly, the longitudinal struts of the outer and middle frames can also be aligned with each other at the joining surfaces in the stacking direction, thus forming a closed-surface heat exchanger side wall in the completed tube stack, which seals the respective narrow side of the heat exchanger in a flow-tight manner. The heat exchanger side wall forms a side plate that ensures the stability of the heat exchanger.
[0015] To further increase the component stiffness of the heat exchanger, it is preferred that the respective tube sheet be constructed as a double wall with an outer and an inner tube sheet. The outer and inner tube sheets define a potting compound chamber between them in the longitudinal direction of the tubes, which can be filled with a potting compound during the subsequent process to ensure a proper connection of the heat exchanger tubes to the tube sheet.
[0016] A simple design for the potting compound chamber is crucial for the mass production of the heat exchanger. Therefore, each of the cross members of the outer and central frames can preferably be designed as a double strut. The double strut comprises an outer and an inner section. In the assembled tube stack, all inner sections can form the inner tube sheet, while all outer sections form the outer tube sheet. To ensure a liquid-tight design of the potting compound chamber, the double strut on the outer frame can additionally have a side chamber wall connecting the inner and outer sections.
[0017] After the laying process, the heat exchanger tubes can extend beyond the cross braces of the outer and central frames in the longitudinal direction. This tube protrusion can be removed from the heat exchanger tubes in a machining step (for example, by milling). This ensures that the tube openings are flush with the outer surface of the tube sheet. During the machining step, a circumferential sealing groove can also be machined into the outer surface of the tube sheet. A housing cover of the manifold housing, with its rim, can then be placed onto this groove using a sealing element. The housing cover can be attached to the respective tube sheet using a suitable joining method (for example, crimping).
[0018] It should be emphasized that in the process sequence, the potting compound is first introduced into the potting compound chamber. Only then does the machining step (i.e., milling step) take place.
[0019] In order to provide access to the potting compound chamber in a structurally simple manner, it is preferred if a potting compound access opening is formed directly in the outer frame of the heat exchanger.
[0020] An embodiment of the invention is described below with reference to the accompanying figures.
[0021] They show: Fig. 1. A view of a heat exchanger in its assembled state; Fig. 2. A partial side view of the heat exchanger with partial elevation; and Fig. 3 to Fig. 10 views each, illustrating an assembly process.
[0022] In the Fig. Figure 1 shows an assembled heat exchanger consisting of a plurality of heat exchanger tubes arranged parallel to and spaced apart from each other. 1 is constructed. The heat exchanger tubes 1 They are permeated with coolant and implemented as microchannels. Furthermore, the heat exchanger tubes extend... 1 in a pipe longitudinal direction x between two distribution housings 3 The two distribution boxes 3 Each has a connection port. 7 on, via which the heat exchanger can be integrated into a coolant circuit not shown. In the Fig. 1. The heat exchanger has closed heat exchanger side walls on its upper and lower narrow sides. 9 on, which the two distribution boxes 3 connect them.
[0023] As from the Fig. 1 or Fig. As further shown in section 2, each of the distribution housings 3 with a tube sheet11 trained, on which the heat exchanger tubes 1 are connected. Fig. 1. The heat exchanger also has a total of five intermediate shelves. 17 on, spaced apart from each other between the two distribution boxes 3 are arranged and through which the heat exchanger tubes run 1 extend.
[0024] As from the Fig. 2 further reveals the tube sheet 11 of the respective distribution housing 3 double-walled with an inner tubular base 19 and an outer pipe floor 21 constructed, with a potting compound chamber in between in the longitudinal direction of the pipe x 23 limited. By the potting compound chamber 23 are the heat exchanger pipes 1 guided. The potting compound chamber 23 is in the Fig. 2 with a potting compound 25 filled, which filled the heat exchanger tubes 1rigid and liquid-tight connection at the pipe base 11 are connected.
[0025] The following will be based on the Fig. 3 to Fig. 10 process steps for the production of the in the Fig. 1 and Fig. The heat exchanger shown in section 2 is described. In the manufacturing process, continuous plastic tubes are supplied wound onto reels. The reels are unwound and cut to the required length of the heat exchanger tubes at a cutting station. 1 Cut to length. The cut heat exchanger tubes 1 become pipe layers 29 In summary, each of the pipe layers 29 features a large number of heat exchanger tubes 1 on, which are in a pipe layer plane R ( Fig. 10) are arranged parallel to each other and at a defined equal distance from each other.
[0026] This is followed by a laying process ( Fig. 3), in which initially a first, still unequipped heat exchanger outer frame 27 is provided. On the first, still unpopulated heat exchanger frame. 27 A first layer of pipes is placed in a stacking direction y. 29 placed. In the further course of the laying process, a number of medium frames are used. 30 each with an intermediate layer of pipes 29 deposited. At the end of the laying process, a second heat exchanger outer frame is added. 31 upon completion of a pipe stack package 33 ( Fig. 3 or Fig. 4) filed.
[0027] During the laying process, after each laying operation, the joining surfaces of the outer and middle frames are cleaned. 27 , 30 , 31 as well as the heat exchanger pipes 1 an adhesive 35 (only in the Fig. 10 (indicated with a dashed line) applied.
[0028] As from the Fig. 3, Fig. 7 and Fig. As can be seen in section 9, the outer and middle frames are 27 , 30 , 31 each with guide grooves 37 formed, into which the heat exchanger tubes are inserted during the laying process 1 be placed in the exact position. In the Fig. 6 and Fig. 7 is the outer frame 27 shown in isolation. Therefore, the outer frame 27 from longitudinal struts 39 , from crossbeams 41 as well as from intermediate struts 43 constructed. The longitudinal struts 39 They extend (in the assembled state) in the longitudinal direction x of the tube on both sides along the outer longitudinal edges of the stacked package. The cross braces 41 They extend on both sides in the transverse direction y of the pipe along the outer lateral edges of the stacked bundle. In the Fig. 8 and Fig. 9 is one of the mid-frames 30 Shown in isolation. Analogous to the outer frame. 27 is also the center frame 30from longitudinal struts 39 , cross braces 41 as well as intermediate struts 43 assembled. All longitudinal struts 39 , cross braces 41 and intermediate struts 43 the middle and outer frames 27 , 30 , 31 are arranged in line with each other in the stacking direction z.
[0029] The respective pipe bed 11 of the distribution housing 3 is according to the Fig. 2 directly from the crossbeams 41 the outer and middle frames 27 , 30 , 31 constructed. The crossbeams 41 In the assembled state, they are aligned with each other in the stacking direction z, or bonded together, thus forming a closed-surface tube sheet. 11 This results in the following. Similarly, the heat exchanger side wall... 9 ( Fig. 1 or Fig. 2) directly from the longitudinal struts 39 the outer and middle frames 27 , 30 , 31constructed, which are bonded together in the stacking direction z, forming the closed-surface heat exchanger side wall 9 Similarly, the intermediate struts 43 the outer and middle frames 27 , 30 , 31 in the stack package 33 together in adhesive bond, forming the intermediate floors 17 ( Fig. 1).
[0030] To create the potting compound chamber 23 in the respective pipe bed 11 is each of the crossbeams 41 the outer and middle frames 27 , 30 , 31 as a double strut with an outer partial strut 45 and an inner partial strut 47 realized ( Fig. 3) All outer partial struts 45 are in the completed stack package 33 in adhesive bonding, specifically forming the outer tube base. 21Similarly, all the inner partial struts are also 47 joined together, forming the inner tube base. 19 . On the outer frame 27 , 31 are the inner and outer partial struts 45 , 47 through a lateral chamber wall 49 ( Fig. 3 or Fig. 7) connected to each other to form the potting compound chamber 23 To be sealed liquid-tight to the outside in the stacking direction z. On the outer frame 27 , 31 Each has an access opening for the potting compound. 51 ( Fig. 5, Fig. 7 or Fig. 10) trained to open the casting compound chamber after the laying process 23 with the potting compound 25 to fill.
[0031] In the Fig. 4 is the stack package completed after the laying process 33 shown. Accordingly, the heat exchanger tubes protrude. 1 the pipe floor 11with a pipe overhang 53 In a milling step following the laying process, the pipe protrusion is removed. 53 from the heat exchanger pipes 1 severed, thereby the pipe outlet openings 13 to be flush with the outer surface of the pipe base, as shown in the Fig. Figure 5 is shown. In addition, a circumferential sealing groove is milled during the milling step. 55 ( Fig. 5) incorporated into the outer surface of the tube sheet. In the assembled state, it is located in the circumferential sealing groove. 55 a sealing element 56 ( Fig. 1) inserted, onto which the housing cover 5 forming a density plane D ( Fig. 1) can be placed on its lid edge. The housing lid 5 can be achieved by a suitable joining process, in particular by the one described in the Fig. 2 crimp connections shown 57 on the pipe base 11 to be attached, in which a suggested circumferential metal ring 58in annular grooves on the housing cover 5 and on the pipe base 11 intervenes. Reference symbol list 1 Heat exchanger tubes 3 distribution boxes 5 Housing covers 7 connection spigots 9 heat exchanger side walls 11 Tube sheet 13 pipe outlet openings 15 Distribution chamber 17 intermediate floors 19 Inner tube sheet 21 Outer tube sheet 23 Potting compound chamber 25 potting compound 27 first heat exchanger outer frame 29 pipe layers 30 center frames 31 second heat exchanger outer frame 33 pipe stacking package 35 Adhesive 37 guide grooves 39 longitudinal struts 41 cross braces 43 intermediate struts 45 outer partial strut 47 inner partial strut 49 Chamber wall 51 Potting compound access opening 53 Tube sheet overhang 55 Sealing groove 56 Sealing element 57 Crimp connection 58 metal ring R pipe layer level D sealing plane QUOTES INCLUDED IN THE DESCRIPTION
[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature
[0000] DE 102011100192 A1
[0005] DE 10336066 A1
[0005] DE 112013004284 T2
[0005]
Claims
[1] Method for manufacturing a heat exchanger with a tube arrangement comprising a plurality of heat exchanger tubes (1) aligned parallel to each other and spaced apart from each other, extending in a tube longitudinal direction (x) between two distributor housings (3), each distributor housing (3) having a tube sheet (11) on which the heat exchanger tubes (1) terminate and are fluidically connected to a distributor chamber (15) of the distributor housing (3), characterized by , that the tube arrangement is formed as a stack package (33) in a laying process, and that in the laying process a plurality of tube layers (29) are stacked in a stacking direction (z), each of which has a plurality of heat exchanger tubes (1) parallel in a tube layer plane (R) and equidistant from one another in a stack transverse direction (y) oriented perpendicular to the stacking direction (z). [2] Method according to claim 1, characterized by, that the tube stacking package (33) has heat exchanger outer frames (27, 31) on both sides in the stacking direction (z) and at least one intermediate heat exchanger middle frame (30), and that in particular each frame (27, 30, 31) is constructed of longitudinal struts (39), transverse struts (41) and, if necessary, intermediate struts (43). [3] Method according to claim 2, characterized by , that the frames (27, 30, 31) have guide grooves (37) into which the heat exchanger tubes (1) can be placed in the correct position during the laying process step. [4] Method according to claim 2 or 3, characterized by, that in the laying process a first, still unassembled, heat exchanger outer frame (27) is provided, on which a first layer of tubes (29) is placed, and that in the further course of the laying process the middle frames (30) are placed with an intermediate layer of tubes (29) each, and that at the end of the laying process the second heat exchanger outer frame (31) is placed with completion of the tube stack package (33), and / or that, in particular, during the laying process an adhesive (34) is applied to the joining surfaces of the outer and middle frames (27, 30, 31) and / or the heat exchanger tubes (1). [5] Method according to claim 2, 3 or 4, characterized by, that the tube sheet (11) of the distributor housing (3) is constructed from the cross braces (41) of the outer and middle frames (27, 30, 31), and that in particular the cross braces (41) of the outer and middle frames (27, 30, 31) are in contact with each other in the stacking direction (z), forming the closed-surface tube sheet (11), and that in particular after the laying process the heat exchanger tubes (1) with a tube overhang (53) project beyond the cross braces (41) of the outer and middle frames (27, 30, 31). [6] Method according to claim 5, characterized by, that after the laying process a chipping step takes place in which the pipe protrusion (53) is cut off from the heat exchanger tubes (1) so that the pipe outlet openings (13) are flush with a tube sheet outer surface, and / or that in the chipping step a circumferential sealing groove (55) is incorporated into the outer surface of the tube sheet, into which a sealing element (56) is inserted, onto which a housing cover (5) of the distributor housing (3) can be placed with its cover edge, and / or that the housing cover (5) is attached to the tube sheet (11) by a suitable joining method (57). [7] Method according to one of claims 5 or 6, characterized by , that the longitudinal struts (39) of the outer and middle frames (27, 30, 31) are in contact with each other in the stacking direction (z), forming a closed surface heat exchanger side wall (9). [8] Method according to any one of the preceding claims, characterized by, that the tube sheet (11) is constructed as a double wall with an outer tube sheet (21) and an inner tube sheet (19), which in between define a potting compound chamber (23) in the longitudinal direction (x) of the tube, which can be filled with a potting compound (25) to connect the heat exchanger tubes (1) to the tube sheet (11) and to seal the distributor housing (3). [9] Method according to claim 8, characterized by , that for the formation of the potting compound chamber (23) each cross brace (41) of the outer and middle frames (27, 30, 31) is a double brace with an outer partial brace (45) and an inner partial brace (47), and that in the tube stack package (33) all inner partial braces (47) form the inner tube sheet (19) and all outer partial braces (45) form the outer tube sheet (21), and that the double brace (41) formed on the outer frame (27, 31) additionally has a side chamber wall (49) which closes off the potting compound chamber (23) to the outside in the stacking direction (z). [10] Heat exchanger manufactured in a method according to one of the preceding claims, wherein in particular the heat exchanger tubes (1) and the outer and middle frames (27, 30, 31) are made of plastic.