Heat exchanger

Abstract

A heat exchanger (1) made of plastic with at least one fluid collection container (2), wherein this fluid collection container (2) has at least one inlet (3) and / or at least one outlet (4) for a fluid and the fluid collection container (2) is connected in a manner that allows the fluid to flow through it to several heat exchanger elements (5), wherein the heat exchanger (1) has at least one sliding bearing (6) arranged at a distance from the fluid collection container (2) and the heat exchanger elements (5) arranged at a distance from each other are mounted by means of the sliding bearing (6) and are displaceable and / or expandable with respect to length and cross-section relative to the sliding bearing (6), characterized in that at least one spring element (16) is arranged on the fluid collection container (2), by means of which the fluid collection container (2) is mounted on the heat exchanger (1).

Description

[0001] The invention relates to a plastic heat exchanger with at least one fluid collection container. This fluid collection container has at least one inlet and / or at least one outlet for a fluid, and the fluid collection container is connected in an at least permeable manner to a plurality of heat exchanger elements through which the fluid can flow. Furthermore, the heat exchanger has at least one plain bearing arranged at a distance from the fluid collection container. The spaced-apart heat exchanger elements are mounted by means of the plain bearing and are displaceable and / or expandable relative to the plain bearing in a manner that allows for variable length and cross-section.

[0002] A variety of heat exchangers in the form of coolers for heat dissipation have long been known in the automotive industry. These are usually made of a metal, particularly aluminum, due to their good thermal conductivity. The disadvantages of such metal coolers are, on the one hand, their weight, which is due to the material, and, on the other hand, the associated manufacturing costs.

[0003] Aside from automotive engineering, there has also been a move to produce heat exchangers from plastics, with this approach being particularly justified by the chemical resistance of the plastics to the media to be cooled or heated.

[0004] DE 10 2010 011 644 A1 describes a tube bundle heat exchanger for heating or cooling flue gases. The tube bundle is supported at several spaced-apart support points. At each of these support points, several holding elements are arranged, each consisting of two sleeves connected to one another via a spacer plate. Such a sleeve circumferentially encloses an individual tube of the bundle. The spacer plate of the holding element also has an opening or an additional spacer sleeve arranged perpendicular to the spacer plate, each of which serves to arrange the holding element on a support rod connected to a frame. When using holding elements with only one opening, separately designed spacer sleeves are also arranged on the support rod between the holding elements, whereby in both cases the spacer sleeves are intended to space apart several holding elements arranged on the support rod.

[0005] DE 196 06 201 A1 discloses a similarly mounted tube bundle heat exchanger, in which the respective support points along the tube bundle are frameless, however, and the individual tubes of the bundle are merely connected to one another via a corresponding holding element per support point. Such a holding element consists of several shell-shaped sleeves arranged in a matrix-like manner, which are spaced apart from one another via webs. The sleeves therefore do not completely enclose the individual tubes in the circumferential direction and form a clamped connection with them. Rows of the matrix arrangement, each formed from sleeves and webs, are each connected via a web that runs orthogonally to the rows and is offset from row to row both in the longitudinal and transverse directions of the individual tubes, resulting in a virtually self-supporting construction of the support points.

[0006] DE 10 2008 038 663 A1 describes another such tube bundle heat exchanger, in which the spaced-apart support points are designed as support struts arranged in a comb-like manner on a frame via a cross member. These combs are spaced apart and alternately aligned orthogonally to each other, whereby the projection of the combs in the longitudinal direction of the individual tubes results in a lattice structure. Each individual tube of the bundle is enclosed by support struts of a comb and forms contact with them.

[0007] Furthermore, DE 10 2013 215 358 A1 discloses a plastic heat exchanger used to cool the vehicle battery of a hybrid or electric vehicle. The heat exchanger has an inlet and an outlet, which are arranged on a distribution and collection element for the coolant. The fluid flows through at least two multi-chamber tubes arranged between the elements, which have a plurality of fluid channels. This design is considered to be significantly disadvantageous, since the one-piece design of the multi-chamber tubes results in a small surface area. Furthermore, a small surface area is associated with lower heat transfer.

[0008] US 5 657 817 A also discloses a heat exchanger which has two fluid collection containers, with grooved tube blocks extending between them as heat exchange surfaces for the heat transfer medium flowing therein.

[0009] Against this background, the object of the invention is to design the heat exchanger of the type mentioned at the outset in such a way that the cooling capacity of the heat exchanger is increased.

[0010] This object is achieved with a heat exchanger according to the features of patent claim 1. The subclaims relate to particularly expedient developments of the invention.

[0011] According to the invention, a plastic heat exchanger with at least one fluid collection container is provided. This fluid collection container has at least one inlet and / or at least one outlet for a fluid, and the fluid collection container is connected at least permeably to a plurality of heat exchanger elements through which the fluid can flow. Furthermore, the heat exchanger has at least one plain bearing arranged at a distance from the fluid collection container. The spaced-apart heat exchanger elements are mounted by means of the plain bearing and are displaceable and / or expandable relative to the plain bearing in a manner that varies in length and cross-section.

[0012] Due to the poorer thermal conductivity of plastic compared to metals, several heat exchanger elements, i.e., at least more than one heat exchanger element, but in particular more than two heat exchanger elements, preferably a plurality of such heat exchanger elements, are connected to the fluid container to increase the cooling capacity of the heat exchanger. It is considered advantageous if the heat exchanger elements are individual, elongated, and designed as hollow bodies, for example, as a tube, in particular essentially a square tube.

[0013] Above all, by arranging as many heat exchanger elements as possible within the heat exchanger's installation space, it is possible to create a large surface area for heat transfer. This requires a thin-walled design and / or a close spacing of the heat exchanger elements, which could lead to their tendency to bend and / or buckle. However, bending or buckling of the thin-walled heat exchanger elements is advantageously avoided due to the support provided by the plain bearing. Such a heat exchanger element can be considered thin-walled if its wall thickness is less than or equal to 0.5 millimeters, in particular 0.35 millimeters.

[0014] The heat exchanger elements are now mounted by the plain bearing in such a way that, despite the mounting, a displacement and / or a change in length and cross-section due to expansion, in the case of a change in length, in particular thermal expansion, is possible. The displacement and longitudinal expansion can occur in particular in the longitudinal direction of the heat exchanger elements. The plain bearing is thus designed in the form of a floating bearing; in addition to the possible displacement and longitudinal expansion of the heat exchanger elements, it should also be designed so that the several heat exchanger elements arranged at a distance from one another and mounted by the plain bearing can expand in the direction of their outer circumference. Likewise, a displacement, i.e. a translational movement of the heat exchanger elements, as well as different longitudinal expansion relative to one another can be enabled.The change in the cross-section of the heat exchanger elements, i.e. an expansion in the direction of their outer circumference, can be caused by the internal pressure created by the fluid flowing through the heat exchanger element.

[0015] The heat exchanger could be designed as a cooler. This cooler could be flowed through by a fluid, e.g., a coolant, including water, and surrounded by another coolant, such as air, so that the thermal energy present in the flowing coolant is transferred to the surrounding coolant, lowering the temperature of the flowing coolant.

[0016] The fluid collection container could have two separate chambers, with one chamber being assigned the inlet and one chamber being assigned the outlet. In this case, it is conceivable that the fluid, after flowing through several heat exchanger elements assigned to the inlet, is recirculated via a deflection container into the heat exchanger elements assigned to the outlet, and the fluid flows through these elements in the direction of the outlet. However, a fluid collection container preferably has one chamber and one inlet or one outlet.

[0017] In addition to the arrangement of a plain bearing, it is of course also conceivable for the heat exchanger to have more than one plain bearing, which are arranged at a distance from one another in the longitudinal direction of the heat exchanger elements.

[0018] According to the invention, it is further provided that at least one spring element is arranged on the fluid collection container, via which the fluid collection container is mounted on the heat exchanger, wherein the spring element could be formed integrally on the fluid collection container. It is conceivable that the spring element is designed, for example, as a spiral spring, in particular as a leaf spring. Furthermore, the attachment of a fluid collection container could also be carried out using additional holding elements in a force-fitting and / or form-fitting manner. The holding elements themselves could be arranged on the heat exchanger by means of fastening means, such as screws, or furthermore by means of a detachable or non-detachable locking connection, such as a snap connection.

[0019] In a particularly advantageous development of the invention, the sliding bearing is designed as at least one comb strip with comb teeth. The comb teeth should at least engage in the spaces between the heat exchanger elements arranged at a distance from one another, and the heat exchanger elements should therefore rest at least partially on the comb teeth. It is conceivable for the sliding bearing to consist of just one such comb strip, which engages from one side into the spaces between the heat exchanger elements. The comb teeth could span the width of the heat exchanger elements completely, or at least partially. However, a design in which the sliding bearing is formed by two comb strips which are not spaced apart from one another in the longitudinal direction and are arranged such that the comb teeth of the comb strips face one another would be preferred.

[0020] In a further advantageous embodiment, at least one projection is formed on the heat exchanger elements in sections transverse to their longitudinal direction, on one or both sides, which, among other things, would create a holding area for the heat exchanger elements. The heat exchanger elements could thus be arranged at virtually any desired distance from one another, as close as possible.

[0021] If the heat exchanger elements are essentially designed as a square tube, the projection, such as a nose, should be formed transversely to the longitudinal direction, on the peripheral section(s), or should be located in the width dimension of the heat exchanger element. If the heat exchanger elements are essentially designed as square tubes, their height should be less than their width, and their width should be less than their length.

[0022] A plurality of projections arranged at a distance from one another in the longitudinal direction are conceivable, whereby these projections could each be arranged on one side or alternately. Preferably, however, the projections are each arranged on two sides and spaced from one another in the longitudinal direction.

[0023] If, in a further development of the invention, the plain bearing is designed as at least one toothed strip with teeth and intermediate tooth regions, this would create a plain bearing by means of which heat exchanger elements on which a projection is formed could be mounted in the plain bearing in a simple manner by arranging a respective projection in an intermediate tooth region of the toothed strip. This would make it possible to mount several heat exchanger elements using the toothed strip. In the simplest case, the plain bearing could consist of a rack in which the heat exchanger elements are mounted on one side. An alternating arrangement of several toothed strips, spaced from one another in the longitudinal direction of the heat exchanger elements, is just as conceivable as the arrangement of two toothed strips on either side of the heat exchange elements, wherein these are not spaced apart in the longitudinal direction and the teeth of the toothed strips are arranged facing one another.

[0024] Furthermore, it is considered advantageous if the plain bearing is formed by spacers arranged in sections between the heat exchanger elements, which could provide a very simple and cost-effective plain bearing. The heat exchanger elements could thus slide against each other via the spacers, with the spacers being supported on an abutment arranged on the heat exchanger, e.g., in the form of a support base, thus forming a quasi-self-supporting structure.

[0025] Furthermore, if the spacers are connected to the heat exchanger elements on one side and by a material bond, or if the spacers are connected to one another via at least one coupling element, this can be considered largely practical. In the case of a material bond, it is conceivable that each spacer is formed as part of a heat exchanger or is arranged on it, for example, by an adhesive connection. On the other hand, it is possible for the spacers not to be connected to the heat exchanger elements, which may, however, require the spacers to be secured to one another so that they do not change their intended position. The coupling element connecting the spacers to one another should therefore be arranged on the heat exchanger.

[0026] The possible designs of the plain bearing could also be combined with one another, so that, for example, one plain bearing is designed as a comb bar, another as a toothed bar, and one in the form of spacers. Further combinations are also possible.

[0027] An advantageous development of the invention is also characterized in that the fluid collection container or at least one of the fluid collection containers is mounted displaceably in the longitudinal direction of the heat exchanger elements, since this makes it possible to compensate for any displacement and / or expansion in the longitudinal direction of the heat exchanger elements. In the event of expansion, for example, a thermally induced longitudinal expansion and / or displacement of the heat exchanger elements, the possibility would thus be provided for the fluid collection container or containers to execute a corresponding translational movement in order to minimize or even prevent any stresses that may arise in the heat exchanger.

[0028] A promising embodiment of the invention is also provided by arranging the fluid collection tanks and plain bearings on a support frame. This support frame can be a separate component on which the fluid collection tanks, heat exchanger elements, and plain bearings are arranged. This support frame can, in turn, be attached to a mounting frame accommodating multiple components. However, it is also conceivable for the support frame to already be a component of the mounting frame, i.e., the support frame is formed within the mounting frame or is integrally connected to it.

[0029] The mounting frame could, for example, be a plastic mounting bracket such as is used in the automotive industry for mounting heat exchangers and / or other vehicle components in the engine compartment.

[0030] It also proves to be extremely promising if the heat exchanger has two fluid collection containers connected via the heat exchanger elements and / or if the heat exchanger elements are subject to tensile stress when the heat exchanger is not flowing through. In the non-flowing state, i.e. when the heat exchanger is at rest, the temperature of the heat transfer can be within a smaller range than when the fluid is flowing through it, as a result of which the heat exchanger elements have a smaller linear expansion. It is therefore advantageous if the heat exchanger elements are connected to the fluid collection containers under tension, whereby this tensile stress decreases during operation, i.e. when the fluid is flowing through it, due to thermal expansion of the heat exchanger elements caused by heating, and the heat exchanger elements are therefore almost stress-free.

[0031] The plastic used for the various components of the heat exchanger, such as heat exchanger elements, fluid collection tanks, support frames, plain bearings or even holding elements, can be the same or a different plastic.

[0032] The invention permits numerous embodiments. To further clarify its basic principle, embodiments are shown in the drawing and are described below. This shows in Fig. 1, Fig. 2 a further development of the heat exchanger according to the invention; Fig. 3 a sectional view through a further development of a plain bearing; Fig. 4 another sectional view of a plain bearing; Fig. 5a a detailed view of heat exchanger elements; Fig. 5b an exploded view of a plain bearing; Fig. 6a, Fig. 6b Side views of the heat exchanger.

[0033] Fig. 1 and Fig. 2 show a further development of the heat exchanger 1 according to the invention, wherein the heat exchanger 1 in Fig. 1 is shown in an exploded view. The heat exchanger 1 is made of plastic and has two fluid collection containers 2. The first of these fluid collection containers 2 has the inlet 3, the second fluid collection container 2 has the outlet 4, through which a fluid, e.g. a coolant, can flow into and out of the heat exchanger 1. The fluid collection containers 2 are connected in a material-permeable but also energy-permeable manner via a plurality of heat exchanger elements 5 through which the fluid can flow. The heat exchanger elements 5 are designed individually, are elongated, and are hollow bodies, with the heat exchanger elements 5 in this embodiment of the heat exchanger 1 essentially being designed as square tubes. Furthermore, three plain bearings 6 are arranged on the heat exchanger 1 in the longitudinal direction 9 of the heat exchanger elements 5, spaced apart from the fluid collection containers 2 and from one another.The heat exchanger elements 5, which are in turn arranged at a distance from one another, are mounted by means of the plain bearings 6 and are displaceably and expandable in terms of length and cross-section relative to the plain bearing 6. For this purpose, each plain bearing 6 is formed from two comb bars 7 with comb teeth 8, wherein the comb bars 7 belonging to a respective plain bearing 6 are not spaced apart in the longitudinal direction 9 and are arranged such that the comb teeth 8 of the comb bars 7 face one another. In addition to the displaceable mounting of the heat exchanger elements 5, both fluid collection containers 2 are also displaceably mounted in the longitudinal direction 9 of the heat exchanger elements 5, wherein for this purpose two spring elements 16 are each arranged on the fluid collection containers 2, via which spring elements 16 the fluid collection container 2 is arranged on the heat exchanger 1. The spring elements 16 are formed in one piece on the respective fluid collection container 2 and are designed as a bending spring in the manner of a leaf spring.Also shown are additional retaining elements 18, which serve to secure the fluid collection containers 2. The retaining elements 18 themselves are fastened to the support frame 17 of the heat exchanger 1 by means of fastening means, in this embodiment screws, whereby the fluid collection containers 2 and the heat exchanger elements 5, as well as the plain bearings 6, are also arranged on the support frame 17.

[0034] In Fig. 3 shows a sectional view through a further development of a plain bearing 6, which is designed in the form of two comb bars 7. The comb teeth 8 engage on two sides in the spaces between the heat exchanger elements 5, which are arranged at a distance from one another and are essentially designed as square tubes, and the heat exchanger elements 5 rest in sections on the comb teeth 8. The comb teeth 8 of the comb bars 7 are aligned facing one another. In addition, the illustration shows that the heat exchanger elements 5 have several fluid chambers 31 separated by spaced-apart intermediate walls 29. These intermediate walls 29 also serve to ensure the flexural stability of the heat exchanger elements 5. The further development of the heat exchanger elements 5 in the Fig. 3 has four fluid chambers 31, however, in further embodiments, the heat exchanger elements 5 can also have fewer or more fluid chambers 31, for example, five fluid chambers 31. Furthermore, the circumferential outer wall 30 of the heat exchanger element 5 is corrugated to form the largest possible surface area. This can also be the case in other embodiments in addition to this further development.

[0035] Fig. Figure 4 contains a further sectional view of a plain bearing 6, wherein the latter is configured as two toothed strips 11 with teeth 12 and intermediate tooth regions 13. Furthermore, a projection 10 is formed on two sides of the heat exchanger elements 5, transverse to their longitudinal direction 9. The heat exchanger elements 5 are essentially configured as square tubes, and the projections 10 are formed transverse to the longitudinal direction 9 on the circumferential sections 19, which lie in the width dimension 20 of the heat exchanger element 5. Furthermore, it can be seen that each projection 10 is arranged in an intermediate tooth region 13 of the toothed strip 11, wherein the toothed strips 11 are arranged such that the teeth 12 of the toothed strips 11 face one another.

[0036] In Fig. Figure 5a shows a detailed view of heat exchanger elements 5, wherein spacers 14 are formed between the heat exchanger elements 5 in sections along the longitudinal direction of the heat exchanger elements 5, thereby forming the plain bearing 6. The spacers 14 are connected to the heat exchanger elements 5 on one side and in a materially bonded manner.

[0037] Fig. Figure 5b, on the other hand, describes an exploded view of a plain bearing 6, in which the spacers 14 are arranged in sections between the heat exchanger elements 5 in the longitudinal direction 9 and are connected to one another via two coupling elements 15. The coupling elements 15 are each designed as a rod 21, which has a threaded section 22 in its end regions. The spacers 14 extend across the width 20 of the heat exchanger elements 5 and also have a recess 23 on both sides of the heat exchanger elements 5. These recesses 23 serve to engage the rods 21 in the spacers 14, so that the rods 21 are each arranged in sections in the recesses 23 of the spacers 14 in their axial direction.The plain bearing 6 also has a head plate 24 and a base plate 25, each of which has two through holes 28 through which the rods 21 pass. The rods 21 are arranged on the head plate 24 and the base plate 25 in a force-locking and form-locking manner by fastening means 26, which are designed here as knurled nuts. For this purpose, spacers 27 are arranged between the head plate 24 and the heat exchanger elements 5, as well as between the base plate 25 and the heat exchanger elements 5.

[0038] Fig. 6a and Fig. 6b show additional side views of the heat exchanger 1, in which the support frame 17 as well as the inlet 3 and outlet 4 are shown. List of reference symbols 1 heat exchanger 2 fluid collection containers 3 Inlet 4 Procedure 5 Heat exchanger element 6 plain bearings 7 comb strip 8 comb teeth 9 Longitudinal direction 10 lead 11 Toothed strip 12 tooth 13 Interdental area 14 spacers 15 coupling element 16 spring element 17 supporting frames 18 Holding element 19 Circumferential section 20 Width 21 bars 22 threaded section 23 Recess 24 headstock 25 base plate 26 fasteners 27 Spacer 28 through hole 29 Partition wall 30 exterior wall 31 Fluid chamber

Claims

[1] Heat exchanger (1) made of plastic with at least one fluid collection container (2), wherein this fluid collection container (2) has at least one inlet (3) and / or at least one outlet (4) for a fluid and the fluid collection container (2) is connected at least permeably to a plurality of heat exchanger elements (5) through which the fluid can flow, wherein the heat exchanger (1) has at least one plain bearing (6) arranged at a distance from the fluid collection container (2) and the heat exchanger elements (5) arranged at a distance from one another are mounted by means of the plain bearing (6) and relative to the plain bearing (6), displaceable and / or expandable in terms of length and cross-section, characterized by that at least one spring element (16) is arranged on the fluid collection container (2), via which the fluid collection container (2) is mounted on the heat exchanger (1). [2] Heat exchanger (1) according to claim 1, characterized bythat the sliding bearing (6) is designed as at least one comb strip (7) with comb teeth (8). [3] Heat exchanger (1) according to one of claims 1 or 2, characterized by that at least one projection (10) is formed on the heat exchanger elements (5) transversely to their longitudinal direction (9) in sections, on one side or on both sides. [4] Heat exchanger (1) according to at least one of the preceding claims, characterized by that the plain bearing (6) is designed as at least one toothed strip (11) with teeth (12) and tooth intermediate regions (13). [5] Heat exchanger (1) according to at least one of the preceding claims, characterized by that the plain bearing (6) is formed by spacers (14) arranged in sections between the heat exchanger elements (5). [6] Heat exchanger (1) according to claim 5, characterized bythat the spacers (14) are connected on one side and materially to the heat exchanger elements (5) or the spacers (14) are connected to one another via at least one coupling element (15). [7] Heat exchanger (1) according to at least one of the preceding claims, characterized by that the fluid collection container (2) or at least one of the fluid collection containers (2) is mounted displaceably in the longitudinal direction (9) of the heat exchanger elements (5). [8] Heat exchanger (1) according to at least one of the preceding claims, characterized by that the fluid collection containers (2), heat exchanger elements (5) and the plain bearings (6) are arranged on a support frame (17). [9] Heat exchanger (1) according to at least one of the preceding claims, characterized bythat the heat exchanger (1) has two fluid collecting containers (2) connected via the heat exchanger elements (5) and / or in a non-flow-through state of the heat exchanger (1) the heat exchanger elements (5) are under tensile stress.

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