Improved modular heat exchanger

Abstract

The plate (19) according to the invention has: a first side (19e) coated with an electrically insulating layer (2), wherein an electrical conductor (17) is applied to or embedded in the electrically insulating layer (18); and a second side surface (19z) on which a projection (15, 16) is provided. The coolable resistor (W) may be composed of a plate pair (B) and a corresponding seal (C). The coolable resistor is compact in structure and high in efficiency, and each single plate pair is easy to replace.

Description

TECHNICAL FIELD

[0001] The invention relates to a plate and to a plate pair which can be connected to a coolable resistance. In particular, such a resistance is used for a brake resistance. BACKGROUND

[0002] In particular in the field of drive technology, especially in commercial vehicles, it is possible to convert excess brake energy into a brake resistance. The kinetic energy of the vehicle is converted into electrical energy, for example, by a regenerative brake (drive in recovery mode) and, if this energy cannot be used for other purposes (for example, it can be stored in a battery), it is converted into a liquid-cooled brake resistance. The resistance can be said to act as a consumer which converts electrical energy into heat, which then has to be dissipated accordingly in order to avoid overheating of the brake resistance.

[0003] In document DE 10 2021 202 037.4, a brake resistance operated by a liquid is disclosed, wherein the brake resistance is composed of a plurality of shaped metal plates. The shaped metal plates have a first side and a second side, and two shaped metal plates are connected to each other at the edge by a press groove, for example by welding.

[0004] On the other side, respectively, an electrically conductive device is provided which is embedded in an insulating layer which generates heat, and on the other side the heat is then conducted out, so that here a flow path is defined through which the coolant can flow.

[0005] The connection of two shaped metal plates by a press groove, in particular a press groove on the edge of the shaped metal plate, for example a circumferential press groove, can be problematic, in particular when the press groove is convex in one direction. The electrically conductive layer can be applied by screen printing, where it is important that a flat surface is present so that the surface can be printed uniformly.

[0006] In addition, a very compact design cannot be achieved with a convex press groove, so that a large amount of space is required if a plurality of shaped metal plates are stacked. SUMMARY

[0007] It is therefore an object of the invention to provide a shaped (metal) plate with a coolable resistance, wherein the shaped (metal) plate can be printed easily and the space requirement can be reduced as much as possible.

[0008] This object is achieved by the plate according to claim 1, the plate pair according to claim 8 and the coolable resistance according to claim 9. Further advantageous design features of the invention are the subject matter of the dependent claims.

[0009] The plate according to the application has a first side which is coated with an electrically insulating layer, wherein an electrical conductor is applied to and embedded in the electrically insulating layer. In addition, the plate has a second side, on which the protrusions are provided.

[0010] The plate is configured to cool a portion of the resistor or a portion of the resistor unit.

[0011] The protrusions are pressed into the plate as protruding portions, which, when two plates are pressed against each other, come into contact with and engage with the opposing protruding portions of the plate, for example by means of laser welding. At the time of welding, a plurality of protruding portions can form the contact points.

[0012] The flow channels can thus be formed. In addition, the protrusions also contribute to the elimination of loads, by means of which the deformation of the plate, for example caused by the pressure of the cooling medium, can be reduced to a minimum. In addition, the protrusions also ensure an increase in the degree of turbulence, and thus also an improved introduction of heat into the cooling medium, where it has been found by means of numerical simulation that the heat transfer can be increased by 15% compared to a conventional pressure groove.

[0013] In addition, it is not necessary to change the flow direction, so that dead angles can be avoided and the heat transfer is improved.

[0014] Preferably, grooves are provided on the first side on the edge (further preferably along the edge), which are suitable for receiving edge sections of a seal. This has the advantage that the two first sides of two opposing plates do not have to be potted as in the prior art, but rather these sides can be detachably connected to each other by means of the seal. The plate edge is also used for connecting the two plates to each other on the second side by means of laser welding.

[0015] Preferably, the electrical conductor is arranged between the protrusions (the electrical conductor is arranged on the first side of the plate, the protrusions on the second side of the plate thus constitute recesses or depressions here, but the term "protrusions" is used uniformly). It is further preferred that the electrical conductor is arranged in a meandering manner around the protrusions (or recesses / depressions). Thus, the electrical conductor is very close to the protrusions (or recesses / depressions), a very long electrical conductor can be configured, and the electrical conductor also has a large area, which further increases the heat transfer.

[0016] Preferably, electrical contact surfaces are provided on the ends of the electrical conductor, which are suitable for contacting one spring element each. The spring elements can be connected to a connection plug, by means of which the electrical current is introduced into the plate. Here, it is not necessary to solder the connection plug or the like, which reduces the production costs. Preferably, the contact surfaces are printed and are provided with an additional film (by means of the soldering process), so that this film serves as a sacrificial layer against wear of the spring contacts.

[0017] Furthermore, it is further preferred that the plate according to the application has at least one, preferably two openings, wherein it is further preferred that (further) protrusions are arranged around the openings on the second side of the plate. These protrusions facilitate the stabilization of the openings, so that no deformation by the fluid occurs here. In addition, a pressing force is also generated on the seal, which further improves the sealing.

[0018] The protrusions are further preferably point-like, cylindrical or hemispherical, so that they can be easily pressed into the plate. In addition, an unstable wake area is thus also formed, which ensures the removal of the heat from the wake area. An edge-sharp profile forms a larger stable wake area, which hinders the removal of the heat.

[0019] A plate pair has two plates, wherein the second sides of the two plates are arranged opposite to each other. The edges of the second sides of the two plates are sealingly connected to each other, preferably by a weld seam.

[0020] The protrusions on the second sides of the two plates are also connected to each other (for example welded together, i.e. weld points, weld seams), so that smaller flow channels are formed. The inflowing cooling medium is distributed evenly in the gap between the two plates and achieves an even heat dissipation.

[0021] This makes it possible to form a stable unit, since the internal pressure is removed by the inflow of the fluid, so that less deformation occurs. The load on the electrically insulating layer can thus be reduced to a minimum. In addition, the flow channel retains its flow cross section, and the flow cross section does not bulge. The large heat exchange surface is essentially achieved by the plate structure. However, the plate structure can easily be deformed due to the internal pressure of the cooling medium. The load is eliminated by means of the protrusions and their connection to the opposite plate.

[0022] It is preferred that a plurality of coolable resistor units and seals are provided, one seal being arranged between each two coolable resistor units (coolable resistor units and seals are stacked). As an outer boundary of the entire coolable resistor, a cover plate is provided, which is in contact with the first side of the plates, but in this case without electric conductors being arranged, wherein all plate pairs and the connecting plates are connected to each other by means of fastening elements. This fastening element is preferably a screw. By means of the fastening elements, all coolable resistor units and all seals can be pressed against each other, so that a compact and in particular sealed structure is formed. At the same time, however, the fastening elements can be loosened again, for example when a plate pair (coolable resistor unit) has to be replaced, for example in the event of a fault or a leak.

[0023] Thus it is possible to stack an arbitrary number of plate pairs very simply, the number being variable depending on the power requirement of the coolable resistor. The liquid can be prevented from penetrating the components with electrical conductors by means of the seal. The protrusions in the plates also facilitate the elimination of the load on the seal, in particular the load on the seal arranged around the opening. Thus it is possible to prevent plastic deformation of the plate structure. Preferably, the seal has an edge section which can be engaged with the recesses of the two opposite first side faces of the plates of the respective plate pair. In this way, a particularly effective sealing effect can be produced accordingly.

[0024] The coolable resistor preferably has at least one inlet and one outlet, which are arranged in the cover plate respectively. It is further preferred that there is a hydraulic connection. All the openings are then arranged above and below and form a first collection area, and all the second openings are also arranged above and below and form a second collection area. The inlet and outlet are either connected to the first collection area (or a section of this collection area) or to the second collection area (or a section of this collection area) or are distributed over both collection areas - i.e. the first collection area is connected to the inlet and the second collection area is connected to the outlet, or vice versa. The collection areas can be divided into sections by the cover plate.

[0025] It is further preferred that at least one of the first openings and the second openings of the coolable resistor unit is closed, but the liquid can nevertheless flow from the inlet to the outlet. It is thus possible to connect a certain number of coolable resistor units in parallel or in series, depending on the individual case, which can be configured completely flexibly without major modifications to the individual elements, for which it is only necessary to close some of the first openings and some of the second openings of the coolable resistor units in the overall system.

[0026] The closed first or second openings facilitate the parallel connection of one part and the series connection of another part of an existing coolable resistor unit, and thus the corresponding guidance of the cooling liquid. Thus, it is possible to divide the two collection areas. It is thus possible to connect a certain number of coolable resistor units in parallel or in series, depending on the individual case. More precisely, it is also possible to continuously increase the flow rate (by reducing the number of plates in the parallel section) by means of a variable configuration of the connections, which facilitates improved heat conduction and compensates for the preheating of the cooling medium.

[0027] The connection of the coolable resistor elements is deliberately determined as a parallel connection, in order to

[0028] - reduce the single current on the spring contacts to a minimum

[0029] - associating the unit load of each plate with the cooling medium temperature. Here, the plate close to the inlet in terms of flow technology bears a greater load (due to the lower temperature of the cooling medium, which leads to a lower conductor temperature, which in turn results in a lower resistance value). The lower resistance value at the inlet compared to the outlet causes a greater current flow, which is proportional to I 2 is inserted into the power calculation. The flow-side last coolable resistance element is loaded with a lower power each. BRIEF DESCRIPTION OF DRAWINGS

[0030] Embodiments of the present application are explained in further detail below with reference to the drawings.

[0031] Figure 1 A first side of a plate for coolable resistance elements according to a first embodiment of the present application is shown;

[0032] Figure 2 A second side of a plate for coolable resistance elements according to a first embodiment of the present application is shown;

[0033] Figure 3 A seal suitable for being arranged between two plate pairs is shown;

[0034] Figure 4 A plate pair (coolable resistance elements) is shown;

[0035] Figure 5 A cross-sectional view of a seal between two plate pairs is shown;

[0036] Figure 6 A cross-sectional view of a seal between two plate pairs is shown, where here in particular the spring contacts of the conductors are shown;

[0037] Figure 7 An isometric view of two plate pairs is shown, between which a seal is arranged;

[0038] Figure 8 A cross-sectional view of a coolable resistance of the present application is shown;

[0039] Figure 9 An outer view of a coolable resistance is shown. DETAILED DESCRIPTION

[0040] Figure 1The first side 19e of the plate 19 is shown in Fig. 1. The plate 19 is generally hexagonal (essentially composed of two triangles and one rectangle) with a long section and a shorter section. On both ends of the long section, a first opening 25a and a second opening 25b are provided, respectively. These openings are at least partially surrounded by a plurality of second protrusions 16, which, however, extend to the second side 19z (not shown here), i.e. the back side. The second protrusions 16 thus have a pressed-in pit shape on the first side 19e. On the edge of the plate 19, a recess 23 is provided, in which a seal (not shown here) can be arranged. In addition, a plurality of first protrusions 15 are distributed over the surface of the first side 19e, in particular the long section of the rectangle, which likewise extend to the second side 19z (not shown here) of the plate 19. The first protrusions 15 thus also have a pit shape on the first side 19e. The electrical conductor 17 extends between the first protrusions 15. This is arranged on an electrically insulating layer 18, which has been applied beforehand on the first side 19e of the plate 19, and is printed, for example, by means of a screen printing process. In addition, the electrical conductor 17 has two electrical contact surfaces 13 on the first surface 19e. The electrical conductor 17 is arranged in a meandering manner around the first protrusions 15. The electrical conductor 17 thus has as large a surface as possible. The direction of flow of the cooling fluid is also indicated by the arrow 21, which, however, flows on the second side 19z (not shown here) of the plate 19. It can be clearly seen here that the direction of flow of the fluid is perpendicular to the main direction of the electrical conductor 17 (the direction in which the electrical conductor 17 mainly extends). On the two outermost points (the vertices of the triangles of the hexagon), receiving sections 26 are provided, which are in the shape of semicircular notches here, which are used to fasten a plurality of plates 19 together by means of fastening elements 7 (not shown here), for example bolts.

[0041] The cooling medium can thus be transferred from the hot load zone to the non-hot load zone. The contact length covered by the thermal dynamics is thus greatly reduced, and overheating is prevented.

[0042] Figure 2 The second side 19z of the plate 19, i.e. the back side of the first side 19e (not shown here), which is the side through which the cooling medium flows, is shown in Fig. 2. The first opening 25a and the second opening 25b can also be seen, in addition to which the first protrusions 15 and the second protrusions 16 can also be seen here.

[0043] Here, a connection region 27 is provided on the plate edge, at which two plates 19 can be welded to one another (the second sides 19z facing one another). The first protrusions 15 are distributed over the plate cross section, while the plurality of second protrusions 16 are distributed around the first opening 25a and the second opening 25b. The first protrusions 15 and the second protrusions 16 are each configured in a point-like or semispherical manner. Here, the receiving sections 26 can also be seen in Fig. 3. Figure 2 The receiving sections 26 can also be seen in Fig. 3.

[0044] In Figure 3 is shown that a sealing element C essentially follows the hexagonal cross section of the plate 19 (not shown). The sealing element C is composed of an outer section Cl that essentially follows the hexagonal shape of the plate and two inner sections C2 that extend inwards from the outer corners of the hexagon and have a circular shape. The outer section Cl is provided for sealing the outer edges between two plates 19 (not shown here), the inner sections C2 are provided for sealing the first or second openings 25a or 25b (not shown here). On one long side of the sealing element C, spring contacts 12 are arranged inwards, which extend upwards and downwards and are therefore suitable for contacting two electrical contact surfaces 13 (not shown here) arranged above and below the sealing element C. On the other side of the spring contacts 12, electrical terminals 11 are provided. The combination of the electrical terminals 11 and the spring contacts 12 can be injection molded in the sealing element C, but can also be inserted through the sealing element.

[0045] In addition, in the area of the two inner sections C2, there are raised sections C3 that help this area to be pressed in particularly firmly and to be elastically deformed, which leads to a better sealing in the area of the first and second openings 25a or 25b (not shown here) that guide the liquid accordingly.

[0046] Figure 4 A cross section along the line A' in Figure 1 is shown, here the inner area 20 is shown when two plates 19 are arranged next to each other (the two first sides 19e are here opposite each other). Thus, an area 20 is formed through which the liquid can flow. In addition, here the soldered contacts 14 are shown, i.e. here the first projections 15 (not shown here) of the two second surfaces 19z of the plates 19 are soldered to each other. In order to prevent a one-sided bending due to printing, the two plates 19 are first soldered to each other and then the electrical conductors 17 are printed alternately (not shown in Figure 4 ). By printing alternately, the stress is balanced and the plates 19 remain flat.

[0047] Figure 5 Mainly the sealing element C is shown, here it is shown that the outer section Cl of the sealing element C engages with the recess 23 shown in Figure 1 on the first side 19e of the plate 19. In addition, here the sealing area 22 is shown, which seals the first or second collection area 9a or 9b, respectively, through which a cooling medium (for example liquid) flows. The collection area is essentially sealed by the inner section C2 of the sealing element C. The forces acting on the sealing element C are indicated by the reference F.

[0048] Figure 6Two plate pairs B (consisting of two plates 19) are shown, between which a sealing element C is arranged. It can also be seen that a force F acts on the plate pairs B. In the sealing element C, spring contacts 12 for electrical contact with the electrical contact surfaces 13 of the plate pairs B are shown, and in addition, an electrical terminal 11 is provided here, which is electrically connected to the spring contacts 12. In addition, a solder contact 14 is shown here, at which the first protrusions 15 (not shown here) of the two second surfaces 19z of the plates 19 are soldered to one another.

[0049] By pressing the two plate pairs B and the sealing element C against one another, a sealed connection is accordingly established, so that no fluid can flow along the second surfaces 19z (not shown here) in the region of the electrical conductor 17 (not shown here).

[0050] Figure 7 An isometric view of two plate pairs B is shown, between which a sealing element C is present. In addition, electrical terminals 11 are shown here, which are connected to the spring contacts 12 (only partially shown here). A sealing element C is arranged between the two plate pairs B in a stacked arrangement. On top, the first side 19e of the plate can be seen, which has the meandering electrical conductor 17 and the electrical contact surfaces 13. The first opening 25 and the second opening 25b can also be seen.

[0051] Figure 8A resistance device A (liquid-cooled resistance) is shown. The resistance device comprises a plurality of coolable resistance elements B (not all of which are shown in detail here). Thus, a plate pair is a coolable resistance element, since it is the smallest unit of the coolable resistance. An upper and a lower cover plate 6 are provided. The upper cover plate 6 is provided with an inlet 5, and the lower cover plate 6 is provided with an outlet 5'. Furthermore, it is shown that a hydraulic connection 8 is provided in each case in the inlet 5 and the outlet 5', which is provided in a quick-connection system. Furthermore, the flow guidance also becomes clear, since closure plates 10 are provided at regular intervals at the left-hand opening, and likewise at the right-hand side. A first collection region 9a is provided on the left-hand side (which is divided into three sections 9a', 9a" and 9a"' by the closure plates 10). Thus, when the cooling medium flows in via the inlet 5 into the first section 9a', a plurality of coolable resistance elements B are flowed through in parallel / series here. A collection region 9b is provided in the right-hand region (divided into sections 9b', 9"). A closure plate 10 is also provided here for division. The cooling medium then reaches the section 9b' of the second collection region 9b. Thus, a certain number of coolable resistance elements B are also flowed through in parallel here, until the first collection region 9a is reached again (now the section 9a"). Here, a closure plate 10 is also provided at a distance, so that the fluid is also deflected to the right (until the fluid reaches the section 9b" of the second collection region 9b), from where it is deflected to the left again, until the fluid reaches the section 9a'" of the first collection region 9a, so that the fluid can flow out via the outlet 5'. Here, by providing the closure plates 10, any number of plate pairs B which can be flowed through in parallel or almost in parallel can be provided, so that the resistance device A can be variably adjusted to a specific cooling power.

[0052] Figure 9 An isometric representation of a resistance device A is shown. Furthermore, it is shown here that a terminal box 4 is provided, on which the dampers 2 for the assembly and the connection cable 1 are provided. Furthermore, the hydraulic connection 8 is shown.

[0053] The application is not restricted to the embodiments described above.

[0054] The geometry of the plates 19 can be arbitrary and is not necessarily hexagonal. Furthermore, the flow channels can be realized in different ways, it not being necessary here for interfaces or openings to be provided on both opposite sides of the hexagons.

[0055] List of reference signs

[0056] A resistance device

[0057] B plate pair / coolable resistance element

[0058] C sealing element (with contact)

[0059] C1 outer section

[0060] C2 inner section

[0061] C3 raised section

[0062] F compression force

[0063] 1 connecting cable (with electromagnetic compatibility shield)

[0064] 2 damper

[0065] 3 contact protection

[0066] 4 terminal box

[0067] 5 inlet

[0068] 5' outlet

[0069] 6 closure plate

[0070] 7 fastener / bolt

[0071] 8 hydraulic connection (quick connection)

[0072] 9a first collection area

[0073] 9a', 9a", 9a"'section

[0074] 9b second collection area

[0075] 9b', 9b" section

[0076] 10 closure plate

[0077] 11 electrical terminal

[0078] 12 spring contact

[0079] 13 electrical contact surface

[0080] 14 soldered contact

[0081] 15 first protrusion

[0082] 16 second protrusion

[0083] 17 electrical conductor

[0084] 18 electrically insulating layer

[0085] 19 single board

[0086] 19e first side of the single board

[0087] 19z second side of the single board

[0088] 20 region / inner region that can be penetrated by a liquid

[0089] 21 flow direction

[0090] 22 sealing region

[0091] 23 recess (for positioning of the seal)

[0092] 24 pressure groove

[0093] 25a first opening

[0094] 25b second opening

[0095] 26 receiving section

[0096] 27 connecting region

Claims

1. Plate (19) having: a first side (19e) which is coated with an electrically insulating layer (2) on which an electric conductor (17) is applied or embedded; and a second side (19z) on which protrusions (15, 16) are provided.

2. The plate (19) according to claim 1, wherein On the first side (19e) a recess (23) is provided on the edge which is suitable for receiving an edge section (Cl) of a seal (C).

3. The plate (19) according to claim 1 or 2, wherein The electric conductor (17) is arranged between the regions provided with protrusions (15, 16) and is preferably arranged meandering around the regions provided with protrusions (15, 16).

4. The plate (19) according to any one of the preceding claims, wherein On each end of the electric conductor (17) an electrical contact surface (13) is provided which is suitable for contacting a spring element (12) each, which is preferably provided in the seal (C).

5. The plate (19) according to any one of the preceding claims, additionally having at least one, preferably two openings (25a, 25b), wherein Preferably, around the openings (25a, 25b) protrusions (16) are provided on the second side (19z) of the plate (19).

6. Plate (19) according to any one of the preceding claims, wherein the protrusions (15, 16) are configured as dots, cylinders or hemispheres.

7. Plate pair (B) consisting of two plates (19) according to any one of the preceding claims, the respective second sides (19e, 19e) of the two plates (19, 19) being arranged opposite each other, the edges of the second sides (19e) of the two plates (19, 19) being sealingly connected to each other, preferably by a weld seam.

8. The plate pair (B) according to claim 7, wherein The protrusions (15, 16) are connected to each other, preferably by a solder joint or a weld seam.

9. Coolable resistor (W) having at least two plate pairs (B) according to claim 8, wherein between two stacked plate pairs (B) a seal (C) is provided, the outer sides of the plate pairs being the first sides (19e) of the plates (9), one cover plate (6) being provided as an outer boundary each, wherein all plate pairs (B) and the two cover plates (6) are connected to each other by fastening means (7), wherein the fastening means (7) are preferably bolts.

10. Coolable resistance (W) according to claim 9 when dependent on claim 2, wherein The edge section (Cl) of the seal (C) is in engagement with the recesses (23) of the two opposite first sides (19e) of the plates (19) of the plate pairs (B).

11. Coolable resistor (W) according to claim 9 or 10, additionally having at least one inlet (5) and outlet (5') each, the inlet (5) and outlet being provided in one cover plate (6) each, all first openings (25a) being arranged above and below each other and forming a first collection area (9a) and all second openings (25b) being arranged above and below each other and forming a second collection area (9b), wherein the inlet (5) and outlet (5') are either connected to the first collection area (9a) or a section (9a', 9a'', 9a''') of this collection area or to the second collection area (9b) or a section (9b', 9b'') of this collection area or are allocated to both collection areas (9a, 9b).

12. Coolable resistance (W) according to claim 11, wherein at least one of the first opening (25a) and / or the second opening (25b) is closed, wherein the liquid is able to flow from the inlet (5) to the outlet (5').

13. Coolable resistance (W) according to claim 11 or 12, wherein the first opening (25a) and / or the second opening (25b) is open.

14. Coolable resistance (W) according to any one of claims 11 to 13, wherein the first opening (25

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