HEAT EXCHANGER FOR COOLING ONE OR MORE ELECTRICAL OR ELECTRONIC DEVICES

Abstract

The present invention relates to a heat exchanger device for cooling one or more electrical or electronic devices, wherein the electrical or electronic device generates heat that must be drained through an outer exchange surface. Improvement in heat transfer requires close contact between the surface of the device to be cooled and of the heat exchanger responsible for removing heat, and this close contact requires the application of large mechanical stresses. The exchanger is configured such that it improves robust response without reducing the exchange capacity with the electrical or electronic device. The present invention presents the advantages of energy efficiency and therefore has a relevant impact on the environment.

Claims

1. A heat exchanger for cooling one or more electrical or electronic devices, comprising: a base comprising an inlet port for the entry of a coolant, an outlet port for the exit of the coolant, a wall extending along a longitudinal direction, the direction which connects the inlet port and the outlet port of the base, a cover attached on the base and configured to establish a chamber for the passage of the coolant between the inlet port and the outlet port of the base and wherein the cover comprises a wall extending along the longitudinal direction; wherein the wall of the base or the wall of the cover or both comprise at least one heat exchange region adapted to transfer heat from an outer area to an inner area of the chamber and opposite the outer area; characterized in that the wall of the base or the wall of the cover or both comprises a structural metallic material which is selected from: steel; and a metallic material comprising aluminum as the ingredient in the highest amount by weight; and, the wall of the base or the wall of the cover or both comprising a structural metallic material extend at least one segment along the longitudinal direction wherein, at least one heat exchange region is arranged between the ends of said segment also according to the longitudinal direction; and at least one heat exchange region comprises, and particularly consists of, a metallic heat transfer material.

2. The heat exchanger according to claim 1, wherein the metallic heat transfer material in the at least one heat exchange region is selected from: steel, preferably carbon steel; a metallic material comprising copper as the ingredient in the highest amount by weight; and a metallic material comprising aluminum as the ingredient in the highest amount by weight.

3. The heat exchanger according to claim 1, wherein the structural metallic material and the metallic heat transfer material are different.

4. The heat exchanger according to claim 1, wherein the structural metallic material and the metallic heat transfer material are the same material.

5. The heat exchanger according to claim 1, wherein the at least one segment of the structural metallic material is such that a plurality of heat exchange regions are arranged between the ends of said segment according to the longitudinal direction.

6. The heat exchanger according to claim 1, wherein the wall of the base, of the cover, or of both, is a flat plate.

7. The heat exchanger according to claim 1, wherein the at least one heat exchange region is a continuous region in the metallic heat transfer material comprised in said region, said region being adapted to receive one or more electronic devices.

8. The heat exchanger according to claim 1, comprising an attachment material between the metallic heat transfer material comprised in the at least one heat exchange region and the structural metallic material.

9. The heat exchanger according to claim 8, wherein the attachment between the metallic heat transfer material comprised in the at least one heat exchange region and the structural metallic material is obtained by leak-tight sealing through the attachment material.

10. The heat exchanger according to claim 1, wherein the cover is made of a sheet metal and comprises a larger flat surface limited along the perimeter by a perimeter wall, wherein the perimeter wall of the cover is fixed to the base.

11. The heat exchanger according to claim 1, comprising one or more fin blocks for heat exchange arranged inside the chamber for the passage of the coolant, wherein the at least one fin block for heat exchange is attached to the inner area of the wall of a heat exchange region and is separated from the internal surface of the chamber located opposite, that is, if the fin block is attached to the wall of the base then it is separated from the cover and, if the fin block is attached to the wall of the cover then it is separated from the base.

12. The heat exchanger according to claim 11, wherein the fins comprise a metallic material comprising copper as the ingredient in the highest amount by weight; or a metallic material comprising aluminum as the ingredient in the highest amount by weight.

13. The heat exchanger according to claim 1, wherein the segment of the structural metallic material is a side wall of the cover.

14. The heat exchanger according to claim 1, wherein it further comprises fixing means configured to exert a force transverse to the wall of the base.

15. A heat exchanger module, comprising at least two adjacent heat exchangers according to claim 11, wherein: the two or more heat exchangers are adapted to receive one or more electrical or electronic devices to be cooled interposed between two adjacent heat exchangers and in thermal contact with the heat exchange regions of both heat exchangers, it comprises fixing means pressing the one or more electrical or electronic devices to be cooled together, and the fixing means press the compressible sealing gaskets together.

Description

DESCRIPTION OF THE DRAWINGS

[0432] These and other features and advantages of the invention will be shown more clearly based on the following detailed description of a preferred embodiment, provided solely by way of illustrative and non-limiting example in reference to the attached figures:

[0433] FIG. 1 This figure schematically shows a front view of a first embodiment of a heat exchanger of the invention attached to a plurality of electronic devices cooled in the operating mode by the heat exchanger.

[0434] FIG. 2 This figure schematically shows the top view of the same first embodiment.

[0435] FIG. 3 This figure schematically shows the top view of a second embodiment in which the exchange regions are in the cover.

[0436] FIG. 4 This figure schematically shows the front view of the second example shown in the preceding figure.

[0437] FIG. 5 This figure schematically shows a top view of an embodiment of a base with a plurality of exchange regions made of a material different from that of the rest of the base.

[0438] FIG. 6 This figure schematically shows the top view of an example such as the one shown in FIG. 5 with the exception that there is a single exchange region which allows cooling a plurality of elements to be cooled.

[0439] FIG. 7 This figure schematically shows, according to a section of the front view of the base, the example shown in FIG. 5.

[0440] FIG. 8 This figure schematically shows a second embodiment of a module formed by the combination of two heat exchangers such as the one shown in the two preceding figures, in which the plurality of electronic devices are located like sandwich between the two exchangers.

DETAILED DESCRIPTION OF THE INVENTION

[0441] According to the first inventive aspect, the present invention relates to a device for evacuating heat from one or more electrical or electronic devices (E). Hereinafter, whenever electronic device (E) is indicated, it shall be understood that it can also be an electrical device (E). FIG. 1 shows a front view of the first embodiment of the invention and this very embodiment is shown in a top view in FIG. 2.

[0442] Both figures show a plurality of electronic devices (E) distributed according to a longitudinal direction X-X either individually or according to rows of two or more electronic devices (E) likewise distributed according to the longitudinal direction (X-X).

[0443] The heat exchanger comprises a base (1) having an inlet port (I) for a liquid coolant and an outlet port (O) for a liquid coolant to allow the circulation of the liquid which serves to remove heat evacuated by the electronic devices (E) when the heat exchanger is in the operating mode.

[0444] Considering the arrangement shown in FIG. 1, while the electronic devices (E) are arranged below the base (1), on the outer surface of a wall (1.1) of the base (1), above the same wall (1.1) is the opposite surface on which there is a cover (2) that forms a chamber (C). The liquid coolant circulates through the chamber (C).

[0445] Although the base (1) shows a wall (1.1) with a large thickness depicted by a horizontal rectangle, the wall (2.1) of the cover (2) is thinner and depicted by means of a thick line. In this embodiment, the wall (1.1) of the base (1) is a thick plate and the wall (2.1) of the cover (2) is sheet metal which has been stamped to form the cover (2).

[0446] Indication of being below or above, as positional references, should be interpreted considering the spatial arrangement shown in the figure given that the device can be in any position and orientation in the operating mode. Relative terms such as these and others such as right, left may be used in the description, it being understood that positional references with respect to the figure may likewise refer to the arrangement relative to one or more elements of the device taken as positional reference with respect to other elements also shown in the figure.

[0447] Considering FIG. 1 and FIG. 2, it can be seen that the cover (2) according to this embodiment has a length according to the longitudinal direction X-X such that the inlet port (I) and the outlet port (O) have direct access to the inside of the chamber (C) because the distance between ports (I, O) is smaller than the length of the cover (2). In this way, the electronic devices (E) are distributed also between the inlet port (I) and the outlet port (O) on a side of the wall (1.1) of the base (1), or one or more fin blocks (3) for heat dissipation are arranged on the other side of the same wall (1.1).

[0448] The fin block or blocks (3) for heat dissipation are located in the internal wall of the chamber (C) and in a region (R) in which the electronic devices are located on the other side of the wall (1.1). This region is the region (R) that will be referred to as a heat exchange region given that it is the region in which heat transfer by conduction through the material of the wall (1.1) occurs.

[0449] The minimum size of a heat exchange region (R) corresponds to the projection of the contact area with the electrical or electronic device (E) according to a direction perpendicular to the wall (1.1, 2.1) where the heat exchange region (R) is located. However, once the electrical or electronic device (E) give off heat to the wall, heat conduction is not only according to the direction perpendicular to the wall, but also to a larger extent transverse, if the wall (1.1, 2.1) is thick. This means that, according to preferred examples, the heat exchange region (R) is more extensive than the minimum region as shown in FIG. 2 in which the use of a heat conducting material in an area in which there are two electrical or electronic devices per heat exchange region (R) has been envisaged.

[0450] It is also considered relevant to clarify that although the electronic devices are depicted by means of a rectangle in the figures and that the entire contact area is also considered to be the area in which the electronic device (E) conducts heat, it is possible to use electronic devices (E) having more extensive contact bases with respect to the regions that actually generate heat. In these cases, the surface of the electronic device (E) is considered to have a limited extension with respect to the region in which heat is generated given that the rest of the base of the electronic device (E) only performs a structural function or another different function.

[0451] In other examples, the contact between the electronic device (E) and the heat exchanger is through a contact paste for heat exchange which is also limited to a specific region, leaving the rest of the area of the electronic device (E) without thermal conduction continuity with the heat exchanger. In these cases, it shall be interpreted that the electronic device (E) has a heat generating region limited to the region in which there is thermal conduction continuity, in this case, the region in which the contact paste for heat exchange extends.

[0452] These same FIGS. 1 and 2 show perforations that serve for the passage of fixing bolts (4) as fixing means, particularly bolts which press the wall (1.1) of the base (1) against the electronic devices (E), favoring a good contact between surfaces which improves heat transfer.

[0453] Likewise, FIG. 1 shows a sealing gasket (5) surrounding the inlet port (I) and a sealing gasket (5) surrounding the outlet port (O). The force exerted by the fixing means (4) not only increase the pressure between the wall (1.1) and the electronic devices (E) but cause the compression of the sealing gaskets (5), ensuring the leak-tight sealing in the inlet port (I) and the outlet port (O).

[0454] The compression of the sealing gaskets (5) gives rise to a force on the base (1) perpendicular to the wall (1.1) of the base (1), vertical according to the orientation of FIG. 1 and upwards, contributing to the bending stresses given also the reactions of the fixing means (4).

[0455] In the embodiment, for example, the fixing means (4) are distributed between the sealing gaskets (5) considering the longitudinal direction X-X, so the fixing means (4) exert a downward force in the intermediate area that is opposite the force exerted by the sealing gaskets (5).

[0456] This force composition causes a significant bending moment which generates deformations particularly in the central area of the heat exchanger, and the deformations, when occur, give rise to the separation between the electronic devices (E) and the external surface of the wall (1.1, 2.1); that is, between the surfaces in which heat exchange occurs, resulting in a drop in heat transfer.

[0457] Considering FIG. 2, the top view allows observing the base (1) as well as the elements in contact with the base (1), with the exception of the fin block (3) which has been eliminated only to facilitate visual access and allow better describing an example of the invention.

[0458] In the top view, the perimeter of the cover (2) is shown with a continuous line, leaving therein the inlet port (I) and the outlet port (O) so that the liquid coolant enters and exits by means of the fluid communication between said ports (I, O) and the chamber (C) defined between the cover (2) and the base (1).

[0459] This same figure in top view shows the area occupied by the electronic devices (E), particularly the area which is in contact with the wall (1.1) of the base (1). This set of areas is shown in the form of black rectangles.

[0460] In the wall (1.1) of the base (1) there are exchange regions (R), wherein the wall (1.1) is formed by a metallic heat transfer material and a wall that is thinner than in the configurations of the state of the art, given that the resistance requirements thereof do not necessarily include absorbing bending stresses, only the pressure exerted by the electronic devices (E) pressed against the outer surface thereof.

[0461] The area representing the heat exchange regions (R) which are made of a metallic heat transfer material is shown in grey. In this embodiment, copper has been chosen as the highly heat conducting material, however it could be any other of the metallic heat transfer materials described above (preferably materials comprising copper or aluminum as the metal in the highest amount by weight).

[0462] Another rectangle is shown externally to the heat exchange regions (R), this time shown with double oblique stripes, depicting a part of the base (1) formed in steel as a structural metallic material and identified with the letters St, however, it could be any other of the structural metallic materials described above (preferably, steel materials and materials comprising aluminum as the metal in the highest amount by weight).

[0463] The configuration according to this embodiment is a frame configuration around the heat exchange regions (R) with transverse segments forming islands in which plates made of the metallic heat transfer material are inserted. The internal regions (R) according to this embodiment are completely surrounded by steel St, although in this embodiment the end regions do not have steel at both longitudinal ends.

[0464] The steel frame verifies that the distance (d) extends longitudinally with d=d.sub.2 which is the distance between the farthest points of the heat exchange regions (R), leaving all of them between the area with steel St reinforcement. That is, the steel part extends longitudinally a segment such that all the heat exchange regions (R) are inside the segment. It is said to be according to the longitudinal direction because solo only a projection according to the longitudinal direction is considered regardless of the position and the dimensions thereof according to other directions (transverse and heightwise).

[0465] However, in an example in which the stress requirements are not so high it would suffice that at least one exchange region (R) has the longitudinal steel St reinforcement, i.e. the distance (d) would verify that d=d.sub.1 as also shown in FIG. 2. In this case, the area with double oblique stripes would also be reduced to the longitudinal extension of the exchange region (R) according to the longitudinal direction. This same configuration with individual reinforcements for a heat exchange region (R), according to another example, is repeated for each and every heat exchange region (R).

[0466] This steel St frame or reinforcement is the one that mainly absorbs the bending moments produced by the forces distributed according to the longitudinal direction X-X.sup.1.

[0467] According to another embodiment, the steel St frame which houses parts made of a metallic heat transfer material completely surrounds each of these parts which in turn form the heat exchange regions (R).

[0468] The distribution on both sides of the fixing means (4) also generates transverse bending moments which, although of lesser importance because their width is smaller than the length of the base (1), can also give rise to undesired deformations. These transverse bending stresses are absorbed by the steel cross members configured inside the steel frame or reinforcement.

[0469] A specific way of carrying out this embodiment consists of extending the steel frame to the rest of the base, i.e. causing the perimeter region with double oblique stripes to coincide with the perimeter of the base (1) such that the entire base is made of steel except for the plates made of heat transfer metallic material located in the heat exchange regions (R). This situation will be described in the examples using FIGS. 5 and 6. The material of the base (1) which is not the steel St part and also not the heat exchange region can be of a third material and particularly either of the two mentioned, i.e., steel or the material of the exchange region.

[0470] According to another embodiment shown in FIG. 3, the cover (2) is the steel (St) part, although it could be any other of the structural metallic materials described above, so that it extends even beyond the inlet port (I) and the outlet port (O) according to the longitudinal direction (X-X) giving rise to the necessary bending stiffness. In this embodiment, the base (1) can be made of a highly heat conducting material or also of steel.

[0471] According to this same example shown in i FIG. 3, the cover has a plurality of heat exchange regions (R) configured in another material or with a smaller thickness, for example, to favor heat exchange with the electrical or electronic devices (E). However, in the case of the cover (2) which, in this embodiment, is configured in a stamped sheet metal, the thickness thereof is thinner and allows suitable heat transmission without reducing its thickness even though it is made of steel.

[0472] This FIG. 3 shows by way of example a heat exchanger without perforations for the fixing means given that the action of attachment and force against the electrical or electronic devices (E) is achieved with an external anchoring configured to press the base (1), the cover (2), or both (1, 2).

[0473] FIG. 4 is a front view schematically depicting the same embodiment which clearly shows the electrical or electronic devices (E) located on the outer surface of the cover (2), such that the heat exchange regions (R) exist on the wall (2.1) of the cover (2).

[0474] In this example, by comparing it with that shown in FIG. 1, it can be seen that the fin block (3) in both cases is attached to the surface of the wall (1.1, 2.1) through which heat conduction which evacuates heat from the electrical or electronic devices occurs and is not attached to the other wall. Particularly, in FIG. 1 the fin block (3) is attached to the wall (1.1) of the base (1) and not to the cover (2) and in FIG. 4 the fin block (3) is attached to the wall (2.1) of the cover (2) but not to the base (1).

[0475] FIG. 5 shows an embodiment of a base (1) without showing the inlet port (I) or the outlet port (O), wherein the wall (1.1) of the base (1) is formed entirely by a steel (St) plate acting as the main resistant element of the heat exchanger, although it could be any other of the structural metallic materials described above. This steel wall (1.1) comprises rectangular windows occupied by parts made of a metallic heat transfer material, giving rise to the heat exchange regions (R). In this embodiment, this metallic heat transfer material is aluminum or copper.

[0476] FIG. 6 schematically shows another embodiment in which the wall (1.1) of the base (1) is now made of steel, although it could be any other of the structural metallic materials described above, and includes a single window in which there is a part made of a metallic heat transfer material, giving rise to a heat exchange region (R) adapted to receive one or a plurality of electronic devices (E) to be cooled.

[0477] If the application for which the heat exchanger is designed has more demanding specifications for use: significant temperature changes, high pressures or stresses which may cause bending, then a more specific example such as the one shown in FIG. 5 or FIG. 6 uses of a metallic sheet which is located covering at least all the attachments between different metallic materials, preferably the entire area of the base (1). This sheet ensures the leaktightness in such attachments after welding.

[0478] According to one embodiment, the sheet melts during passage through the furnace intended to cause the brazing of the rest of the parts. In this embodiment, the sheet does not only ensure leaktightness with the part or parts made of a metallic heat transfer material in the jheat exchange region (R), but rather also melts during passage through the furnace and allows attachment with the fin block or blocks (3).

[0479] According to another embodiment, between the sheet and the substrate formed by the wall (1.1) that is made of steel, although it could be any other of the structural metallic materials described above, and the parts made of a metallic heat transfer material, there is placed a brazing paste which greatly secures the attachment without the metallic sheet necessarily melting.

[0480] Determining whether or not the sheet melts is by means of selecting a metal with a melting point below or above, respectively, the established temperature of the welding furnace.

[0481] The sheet is preferably very thin so that it does not increase thermal resistance in the heat exchange region (R).

[0482] FIG. 7 shows the section of FIG. 5 in which the structure resulting from inserting parts made of a different material, a metallic heat transfer material, into the base (1), giving rise to the heat exchange regions (R), can be seen.

[0483] FIG. 8 shows a sandwich-like configuration in which two heat exchangers configured according to any of the described embodiments are located with the outer areas configured to be in contact with the electronic devices (E) and to face one another, particularly with both being in contact with the electronic devices (E) that are retained configuring a sandwich.

[0484] In all the cases described as detailed examples and based on the figures, the fin block (3) is spaced apart from the cover (2) given that the steel part provides sufficient bending stiffness to the heat exchanger. This allows using a single weld between the fin block (3) and the internal surface of the wall (1.1) of the base (1) without attachment with the internal surface of the cover being necessary. Internal surfaces are understood to mean those which give rise to the inside of the chamber (C).

[0485] The example of FIG. 8 show coinciding inlets and outlets of the exchanger located above and below because they are depicted in a front view, although in a top view they are offset, preventing mechanical interference; for example, the heat exchanger located at the upper part according to the orientation of the figure has the inlet for the liquid coolant on the right and the outlet on the left and, the heat exchanger located at the lower part also according to the orientation of the figure has the inlet for the liquid coolant on the left and the outlet on the right.