The present invention relates to a method for cooling at least one object by means of a turbulator placed in a cavity of a baseplate. The invention further relates to a cooling device and use of a cooling device.
Power electronics such as rectifiers, inverters, converters, semiconductors, transistors and other often generates much heat during use and it is therefore known to cool these devices to ensure their function and to prevent damage.
From EP 2 207 201 B1 it is known to place an electronic component that requires cooling on top of a plate where the bottom side of the plate is cooled by liquid which is guided along the plate by means of a distributing element. But the heat transfer in such an arrangement is not particularly efficient.
Thus, from U.S. Pat. No. 9,638,477 B1 it is known to place an electronic device on a plate comprising a turbulator extending from the bottom of the plate. The plate is then positioned on a manifold so that the turbulator extends down into a cavity in the manifold, and a flow of cooling liquid is established in the cavity. Forming the turbulator integrally with the plate ensures good heat conductivity but this design is complex and costly.
It is therefore an object of the present invention to provide for a more simple and cost-efficient technique for cooling an object.
The invention relates to a method for cooling at least one object. The method comprises the steps of
Forming the turbulator as a separate part is advantageous in that a turbulator having an efficient design in relation to generating turbulence in the flow of cooling fluid hereby can be manufactured in a separate process e.g., by punching, stamping or a similar process where the turbulator can be manufactured fast and efficiently in a simple mechanical process. And by connecting the object to the connection surface so that the object deforms and compresses the turbulator is advantageous in that the turbulator hereby presses firmly against the object and the bottom of the cavity hereby ensuring good heat conduction between the object and the turbulator while at the same time ensuring that the cooling fluid cannot flow over or under the turbulator—i.e. all the cooling fluid is guided through the turbulator thus increasing the efficiency of the cooling device to which the object is attached.
In an aspect, the method further comprises the step of arranging a gasket between the object and the baseplate.
Arranging a gasket between the object and the baseplate is advantageous in that this reduces the risk of the cooling fluid leaking out between the object and the baseplate.
In an aspect, the at least one object is connected tightly to the baseplate.
Connecting the object tightly to the baseplate is advantageous in that this reduces the risk of the cooling fluid leaking out between the object and the baseplate and it ensure good heat conduction between the baseplate and the object.
In an aspect, the turbulator is extending out of the cavity so that the at least one object deforms the turbulator and forces the turbulator into the cavity.
Forming the turbulator so that it is slightly higher than the depth of the cavity and thereby is extending out of the cavity is advantageous in that an object with a flat bottom side hereby will compress the turbulator when the bottom part of the object is connected tightly to the connection surface—i.e., this ensures a simple design of the object.
In an aspect, at least a bottom part of the at least one object is extending into the cavity, when the at least one object is connected to the connection surface, so that the bottom part of the at least one object deforms the turbulator and forces the turbulator into the cavity.
Forming the object so that a bottom part is projecting into the cavity and thereby compresses and deforms the turbulator when the object is connected to the connection surface is advantageous in that turbulators that are slightly lower than the depth of the cavity hereby also can be compressed to ensure good heat conduction between the cooling fluid, the turbulator and the object.
In an aspect, the at least one object comprises a contact face arranged to be connected to the connection surface and wherein the bottom part is protruding from the contact face.
Hereby is achieved an advantageous embodiment of the invention.
In an aspect, at least a part of the connection surface is sloping downwards towards the at least one cavity so that at least a part of the at least one object is bend in a downward arc, whereby the at least one object deforms the turbulator and forces the turbulator into the cavity, when the at least one object is connected to the connection surface.
Forming at least some of the connection surface around the cavity so that it is sloping downwards towards the cavity is advantageous in that this will entail that the object is at least slightly bend downwards across the cavity whereby the object deforms and compresses the turbulator when the object is connected to the connection surface.
This is advantageous in that it hereby in a simple manner is ensured that the object presses firmly against the turbulator and in that this modification is easy to make on existing cooling systems simply by machining the edges around the cavities.
In an aspect, the at least one object is connected to the connection surface by means of at least one connection means.
Connecting the object to the connection surface by means of connection means is advantageous in that the object hereby can be easily connected and disconnected.
It should be noticed, that in this context the term “connection means” should be understood as any kind of connector suited for connecting an object to a connection surface. I.e., the term includes any kind of screws, bolts, rivets or other.
In an aspect, the at least one connection means comprises bolts.
Connecting the object to the connection surface by means of bolts is advantageous in that bolts are excellent for generating the downward force needed to compress the turbulator and form a tight connection between the object and the connection surface.
In an aspect, the at least one object fully covers the at least one cavity when the at least one object is connected to the connection surface.
Forming the object so that it fully covers the cavity when the object is connected to the connection surface is advantageous in that no further sealing arrangement or other are needed.
In an aspect, the at least one object comprises heat generating power electronics.
Power electronics generates much heat and therefore needs efficient cooling, and it is therefore particularly advantageous to cool heat generating power electronics by means of the present invention. Furthermore, power electronics are relatively dimensionally stable and therefore suited for being cooled by a method according to the present invention.
In an aspect, the at least one object comprises an intermediate plate.
Making the object comprise an intermediate plate is advantageous in that this enables that e.g. delicate power electronics can be connected to the intermediate plate in one process and the more forceful connection of the intermediate plated to the connection surface can be performed in another separate process. Furthermore, the intermediate plate enables standardized connection of the object on the connection surface even if e.g., the heat generating power electronics connected to the plate vary in design.
In an aspect, the method comprises the step of connecting the intermediate plate to the connection surface and subsequently connecting the power electronics to the intermediate plate.
Connecting the intermediate plate to the connection surface in a separate process is advantageous in that this hereby can be done by means of processes that might otherwise damage the power electronics—e.g., such as soldering or welding.
Furthermore, this ensures that the power electronics can be replaced without exposing the cavity—i.e., without having to drain and refill the cooling fluid.
In an aspect, the method comprises the step of connecting the intermediate plate to the connection surface by means of soldering.
Soldering ensures a strong and tight connection that at the same time ensures good heat conduction.
In an aspect, the at least one object deforms the turbulator so that the height of the turbulator is reduced by between 0.1% and 30%, preferably between 0.5% and 20% and most preferred between 1% and 10%.
If the turbulator is compressed too much its efficiency might be affected and it requires too much force to mount the object. However, if the turbulator is compressed too little the heat conduction is reduced. Thus, the present height reduction ranges present an advantageous relationship between usability and efficiency.
Furthermore, if the turbulator is compressed too much the turbulator might be plastically deformed—instead of just elastically deformed—which could affect the functionality of the turbulator if it was reused—i.e., if the object was dismounted and remounted.
The invention further relates to a cooling device comprising a baseplate having at least one cavity extending from a connection surface of the baseplate and into the baseplate and wherein a cooling fluid channel connects the at least one cavity with a cooling fluid inlet and a cooling fluid outlet of the baseplate. The cooling device further comprises a turbulator arranged in the at least one cavity, and at least one object being connected to the connection surface so that the at least one object deforms the turbulator and forces the turbulator into the cavity.
Designing the cooling device and/or the object so that the object compresses the turbulator in the cavity is advantageous in that good heat conduction between the object and the turbulator hereby is ensures while at the same time ensuring that the turbulator is correctly positioned in the cavity, so that all cooling fluid have to pass through the turbulator.
In an aspect, the at least one object deforms the turbulator so that the height of the turbulator is reduced by between 0.1% and 30%, preferably between 0.5% and 20% and most preferred between 1% and 10% when the at least one object is connected to the connection surface.
If the turbulator is compressed too much its efficiency might be affected and it requires too much force to mount the object. However, if the turbulator is compressed too little the heat conduction is reduced. Thus, the present height reduction ranges present an advantageous relationship between usability and efficiency.
In an aspect, the height of the turbulator is reduced by at least 0.1 millimeter when the at least one object is connected to the connection surface.
Compressing the turbulator so that the height of the turbulator is reduced by at least 0.1 millimeter is advantageous in that this ensures that the tabulator presses firmly against the object.
In an aspect, the height of the turbulator is reduced between 0.1 and 2 millimeters when the at least one object is connected to the connection surface.
the present height reduction range ensures that the tabulator presses firmly against the object while at the same time ensuring that the efficiency of the turbulator is affected or that it requires too much force to mount the object.
In an aspect, the cooling device further comprises a gasket encircling the at least one cavity.
Arranging a gasket between the object and the baseplate all around the cavity is advantageous in that this reduces the risk of the cooling fluid leaking out between the object and the baseplate.
In an aspect, the gasket is arranged in a baseplate groove in the connection surface or in an object grove in the object.
Arranging the gasket in a groove in the connection surface or the object is advantageous in that this ensures the correct position of the gasket is maintained at all times—thus, simplifying the mounting and dismounting procedure.
In an aspect, the height of the turbulator is greater than the depth of the at least one cavity before the at least one object is connected to the connection surface.
Forming the turbulator so that it is at least slightly higher than the depth of the cavity before the object is connected to the connection surface is advantageous in that the turbulator thereby is extending out of the cavity whereby an object with a flat bottom side will easily compress the turbulator when the bottom part of the object is connected tightly to the connection surface—i.e., this ensures a simple design of the object.
In an aspect, at least a part of the connection surface is sloping downwards towards the at least one cavity so that at least a part of the at least one object is bend in a downward arc, whereby the at least one object deforms the turbulator and forces the turbulator into the at least one cavity, when the at least one object is connected to the connection surface.
Forming at least some of the connection surface around the cavity so that it is sloping downwards towards the cavity is advantageous in that this will entail that the object is at least slightly bend downwards across the cavity whereby the object deforms and compresses the turbulator when the object is connected to the connection surface. This is advantageous in that it hereby in a simple manner is ensured that the object presses firmly against the turbulator and in that this modification is easy to make on existing cooling systems simply by machining the edges around the cavities.
In an aspect, the baseplate comprises connection means for connecting the object to the connection surface.
Connecting the object to the connection surface by means of connection means is advantageous in that the object hereby can be easily connected and disconnected.
In an aspect, the connection means comprises threaded holes.
Making the baseplate comprise threaded holes is advantageous in that a tight and forceful connection between the object and the baseplate hereby can be made is a simple manner.
In an aspect, the turbulator is made of metal.
Forming the turbulator of metal is advantageous in that metal is an excellent conductor of heat.
In an aspect, the metal is aluminium.
Forming the turbulator of aluminium is advantageous in that aluminium is inexpensive, easy to machine and it is an excellent conductor of heat.
In an aspect, the turbulator is made of plastic.
Forming the turbulator of plastic is advantageous in such a turbulator is easy to manufacture even if it has a complex design and it is very inexpensive.
In an aspect, the baseplate is made of metal.
Forming the baseplate of metal is advantageous in that metal is an excellent conductor of heat.
In an aspect, the metal is aluminium.
Forming the baseplate of aluminium is advantageous in that aluminium is inexpensive, easy to machine and it is an excellent conductor of heat.
In an aspect, the at least one object is connected to the connection surface by means of at least one connection means.
Connecting the object to the connection surface by means of connection means is advantageous in that the object hereby can be easily connected and disconnected.
In an aspect, the at least one connection means comprises bolts.
Connecting the object to the connection surface by means of bolts is advantageous in that bolts are excellent for generating the downward force needed to compress the turbulator and form a tight connection between the object and the connection surface.
In an aspect, the at least one object comprises heat generating power electronics.
Power electronics generates much heat and therefore needs efficient cooling, and it is therefore particularly advantageous to cool heat generating power electronics by means of the present invention. Furthermore, power electronics are relatively dimensionally stable and therefore suited for being cooled by a method according to the present invention.
In an aspect, the at least one object comprises an intermediate plate.
Making the object comprise an intermediate plate is advantageous in that this enables that e.g. delicate power electronics can be connected to the intermediate plate in one process and the more forceful connection of the intermediate plated to the connection surface can be performed in another separate process. Furthermore, the intermediate plate enables standardized connection of the object on the connection surface even if e.g., the heat generating power electronics connected to the plate vary in design.
In an aspect, the intermediate plate is connected to the connection surface and the power electronics is connected to the intermediate plate.
Connecting the intermediate plate to the connection surface in a separate process is advantageous in that this hereby can be done by means of processes that might otherwise damage the power electronics—e.g., such as soldering or welding. Furthermore, this ensures that the power electronics can be replaced without exposing the cavity—i.e., without having to drain and refill the cooling fluid.
In an aspect, the intermediate plate is connected to the connection surface by means of soldering.
Soldering ensures a strong and tight connection that at the same time ensures good heat conduction.
The invention also relates to use of a cooling device according to any of the previously discussed cooling devices for performing the method according to any of the previously discussed methods.
Hereby is achieved an advantageous embodiment of the invention.
The invention will be explained further herein below with reference to the figures in which:
In this embodiment the baseplate 3 is made from a single block of machined aluminium, but in another embodiment the baseplate 3 could be cast and/or the baseplate 3 could be made in from another material such as stainless steel, brass, cobber or another metal, the baseplate could be made from a composite material, ceramic or other or any combination of the above.
In this embodiment the baseplate 3 comprises six cavities 2 extending from the connection surface and down into the baseplate 3. However, in another embodiment the baseplate 3 could comprise another number of cavities 2 such as one, two, four, eight or even more. In this embodiment the cavities 2 are milled in the baseplate 3 but in another embodiment the cavities 2 could also or instead be formed by spark machining, drilling, stamping or other or any combination thereof or the cavities 2 could be formed in a casting process.
In this embodiment the cavities 2 are initially formed in the contact surface 4 of the baseplate 3 through milling. Connection means 9 in the form of threaded holes are also formed in the baseplate 3 along with a cooling fluid channel (not shown but discussed in relation to
The object 1 is then connected to the contact surface 4 by means of connection means 9 which in this embodiment is bolts extending through a hole in the object and into threaded holes in the baseplate 3. However, in another embodiment the connection means 9 could also or instead comprise a clamping device, adhesive, welding or other or any combination thereof.
In this embodiment the turbulator 5 is made from drawn aluminium sheet metal but in another embodiment the turbulator 5 could also or instead be made through casting, milling, 3D printing or other and/or the turbulator 5 could be made from cobber, stainless steel, brass, or another metal and/or the turbulator 5 could be made from a composite material, ceramic, plastic or other or any combination hereof.
The main function of the turbulator 5 is to turn laminar flow of the cooling fluid flowing through the cavity 2 into turbulent flow, in that a turbulent flow will mix up the cooling fluid as it passes through the cavity 2 and thereby increase the contact with the turbulator 5 and the object 1, whereby the heat exchange is increased. It should be noted that turbulators 5 can be made with a multitude of designs—e.g.
with labyrinth channels, heat sink ribs or fins arranged in a pattern—such as herringbone, alternate directions, zig-zag or other-, coils, balls, twisted wire rod, as steel wool or other or any combination thereof. During the connection process the object 1 will deform the turbulator 5 and force it into the cavity 2. Since the height H of the turbulator 5 is only reduced by approximately 6% in this embodiment, when the object 1 compresses the turbulator 5, and given the design of the turbulator 5, the turbulator 5 is only subject to elastic deformation in this embodiment but in another embodiment the turbulator 5 could also be subject to plastic deformation.
Once the object 1 is tightly connected to the contact surface 4 a flow of cooling fluid is established through a cooling fluid channel (not shown) to direct cooling fluid through the cavity 2 and the turbulator 5 to cool the object 1.
In this embodiment the object 1 comprises an intermediate plate 10 which is extending continuously across all the cavities 2 in the baseplate 3. However, in another embodiment at least some of the cavities 2 could be provided with individual intermediate plates 10. In this embodiment turbulators 5 are first arranged in the cavities 2 so that they extend slightly out of the cavities 2—because they are higher than the depth D of the cavities 2. The intermediate plate 10 is then connected tightly to the contact surface 4 of the baseplate 3 by means of soldering and as the intermediate plate 10 is forced against the contact surface 4, the turbulators 5 are deformed and forced down into the cavities so that they are flush with the contact surface 4 and presses firmly against the intermediate plate 10.
However, in another embodiment the intermediate plate 10 could be connected to the contact surface 4 by means of adhesive, welding, bolts, rivets or other or any combination thereof.
In this embodiment the object 1 comprises power electronics 17 in the form of converters and in this embodiment the power electronics 17 is connected to the intermediate plate 10 by means of bolts after the intermediate plate 10 has been connected to the baseplate 3. Through this design the power electronics 17 can be replaced while the cavities 2 are still filled with cooling fluid. In another embodiment the power electronics 17 could be connected to the intermediate plate 10 before the intermediate plate 10 is connected to the baseplate 3 and the power electronics 17 could be connected to the intermediate plate 10 by means of other connection means 9 as previously exemplified.
In this embodiment a bottom part 7 of the object 1 is protruding from a contact face 8 at the underside of the object 1. Thus, in this embodiment the turbulator 5 is not formed to extend out of the cavity 2. In this embodiment the turbulator 5 is initially substantially flush with the contact surface 4 of the baseplate 3 but when the object 1 is connected, so that the contact face 8 of the object 1 is forced against the contact surface 4 of the baseplate 3, the protruding bottom part 7 of the object 1 is extending into the cavity 2 so that it deforms the turbulator 5 and forces the turbulator 5 into the cavity 2. In another embodiment the turbulator 5 could initially be formed with a height H shorter than the depth D of the cavity 2 depending on the extend of the protruding bottom part 7 of the object 1.
In this embodiment the contact surface 4 is formed with sloping edges 18 around the cavity 2, wherein the edges 18 are sloping downwards towards the cavity 2 as indicated by the angular arrows on
In the embodiment discloses in
Placing the gasket 6 in a groove 15, 16 simplifies assembly and ensures that the gasket 6 stays in the right place but in another embodiment the baseplate 3 and the object 1 would not be provided with grooves 15, 16 and the gasket 6 would be placed directly between the baseplate 3 and the object 1. In this embodiment the gasket 6 is an O-ring made from rubber but in another embodiment the gasket 6 could have another shape, such as oval, rectangular, flat, or other and/or the gasket 6 could be made in another material such as cobber, plastic, a composite material or other or the gasket 6 could be formed by a sealing paste.
In relation to
In this embodiment the object 1 comprises an intermediate plate 10 as described in relation to
In each of the embodiments disclosed in
In this embodiment the cooling fluid is a glycol and water solution but in another embodiment the cooling fluid could be brine, water, ammonia, or another form of natural or artificial cooling fluid suitable for exchanging heat with the objects 1 to cool the objects 1.
In the foregoing, the invention is described in relation to specific embodiments of objects 1, baseplates 3, turbulators 5 and other as shown in the drawings, but it is readily understood by a person skilled in the art that the invention can be varied in numerous ways within the scope of the appended claims.
Filing Document | Filing Date | Country | Kind |
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PCT/DK2021/050021 | 1/21/2021 | WO |