REFRIGERATION

Description

State of the art

[0001] The present invention relates to a cooling device for cooling components and an electronic arrangement.

[0002] Power semiconductors in power electronics typically conduct high currents, which can lead to significant heat loss. Cooling of such power semiconductors is often necessary, for example, to prevent damage from overheating.

[0003] For cooling, for example, liquid cooling or air cooling can be used. So-called pulsating heat pipe structures can also be used as cooling devices. These are particularly suitable for direct integration into existing components with the aim of efficiently dissipating heat from thermal hotspots to heat sinks. The heat is usually first spread from the point of heat introduction by means of heat conduction. A cooling device designed as a pulsating heat pipe comprises a cooling channel in the cooling device, which has a meandering shape and is filled with a working fluid that is present in the cooling channel in both gaseous and liquid form. In the cooling device, heat is transferred to the cooling channel in a basic area, so that the working fluid in the cooling channel evaporates locally. This creates pressure gradients that transport the working fluid through the cooling channel.

[0004] The vapor bubbles also migrate into a condenser section of the cooling channel and condense there. The heat is thus dissipated to the environment via the walls of the condenser and, for example, via fins. Overall, the heat introduced into the cooling device in the base area is distributed throughout the entire cooling device. A cooling device designed as a pulsating heat pipe thus serves as a heat-spreading design element. Meandering pulsating heat pipes are known from the prior art. A cooling device according to the preamble of claim 1 is known from document US 2021 / 136954 A1. Disclosure of the invention

[0005] According to the invention, a cooling device according to claim 1 is proposed for cooling components. The cooling device comprises a cooling channel formed in the cooling device, which has a plurality of central segments and a plurality of deflection segments, wherein the cooling channel is filled with a working fluid that is present in both gaseous and liquid form in the cooling channel. Furthermore, the cooling device comprises a base region of the cooling device, which can be connected in a heat-conducting manner to a component to be cooled, a deflection region of the cooling device, and an intermediate region between the base region and the deflection region, wherein the central segments each extend from the base region to the deflection region, wherein the deflection segments each form a reversal of direction within the base region and within the deflection region and each connect two central segments to one another.According to the invention, a first deflection segment in the base region connects two first middle segments to one another, wherein at least two second middle segments are arranged between the two first middle segments, wherein the two second middle segments are connected to one another in the base region by means of a second deflection segment. Advantages of the invention

[0006] Compared to the prior art, the cooling device features a cooling channel geometry that enables multi-dimensional heat spreading using the cooling channel. The heat is not only transported from the base area of ​​the cooling device, where the component to be cooled rests, to the center segments and the deflection area (y-direction), but is also transported along the base area (x-direction). For example, the heat is spread parallel to the support surface on which the component to be cooled rests on the base area of ​​the heat sink. The cooling channel, filled with the working fluid, alternates between a hot and a cold area. This maintains the pressure gradients in the cooling channel that drive the pulsating heat pipe and are necessary for the heat sink to operate as a pulsating heat pipe.This allows heat to be advantageously conducted in an additional spatial direction (x-direction) using pulsating heat pipes, rather than through thermal conduction in the solid body as in the prior art. By spreading the heat in a further spatial direction (x-direction) within the cooling device using the pulsating heat pipe, the overall thermal resistance of the cooling device is reduced, as a very small temperature difference allows a large amount of heat to be transported over longer distances. The heat is distributed over a large area, resulting in advantageously simple heat dissipation even with small temperature differences.

[0007] Thus, in the cooling device according to the invention, a cooling channel functioning as a pulsating heat pipe is used to spread the heat in the x-direction. The cooling channel, which functions as a pulsating heat pipe, then bends in the y-direction, thus spreading the heat in both the x-direction and the y-direction. The entire spreading takes place via the pulsating heat pipe and not via heat conduction. This results in a very small temperature difference.

[0008] Due to the improved heat spreading and heat conduction provided by the pulsating heat pipe, the material of the channel walls plays a less important role. It is therefore also conceivable to implement corresponding cooling devices using materials with comparatively poorer thermal conductivity, such as steel. Furthermore, relatively little raw material is required for the cooling device, since no solid base plate is required for heat spreading in the x-direction; instead, heat spreading in the x-direction occurs through the cooling channel itself. This significantly reduces the material costs and weight of the cooling device.

[0009] A further advantage of the cooling device according to the invention lies in the overall asymmetrical geometry of the cooling channel in the cooling device, due to the deflection segments in the deflection area. This asymmetrical geometry of the cooling channel promotes the start-up of the pulsating heat pipe in the cooling device. Furthermore, the heat input into the cooling channel of the cooling device is initially very limited locally, thus promoting high pressure gradients in the working fluid of the pulsating heat pipe, thus achieving better start-up behavior of the pulsating heat pipe.

[0010] Further advantageous embodiments and refinements of the invention are made possible by the features specified in the subclaims. According to an advantageous embodiment, the first center segments and the second center segments extend in a common plane.

[0011] According to the invention, the first deflection segment and the second deflection segment run in a common plane.

[0012] According to the invention, the first deflection segment has a first intermediate section in which the deflection segment extends straight between two first deflection sections, wherein the second deflection segment has a second intermediate section in which the second deflection segment extends straight between two second deflection sections. In the straight intermediate sections, the working fluid can advantageously be guided well along the base region in the x-direction. If the intermediate section extends straight, the cooling device can have a flat support surface for the component to be cooled in this region. The cooling channel then extends in the intermediate section, for example, parallel to the flat contact surface, so that the heat can be dissipated evenly from the component.

[0013] According to the invention, the first intermediate section runs parallel to the second intermediate region. This allows for advantageously good and uniform heat dissipation through the cooling device.

[0014] According to an advantageous embodiment, the at least one cooling channel is formed in a curved cooling element, in particular in a curved tube. This allows the cooling device to be manufactured in an advantageously simple manner and advantageously be designed to be stable.

[0015] According to an advantageous embodiment, a flat support surface is formed on the cooling device in the base area of ​​the cooling device, against which the component can be placed. The heat of the component to be cooled can be transferred to the cooling element and to the working fluid in the cooling element via the support surface.

[0016] According to an advantageous embodiment, further pairs of center segments are arranged between the two second center segments, each of which is connected to one another by means of a further deflection segment in the base region. This achieves a particularly advantageous geometry of the cooling channel, through which heat can be conducted by means of a pulsating heat pipe both along the base region (x-direction) and away from the base region toward the deflection region (y-direction).

[0017] According to an advantageous embodiment, the cooling device is provided with a plurality of channels that are fluidically separated from one another and run parallel to one another. By having a plurality of parallel channels, the cooling device can be further improved and a larger surface area is provided for heat to be dissipated from the component.

[0018] Furthermore, the invention leads to an electronics assembly comprising the described cooling device. Furthermore, the electronics assembly comprises a component to be cooled, which is in particular a semiconductor component, for example, of a motor vehicle. The component to be cooled is thermally conductively connected to the base area of ​​the cooling device. The cooling device enables particularly effective and reliable cooling of the component to prevent overheating. Short description of the drawings

[0019] An embodiment of the invention is illustrated in the drawing and will be explained in more detail in the following description. It shows Fig. 1 is a schematic representation of an embodiment of the cooling device according to the invention, Fig. 2 is an embodiment of a cooling element from which the cooling device can be made. Embodiments of the invention

[0020] The Figur 1 shows an embodiment of an electronic arrangement 100 with a cooling device 1. The cooling device 1 can be used for cooling electronics or other hotspots of all kinds, for example for cooling power electronics in electric vehicles, passive battery cooling, cooling of engine control units, charging stations or drive units in eBikes.

[0021] The Fig. 1 The electronic arrangement 100 shown comprises a component 101, for example with power electronics, for example a semiconductor component, and a cooling device 1. The cooling device 1 is designed to cool the component 101. For this purpose, a base region 2 of the cooling device 1 is connected to the component 101 in a thermally conductive manner. For this purpose, the component 101 rests, for example, directly or indirectly, on the base region 2 of the cooling device 1. For this purpose, a flat support surface 9, against which the component 101 rests, is formed on the cooling device 1 in the base region 2. If the cooling channel 1 is formed, for example, in a curved cooling element 8, for example in a curved tube, an outer side of the curved cooling element 8, for example of the curved tube, can be flattened, so that a flat support surface 9 is created.

[0022] The cooling device 1 comprises a cooling channel 5. The cooling channel 5 is preferably tubular. The cooling channel 5 can, for example, be formed in a bent cooling element 8, in particular in a bent tube. However, the cooling channel 5 can also run, for example, in solid metal parts, for example in the form of a cooling channel 5 milled into a plate or as a cooling channel 5 between metal sheets. The cooling channel 5 can run through several parts of the cooling device 1, for example several pipe sections, which are connected to one another, for example by brazed joints. The cooling channel 5 can, for example, have a circular, an elliptical, or a rectangular cross-section. The cooling channel 5 can, for example, have a diameter of approximately 0.5 to 2 mm. The cooling device 1 can, for example, also comprise several cooling channels 5.The cooling channels can, for example, run parallel to one another and are fluidically separated from one another. If the cooling device 1 comprises several cooling channels 1, the cooling device 1 can, for example, be designed as a curved, flat tube, also called a multiport tube, with several cooling channels 5 running parallel to one another. An exemplary embodiment of such a cooling element 8 designed as a flat tube is shown in FIG. Fig. 2 The Fig. 2 The cooling element 8 shown can, for example, be designed according to the Fig.1 shown course of the cooling channel 5 and then form the body of the cooling device 1.

[0023] An embodiment of the course of the cooling channel 5 is shown in Fig. 1 shown. The cooling channel 5 comprises several central segments 51 and several deflection segments 52. The central segments 51 and the deflection segments 52 represent sections of the cooling channel 5. In addition to the base region 2, the cooling device 1 further comprises a deflection region 3. Furthermore, the cooling device 1 comprises an intermediate region 4, which is arranged between the base region 2 and the deflection region 3. The central segments 51 of the cooling channel 5 extend from the base region 2 via the intermediate region 4 to the deflection region 3. Each deflection segment 52 of the cooling channel 5 is arranged either in the base region 2 of the cooling device 1 or in the deflection region 3 of the cooling device 1. The deflection segments 52 each form a direction reversal within the base region 2 and within the deflection region 3. The deflection segments 52 each connect two central segments 51 to one another. As in Figur 1 As can be seen, the cooling channel 5 extends from the base region 2 of the cooling device 1 through an intermediate region 4 to a deflection region 3. The middle segments 51 each extend from the base region 2 to the deflection region 3, i.e. through the intermediate region 4. All middle segments 51 are straight and arranged parallel to one another. The middle segments 51 are all arranged in a common plane in the cooling device 1. The deflection segments 52 are each arranged at the ends of the middle segments 51 within the deflection region 3 and within the base plate 2 and each form a reversal of direction. In each case, one deflection segment 52 connects two middle segments 51 to one another. The cooling channel 5 is preferably closed.For this purpose, the cooling channel 5 preferably has a connecting region 58, which is preferably located within the deflection region 3 and which forms a closed circuit of the cooling channel 5. Further preferably, the cooling channel 5 has a valve (not shown in the figures) to enable, for example, evacuation of the cooling channel 5 and filling of the cooling channel 5 with the working fluid 6.

[0024] As in Fig. 1 As shown, the cooling device 1 comprises several pairs of center segments 51. The two center segments 51 of a pair of center segments 51 are each connected to one another by a deflection segment 52 in the base region 2 of the cooling device 1. In this embodiment, the cooling device 1 comprises six pairs of center segments 51 and correspondingly six deflection segments 52 in the base region 2 of the cooling device 1. Each of the deflection segments 52 in the base region 2 of the cooling device 1 connects the two center segments 51 of a pair of center segments 51 to one another. As shown in Fig. 1 As shown, two first center segments 51a form a first pair of center segments 51, wherein the two first center segments 51a are connected to one another by a first deflection segment 52a in the base region 2 of the cooling device 1. Furthermore, two second center segments 51b form a second pair of center segments 51, wherein the two second center segments 51b are connected to one another by a second deflection segment 52b in the base region 2 of the cooling device 1.

[0025] Furthermore, two third center segments 51c form a third pair of center segments 51, wherein the two third center segments 51c are connected to one another by a third deflection segment 52c in the base region 2 of the cooling device 1. Furthermore, the cooling device 1 in this exemplary embodiment further comprises a fourth pair of two fourth center segments 51d, which are connected to one another by a fourth deflection segment 52d in the base region 2, a fifth pair of two fifth center segments 51e, which are connected to one another by a fifth deflection segment 52e in the base region 2, and a sixth pair of two sixth center segments 51f, which are connected to one another by a sixth deflection segment 52f in the base region 2. However, the cooling device 1 can also comprise more or fewer pairs of center segments 51.

[0026] The center segments 51 extend in a y-direction from the base region 2 of the cooling device 1 to the deflection region 3 of the cooling device 1. The y-direction thus runs from the base region 2 of the cooling device 1 to the deflection region 3 of the cooling device 1. If, for example, a support surface 9 is formed on the cooling device 1, the y-direction can run perpendicular to the support surface 9, for example. The y-direction is perpendicular to an x-direction. The center segments 51 run parallel to one another. The center segments 51 are arranged next to one another with respect to the x-direction. The center segments 51 run in a common plane. The common plane in which the center segments 51 run is spanned by the x-direction and the y-direction. As shown in Fig. 1 As shown, the deflection segments 52 also run in this common plane.

[0027] The two second center segments 51b are arranged between the two first center segments 51a. Furthermore, in this exemplary embodiment, the two third center segments 51c are arranged between the two second center segments 51b. Furthermore, as in this exemplary embodiment, the two fourth center segments 51d can be arranged between the two third center segments 51c, the two fifth center segments 51e can be arranged between the two fourth center segments 51d, and / or the two sixth center segments 51f can be arranged between the two fifth center segments 51e.

[0028] Each of the deflection segments 51 in the base region 2 of the cooling device 1 has one intermediate section 56 and two deflection sections 57. The intermediate section 56 of a deflection segment 51 extends between the deflection sections 57 of this deflection segment 51. The intermediate section 56 of the deflection segment 51 extends, for example, in the x-direction. The intermediate section 56 of the deflection segment 51 extends, for example, parallel to the support surface 9 of the base region 2 of the cooling device 1. The intermediate section 56 of the deflection segment 51 runs straight between the two deflection sections 57 of the deflection segment 51. At the intermediate sections 56 of the deflection segments 51, the cooling channel 5 runs straight, for example in the x-direction. At the deflection sections 57 of the deflection segment 51, the cooling channel 5 bends from the y-direction to the x-direction or from the x-direction to the y-direction. As shown in Fig. 1 As shown, the intermediate sections 56 of the deflection segments 51 run parallel to one another in this embodiment. For example, the first intermediate section 56a of the first deflection segment 51a runs parallel to the second intermediate section 56b of the second deflection segment 51b. Fig. 1 In the illustrated embodiment, the intermediate sections 56 of all deflection segments 51 run parallel to one another. If the cooling channel 5 is formed in a cooling element 8 designed as a bent tube, the parts of the tube in which the intermediate sections 56 of the cooling channel 5 are formed can run parallel to one another and / or rest on one another. This advantageously achieves good heat conduction in the base region 2 of the cooling device 1 between the intermediate sections 56 of the individual deflection segments 51. The heat is spread in the x-direction via the intermediate sections 56 running in the base region 2 of the cooling device 1.

[0029] The principle of the Fig. 1 The embodiment of the cooling device 1 shown can also be applied to the third spatial direction, i.e., in a z-direction perpendicular to the x-direction and perpendicular to the y-direction. In this case, the Fig. 1 The deflection segments 52 of the cooling channel 5 shown in the base region 2 of the cooling device 1, which run parallel in the x-direction, may, for example, crosswise in the x-direction and in the z-direction, so that the heat is spread in the base region 2 of the cooling device 1 in the x-direction and z-direction. Thus, the heat can advantageously be spread in all three spatial directions predominantly through the cooling channel 5, which operates as a pulsating heat pipe.

[0030] Within the cooling channel 5 is a working fluid 6, which exists simultaneously in a liquid and gaseous state. The working fluid 6 exists in the cooling channel 5 in both gaseous and liquid states, in other words, partly gaseous and partly liquid. This means that the working fluid 6 exists in two phases within the cooling channel 5. In particular, gas bubbles and liquid columns exist simultaneously within the cooling channel 5. At a nominal temperature, the gas bubbles and the liquid columns preferably occupy a similar volume. Particularly preferably, the gaseous portion of the working fluid 6 occupies 30% to 70% of the internal volume of the cooling channel 5 at the nominal temperature, with the remaining internal volume being occupied by the liquid portion of the working fluid 6. Depending on the temperature of the cooling device 1, the volume ratio changes due to evaporation or condensation of the working fluid 6.Thus, the cooling channel 5 in the cooling device 1 can be operated as a pulsating heat pipe.

[0031] When the base region 2 of the cooling device 1 is heated by the component 101, the cooling channel 5 and the working fluid 6 located therein are heated. Through a combination of evaporation, condensation, convective heat transport, and heat conduction, the heat is transported away from the base region 2 of the cooling device 1, thus cooling the semiconductor component 101. Particularly preferably, the working fluid 6 has a critical temperature that is greater than a maximum operating temperature. Preferably, the working fluid 6 has a critical temperature of at least 233 K, preferably at least 273 K, particularly preferably at least 373 K, and in particular a maximum of 533 K. The critical temperature is considered to be the temperature of a substance at its critical point.This ensures that the working fluid 6 can be present in two phases within the cooling channel 5 in a preferred operating range, in which the working fluid 6 is present in particular at temperatures of 222 K to 473 K, in particular of 273 K to 373 K. The working fluid 6 is preferably an organic refrigerant, which is used, for example, in vehicle air conditioning systems, such as in particular 2,3,3,3-tetrafluoropropene, also referred to as R1234yf, R1233zd(E), etc. The working fluid 6 particularly preferably has a melting point which is a maximum of 273 K, preferably a maximum of 233 K, particularly preferably a maximum of 213 K.

[0032] Of course, further embodiments and mixed forms of the embodiments shown are also possible.

Claims

1. Cooling device for cooling components (101), comprising: - a cooling channel (5) formed in the cooling device (1), which has multiple middle segments (51) and multiple diversion segments (52), wherein the cooling channel (5) is filled with a working medium (6) which is simultaneously gaseous and liquid in the cooling channel (5), - a base region (2) of the cooling device (1), which is connectable in a thermally conductive manner to a component (101) to be cooled, - a diversion region (3) of the cooling device (1), - an intermediate region (4) between the base region (2) and the diversion region (3), wherein the middle segments (51) each extend from the base region (2) to the diversion region (3), wherein the diversion segments (52) each provide a reversal of direction within the base region (2) and within the diversion region (3) and each connect two middle segments (51) to one another, wherein a first diversion segment (52a) connects two first middle segments (51a) to one another in the base region (2), wherein at least two second middle segments (51b) are arranged between the two first middle segments (51a), wherein the two second middle segments (51b) are connected to one another in the base region (2) by means of a second diversion segment (52b), and wherein the first diversion segment (52a) and the second diversion segment (52b) extend in a common plane, characterized in that the first diversion segment (52a) has a first intermediate portion (56a) in which the diversion segment (52a) extends straight between two first diversion portions (57a), wherein the second diversion segment (52b) has a second intermediate portion (56b) in which the second diversion segment (52b) extends straight between two second diversion portions (57b), and in that the first intermediate portion (56a) extends parallel to the second intermediate portion (56b).

2. Cooling device according to one of the preceding claims, characterized in that the first middle segments (51a) and the second middle segments (51b) extend in a common plane.

3. Cooling device according to one of the preceding claims, characterized in that the at least one cooling channel (5) is formed in a bent cooling element (8), in particular in a bent tube.

4. Cooling device according to Claim 3, characterized in that the intermediate portions (56) bear one on the other.

5. Cooling device according to Claim 3, characterized in that a planar bearing surface (9) against which the component (101) is able to be made to bear is formed at the cooling device (1) in the base region (2) of the cooling device (1).

6. Cooling device according to one of the preceding claims, characterized in that, between the two second middle segments (51b), there are arranged further pairs of middle segments (51c, 51d, 51e, 51f) which are in each case connected to one other in the base region (2) by means of a further diversion segment (52c, 52d, 52e, 52f).

7. Cooling device according to one of the preceding claims, characterized in that, in the cooling device (1), there are formed multiple channels (5) which are fluidically separated from one another and which extend parallel to one other.

8. Electronics arrangement comprising: - a component (101), in particular a semiconductor component, and - a cooling device (1) according to one of the preceding claims, - wherein the component (101) is connected in a thermally conductive manner to the base region (2) of the cooling device (1), in particular to at least one diversion segment (52) of the cooling device (1).