Pulsating heatpipe heat sink and cooling device with a pulsating heatpipe heat sink

Abstract

The invention relates to a pulsating heatpipe heat sink (10; 10a-10d; 10f-10h), comprising a housing (12) in which at least one channel (18; 18a; 18b; 18d) is formed for guiding an evaporable cooling medium, an evaporator section (22; 22a-22d; 22f-22h) for arranging at least one component (1) to be cooled, and a condenser section (24; 24a-24d; 24f-24h; 24x; 24y; 24z) arranged at a distance (A) from the evaporator section (22; 22a-22d; 22f-22h), wherein the condenser section (24; 24a-24d; 24f-24h; 24x; 24y; 24z) is configured to include a preferably separate element to be connected to the cooling element (20), wherein the at least one channel (18; 18a; 18b; 18d) extends at least between the evaporator area (22; 22a-22d; 22f-22h) and the condenser area (24; 24a-24d; 24f-24h; 24x; 24y; 24z).

Description

Technical field

[0001] The invention relates to a pulsating heatpipe heat sink, hereinafter also referred to simply as a heatpipe heat sink, for cooling at least one component, which is characterized by a particularly advantageous design of the at least one channel serving to guide a cooling medium. Furthermore, the invention relates to a cooling device comprising a pulsating heatpipe heat sink designed according to the invention and a heat sink connected to the housing of the heatpipe heat sink. State of the art

[0002] Pulsating heat pipe heat sinks using a vaporizable cooling medium arranged in a channel are known in various forms from the prior art. For example, WO 2020 / 207669 A1 discloses the arrangement of channels for guiding the cooling medium in a star-shaped pattern around a centrally located evaporator section, which is thermally connected to a heat-generating component. The star-shaped sections of the channels form a condenser section of the heat pipe heat sink. Due to the star-shaped arrangement of the channels, a homogeneous temperature distribution is generally achieved across the surface of the heat pipe heat sink.Furthermore, the centrally arranged evaporator area, from which the individual cooling channels extend radially outwards, is subdivided by rib-shaped structures, which, however, do not extend over the entire height of the cross-section in the evaporator area, so that the evaporator area itself is not designed as a channel.

[0003] Furthermore, it is known from EP 3 147 621 B1 to form a channel for guiding the cooling medium in a meandering shape, wherein the evaporator area and the condenser area are arranged separately from each other on different areas of the heat pipe cooling body. Disclosure of the invention

[0004] The pulsating heatpipe heat sink according to the invention, with the features of claim 1, has the advantage that it enables particularly effective cooling of the at least one heat-generating component in a compact design. This is achieved by a special arrangement of the individual channel sections of the at least one channel within the housing of the heatpipe heat sink. In particular, a kind of geometric spreading between the evaporator area and the condenser area is proposed, which makes it possible to stretch the condenser area in one direction compared to the evaporator area. This enables improved heat dissipation to the environment and / or more effective cooling of the cooling medium compared to the prior art.

[0005] In light of the above explanations, a pulsating heatpipe heat sink according to the invention, comprising the features of claim 1, therefore has a housing in which at least one channel for guiding a vaporizable medium is formed. Furthermore, the heatpipe heat sink has an evaporator section for arranging at least one component to be cooled, and a condenser section arranged at a distance from the evaporator section, wherein the condenser section is configured to be connected to a cooling element, preferably designed as a separate element. The at least one channel extends at least between the evaporator section and the condenser section, wherein the at least one channel has several first channel sections in the evaporator section and several second channel sections in the condenser section.The first channel sections and the second channel sections are connected by means of third channel sections, wherein the evaporator area has at least one first extension and the condenser area has at least one second extension, wherein the largest second extension is larger than the largest first extension, and wherein the condenser area is located at or near an edge region of the housing.

[0006] Preferably, the condenser area or the second channel sections extend over the entire length of the edge area of ​​the heatpipe heat sink in order to maximize the length of the second channel sections.

[0007] Advantageous further developments of the pulsating heatpipe heat sink according to the invention are listed in the dependent claims.

[0008] In a particularly preferred geometric embodiment of the capacitor region, it is provided that the capacitor region is rectangular with two second extensions, wherein the larger of the two second extensions is at least five times, preferably at least ten times, as large as the smaller of the two second extensions.

[0009] Furthermore, it can be provided that the first and / or second and / or third channel sections are each arranged at least partially parallel to each other. Such a parallel arrangement of the channel sections makes it possible to arrange several channel sections of the at least one channel on a relatively small installation space of the heat pipe heat sink in order to maximize the heat transfer surface to the cooling medium or the environment.

[0010] In a preferred design embodiment of the third channel sections, it may also be provided that the third channel sections are arranged at least partially at an oblique angle to the first channel sections and / or are curved and / or consist of at least two straight sections arranged at an angle to each other.

[0011] It may also be provided that at least one channel on the side of the evaporator area facing away from the condenser area has arc-shaped return sections connected to the first channel sections, which connect two first channel sections arranged parallel to each other.

[0012] To increase the cooling performance of the heatpipe heat sink, it can also be provided that condenser areas are arranged on both sides of the evaporator area, wherein the arrangement or design of the at least one channel is preferably symmetrical to a line of symmetry.

[0013] To increase the performance or operational reliability of the heat pipe heat sink, it may also be provided that two separate channels for the cooling medium are formed in the housing.

[0014] There are also different possibilities regarding the arrangement and design of the second channel sections. In particular, it is also possible for the second channel sections in the condenser area to be curved or meandering, so that, viewed in the direction of the larger of the two second extensions, there are several second channel sections. This can increase the heat transfer path of the at least one channel for the cooling medium in the condenser area.

[0015] As an alternative to the last proposed solution, it is suggested that the second channel sections are designed to be straight. This typically allows for a maximization of the density of second channel sections in the capacitor region, since the number / size of the gaps between the second channel sections is particularly small.

[0016] Finally, the invention also includes a cooling device with a pulsating heatpipe heat sink as described above and a heat sink connected to the housing, preferably designed as a separate component.

[0017] Further advantages, features and details of the invention will become apparent from the following description of preferred embodiments of the invention and from the drawings. Brief description of the drawings Fig. Figure 1 shows a simplified longitudinal section of a first embodiment of a pulsating heatpipe heat sink, Fig. 2 a cross-section through the heat pipe heat sink of the Fig. 1 in level II-II of the Fig. 1, Fig. 3 to Fig. 5 simplified longitudinal sections of opposite the Fig. 1 modified heatpipe heat sinks, Fig. 5 to Fig. 8 different channel configurations in the condenser area of ​​a heat pipe heat sink in longitudinal section, Fig. 9 a simplified longitudinal section through a heat pipe heat sink with two separate channels for a cooling medium and two condenser areas and Fig. 10 to Fig. 12 simplified longitudinal sections in the area of ​​further modified heatpipe heat sinks. Embodiments of the invention

[0018] Identical elements or elements with the same function are represented in the figures by the same reference numbers.

[0019] The in the Fig. 1 and Fig. The cooling device 100 shown in Figure 2 has a pulsating heat pipe heat sink 10 and serves to cool at least one component 1. The at least one component 1 can be, for example, an electronic component such as an IC or a power component that generates heat during operation. In particular, the heat pipe heat sink 10 can also be a component of, for example, a control unit or other assembly, for example, for automotive applications.

[0020] The heat pipe heat sink 10 has a preferably flat, cuboid-shaped housing 12 made of metal, which ideally consists of a base body 14 and a cover element 16 that closes and covers the base body 14. At least one groove-like channel 18 is formed in the base body 14 for guiding a vaporizable cooling medium (not shown). The heat pipe heat sink 10, its housing 12, and the at least one channel 18 can be manufactured in a manner known from the prior art, either by a forming process or by machining processes.

[0021] As an example, an additional cooling element 20 is thermally connected to the housing 12 on the side facing away from component 1. The additional cooling element 20 can, for example, be a body with cooling fins or similar features, which is preferably, but not exclusively, designed as a component separate from the housing 12, with the cooling element 20 being thermally connected to the housing 12. However, it is also conceivable to design the housing 12 and the cooling element 20 as a monolithic component in the case of additive manufacturing of the heat pipe heat sink 10.

[0022] The heat pipe heat sink 10 has an evaporator area 22, in which the component 1 to be cooled is thermally connected to the housing 12 of the heat pipe heat sink 10 on the outside of the housing 12, for example by means of a thermally conductive adhesive (not shown). The evaporator area 22 is, as shown in the Fig. As can be seen, the evaporator section 22 is rectangular and preferably square, with two first extensions a and b. In the case of the exemplary square evaporator section 22, the two first extensions a and b are of equal size. The geometry and size of the evaporator section 22 depend on the shape, size, number, and heat output of the heat-generating component(s) 1.

[0023] At a distance A from the evaporator area 22, the heat pipe heat sink 10 has a condenser area 24. Viewed in the plane of the housing 12, the condenser area 24 is rectangular or strip-shaped with two secondary extensions c and d, where extension d is a multiple of extension c, and the second extension d is in turn a multiple of the first extensions a and b of the evaporator area 22. The condenser area 24, in which the additional cooling element 20 is also arranged, is located in an edge region 26 of the housing 12 and preferably terminates flush with the edge region 26 on the side facing away from the evaporator area 22.

[0024] As an example, a single, self-contained or continuous channel 18 is provided in the housing 12. In the evaporator section 22, the channel 18 has several straight first channel sections 28 arranged parallel to each other, extending in the direction of the first extension a. The condenser section 24 also has several straight second channel sections 30 arranged parallel to each other, extending in the direction of the second extension d.

[0025] The first channel sections 28 are arranged at right angles to the second channel sections 30. The first channel sections 28 are connected to the second channel sections 30 via third channel sections 32. The third channel sections 32 run between the evaporator section 22 and the condenser section 24 in a so-called adiabatic zone. The third channel sections 32 comprise several sections 34 arranged parallel to each other and aligned with the first channel sections 28, as well as sections 36 arranged parallel to each other at an oblique angle α of, for example, approximately 60°. The sections 36 are connected to the first channel sections 28 and the second channel sections 30 via curved sections 38, 39. Furthermore, the second channel sections 30 each have a length, viewed in the direction of the second extension d, that corresponds approximately to half of the second extension d.The connection between the arc sections 39 and the second canal sections 30, as well as between the second canal sections 30 and sections 34, is made via 90° deflection arcs 33, 37.

[0026] On the side of the evaporator section 22 facing away from the condenser section 24, the first channel sections 28 are coupled to semicircularly shaped return sections 40, 42 connecting them. While the return sections 40 connect two immediately adjacent first channel sections 28, the return sections 42 each connect two first channel sections 28 arranged with at least one first channel section 28 in between. By way of example only, the arrangement and configuration of the channel 18 described so far is mirror-symmetrical about a line of symmetry 44, which runs at the midpoint of the second extent d.

[0027] Furthermore, it is explained that in the presentation of the Fig. 1. The cross-section of channel 18 and / or channel sections 28, 30, 32 is the same size. However, it can also be variable or have areas with different cross-sections. Preferably, the cross-section of channel 18 is rectangular.

[0028] In the Fig. Figure 3 shows a heatpipe heat sink 10a, which is connected to the heatpipe heat sink 10 alongside a different number of first channel sections 28a, second channel sections 30a and third channel sections 32a. Fig. 1 differs in that some of the second channel sections 30a run directly adjacent to the condenser section 24a on the side facing the evaporator section 22a. Furthermore, the arrangement of channel 18a is not symmetrical to a straight line 45, since a return section 46 is provided on one side of the straight line 45, bridging several first channel sections 28a. In the area of ​​the return section 46, return sections 40 are provided between the two first channel sections 28a connected to the return section 46, as well as on the other side of the straight line 45, connecting two immediately adjacent first channel sections 28a. The first channel sections 28a that are furthest away from the straight line 45 are also located outside the evaporator section 22a.

[0029] The one in Fig. The heat pipe cooling element 10b shown in Figure 4, with its channel 18b, is preferably symmetrical about the line of symmetry 44b. The two first channel sections 28b, which are maximally spaced apart in the evaporator section 22b, are connected to each other by means of a return section 42b on the side facing away from the condenser section 24b, while the other first channel sections 28b are connected to each other by means of return sections 40, which connect two first channel sections 28b arranged directly next to each other. Furthermore, the second channel sections 30b in the condenser section 24b are semicircular or arc-shaped. The second channel sections 30b connect two third channel sections 32b arranged directly next to each other.The third channel sections 32b have both sections 36 running at the oblique angle α, and sections 43 running parallel to the first channel sections 28b, which are connected to the second channel sections 30b.

[0030] The one in Fig. The heatpipe heatsink 10c shown in Figure 5 differs from the heatpipe heatsink 10b according to the diagram. Fig. 4 essentially by the fact that the second channel sections 30c are arc-shaped with parallel sections 48 in the condenser area 24c. This allows for a larger heat transfer path in the condenser area 24c. The evaporator area 22c corresponds in its design to the evaporator area 22b of the heat pipe heat sink 10b.

[0031] In the Fig. Figures 6 to 8 are modified second channel sections 30x, 30y and 30z in the capacitor region 24x, 24y and 24z compared to the second channel sections 30, 30a to 30c described so far, wherein the second channel sections 30x, 30y and 30z each extend over a sub-region of the second extent d, so that, viewed in the direction of the second extent d, several second channel sections 30x, 30y and 30z are present in the capacitor region 24x, 24y and 24z.

[0032] The second channel sections 30x according to the Fig. 6 are each meandering or formed from several semicircular sections 50 with alternating curvature direction.

[0033] Similarly, the second channel sections 30y are also according to the Fig. 7 meandering or multiply curved, the third channel sections 32y which open into the capacitor area 24y and are arranged parallel to each other are, however, arranged at an angle β in relation to the strip-shaped capacitor area 24y.

[0034] The one in Fig. The second channel sections 30z shown in Figure 8 have a total of four sections 52 arranged side by side and parallel to each other in the direction of the second extension c. Two sections 52 arranged directly next to each other are connected to each other by an arc section 54. While three sections 52 are located entirely within the condenser area 24z, one section 52 runs directly next to the condenser area 24z on the side facing the evaporator area.

[0035] The one in Fig. The heat pipe cooling element 10d shown in Figure 9 has a centrally located evaporator area 22d. Two condenser areas 24d are arranged on either side of the evaporator area 22d. Furthermore, the heat pipe cooling element 10d has two separate channels 18d with four open ends 56 to 59. The two channels 18d are symmetrical about a line of symmetry 44d. The first channel sections 28d and the second channel sections 30d are each straight and parallel to each other.

[0036] The one in Fig. The heat pipe cooling element 10f shown in Figure 10 is symmetrical about a line of symmetry 44f and has U-shaped first channel sections 28f in the evaporator area 22f. The two first channel sections 28f, arranged on one side of the line of symmetry 44f, are connected to each other by a U-shaped connecting section 72, and are also connected via the third channel sections 32f with sections arranged at right angles to each other to two second channel sections 30f running in the evaporator area 24f.

[0037] The one in Fig. 11 heatpipe cooling bodies 10g shown, symmetrically formed to a symmetry line 44g, have arc-shaped third channel sections 32g, and the first channel sections 28g within the evaporator area 22g are each composed of semicircular sections 49.

[0038] Finally, the one in Fig.Figure 12 shows heat pipe cooling elements 10h, which also have arc-shaped third channel sections 32h. The first channel sections 28h, located within the evaporator area 22h, are each multiply curved and nested or intertwined.

[0039] During operation of the heat pipe heat sink 10, 10a to 10d, 10f to 10h, the coolant located in the channel 18, 18a, 18b, 18d in the evaporator area 22, 22a to 22d, 22f to 22h is evaporated due to the heat of component 1 and, due to the formation of vapor bubbles, enters the condenser area 24, 24a to 24d, 24f to 24h, 24x, 24y, 24z. There, the coolant condenses and flows back towards the evaporator area 22, 22a to 22d, 22f to 22h.

[0040] The pulsating heatpipe heat sink 10, 10a to 10d, 10f to 10h described so far can be adapted or modified in various ways without deviating from the inventive concept. This concept consists in the evaporator section 22, 22a to 22d, 22f to 22h having two first extensions a and b, and the condenser section 24, 24a to 24d, 24f to 24h, 24x, 24y and 24z having two second extensions c and d. The larger of the two first extensions a and b is smaller, preferably at most half the size, of the larger of the two second extensions c and d.Furthermore, the evaporator area 22, 22a to 22d, 22f to 22h is preferably approximately square, such that the two first extensions a and b are approximately equal in size, while the condenser area 24, 24a to 24d, 24f to 24h, 24x, 24y and 24z is strip-shaped, wherein the larger of the two second extensions c and d is at least five times as large as the smaller of the two second extensions c and d. QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] WO 2020 / 207669 A1

[0002] EP 3 147 621 B1

[0003]

Claims

[1] Pulsating heatpipe heat sink (10; 10a-10d; 10f-10h), comprising a housing (12) in which at least one channel (18; 18a; 18b; 18d) is formed for guiding an evaporable cooling medium, comprising an evaporator region (22; 22a-22d; 22f-22h) for arranging at least one component (1) to be cooled, comprising a condenser region (24; 24a-24d; 24f-24h; 24x; 24y; 24z) arranged at a distance (A) from the evaporator region (22; 22a-22d; 22f-22h), wherein the condenser region (24; 24a-24d; 24f-24h; 24x; 24y; 24z) is configured to include a cooling element preferably designed as a separate element (20) to be connected, wherein the at least one channel (18; 18a; 18b; 18d) extends at least between the evaporator section (22; 22a-22d; 22f-22h) and the condenser section (24; 24a-24d; 24f-24h; 24x; 24y; 24z), wherein the at least one channel (18; 18a; 18b; 18d) in the evaporator section (22; 22a-22d; 22f-22h) has several first channel sections (28; 28a; 28b; 28f; 28g;28h) and in the condenser area (24; 24a-24d; 24f-24h; 24x; 24y; 24z) has several second channel sections (30; 30a; 30b; 30c; 30d; 30f; 30x; 30y; 30z), wherein the first channel sections (28; 28a; 28b; 28d; 28f; 28g; 28h) and the second channel sections (30; 30a; 30b; 30c; 30d; 30f; 30x; 30y; 30z) are connected by means of a connection between the evaporator area (22; 22a-22d; 22f-22h) and the condenser area (24; 24a-24d; 24f-24h; third channel sections (32; 32a; 32b; 32f; 32g; 32h; 32y) extending from 24x; 24y; 24z) are connected, wherein the evaporator section (22; 22a-22d; 22f-22h) has at least one first extension (a, b) and the condenser section (24; 24a-24d; 24f-24h; 24x; 24y; 24z) has at least one second extension (c, d), wherein the largest second extension (d) is larger than the largest first extension (a, b), and wherein the condenser section (24; 24a-24d; 24f-24h; 24x; 24y; 24z) is arranged at or near an edge region (26) of the housing (12). [2] Heatpipe heat sink according to claim 1, characterized by , that the capacitor area (24; 24a-24d; 24f-24h; 24x; 24y; 24z) is rectangular with two second extensions (c, d), wherein the larger of the two second extensions (d) is at least five times, preferably at least ten times, larger than the smaller of the two second extensions (c). [3] Heatpipe heat sink according to claim 1 or 2, characterized by , that the first channel sections (28; 28a; 28b; 28d; 28f; 28g; 28h) and / or the second channel sections (30; 30a; 30b; 30c; 30d; 30f; 30x; 30y; 30z) and / or third channel sections (32; 32a; 32b; 32f; 32g; 32h; 32y) are each arranged at least partially parallel to each other. [4] Heatpipe heat sink according to any one of claims 1 to 3, characterized by, that the third channel sections (32; 32a; 32b; 32f; 32g; 32h; 32y) are arranged at least partially at an oblique angle (α) to the first channel sections (28; 28a; 28b; 28d; 28f; 28g; 28h) and / or are arc-shaped and / or consist of at least two straight sections arranged at an angle to each other. [5] Heatpipe heat sink according to any one of claims 1 to 4, characterized by , that the at least one channel (18; 18a; 18b) on the side of the evaporator section (22; 22a to 22c) facing away from the condenser section (24; 24a-24c) has arc-shaped return sections (40, 42; 42b) connected to the first channel sections (28; 28a; 28b) which connect two first channel sections (28; 28a; 28b) arranged parallel to each other. [6] Heatpipe heat sink according to any one of claims 1 to 4, characterized by, that condenser areas (24d) are arranged on both sides of the evaporator area (22d), wherein the arrangement or design of the at least one channel (18d) is preferably symmetrical to a line of symmetry (44d). [7] Heatpipe heat sink according to any one of claims 1 to 6, characterized by , that in the housing (12) two separate channels (18d) for the cooling medium are formed. [8] Heatpipe heat sink according to any one of claims 1 to 7, characterized by , that the second channel sections (30b; 30c; 30x; 30y; 30z) are arc-shaped or meander-shaped, so that, viewed in the direction of the larger of the two second extensions (d), there are several second channel sections (30; 30c; 30x; 30y; 30z). [9] Heatpipe heat sink according to any one of claims 1 to 7, characterized by , that the second channel sections (30; 30a; 30d) are straight. [10] Cooling device (100) comprising a pulsating heatpipe heat sink (10; 10a-10d; 10f-10h) designed according to one of claims 1 to 9 and an additional heat sink (20) connected to the housing (12), preferably designed as a separate component.

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