Pulsating heat pipe heat sink and cooling device having a pulsating heat pipe heat sink

Abstract

The invention relates to a pulsating heat pipe heat sink (10; 10a–10d; 10f–10h) comprising: a housing (12) in which at least one channel (18; 18a; 18b; 18d) for conveying an evaporable cooling medium is formed; an evaporator region (22; 22a–22d; 22f–22h) in which at least one component (1) to be cooled can be disposed; and a condenser region (24; 24a–24d; 24f–24h; 24x; 24y; 24z; 24z) which is spaced 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 designed to be connected to a cooling element (20) which is preferably a separate element, and wherein the at least one channel (18; 18a; 18b; 18d) extends at least between the evaporator region (22; 22a–22d; 22f–22h) and the condenser region (24; 24a–24d; 24f–24h; 24x; 24y; 24z).

Description

[0001] R.404736

[0002] Description

[0003] title

[0004] Pulsating heatpipe heat sink and cooling device with a pulsating heatpipe heat sink

[0005] Technical field

[0006] 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.

[0007] State of the art

[0008] Pulsating heatpipe 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 shape 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 heatpipe heat sink. Due to the star-shaped arrangement of the channels, a homogeneous temperature distribution is generally achieved across the surface of the heatpipe heat sink. Furthermore, the centrally located evaporator section, from which the individual cooling channels project radially outwards, is subdivided by rib-like structures, which, however, do not extend over the entire height of the cross-section in R.404736.

[0009] - 2 -

[0010] The evaporator area is sufficient so that the evaporator area itself is not designed as a channel.

[0011] Furthermore, it is known from EP 3 147621 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.

[0012] Disclosure of the invention

[0013] 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.

[0014] 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, with the evaporator area having at least one first R.404736.

[0015] - 3 -

[0016] Extension and the capacitor area has at least one second extension, wherein the largest second extension is larger than the largest first extension, and wherein the capacitor area is located at or near an edge region of the housing.

[0017] 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.

[0018] Advantageous further developments of the pulsating heatpipe heat sink according to the invention are listed in the dependent claims.

[0019] 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.

[0020] 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.

[0021] 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.

[0022] 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 R.404736

[0023] - 4 - connect two parallel first channel sections.

[0024] 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.

[0025] 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.

[0026] 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.

[0027] As an alternative to the last proposed solution, it is suggested that the second channel sections 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.

[0028] 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.

[0029] 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. R.404736

[0030] - 5 -

[0031] Brief description of the drawings

[0032] Fig. 1 shows a simplified longitudinal section of a first embodiment of a pulsating heatpipe heat sink,

[0033] Fig. 2 shows a cross-section through the heat pipe heat sink of Fig. 1 in the plane ll-ll of Fig. 1,

[0034] Fig. 3 to

[0035] Fig. 5 simplified longitudinal sections of heat pipe heat sinks modified compared to Fig. 1,

[0036] Fig. 5 to

[0037] Fig. 8 shows different channel configurations in the condenser area of ​​a heat pipe heat sink in longitudinal section.

[0038] Fig. 9 shows a simplified longitudinal section through a heat pipe heat sink with two separate channels for a cooling medium and two condenser areas and

[0039] Fig. 10 to

[0040] Fig. 12 simplified longitudinal sections in the area of ​​further modified heatpipe heat sinks.

[0041] Embodiments of the invention

[0042] Identical elements or elements with the same function are represented in the figures by the same reference numbers.

[0043] The cooling device 100 shown in Figures 1 and 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, R.404736

[0044] - 6 - generates heat during operation. In particular, the heat pipe cooling element 10 can also be a component of, for example, a control unit or other assembly, for example for automotive applications.

[0045] 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.

[0046] 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.

[0047] 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). As can be seen in Fig. 1, the evaporator area 22 is rectangular and preferably square with two first extensions a and b. In the case of the exemplary square evaporator area 22, the two first extensions a and b are of equal size. The geometry and size of the evaporator area 22 depend on the shape / size / number and heat dissipation of the heat-generating component(s) 1. R.404736

[0048] - 7 - 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.

[0049] 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.

[0050] 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 extent d, that corresponds approximately to half of the second extent d.The connection between the arch 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 bends 33, 37. R.404736.

[0051] - 8 -

[0052] 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.

[0053] Furthermore, it is explained that in the illustration of Fig. 1, the cross-section of the channel 18 and the channel sections 28, 30, 32 are all the same size. However, it can also be variable or have areas with different cross-sections. Preferably, the cross-section of the channel 18 is rectangular.

[0054] Figure 3 shows a heat pipe heat sink 10a, which differs from the heat pipe heat sink 10 of Figure 1 in that some of the second channel sections 30a run directly adjacent to the condenser section 24a on the side facing the evaporator area 22a. Furthermore, the arrangement of the channel 10a is not symmetrical about a straight line 45, since a feedback section 46 is provided on one side of the line 45, bridging several first channel sections 28a. In the area of ​​the feedback section 46, feedback ports 40 are provided between the two first channel sections 28a connected to the feedback section 46, as well as on the other side of the line 45, connecting two immediately adjacent first channel sections 28a.Furthermore, the first channel sections 28a, which are at their maximum distance from the straight line 45, are located outside the evaporator area 22a.

[0055] The heat pipe cooling element 10b shown in Fig. 4, with its channel 18b, is preferably designed symmetrically with respect to the line of symmetry 44b. The two first R.404736, which are maximally spaced apart from each other in the evaporator area 22b,

[0056] - 9 -

[0057] Channel sections 28b are connected to each other by means of a feedback section 42b on the side facing away from the capacitor section 24b, while the other first channel sections 28b are connected to each other by means of feedback sections 40, which connect two immediately adjacent first channel sections 28b. Furthermore, in the capacitor section 24b, the second channel sections 30b are semicircular or arc-shaped. The second channel sections 30b connect two immediately adjacent third channel sections 32b. The third channel sections 32b have sections 36 running at the oblique angle α, as well as sections 43 running parallel to the first channel sections 28b, which are connected to the second channel sections 30b.

[0058] The heat pipe heat sink 10c shown in Fig. 5 differs from the heat pipe heat sink 10b according to Fig. 4 essentially in 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.

[0059] In Figures 6 to 8, modified second channel sections 30x, 30y and 30z are shown 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 partial 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.

[0060] The second channel sections 30x according to Fig. 6 are each meander-shaped or formed from several semicircular sections 50 with alternating curvature direction.

[0061] Similarly, the second channel sections 30y according to Fig. 7 are also designed in a meandering or multiple curved shape, while the third R.404736, which open into the capacitor area 24y, are arranged parallel to each other.

[0062] - 10 -

[0063] However, channel sections 32y are arranged at an angle β relative to the strip-shaped capacitor area 24y.

[0064] The second channel sections 30z shown in Fig. 8 have a total of four sections 52 arranged side by side and parallel to each other when viewed 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.

[0065] The heat pipe cooling element 10d shown in Fig. 9 has a centrally located evaporator section 22d. Two condenser sections 24d are arranged on either side of the evaporator section 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.

[0066] The heat pipe cooling element 10f shown in Fig. 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.

[0067] The heat pipe cooling element 10g shown in Fig. 11, which is symmetrically designed with respect to a line of symmetry 44g, has arc-shaped third channel sections 32g, and the first channel sections 28g within the evaporator area 22g are each composed of semicircular sections 49. R.404736

[0068] - 11 -

[0069] Finally, the heat pipe cooling element 10h shown in Fig. 12 also has arc-shaped third channel sections 32h. The first channel sections 28h, arranged within the evaporator area 22h, are each formed with multiple curves and are nested or intertwined.

[0070] 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.

[0071] 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.

Claims

R.404736 - 12 - 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 a vaporizable cooling medium, comprising an evaporator section (22; 22a-22d; 22f-22h) for arranging at least one component (1) to be cooled, comprising 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 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 in that, R.404736 - 13 - 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 cooling element according to claim 1 or 2, characterized in 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 cooling element according to one of claims 1 to 3, characterized in that the third channel sections (32; 32a; 32b; 32f; 32g; 32h; 32y) are arranged at least partially at an oblique angle (a) 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 one of claims 1 to 4, characterized in that the at least one channel (18; 18a; 18b) on the side of the evaporator area (22; 22a to 22c) facing away from the condenser area (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 cooling element according to one of claims 1 to 4, characterized in 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). R.404736 - 14 - 7. Heatpipe heat sink according to one of claims 1 to 6, characterized in that two separate channels (18d) for the cooling medium are formed in the housing (12).

8. Heatpipe cooling sink according to one of claims 1 to 7, characterized in that the second channel sections (30b; 30c; 30x; 30y; 30z) are arc-shaped or meander-shaped, such that several second channel sections (30; 30c; 30x; 30y; 30z) are present in the direction of the larger of the two second extensions (d).

9. Heatpipe cooling element according to one of claims 1 to 7, characterized in 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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