Cooling system and server

Abstract

A cooling system includes a liquid cooling plate, a first thermosiphon device, and a second thermosiphon device. The liquid cooling plate has a U-shaped flow channel, which sequentially includes a first section, a second section, a third section, and a fourth section, with the first section opposite to the fourth section and the second section opposite to the third section. The first thermosiphon device is thermally coupled to the liquid cooling plate corresponding to the first and fourth sections. The second thermosiphon device is thermally coupled to the liquid cooling plate corresponding to the second and third sections. A server includes a first processor, a second processor, and the aforementioned cooling system. The first thermosiphon device is thermally coupled to the first processor, and the second thermosiphon device is thermally coupled to the second processor.

Description

[Technical Field]

[0001] This invention relates to a cooling system, and more particularly to a cooling system utilizing thermosiphon and a cooling system for servers. [Previous Technology]

[0002] In cooling systems using multiple thermosiphon units, considering ease of installation and manufacturing tolerances, each thermosiphon unit is generally designed to operate independently. For example, fins are installed on the condensers of individual thermosiphon units, allowing each unit to exchange heat independently with the outside environment. In certain application scenarios, such as when thermosiphon units are used in servers (or computers) within a server rack, the condenser of the thermosiphon unit can first exchange heat with a liquid cooling plate, which then dissipates heat through external heat dissipation devices (such as heat sink fins) via transfer pipes. The aforementioned transfer pipes are typically connected to manifolds on the server rack via quick connectors, so one liquid cooling plate will have two quick connectors corresponding to the inlet and outlet, and two liquid cooling plates will have four quick connectors. However, in the space of a current 1U server, one manifold typically only allows for one quick connector, therefore, four manifolds need to be installed on the server rack, with one quick connector installed on each manifold. In addition to increasing setup costs, these transmission pipes, quick connectors, and manifolds will also take up a lot of space in server chassis and racks, increasing airflow resistance and negatively impacting the cooling performance of other air-cooled components in the server chassis and racks. [Summary of the Invention]

[0003] In view of the problems in the prior art, one object of the present invention is to provide a cooling system that uses the same liquid cooling plate to exchange heat with two thermosiphon devices.

[0004] A cooling system according to one embodiment of the present invention includes a liquid cooling plate, a first thermosiphon device, and a second thermosiphon device. The liquid cooling plate has a U-shaped flow channel, which sequentially includes a first section, a second section, a third section, and a fourth section, wherein the first section is opposite to the fourth section, and the second section is opposite to the third section. The first thermosiphon device is thermally coupled to the liquid cooling plate corresponding to the first section and the fourth section. The second thermosiphon device is thermally coupled to the liquid cooling plate corresponding to the second section and the third section. Therefore, the cooling system uses the same liquid cooling plate and two thermosiphon devices for heat exchange, and compared to the general configuration of thermosiphon devices (i.e., one thermosiphon device paired with one liquid cooling plate and two transmission pipes), the cooling system reduces the number of transmission pipes connected to the liquid cooling plate externally, that is, reduces the number of connection interfaces (e.g., via quick connectors) with external manifolds (e.g., those installed in server racks). Furthermore, when the cooling system is in operation, although the working fluid temperature in each section of the liquid cooling plate will be different, the average working fluid temperature in the first section and the fourth section will be similar to the average working fluid temperature in the second section and the third section in principle, so that the heat exchange capacity provided by the liquid cooling plate to the first thermosiphon device and the second thermosiphon device will also be similar.

[0005] Another object of the present invention is to provide a server whose cooling system utilizes the same liquid cooling plate and two thermosiphon devices for heat exchange.

[0006] A server according to one embodiment of the present invention includes a first processor, a second processor, and a cooling system. The cooling system includes a liquid cooling plate, a first thermosiphon device, and a second thermosiphon device. The liquid cooling plate has a U-shaped flow channel, which sequentially includes a first segment, a second segment, a third segment, and a fourth segment, wherein the first segment and the fourth segment are opposite each other, and the second segment and the third segment are opposite each other. The first thermosiphon device is thermally coupled to the liquid cooling plate corresponding to the first segment and the fourth segment. The second thermosiphon device is thermally coupled to the liquid cooling plate corresponding to the second segment and the third segment. The first thermosiphon device is thermally coupled to the first processor, and the second thermosiphon device is thermally coupled to the second processor. Therefore, the server's cooling system uses a single liquid cooling plate and two thermosiphons for heat exchange. Compared to a typical thermosiphon configuration (one thermosiphon paired with one liquid cooling plate and two transfer pipes), this server's cooling system reduces the number of transfer pipes connecting the liquid cooling plate to the outside, thus reducing the number of connection interfaces (e.g., via quick connectors) with external manifolds (e.g., those located within the server rack). Furthermore, while the working fluid temperature varies across different sections of the liquid cooling plate during operation, the average working fluid temperature in the first and fourth sections is generally similar to that in the second and third sections. This ensures that the liquid cooling plate provides similar heat exchange capabilities to the first and second thermosiphons; in other words, the first and second thermosiphons can provide similar heat dissipation efficiencies to the first and second processors, respectively.

[0007] The advantages and spirit of the present invention can be further understood from the following detailed description of the invention and the accompanying drawings. [Simplified Explanation of the Diagram]

[0041] Figure 1 is a schematic diagram of a cooling system according to one of the first embodiments.

[0042] Figure 2 is an exploded view of the cooling system in Figure 1.

[0043] Figure 3 is a schematic diagram of the liquid cooling plate in Figure 2 from another perspective.

[0044] Figure 4 is an exploded view of the liquid cooling plate in Figure 2.

[0045] Figure 5 is a cross-sectional view of the liquid cooling plate along line XX in Figure 2.

[0046] Figure 6 is a cross-sectional view of the liquid cooling plate along line YY in Figure 2.

[0047] Figure 7 is a schematic diagram of the interior of a server according to one of the second embodiments.

Implementation Method

[0048] Please refer to Figures 1 and 2. A cooling system 1 according to a first embodiment includes a first thermosiphon device 12, a second thermosiphon device 14, and a liquid cooling plate 16. The first thermosiphon device 12 and the second thermosiphon device 14 are thermally coupled to the liquid cooling plate 16. Through heat exchange between the first thermosiphon device 12, the second thermosiphon device 14, and the liquid cooling plate 16, the liquid cooling plate 16 can absorb the heat energy within the first thermosiphon device 12 and the second thermosiphon device 14, thereby achieving a heat dissipation effect.

[0049] In the first embodiment, the first thermosiphon device 12 includes a condenser 122, an evaporator 124, two transmission pipes 126a and 126b connecting the condenser 122 and the evaporator 124, and a working fluid (not shown in the figure) circulating within the aforementioned components. The first thermosiphon device 12 is thermally coupled to the liquid cooling plate 16 via the condenser 122; for example, but not limited to, the condenser 122 is directly attached to a first outer surface 16a of the liquid cooling plate 16 (in practice, a thermal interface material can be filled between the two). In this way, the first thermosiphon device 12 can absorb heat energy from a heat-generating element (e.g., a processor, which generates heat during operation and is thermally coupled to the evaporator 124, for example, in direct contact, and a thermal interface material can also be filled between them) via the evaporator 124, and then exchange heat with the liquid cooling plate 16 via the condenser 122, thereby achieving the effect of heat dissipation for the heat-generating element. Similarly, the second thermosiphon device 14 includes a condenser 142, an evaporator 144, two transmission pipes 146a and 146b connecting the condenser 142 and the evaporator 144, and a working fluid (not shown in the figure) circulating within the aforementioned components. The second thermosiphon device 14 is thermally coupled to the liquid cooling plate 16 via the condenser 142; for example, but not limited to, the condenser 142 is directly attached to the first outer surface 16a of the liquid cooling plate 16 (in practice, a thermal interface material can be filled between the two). In this way, the second thermosiphon device 14 can absorb heat energy from a heat-generating element (e.g., another processor, the relevant description of which is the same as the aforementioned processor, and will not be repeated) via the evaporator 144, and then exchange heat with the liquid cooling plate 16 via the condenser 142, thereby achieving the effect of heat dissipation from the heat-generating element. In practice, the first thermosiphon device 12 and the second thermosiphon device 14 can be implemented by conventional thermosiphon devices, so other descriptions of heat transfer by the first thermosiphon device 12 and the second thermosiphon device 14 will not be repeated. In addition, in the first embodiment, the first outer surface 16a (i.e., the upper surface of the liquid cooling plate 16) is not a single plane, but forms two grooves to match the structural contours of the condensers 122 and 142, but in practice, it is not limited to this.

[0050] Please also refer to Figures 3 to 6. The liquid cooling plate 16 includes an upper cover 16c and a lower cover 16d, which are combined to form a flow channel structure 160. The flow channel structure 160 has a U-shaped flow channel 162 (or a U-shaped flow channel portion), and the two ends of the U-shaped flow channel 162 are respectively connected to an inlet 164 and an outlet 166 of the flow channel structure 160. The liquid cooling plate 16 uses water as its working fluid, for example, but not limited to, to transfer heat energy. Water enters the liquid cooling plate 16 through the inlet 164 and exits the liquid cooling plate 16 through the outlet 166. In practice, transfer pipes are connected to the inlet 164 and the outlet 166. Quick connectors can be installed at the ends of the transfer pipes for easy connection to external pipelines (e.g., manifolds on server racks). The liquid cooling plate 16 includes a plurality of heat dissipation fins 168 disposed on a second outer surface 16b (located on the lower cover 16d) of the liquid cooling plate 16 relative to one of the first outer surface 16a (located on the upper cover 16c), which helps to improve the heat dissipation efficiency of the liquid cooling plate 16.

[0051] Furthermore, the U-shaped flow channel 162 sequentially (e.g., according to the flow of water within the U-shaped flow channel 162) includes a first section 162a, a second section 162b, a third section 162c, and a fourth section 162d (represented by dashed boxes in Figure 5). The first section 162a is opposite to the fourth section 162d, and the second section 162b is opposite to the third section 162c. The condenser 122 of the first thermosiphon device 12 (its projected position in Figure 5 is indicated by chain lines) is thermally coupled to the first outer surface 16a corresponding to the first section 162a and the fourth section 162d, and the condenser 142 of the second thermosiphon device 14 (its projected position in Figure 5 is indicated by chain lines) is thermally coupled to the first outer surface 16a corresponding to the second section 162b and the third section 162c. Generally, the water temperature in the U-shaped flow channel 162 gradually increases from the first section 162a to the fourth section 162d, so that the average water temperature that exchanges heat with the condenser 122 of the first thermosiphon device 12 is similar to the average water temperature that exchanges heat with the condenser 142 of the second thermosiphon device 14, thereby reducing the difference in heat dissipation performance between the liquid cooling plate 16 and the first thermosiphon device 12 and the second thermosiphon device 14.

[0052] In the first embodiment, a plurality of first to fourth fins 170a to d are respectively provided in the first to fourth sections 162a to d, which can expand the heat transfer area to enhance the heat exchange between the working fluid and the liquid cooling plate 16 (that is, enhance the heat exchange between the liquid cooling plate 16 and the condensers 122 and 142). The fins 170a to d in each section 162a to d extend parallel to the extension direction of each section 162a to d and are connected to the relative inner wall surface 1622 of each section 162a to d. The first section 162a and the second section 162b extend in the same direction (e.g., parallel to direction D1, indicated by double-headed arrows in the figure), and the third section 162c and the fourth section 162d also extend in the same direction (e.g., parallel to direction D1); however, this is not a limitation in practice. In practice, other microstructures can also be provided on the inner wall of the U-shaped flow channel 162, which can also increase the heat transfer area to enhance the heat exchange between the working fluid and the liquid cooling plate 16. Furthermore, taking the first section 162a as an example, the first fin 170a can increase heat transfer efficiency by disrupting the boundary layer generated on its surface through the discontinuous change in its extension cross-section along its extension direction (direction D1). In this embodiment, the first fin 170a has a notch 1702, which causes the extension cross-section of the first fin 170a to change discontinuously at the edge of the notch 1702. In practice, other microstructures can also be formed on the surface of the first fin 170a to disrupt the boundary layer generated on the surface of the first fin 170a, which can also increase heat transfer efficiency. The foregoing description of the first fin 170a also applies to the second to fourth fins 170b-d, and will not be repeated here.

[0053] Furthermore, in the first embodiment, the U-shaped flow channel 162 has a cavity section 162e and 162f (represented by dashed boxes in Figure 5) between the first section 162a and the second section 162b, and between the third section 162c and the fourth section 162d, respectively, without fins. Therefore, the flow resistance between the first section 162a and the second section 162b (i.e., the flow resistance of the cavity section 162e) is less than the flow resistance of the first section 162a and the second section 162b, and the flow resistance between the third section 162c and the fourth section 162d (i.e., the flow resistance of the cavity section 162f) is less than the flow resistance of the third section 162c and the fourth section 162d. This flow resistance difference helps the working fluid to mix in the cavity sections 162e and 162f before flowing into the second section 162b and the fourth section 162d, increasing the uniformity of the working fluid temperature and avoiding the generation of local hot spots.

[0054] According to the first embodiment, the first thermosiphon device 12 and the second thermosiphon device 14 share the same liquid cooling plate 16. Therefore, compared with the configuration of a typical thermosiphon device (i.e., one thermosiphon device with one liquid cooling plate and two transmission pipes), the cooling system 1 uses fewer liquid cooling plates and can reduce the number of externally connected transmission pipes, that is, reduce the number of connection interfaces (e.g., through quick connectors) with external manifolds (e.g., those installed in server racks). On the other hand, the cooling system 1 can avoid the increase in manufacturing costs caused by using multiple liquid cooling plates, and can also avoid or suppress interference with heat dissipation airflow (e.g., heat dissipation airflow inside electronic equipment equipped with the cooling system 1) and increase its flow resistance.

[0055] Please refer to Figure 7. A server 3 according to a second embodiment includes a device housing 30 (its top cover is not shown in the figure to show the internal configuration of the server 3) and a motherboard 32, a first processor 34, a second processor 36, and a cooling system disposed within the device housing 30 (for ease of explanation, the aforementioned cooling system 1 is used as an example; therefore, for related descriptions of the cooling system 1, please refer to the preceding text, and it will not be repeated here). Other components of the server 3 (e.g., storage devices, power supplies, fans, etc.) are not shown in the figure to simplify the drawing. The first processor 34 and the second processor 36 dissipate heat via the cooling system 1, and their hidden outlines are drawn in the figure with dashed lines. The first thermosiphon device 12 of the cooling system 1 is thermally coupled to the first processor 34 via an evaporator 124; for example, but not limited to, the evaporator 124 is directly attached to the upper surface of the first processor 34 (in practice, a thermal interface material can be filled between the two). The second thermosiphon device 14 of the cooling system 1 is thermally coupled to the second processor 36 via an evaporator 144; for example, but not limited to, the evaporator 144 is directly attached to the upper surface of the second processor 36 (in practice, a thermal interface material can be filled between them). The liquid cooling plate 16 of the cooling system 1 is located behind the device housing 30. The inlet 164 and outlet 166 of the liquid cooling plate 16 will, in principle, protrude from the device housing 30 to facilitate connection with external piping (e.g., the manifold of the cabinet). For example, the working fluid of the liquid cooling plate 16 flows to an external heat exchanger for heat dissipation through this piping. In this way, the heat generated by the first processor 34 and the second processor 36 during operation can be dissipated via the first thermosiphon device 12 and the second thermosiphon device 14, respectively.

[0056] Furthermore, in the second embodiment, the first processor 34 and the second processor 36 are arranged one after the other, with the first processor 34 located between the second processor 36 and the liquid cooling plate 16. The transmission pipes 146a and 146b of the second thermosiphon device 14 cross over the evaporator 124. The heat dissipation fins 168 of the liquid cooling plate 16 extend parallel to the front-back direction of the device housing 30, which is beneficial for heat dissipation by utilizing the heat dissipation airflow (indicated by hollow arrows in the figure, for example, generated by a fan) within the device housing 30. Moreover, compared to the configuration of a typical thermosiphon device (i.e., one thermosiphon device paired with one liquid cooling plate and two transmission pipes), the cooling system 1 reduces the number of transmission pipes (shown as dashed lines in Figure 7) connected to the external liquid cooling plate 16. The need for manifolds installed in the cabinet (e.g., where the server 3 is installed) is also reduced. Therefore, the server 3 can avoid the increase in manufacturing costs caused by using multiple liquid cooling plates, and can also avoid or suppress interference with the heat dissipation airflow within the server 3 and the cabinet, thereby reducing its flow resistance.

[0057] In one embodiment of the present invention, the cooling system and server of the present invention can be used for artificial intelligence (AI) computing, edge computing, and can also be used as a 5G server, cloud server or vehicle networking server.

[0058] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent application of the present invention shall be covered by the present invention.

Claims

1. A cooling system comprising: a liquid-cooled plate having a U-shaped flow channel, the U-shaped flow channel sequentially comprising a first section, a second section, a third section, and a fourth section, the first section opposite to the fourth section, the second section opposite to the third section, the flow resistance of the U-shaped flow channel between the first section and the second section being less than the flow resistance of the first section and the flow resistance of the second section, a plurality of first fins disposed in the first section, a plurality of second fins disposed in the second section, the U-shaped flow channel comprising a cavity section located between the first section and the second section, the cavity section having no fins disposed therein; a first thermosiphon device thermally coupled to the liquid-cooled plate corresponding to the first section and the fourth section; and a second thermosiphon device thermally coupled to the liquid-cooled plate corresponding to the second section and the third section.

2. The cooling system as claimed in claim 1, wherein the first thermosiphon device includes a condenser, an evaporator and two transmission pipes connecting the condenser and the evaporator, and the first thermosiphon device is thermally coupled to the liquid cooling plate via the condenser.

3. The cooling system as claimed in claim 1, wherein a plurality of fins are provided in the U-shaped flow channel.

4. The cooling system as claimed in claim 1, wherein the first section and the second section extend in the same direction, and the plurality of first fins and the plurality of second fins extend parallel to that direction.

5. The cooling system as claimed in claim 1, wherein the first fin and the first section extend in the same direction, and the cross-section of the first fin extending in that direction has a discontinuous change.

6. The cooling system as claimed in claim 1, wherein the first fin is connected to the opposing inner wall surface of the first section.

7. The cooling system as claimed in claim 1, wherein the liquid cooling plate has a first outer surface and a second outer surface, the first thermosiphon device and the second thermosiphon device are thermally coupled to the liquid cooling plate via the first outer surface, and a plurality of heat dissipation fins are disposed on the second outer surface.

8. The cooling system as claimed in claim 7, wherein the first outer surface is relative to the second outer surface.

9. A server comprising: a first processor; a second processor; and a cooling system as described in any one of claims 1 to 8, the first thermosiphon being thermally coupled to the first processor, and the second thermosiphon being thermally coupled to the second processor.

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