Heat dissipation devices and server cooling systems

Abstract

To provide a heat dissipation device and server cooling system that can suitably achieve efficient cooling while suppressing installation costs and equipment space. [Solution] In the server cooling system S according to this embodiment, the heat dissipation device 1 comprises an air-cooled heat exchanger 30 having a heat exchange core 30 including a first surface 30A and a second surface 30B, and a plurality of blowers 20 that cause air to flow as a gas through the rotation of an impeller so that air passes from the first surface 30A to the second surface 30B. The heat exchange core 30 has a plurality of tubes 313, 323 through which a heat transfer medium that is exchanged with air flows. The tubes 313, 323 each extend in a meandering manner from the second surface 30B side to the first surface 30A side, and the heat transfer medium flows from the second surface 30B side to the first surface 30A side in each of the tubes 313, 323.

Description

[Technical Field]

[0001] Embodiments of the present invention relate to a heat dissipation device and a server cooling system. [Background technology]

[0002] In recent years, demand for cloud services and generative AI has been rapidly increasing, leading to a rapid expansion in the construction of new data centers.

[0003] Data centers house various types of equipment, such as servers. Modern data centers feature servers equipped with numerous computing devices, including CPUs and GPUs. These computing devices perform significantly more demanding computational tasks than in the past.

[0004] The power consumption of computing devices increases in proportion to the processing load they perform. Therefore, the power consumption of servers and other equipment in data centers today is extremely high.

[0005] Furthermore, the amount of heat generated and the temperature of computing units increase in proportion to the processing load and power consumption of the computing units. Although the operating temperature range for computing units is generally set relatively high, excessive temperature increases in the computing units can cause malfunctions. Therefore, it is necessary to properly cool equipment such as servers in data centers.

[0006] Cooling of servers and other equipment has been a long-standing practice (e.g., JP2017-33427A). However, in today's data centers, the amount of heat generated by servers and other equipment has increased significantly compared to the past, requiring a much larger cooling capacity to cool the equipment. [Overview of the Initiative]

[0007] As mentioned above, the computing devices in servers and other equipment installed in data centers today perform computationally intensive tasks compared to the past. Therefore, the power consumption of servers and other equipment has increased significantly. Furthermore, the heat generated by computing devices also tends to be considerably higher than before. Consequently, the increased power consumption for computation and the increased power consumption for cooling are becoming problems in modern data centers.

[0008] COP (Coefficient of Performance) is an index used to evaluate the efficiency of cooling relative to power consumption. COP is determined by cooling capacity / power consumption, and a higher COP indicates higher cooling efficiency. In previous data centers, power consumption related to computing and cooling was not excessive, so it cannot necessarily be said that cooling equipment was designed with COP as a primary consideration. However, in future data center cooling, it is desirable to improve COP as much as possible.

[0009] Furthermore, in the construction of cooling systems for data centers, where large amounts of heat generation are anticipated, effective cooling cannot be achieved without more thorough consideration of factors such as installation costs and the characteristics of the data center's interior than before.

[0010] In more detail, while older data centers could generally cool their equipment sufficiently with only low-power air-cooled heat dissipation systems, these older systems are insufficient to adequately dissipate the heat generated by equipment in modern data centers, and therefore cannot adequately meet the required cooling needs. In this situation, it might seem that installing cooling towers, similar to those in semiconductor manufacturing plants, could efficiently cool the equipment in a data center. However, installing cooling towers may be overkill for data center cooling needs, making the installation cost a problem. Furthermore, considering the operation of the cooling towers, it cannot necessarily be said that it would be more efficient in terms of power consumption.

[0011] On the other hand, if an air-cooled heat dissipation device is used as before, a large cooling capacity can be ensured by driving the fan with a large airflow. However, in this case, the COP may increase. Also, dust may be stirred up, creating undesirable conditions for equipment maintenance. Furthermore, noise may also become a problem. In addition, increasing the airflow increases pressure loss, which may cause saturation of the cooling performance.

[0012] Furthermore, the use of cooling towers and high-volume fans can lead to an increase in the size of the heat dissipation equipment or the entire facility including the heat dissipation equipment. While data centers generally have relatively large spaces for equipment installation, reducing the space occupied by cooling equipment such as heat dissipation devices would allow for an increase in the number of servers and other equipment that can be installed. Therefore, efficiently performing cooling while minimizing the space occupied by cooling equipment is naturally desirable.

[0013] As described above, there are various considerations regarding the cooling required for future data centers, and establishing effective cooling methods is still in the trial-and-error stage.

[0014] In particular, the inventors of this case anticipate that server racks with a heat output of approximately 150 kW per unit will be widely adopted in future data centers. Specifically, if such server racks can be cooled in a manner suitable for data centers and with extreme efficiency, it will greatly contribute to resolving the power consumption problems anticipated in future data centers.

[0015] This disclosure was conceived based on the above background, and aims to provide a heat dissipation device and server cooling system that can suitably achieve efficient cooling while suppressing introduction costs and equipment occupied space.

[0016] Embodiments of the present invention relate to the following aspects.

[0017] <1> An air-cooled heat exchanger having a heat exchange core including a first surface and a second surface opposite the first surface, The system comprises a plurality of blowers that cause the gas to flow from the first surface to the second surface by the rotation of an impeller, The heat exchange core has a plurality of tubes through which a heat transfer medium to be exchanged with the gas flows. A heat dissipation device wherein each of the tubes extends in a meandering manner from the second surface to the first surface, and the heat transfer medium flows in each of the tubes from the second surface to the first surface.

[0018] <2> The heat exchanger has an inlet that receives the heat transfer medium from the outside and allows it to flow into the tube. Each of the aforementioned tubes branches in parallel from the inlet, <1> The heat dissipation device described above.

[0019] <3> The tube forms a meandering shape by alternately connecting a main flow channel element that extends in a straight line and a U-shaped folded flow channel element. Multiple blowers are arranged such that the extension of the rotation axis of the impeller is perpendicular to the second surface. The adjacent main flow channel elements connected by the aforementioned folded flow channel elements do not overlap in any part when viewed in the direction from the first surface to the second surface. <1> or <2> The heat dissipation device described above.

[0020] <4> The heat exchanger has a plurality of plate fins that extend parallel to the direction from the first surface to the second surface and are arranged in a direction perpendicular to the direction from the first surface to the second surface. The tube extends in a meandering manner from the second surface side toward the first surface side while penetrating through the plurality of plate fins, and contacts the plate fins. <1> ~ <3> A heat dissipation device as described in any of the following.

[0021] <5> The heat dissipation device according to claim 1, wherein the multiple blowers are arranged in multiple rows and multiple columns.

[0022] <6> The areas of the first and second surfaces of the heat exchange core are, respectively, 1.5 m². 2Above 1.7 m 2 Set it below, The air volume of the gas flowing through the plurality of blowers is set to be 345 m 3 / min or more and 375 m 3 / min or less, Select the heat medium and set the flow rate of the heat medium so that the value (C·L) obtained by multiplying the specific heat C (kJ / kg·K) of the heat medium at 20°C to 40°C by the flow rate L (L / min) of the heat medium is between 250 and 320, The waste heat removal device according to any one of <1> to <5>, which outputs a cooling capacity of 140 kW or more and 160 kW or less.

[0023] <7> The waste heat removal device according to <6>, wherein the heat medium cooling efficiency (LPM / kW) determined by dividing the flow rate (L / min: LPM) of the heat medium by the cooling capacity is not less than 1.4.

[0024] <8> The waste heat removal device according to <6> or <7>, which has a COP of 15 or more and outputs a cooling capacity of 140 kW or more and 160 kW or less.

[0025] <9> The heat exchanger extends parallel to the direction from the first surface to the second surface and has a plurality of plate fins arranged in a direction perpendicular to the direction from the first surface to the second surface, The tube extends while meandering from the second surface side to the first surface side while passing through the plurality of plate fins and contacts the plate fins, The total area of the heat exchange surfaces of the plurality of plate fins and the heat exchange surface area of the tube is 600 m 2 or more. The waste heat removal device according to any one of <1> to <8>.

[0026] <10> The heat exchange core includes a first heat exchange core and a second heat exchange core, and the first heat exchange core and the second heat exchange core are arranged adjacent to each other, The heat exchanger includes, as the inlet section, an inlet section connected to the tube of the first heat exchange core and an inlet section connected to the tube of the second heat exchange core, which are separated from each other. The inlet connected to the tube of the first heat exchange core and the inlet connected to the tube of the second heat exchange core each extend in a direction in which the first heat exchange core and the second heat exchange core are adjacent to each other. The inlet connected to the tube of the first heat exchange core and the inlet connected to the tube of the second heat exchange core are arranged such that they are offset in the direction from the first surface toward the second surface, and that, when viewed in the direction from the first surface toward the second surface, the end of the inlet connected to the tube of the first heat exchange core on the second heat exchange core side overlaps the end of the inlet connected to the tube of the second heat exchange core on the first heat exchange core side. <2> The heat dissipation device described above.

[0027] <11> The inlet for the heat transfer medium in the inlet connected to the tube of the first heat exchange core and the inlet for the heat transfer medium in the inlet connected to the tube of the second heat exchange core open in a direction from the first surface toward the second surface or in the opposite direction. <10> The heat dissipation device described above.

[0028] <12> The heat dissipation device comprises two of the heat exchangers, The two heat exchangers are arranged to form a V-shape. Some of the blowers are arranged so that the extension of the rotation axis of the impeller intersects with the second surface of one of the two heat exchangers, and other parts of the blowers are arranged so that the extension of the rotation axis of the impeller intersects with the second surface of the other of the two heat exchangers, <1> ~ <11> A heat dissipation device as described in any of the following.

[0029] <13> The setting of the airflow rate of the gas flowed by the multiple blowers or the setting of the rotation speed of the multiple blowers differs depending on the distance between each blower and the adjacent heat exchanger. <12> The heat dissipation device described above.

[0030] <14> the above <1> ~ <13> A heat dissipation device as described in any of the following, The server rack is supplied with the heat transfer medium from the heat dissipation device, The server rack has a cooling channel that receives and circulates the heat transfer medium after heat exchange with the gas, and the server cooling system returns the heat transfer medium flowing out of the cooling channel to the heat dissipation device.

[0031] According to embodiments of the present invention, efficient cooling can be suitably achieved while suppressing introduction costs and equipment space. [Brief explanation of the drawing]

[0032] [Figure 1] This is a perspective view of a server cooling system according to one embodiment. [Figure 2] This is a view of the heat dissipation device that constitutes the server cooling system shown in Figure 1, as seen in the direction of arrow II in Figure 1. [Figure 3] This is a cross-sectional view of the heat dissipation device along the line III-III in Figure 2. [Figure 4] Figure 3 shows the heat exchanger that makes up the heat dissipation device, viewed in the direction of arrow IV. [Figure 5] Figure 4 is a side view of the heat exchanger. [Figure 6] Figure 5 is a top view of the heat exchange core (upper heat exchange core) in the heat exchanger shown. [Figure 7] This diagram shows the heat exchange core with the plate fins removed, as shown in Figure 6. [Figure 8] This is a cross-sectional view along the line VIII-VIII in Figure 7. [Figure 9] Figure 1 illustrates the connection configuration between the heat dissipation device and the server rack, which constitute the server cooling system shown in Figure 1. [Figure 10]Figure 1 shows a table illustrating an example of the specifications of a server cooling system. [Figure 11] This figure shows a heat dissipation device according to the first modified example. [Figure 12] This figure shows a heat dissipation device according to a second modified example. [Figure 13] This figure shows a heat dissipation device according to a third modified example. [Figure 14] This figure shows a heat dissipation device according to the fourth modified example. [Figure 15] This figure shows a heat dissipation device according to the fifth modified example. [Figure 16] This is a cross-sectional view of the fifth modified example along the line XVI-XVI in Figure 15. [Modes for carrying out the invention]

[0033] One embodiment will be described below.

[0034] <Server Cooling System Configuration> Figure 1 is a perspective view of a server cooling system S according to one embodiment. The server cooling system S comprises a heat dissipation device 1 and a server rack 100.

[0035] The heat dissipation device 1 and the server rack 100 are installed adjacent to each other horizontally. Figure 1 shows an example of the server cooling system S being installed in a data center. However, the server cooling system S is not limited to use in data centers.

[0036] The server rack 100 houses multiple servers 102, which are electronic devices, inside the rack body 101. The rack body 101 has shelves arranged vertically (not shown). In the illustrated example, the servers 102 are installed on each of the multiple shelves in the rack body 101. As a result, the multiple servers 102 are housed inside the rack body 101 so that they overlap vertically. The servers 102 may include, for example, computing devices such as CPUs and GPUs, memory, etc.

[0037] <Heat dissipation device> The heat dissipation device 1 is a device that removes heat generated from the server 102 inside the rack body 101, thereby cooling the server 102. The heat dissipation device 1 comprises a rectangular parallelepiped housing 10, an air-cooled heat exchanger 30 (see Figures 3, 4, etc.), and a blower 20.

[0038] The enclosure 10 is open on both sides: in the direction where the heat dissipation device 1 and the server rack 100 are adjacent, and in the direction perpendicular to the horizontal plane. The enclosure 10 houses the heat exchanger 30 inside. The blower 20 is held in the enclosure 10 so as to fill the open portion on one side of the enclosure 10.

[0039] The heat exchanger 30 is an air-cooled type that cools the heat transfer medium, which is a liquid circulating inside it, by exchanging heat with air, which is a gas. The blower 20 causes air to flow so that it passes through the heat exchanger 30, thereby promoting heat exchange between the heat transfer medium and the air.

[0040] In the heat dissipation device 1, the heat transfer medium cooled in the heat exchanger 30 is supplied to the server rack 100. At this time, the heat transfer medium absorbs heat from the server 102, cooling the server 102. After cooling the server 102, the heat transfer medium returns to the heat exchanger 30. The heat transfer medium that returns to the heat exchanger 30 is cooled again by air and then supplied again to the server rack 100. The blower 20 and heat exchanger 30 that constitute the heat dissipation device 1 will be described in detail below.

[0041] (Blower) Figure 2 is a view of the heat dissipation device 1 in the direction of arrow II in Figure 1. Figure 3 is a cross-sectional view of the heat dissipation device 1 along the line III-III in Figure 2.

[0042] As shown in Figure 2, the heat dissipation device 1 is equipped with a plurality of blowers 20. In this embodiment, the plurality of blowers 20 are arranged adjacent to the heat exchanger 30 and in multiple rows and columns. More specifically, the blowers 20 are adjacent to the heat exchanger 30 in the horizontal direction. The state in which the blowers 20 are adjacent to the heat exchanger 30 in the horizontal direction means that a straight line extending horizontally from any part of the blower 20 passes through any part of the heat exchanger 30.

[0043] In Figure 3, reference numeral 30C indicates the heat exchange core 30C in a heat exchanger 30 that exchanges heat between a heat transfer medium and air. The heat exchange core 30C includes a first surface 30A and a second surface 30B opposite to the first surface 30A. Multiple blowers 20 are arranged so as to be adjacent to the second surface 30B of the heat exchange core 30C. In particular, it is preferable that the blowers 20 are arranged so as to be adjacent to the second surface 30B of the heat exchange core 30C with the extension of the rotation axis Ax of their impeller 21 (described later) intersecting the second surface 30B of the heat exchange core 30C, and in this embodiment, they are arranged in this manner. The first surface 30A of the heat exchange core 30C faces one side in the direction in which the housing 10 opens, and the second surface 30B of the heat exchange core 30C faces the other side in the direction in which the housing 10 opens.

[0044] The blower 20 includes an impeller 21 and a casing 22 that rotatably supports the impeller 21 around a rotation axis Ax. The blower 20 is of the axial flow type. The blower 20 causes air to flow through the heat exchange core 30C from the first surface 30A to the second surface 30B by the rotation of the impeller 21. Each of the multiple blowers 20 is arranged adjacent to the second surface 30B of the heat exchange core 30C, specifically in a state where the extension of the rotation axis Ax of its impeller 21 intersects with the second surface 30B, or more precisely, perpendicular to it. In this embodiment, the rotation axis Ax of the impeller 21 of each blower 20 is aligned horizontally (parallel), but the blowers 20 may be arranged so that the rotation axis Ax of the impeller 21 is inclined with respect to the horizontal.

[0045] In this embodiment, multiple blowers 20 are specifically arranged in an 8-row, 4-column configuration. That is, the heat exchanger 30 is equipped with 32 blowers 20. The number and arrangement of the blowers 20 are not limited, and there may be only one blower 20. However, when multiple blowers 20 are used, if some of the blowers 20 are damaged, the remaining blowers 20 can continue to circulate air, thereby suppressing a decrease in the function of the heat dissipation device 1. In addition, compared to using one large blower, the power required to obtain the desired cooling capacity can be reduced.

[0046] In particular, when the blowers 20 are arranged in four or more rows and four or more columns, distributing two or more blowers 20 vertically or horizontally with respect to the center or vicinity of the heat exchange core 30C effectively suppresses the deterioration of the heat dissipation device 1's function when some of the blowers 20 are damaged. In this embodiment, 16 blowers 20 are distributed vertically and horizontally with respect to the center of the heat exchange core 30C. When multiple blowers 20 are used, each blower 20 may have the same structure and size, or they may have different structures and / or sizes. In this embodiment, each blower 20 has the same structure and size, and basically, when the same power is applied, they are driven at the same rotational speed and output the same airflow. In this embodiment, all of the multiple blowers 20 are driven to output the same airflow, but the airflow or rotational speed of some blowers 20 may be different from others. For example, within the housing 10 or the array of blowers 20, the frictional resistance to airflow may be greater on the outer periphery than on the center. Taking this into consideration, the airflow rate or rotational speed of the blower 20 located on the outer periphery (towards the housing 10) of the multiple blowers 20 may be set to be greater than that of the blower 20 located closer to the center.

[0047] Furthermore, if the blowers 20 are arranged in four or more rows and four or more columns, the amount of air passing linearly from the first surface 30A to the second surface 30B can be increased. In this case, it may be advantageous in terms of suppressing pressure loss and improving heat exchange efficiency. In this embodiment, the blowers 20 are arranged adjacent to the second surface 30B, but the blowers 20 may also be arranged adjacent to the first surface 30A, and the gas may flow from the first surface 30A to the second surface 30B. However, since the temperature of the gas rises when it passes through the blowers 20, from the viewpoint of cooling efficiency, it is preferable that the blowers 20 be arranged downstream of the heat exchange core 30C, that is, adjacent to the second surface 30B.

[0048] (heat exchanger) The heat exchanger 30 includes a heat exchange core 30C, which includes the first surface 30A and the second surface 30B described above. As shown in Figure 3, the heat exchange core 30C has a plurality of tubes 313, 323 through which a heat transfer medium flows. The heat exchange core 30C cools the heat transfer medium by exchanging heat between the heat transfer medium flowing through the tubes 313, 323 and the air passing through the heat exchange core 30C. The first surface 30A and the second surface 30B are parallel to each other, but they may be non-parallel.

[0049] Figure 4 is a view of the heat exchanger 30 in the direction of arrow IV in Figure 3. Figure 5 is a side view of the heat exchanger 30 shown in Figure 4. As shown in Figures 3 to 5, the heat exchange core 30C in this embodiment includes an upper heat exchange core 310 and a lower heat exchange core 320. The upper heat exchange core 310 is superimposed on the lower heat exchange core 320 from above. The upper heat exchange core 310 corresponds to the first heat exchange core, and the lower heat exchange core 320 corresponds to the second heat exchange core, and they are arranged adjacent to each other.

[0050] The upper heat exchange core 310 includes an upper first surface 310A and an upper second surface 310B opposite to the upper first surface 310A. The lower heat exchange core 320 includes a lower first surface 320A and a lower second surface 320B opposite to the lower first surface 320A. The upper first surface 310A and the lower first surface 320A, when arranged vertically, constitute the first surface 30A of the heat exchange core 30C. The upper second surface 310B and the lower second surface 320B, when arranged vertically, constitute the second surface 30B of the heat exchange core 30C.

[0051] Both the upper heat exchange core 310 and the lower heat exchange core 320 are, in general terms, rectangular parallelepipeds. The upper part and both sides of the upper heat exchange core 310 are covered and connected to the upper frame 311. The lower part and both sides of the lower heat exchange core 320 are covered and connected to the lower frame 321. The upper heat exchange core 310 and the lower heat exchange core 320 are integrated by the upper frame 311 and the lower frame 321 being connected vertically, thereby forming the heat exchange core 30C.

[0052] The heat exchanger 30 has inlet sections 315 and 325 that receive the heat transfer medium from the outside (server rack 100 side) and allow it to flow into the tubes 313 and 323, and outlet sections 316 and 326 that receive the heat transfer medium flowing out of the tubes 313 and 323 and allow it to flow out to the outside (server rack 100 side).

[0053] In this embodiment, the upper heat exchange core 310 has a tube 313, and the lower heat exchange core 320 has a tube 323. As shown in Figures 4 and 5, the heat exchanger 30 includes, as inlets 315 and 325, an upper inlet 315 connected to the tube 313 of the upper heat exchange core 310 and a lower inlet 325 connected to the tube 323 of the lower heat exchange core 320, respectively. The heat exchanger 30 also includes, as outlets 316 and 326, an upper outlet 316 connected to the tube 313 of the upper heat exchange core 310 and a lower outlet 326 connected to the tube 323 of the lower heat exchange core 320, respectively.

[0054] Each tube 313 in the upper heat exchange core 310 is connected at its upstream end to the upper inlet 315 so as to branch in parallel from the upper inlet 315. Each tube 313 in the upper heat exchange core 310 is connected at its downstream end to the upper outlet 316. Similarly, each tube 323 in the lower heat exchange core 320 is connected at its upstream end to the lower inlet 325 so as to branch in parallel from the lower inlet 325. Each tube 323 in the lower heat exchange core 320 is connected at its downstream end to the lower outlet 326.

[0055] More specifically, the upper inlet section 315 is connected to an upper inlet pipe 315P having a heat transfer medium inlet 315a and a plurality of upper first relay pipes 315b. The upper outlet section 316 is connected to a plurality of upper second relay pipes 316a and an upper outlet pipe 316P having a heat transfer medium outlet 316b. The plurality of upper first relay pipes 315b are connected to the upstream end of the corresponding tube 313. The plurality of upper second relay pipes 316a are connected to the downstream end of the corresponding tube 313. The plurality of upper first relay pipes 315b and the plurality of upper second relay pipes 316a are arranged vertically, and the plurality of tubes 313 to which they are connected are also arranged vertically.

[0056] With the connection configuration described above, in the upper heat exchange core 310, the heat transfer medium flowing from the inlet 315a into the upper inlet 315 flows from the upper inlet 315 into each tube 313 via each upper first relay pipe 315b. The heat transfer medium flowing out from the downstream end of each tube 313 flows into the upper outlet 316 via each upper second relay pipe 316a and can flow out from the outlet 316b of the upper outlet 316.

[0057] Similarly, the lower inlet 325 is connected to a lower inlet pipe 325P having a heat transfer medium inlet 325a and a plurality of lower first relay pipes 325b. The lower outlet 326 is connected to a plurality of lower second relay pipes 326a and a lower outlet pipe 326P having a heat transfer medium outlet 326b. The plurality of lower first relay pipes 325b are connected to the upstream end of the corresponding tube 323. The plurality of lower second relay pipes 326a are connected to the downstream end of the corresponding tube 323. The flow of the heat transfer medium on the lower side is the same as the flow of the heat transfer medium on the upper side described above.

[0058] In this embodiment, the inlets 315a, 325a of the heat transfer medium in the upper inlet 315 and the lower inlet 325, and the outlets 316b, 326b of the heat transfer medium in the upper outlet 316 and the lower outlet 326, open in the direction from the second surface 30B toward the first surface 30A. The upper inlet pipe 315P, the upper outlet pipe 316P, the lower inlet pipe 325P, and the lower outlet pipe 326P extend in the direction from the second surface 30B toward the first surface 30A. In this case, the lateral protrusion of the inlet and outlet portions of the heat transfer medium is suppressed, which is advantageous in terms of suppressing the overall size of the heat exchanger 30 and securing the area of ​​the heat exchange core 30C. The inlets 315a, 325a and outlets 316b, 326b may also open in the direction from the first surface 30A toward the second surface 30B. Furthermore, the inlets 315a and 325a of the heat transfer medium in the upper inlet 315 and lower inlet 325 are formed on the lower side of the corresponding heat exchange core. The outlets 316b and 326b of the heat transfer medium in the upper outlet 316 and lower outlet 326 are formed on the upper side of the corresponding heat exchange core. In this case, the flow lengths of the parallel branched heat transfer medium become uniform, enabling uniform cooling throughout the entire heat exchange core.

[0059] As shown in Figure 5, the upper inlet 315 and the lower inlet 325 are both pipes. The upper inlet 315 and the lower inlet 325 are positioned to the side of one side of the heat exchange core 30C, closer to the second surface 30B. The upper inlet 315 and the lower inlet 325 extend in the vertical direction, in other words, in the direction in which the upper heat exchange core 310 and the lower heat exchange core 320 are adjacent to each other. Here, the upper inlet 315 and the lower inlet 325 are positioned offset in the direction from the first surface 30A to the second surface 30B. Furthermore, when viewed in the direction from the first surface 30A to the second surface 30B, the lower part of the upper inlet 315 overlaps the upper part of the lower inlet 325 (see also Figure 4). In other words, the upper end of the lower inlet 325 is located above the lower end of the upper inlet 315, and the upper part of the lower inlet 325, including its upper end, overlaps with the upper inlet 315.

[0060] Similarly, the upper outlet section 316 and the lower outlet section 326 are also pipes. The upper outlet section 316 and the lower outlet section 326 are positioned to the side of one side of the heat exchange core 30C, closer to the first surface 30A. The upper outlet section 316 and the lower outlet section 326 extend in the vertical direction. The upper outlet section 316 and the lower outlet section 326 are also positioned so as to be offset in the direction from the first surface 30A toward the second surface 30B. Furthermore, when viewed in the direction from the first surface 30A toward the second surface 30B, the lower part of the upper outlet section 316 is positioned to overlap the upper part of the lower outlet section 326.

[0061] In this embodiment, the upper inlet 315 and the lower inlet 325 are arranged so as to be offset in the direction from the first surface 30A to the second surface 30B. Also, the upper outlet 316 and the lower outlet 326 are arranged so as to be offset in the direction from the first surface 30A to the second surface 30B. In this case, it is possible to bring the upper heat exchange core 310 and the lower heat exchange core 320 closer together in the vertical direction while avoiding unwanted interference between the members, which is advantageous in terms of suppressing the overall size and securing the area of ​​the heat exchange core 30C.

[0062] Furthermore, in this embodiment, as shown in Figure 5, the upstream end positions of each tube 313 of the upper heat exchange core 310 and the upstream end positions of each tube 323 of the lower heat exchange core 320 are the same in the direction from the first surface 30A to the second surface 30B. On the other hand, as described above, the upper inlet 315 and the lower inlet 325 are offset in the direction from the first surface 30A to the second surface 30B.

[0063] Here, the upper first relay pipe 315b connected to the upper inlet 315 is formed in the shape of an arc or a roughly L-shape, and the lower first relay pipe 325b is formed in the shape of a straight pipe. The upper inlet 315 is located closer to the first surface 30A than the lower inlet 325, and the arc or roughly L-shaped upper first relay pipe 315b moves in the direction from the first surface 30A to the second surface 30B, approaching the upstream end of the tube 313 and connecting with the tube 313. The lower inlet 325 is positioned to face the upstream end of each tube 323 of the lower heat exchange core 320, and connects to the upstream end of each tube 323 by the straight lower first relay pipe 325b at the shortest distance. As a result, without shifting the position of the upstream end of each tube 313 of the upper heat exchange core 310 and the position of the upstream end of each tube 323 of the lower heat exchange core 320, fluid connection between each tube 313 of the upper heat exchange core 310 and the upper inlet 315, and fluid connection between each tube 323 of the lower heat exchange core 320 and the lower inlet 325 are ensured.

[0064] On the other hand, the upper second relay pipe 316a connected to the upper outlet section 316 is formed in a straight pipe shape, while the lower second relay pipe 326a is formed in an arc shape or a roughly L-shaped pipe shape. This ensures fluid connection between each tube 313 of the upper heat exchange core 310 and the upper outlet section 316, and between each tube 323 of the lower heat exchange core 320 and the lower outlet section 326, without shifting the positions of the downstream ends of each tube 313 of the upper heat exchange core 310 and the downstream ends of each tube 323 of the lower heat exchange core 320. With this connection configuration, it is possible to standardize the structure of the upper heat exchange core 310 and the lower heat exchange core 320, which is advantageous in terms of ease of manufacture. In addition, differences in heat exchange performance between the upper and lower sections are suppressed, enabling effective heat exchange.

[0065] Figure 6 is a top view of the heat exchange core 30C (upper heat exchange core 310) in the heat exchanger 30 shown in Figure 5. Figure 6 shows the plate fins 314 provided on the upper heat exchange core 310. The plate fins 314 extend parallel to the direction from the first surface 30A to the second surface 30B and are spaced apart in a direction perpendicular to that direction. The tube 313 extends in a meandering manner from the second surface 30B side to the first surface 30A side, penetrating the multiple plate fins 314, and contacting the plate fins 314. Specifically, the tube 313 penetrates the plate fins 314 in a direction perpendicular to the plate fins 314. In this embodiment, the multiple plate fins 314 are provided so that their heat exchange surfaces (two surfaces facing opposite directions in the thickness direction) are parallel in the vertical direction. As shown in Figure 4, the lower heat exchange core 320 is also provided with plate fins 324 similar to the plate fins 314.

[0066] As described above, the upper inlet 315 and the lower inlet 325 are positioned closer to the second surface 30B. The upper outlet 316 and the lower outlet 326 are positioned closer to the first surface 30A. Here, the tubes 313 and 323 extend from the second surface 30B side towards the first surface 30A side, each in a meandering manner in the left-right direction in this example. As a result, in the heat exchanger 30, the heat transfer medium flows from the second surface 30B side towards the first surface 30A side in each of the tubes 313 and 323. On the other hand, air flows from the first surface 30A side to the second surface 30B side due to the drive of the blower 20. In other words, the heat exchanger 30 is configured as a counterflow type heat exchanger that exchanges heat by moving the heat transfer medium and air in opposite directions.

[0067] Figure 7 shows the upper heat exchange core 310 shown in Figure 6 with the plate fins 314 removed. Figure 8 is a cross-sectional view along the line VIII-VIII in Figure 7. The shape of the tube 313 will be described in detail below with reference to Figures 6 to 8.

[0068] As shown in Figures 6 and 7, the tube 313 forms a meandering shape by alternately connecting linearly extending main flow channel elements 313a and U-shaped folded flow channel elements 313b. The multiple main flow channel elements 313a are arranged parallel to each other and aligned in the direction of airflow due to the drive of the blower 20. The main flow channel element 313a located furthest upstream in the direction of airflow constitutes the first surface 30A, and the main flow channel element 313a located furthest downstream in the direction of airflow constitutes the second surface 30B. The heat exchange core 30C has a roughly rectangular parallelepiped shape, and the first surface 30A and the second surface 30B correspond to two surfaces facing opposite directions in the roughly rectangular parallelepiped shape.

[0069] The main flow channel element 313a constituting the second surface 30B connects the end opposite to the end connected to the return flow channel element 313b to the upper first relay pipe 315b. The main flow channel element 313a constituting the first surface 30A connects the end opposite to the end connected to the return flow channel element 313b to the upper second relay pipe 316a.

[0070] Furthermore, referring to Figure 8, two adjacent main flow channel elements 313a connected by the return flow channel element 313b do not overlap in any part when viewed in the direction from the first surface 30A to the second surface 30B (from left to right in Figure 8). Specifically, in this embodiment, two adjacent main flow channel elements 313a connected by the return flow channel element 313b are separated by a distance d1 in the vertical direction, and do not overlap overall when viewed in the direction from the first surface 30A to the second surface 30B. In addition, between two vertically adjacent tubes 313, the main flow channel elements 313a of one tube 313 and the main flow channel elements 313a of the other tube 313 that are close to each other are also separated by a distance d2 in the vertical direction.

[0071] When the arrangement of the main flow elements 313a described above is adopted, air can easily come into contact with each main flow element 313a, which can be advantageous in terms of improving heat exchange efficiency and can suppress an excessive increase in pressure loss. The tube 323 in the lower heat exchange core 320 has the same shape as the tube 313.

[0072] In this embodiment, plate fins 314 and 324 are used as fins in the heat exchanger 30, but corrugated fins or disc-shaped fins may also be used. However, in this embodiment, plate fins are used from the viewpoint of suppressing an excessive increase in pressure loss.

[0073] (Connection method between heat dissipation device and server rack) The connection configuration between the heat dissipation device 1 and the server rack 100 will be described below with reference to Figure 9. The heat dissipation device 1 is equipped with a first pump 41 and a second pump 42 for circulating a heat transfer medium. The first pump 41 and the second pump 42 may be, for example, centrifugal pumps driven by electric motors, but their type is not particularly limited.

[0074] The first pump 41 is connected to the inlet 315a of the upper inlet 315, which is connected to the upper heat exchange core 310. The second pump 42 is connected to the inlet 325a of the lower inlet 325, which is connected to the lower heat exchange core 320. In other words, in this embodiment, the upper heat exchange core 310 and the lower heat exchange core 320 are supplied with a heat transfer medium from separate pumps 41 and 42. This can reduce the load on each pump 41 and 42. In particular, in this embodiment, since the upper heat exchange core 310 and the lower heat exchange core 320 are stacked vertically, if a single pump were used, a large amount of power would be required to secure the necessary head, so the energy saving effect of separating the pumps is significant. However, the heat transfer medium may be supplied to the entire heat exchange core 30C from a single pump.

[0075] The heat transfer medium that flows into tube 313 from the upper inlet 315 flows in a meandering manner from the second surface 30B to the first surface 30A and flows out from outlet 316b. The heat transfer medium that flows into tube 323 from the lower inlet 325 flows in a meandering manner from the second surface 30B to the first surface 30A and flows out from outlet 326b. The heat transfer medium that flows out from outlets 316b and 326b then merges and flows into the server rack 100.

[0076] The server rack 100 has multiple cooling channels 110 that receive and circulate the heat transfer medium after heat exchange with air, and returns the heat transfer medium flowing out of the cooling channels 110 to the heat dissipation device 1. The heat transfer medium flowing through the cooling channels 110 absorbs heat from the server 102. The heat transfer medium flowing out of the cooling channels 110 is then drawn back to the heat dissipation device 1 by the first pump 41 and the second pump 42, and is cooled again.

[0077] In Figure 9, arrow α indicates the direction of air flow caused by the drive of the blower 20. Arrow β indicates the direction of the heat transfer medium flowing from the second surface 30B to the first surface 30A in the upper heat exchange core 310 and the lower heat exchange core 320. Heat exchange between the air and the heat transfer medium occurs in a counterflow manner.

[0078] In the server cooling system S according to the embodiment described above, the heat dissipation device 1 comprises an air-cooled heat exchanger 30 having a heat exchange core 30C including a first surface 30A and a second surface 30B opposite to it, and a plurality of blowers 20 provided adjacent to the second surface 30B, which move air as a gas through the rotation of an impeller so that it passes from the first surface 30A to the second surface 30B. The heat exchange core 30C has a plurality of tubes 313, 323 through which a heat transfer medium that is exchanged with air flows. The tubes 313, 323 each extend in a meandering manner from the second surface 30B side to the first surface 30A side, and the heat transfer medium flows from the second surface 30B side to the first surface 30A side in each of the tubes 313, 323.

[0079] In this configuration, air and the heat transfer medium exchange heat in a counter-flow manner within the heat exchange core 30C, resulting in uniform heat exchange between the entire tubes 313 and 323 and the air, thereby improving heat exchange efficiency. Furthermore, by using multiple blowers 20, the load on each blower required to obtain the desired cooling capacity can be reduced. This reduces the power, noise, and size of the heat exchange core required to obtain the desired cooling capacity. Additionally, by passing the heat transfer medium through multiple tubes 313 and 323, the overall flow length and flow shape complexity of the tubes 313 and 323 can be reduced. This reduces the power required for the pumps to circulate the heat transfer medium and thus the power consumption of the pumps required to obtain the desired cooling capacity. As a result, the COP can be improved. Moreover, by employing air cooling, the initial cost can be reduced, and as mentioned above, the power required for the blowers to obtain the desired cooling capacity can be reduced, thus suppressing the scattering of dust and other particles. Therefore, efficient cooling can be suitably achieved while reducing initial costs and the space occupied by the equipment.

[0080] Furthermore, the heat exchanger 30 has inlet sections 315 and 325 that receive the heat transfer medium from the outside and allow it to flow into the tubes 313 and 323. The tubes 313 and 323 are connected to the inlet sections 315 and 325 so as to branch in parallel from appropriate points on the inlet sections 315 and 325. In this case, by allowing the heat transfer medium to flow in parallel from the inlet sections 315 and 325 into the corresponding multiple tubes 313 and 323, the power of the pumps (41 and 42) for circulating the heat transfer medium can be effectively reduced, and the structure of the inflow path of the heat transfer medium into the tubes 313 and 323 can be simplified.

[0081] Furthermore, the multiple blowers 20 are arranged such that the extension of the rotation axis Ax of the impeller 21 is perpendicular to the second surface 30B, and the tube 313 forms a meandering shape by alternately connecting linearly extending main flow path elements 313a and U-shaped folded flow path elements 313b. When viewed from the direction from the first surface 30A to the second surface 30B, adjacent main flow path elements 313a connected by the folded flow path elements 313b do not overlap in at least part. In this case, air can easily come into contact with each main flow path element 313a, improving heat exchange efficiency and effectively reducing the power of the blowers 20. The tube 323 has a similar structure to the tube 313.

[0082] Furthermore, the heat exchanger 30 has multiple plate fins 314, 324 that extend parallel to the direction from the first surface 30A to the second surface 30B, and are arranged in a direction perpendicular to that direction, in this example, horizontally. The tubes 313, 323 extend in a meandering manner from the second surface 30B side to the first surface 30A side, penetrating the plate fins 314, 324, and are in contact with the plate fins 314, 324. In this case, the heat exchange efficiency is improved by heat dissipation from the plate fins 314, 324, and in particular, the extension of the plate fins 314, 324 parallel to the axial flow direction suppresses pressure loss, thereby effectively reducing the power of the blower 20.

[0083] Furthermore, the multiple blowers 20 are arranged in multiple rows and multiple columns. In this case, even if some of the blowers 20 fail, the blowing function can be effectively maintained, and a decrease in cooling performance can be suppressed. In addition, compared to a configuration in which a single blower is installed to cover a wide area of ​​the heat exchange core 30C, the power required to obtain the desired airflow can be reduced, and a larger effective area for heat exchange of the heat exchange core 30C can be secured. As a result, the power of the blowers 20 required to obtain the desired cooling capacity can be effectively reduced, and the cooling efficiency can be improved.

[0084] Furthermore, the heat exchange core 30C includes an upper heat exchange core 310 and a lower heat exchange core 320, with the upper heat exchange core 310 being superimposed on the lower heat exchange core 320 from above. The heat exchanger 30 includes inlets 315 and 325, an upper inlet 315 connected to a tube 313 in the upper heat exchange core 310 and a lower inlet 325 connected to a tube 323 in the lower heat exchange core 320. The upper inlet 315 and the lower inlet 325 each extend in the vertical direction. The upper inlet 315 and the lower inlet 325 are positioned such that they are offset in the direction from the first surface 30A to the second surface 30B, and that when viewed in the direction from the first surface 30A to the second surface 30B, the lower part of the upper inlet 315 overlaps the upper part of the lower inlet 325.

[0085] In this case, the heat transfer medium can be supplied to the upper heat exchange core 310 and the lower heat exchange core 320 by branching from two pumps 41 and 42, thus reducing the power consumption of pumps 41 and 42. Furthermore, by arranging the lower part of the upper inlet 315 to overlap the upper part of the lower inlet 325, the overall occupied area of ​​the heat exchanger 30 can be reduced while ensuring a larger overall size for the heat exchange core 30C, thereby improving heat exchange efficiency.

[0086] (Example of setting conditions) Hereinafter, an example of a specific usage mode of the above server cooling system S will be described. The inventor of the present invention assumes that a server rack with a heat generation amount of about 150 kW per unit will be introduced in large numbers in future data centers. And the above server cooling system S can be configured to function extremely effectively at a cooling capacity of 150 kW or in the vicinity thereof. Specifically, by setting the following conditions (1) to (3) for the exhaust heat device 1, it becomes possible to cause the exhaust heat device 1 to perform cooling at 150 kW or in the vicinity thereof with an extremely high COP (Coefficient Of Performance).

[0087] ·Condition (1): The areas of the first surface 30A and the second surface 30B of the heat exchange core 30C are each set to be 1.5 m 2 or more and 1.7 m 2 or less. ·Condition (2): The air volume of the gas (air) flowing through the plurality of blowers 20 is set to be 345 m 3 / min or more and 375 m 3 / min or less. ·Condition (3): The heat medium is selected and the flow rate of the heat medium is set so that the value (C·L) obtained by multiplying the specific heat C (kJ / kg·K) of the heat medium at 20°C to 40°C by the flow rate L (L / min) of the heat medium is between 250 and 320.

[0088] With the above conditions, the server cooling system S can output a cooling capacity of 140 kW or more and 160 kW or less with a COP of 15 or more. The inventor of the present case has confirmed more specifically that the server cooling system S can output a cooling capacity of 140 kW or more and 160 kW or less with an average COP of 20 or more and at least a COP of 15 or more even if there are fluctuations due to various conditions.

[0089] When the condition of the above condition (1) is set, the fin size that can be installed and the size of the heat exchange part are generally determined. Desirably, the total of the heat exchange surface areas of the plate fins 314 and 324 provided in the heat exchanger 30 and the heat exchange surface areas of the tubes 313 and 323 is 600 m 2It is best to set the parameters as described above. The heat exchange surfaces of the plate fins 314 and 324 refer to the two surfaces of the plate fins 314 and 324 that face opposite each other in the thickness direction. The heat exchange surfaces of the tubes 313 and 323 refer to the outer surfaces of the tubes 313 and 323 that are exposed to the outside. The sum of the areas of these two surfaces is determined by adding the sum of the areas of the two surfaces of the plate fins 314 and 324 multiplied by the total number of plate fins 314 and 324, and the surface area of ​​the outer surfaces of the tubes 313 and 323 excluding the connection parts with the plate fins 314 and 324. Furthermore, the outer diameter D of tubes 313 and 323 may be between 8 mm and 20 mm, and for example, the spacing between adjacent tubes 313 and 323 in the vertical direction in Figure 5 may be between 0.5D and 0.45D.

[0090] The airflow rate specified in condition (2) above is not excessively large, but rather a value that is beneficial in terms of power reduction. In addition, it is desirable from the viewpoint of suppressing noise and dust dispersion. The airflow rate of the gas (air) circulated by the multiple blowers 20 in condition (2) is determined by the sum of the airflow rates set for each blower 20.

[0091] In addition to the above conditions (1) to (3), it is preferable that the heat exchange core 30C be configured such that the pressure loss when air with a wind speed of 5.5 m / s passes through it is 5 Pa or less.

[0092] Figure 10 shows a table illustrating an example of the specifications for a server cooling system S that satisfies the above conditions (1) to (3) and uses an aqueous polyethylene glycol solution with a specific heat of 3.841 (kJ / kg·K) at 40°C as the heat transfer medium, outputting a cooling capacity of 150kW. In this example, when server 102 in server rack 100 heats up to 70°C and generates 150kW of heat, server 102 is cooled down to 40°C and 150kW of heat is absorbed. In the example specifications in Figure 10, 150kW cooling is achieved with a COP of 15 or higher.

[0093] According to the inventors' knowledge, a typical cooling system used in conventional data centers to achieve 150kW of cooling would have a COP of approximately 5 to 10. Compared to this conventional system, the server cooling system S according to this embodiment can output equivalent cooling capacity with roughly twice the COP (15 or more in this example). The cooling capacity of such a server cooling system S greatly contributes to energy saving.

[0094] The heat transfer medium circulating through the heat exchanger 30 is not particularly limited. For example, a fluorine-based inert liquid with a specific heat of approximately 1,000 to 1,200 (kJ / kg·K) at 20°C may be used as the heat transfer medium. In this case, the flow rate of the heat transfer medium is set to approximately 195 to 320 (L / min). When the flow rate is relatively high in this way, it is expected that effective cooling can be achieved by increasing the number of flow paths in the server rack 100 or by making the flow path shape more complex and circulating a large amount of heat transfer medium. Furthermore, since fluorine-based inert liquids have relatively low viscosity, the pump power will not be excessively high. When using a heat transfer medium with a relatively low specific heat in this way, it is preferable to set the heat transfer medium cooling efficiency (LPM / kW), which is determined by dividing the flow rate of the heat transfer medium (L / min: LPM) by the cooling capacity, to 1.4 or higher. This heat transfer medium cooling efficiency may be 1.4 to 1.6 or 1.45 to 1.55.

[0095] <Variation> Modified examples are described below. Components in the following modified examples that are the same as those in the embodiments described above are denoted by the same reference numerals, and redundant explanations are omitted.

[0096] (First variation) Figure 11 shows a heat dissipation device according to the first modified example. In this modified example, four blowers 20 are arranged in a vertical row. In the heat exchanger 30, the first pump 41 is connected to the upper side, and the second pump 42 is connected to the lower side. The use of multiple pumps is beneficial in specifications where the heat exchanger is long in the vertical direction.

[0097] (Second variation) Figure 12 shows a heat dissipation device according to a second modified example. In this modified example, the heat exchange core 30C of the heat exchanger 30 does not have a multi-stage structure. The heat exchange core 30C consists only of the portion corresponding to the upper heat exchange core 310. Multiple blowers 20 are arranged adjacent to the heat exchange core 30C in a 4x4 arrangement. In the above embodiment, the heat exchange core 30C is configured to connect the upper heat exchange core 310 and the lower heat exchange core 320, but the heat exchange core 30C may also be configured to connect three or more heat exchange core elements.

[0098] (Third variation) Figure 13 shows a heat dissipation device according to a third modified example. More specifically, Figure 13 is a view of the inside of the heat dissipation device along a horizontal direction perpendicular to the direction in which gaseous air flows by the blower 20. The heat dissipation device according to the third modified example comprises a first heat exchanger 30-1 and a second heat exchanger 30-2. The first heat exchanger 30-1 and the second heat exchanger 30-2 are separated from each other and are not connected.

[0099] The first heat exchanger 30-1 and the second heat exchanger 30-2 are rectangular parallelepipeds or plate-shaped, and are arranged so as to be adjacent to each other vertically and form a V-shape when viewed horizontally.

[0100] The first heat exchanger 30-1 and the second heat exchanger 30-2 are each configured with the upper heat exchange core 310 described in the above embodiment as their main component. In Figure 13, the same reference numerals are used for the elements constituting the upper heat exchange core 310 in the elements constituting the first heat exchanger 30-1 and the second heat exchanger 30-2. Although not shown, the first heat exchanger 30-1 and the second heat exchanger 30-2 each have a plurality of plate fins 314 that extend parallel to the direction from the first surface 30A to the second surface 30B and are arranged in a direction perpendicular to the direction from the first surface 30A to the second surface 30B, in this example, horizontally. The tubes 313 in the first heat exchanger 30-1 and the second heat exchanger 30-2 are arranged so as to be aligned in the direction in which the first heat exchanger 30-1 and the second heat exchanger 30-2 are inclined. On the other hand, if the first heat exchanger 30-1 and the second heat exchanger 30-2 are arranged to form a V-shape as in this modified example, suitable heat exchange can be performed even if the tubes 313 are arranged in a matrix rather than a staggered arrangement as in the above embodiment, so a matrix arrangement may be adopted.

[0101] Multiple blowers 20 are arranged adjacent to the first heat exchanger 30-1 (second surface 30B) and the second heat exchanger 30-2 (second surface 30B), which are arranged to form a V-shape. Multiple blowers 20 are arranged on the same plane. More specifically, some of the multiple blowers 20 are arranged adjacent to the first heat exchanger 30-1, and other parts of the multiple blowers 20 are arranged adjacent to the second heat exchanger 30-2. Although not shown in the illustration, in this example, 16 blowers 20 arranged in 4 rows and 4 columns are arranged adjacent to the first heat exchanger 30-1, and 16 blowers 20 arranged in 4 rows and 4 columns are arranged adjacent to the second heat exchanger 30-2. More specifically, 16 blowers 20, which are part of the multiple blowers 20, are arranged adjacent to the first heat exchanger 30-1, such that the extension of the rotation axis Ax of each impeller 21 intersects with the second surface 30B of the heat exchange core 30C of the first heat exchanger 30-1. Another 16 blowers 20, which are part of the multiple blowers 20, are arranged adjacent to the second heat exchanger 30-2, such that the extension of the rotation axis Ax of each impeller 21 intersects with the second surface 30B of the heat exchange core 30C of the second heat exchanger 30-2. However, there is no particular limit to the number of blowers 20 used.

[0102] In the example shown in Figure 13, the first heat exchanger 30-1 and the second heat exchanger 30-2 are arranged to form an obtuse V-shape, but they may also be arranged to form an acute V-shape, or the first heat exchanger 30-1 and the second heat exchanger 30-2 may be arranged so as not to be tilted symmetrically.

[0103] Furthermore, in Figure 13, the symbols L1 to L4 represent the multiple (four) blowers 20 arranged vertically, and the distance from each blower 20 to the first heat exchanger 30-1 (its heat exchange core 30C). The closer to the V-shaped bottom, the longer the distance from the blower 20 to the heat exchange core 30C, with the relationship L1 > L2 > L3 > L4. In this third modified example, the setting of the airflow rate of the gas flowed by the multiple blowers 20 and / or the setting of the rotational speed of the multiple blowers 20 differs depending on the distance between each blower 20 and the first heat exchanger 30-1 adjacent to each blower 20.

[0104] More specifically, in this modified example, each blower 20 has the same structure and size, and is basically driven at the same rotational speed and outputs the same airflow when the same power is supplied. In this modified example, the value of the power supplied to the blower 20 is changed according to the distance between the blower 20 and the first heat exchanger 30-1.

[0105] Specifically, as in this modified example, when the first heat exchanger 30-1 is inclined in the vertical direction and the rotation axis of the blower 20 is aligned horizontally, the air flowing horizontally may flow inclined in a direction perpendicular to the first surface 30A and the second surface 30B of the first heat exchanger 30-1 as it passes through it. In this case, the air flowing out from the second surface 30B of the first heat exchanger 30-1 may generally tend to flow with a component that flows from the blower 20 side, where the distance to the heat exchange core 30C is shorter, towards the blower 20 side, where the distance is longer. In this case, the proportion of the air component that is inclined relative to the impeller 21 in the air drawn in by the blower 20 becomes larger, and there is a risk that the smooth flow of air may be impaired. Therefore, for example, the airflow rate of the blower 20 may be set such that the relationship is as follows: airflow rate of blower 20 when the distance to the heat exchange core 30C is L1 < airflow rate of blower 20 when the distance to the heat exchange core 30C is L2 < airflow rate of blower 20 when the distance to the heat exchange core 30C is L3 < airflow rate of blower 20 when the distance to the heat exchange core 30C is L4. In other words, the rotational speed of blower 20 may be set such that the relationship is as follows: rotational speed of blower 20 when the distance to the heat exchange core 30C is L1 < rotational speed of blower 20 when the distance to the heat exchange core 30C is L2 < rotational speed of blower 20 when the distance to the heat exchange core 30C is L3 < rotational speed of blower 20 when the distance to the heat exchange core 30C is L4. For example, with such a setting, air can pass through the first heat exchanger 30-1 more easily, and the cooling efficiency may be improved. In other words, by suppressing pressure loss, cooling efficiency can be improved.

[0106] In other words, when the first heat exchanger 30-1 and the second heat exchanger 30-2 are arranged to form a V-shape, and the distance from each blower 20 to the heat exchanger is not constant, the airflow rate or rotational speed of the blower 20 whose distance to the heat exchange core 30C is relatively short can be increased compared to the blower 20 whose distance to the heat exchange core 30C is longer, thereby allowing air to flow smoothly. However, depending on the structure of the heat dissipation device, the airflow rate or rotational speed of the blower 20 whose distance to the heat exchange core 30C is shorter can be reduced compared to the blower 20 whose distance to the heat exchange core 30C is longer, and this may be more advantageous in some cases.

[0107] (Fourth variation) Figure 14 shows a heat dissipation device according to the fourth modified example. More specifically, Figure 14 is a view of the inside of the heat dissipation device. The heat dissipation device according to the fourth modified example includes a first heat exchanger 30-1 and a second heat exchanger 30-2, similar to the third modified example. However, it differs from the third modified example in that the first heat exchanger 30-1 and the second heat exchanger 30-2 are arranged to be adjacent horizontally and form a V-shape when viewed from above.

[0108] In Figure 14, sixteen blowers 20 arranged in four rows and four columns are positioned adjacent to the first heat exchanger 30-1, and sixteen blowers 20 arranged in four rows and four columns are positioned adjacent to the second heat exchanger 30-2. More specifically, sixteen blowers 20, which are part of a group of blowers 20, are positioned adjacent to the first heat exchanger 30-1 such that the extension of the rotation axis Ax of each impeller 21 intersects with the second surface 30B of the heat exchange core 30C of the first heat exchanger 30-1. Another group of sixteen blowers 20, which are part of the group of blowers 20, are positioned adjacent to the second heat exchanger 30-2 such that the extension of the rotation axis Ax of each impeller 21 intersects with the second surface 30B of the heat exchange core 30C of the second heat exchanger 30-2. However, the number of blowers 20 used is not particularly limited. Furthermore, in the example shown in Figure 14, the first heat exchanger 30-1 and the second heat exchanger 30-2 are arranged to form an obtuse V-shape, but they may also be arranged to form an acute V-shape, or the first heat exchanger 30-1 and the second heat exchanger 30-2 may be arranged symmetrically without tilting. Although not shown, the first heat exchanger 30-1 and the second heat exchanger 30-2 each have multiple plate fins 314 that extend parallel to the direction from the first surface 30A to the second surface 30B and perpendicular to that direction, in this example, horizontally.The tubes 313 in the first heat exchanger 30-1 and the second heat exchanger 30-2 are arranged so that the first heat exchanger 30-1 and the second heat exchanger 30-2 are aligned vertically.

[0109] In Figure 14, the symbols L1' to L4' represent the multiple (four) blowers 20 arranged horizontally, and the distance from each blower 20 to the first heat exchanger 30-1 (its heat exchange core 30C). The closer to the bottom of the V-shape, the longer the distance from the blower 20 to the heat exchange core 30C, with the relationship L1'>L2'>L3'>L4'. In the fourth modified example, the setting of the airflow rate of the gas flowed by the multiple blowers 20 and / or the setting of the rotation speed of the multiple blowers 20 differs according to the distance between each blower 20 and the adjacent first heat exchanger 30-1.

[0110] More specifically, in this modified example, each blower 20 has the same structure and size, and is basically driven at the same rotational speed and outputs the same airflow when the same power is supplied. Furthermore, in this modified example, the value of the power supplied to the blower 20 is changed according to the distance between the blower 20 and the first heat exchanger 30-1.

[0111] Specifically, as in this modified example, when the rotation axis of the blower 20 is aligned horizontally and the first heat exchanger 30-1 is inclined with respect to a direction perpendicular to the rotation axis of the blower 20 in the horizontal plane, the air flowing horizontally may flow inclined in a direction perpendicular to the first surface 30A and the second surface 30B of the first heat exchanger 30-1 as it passes through it. In this case, the air flowing out from the second surface 30B of the first heat exchanger 30-1 may generally tend to flow with a component that flows from the blower 20 side, where the distance to the heat exchange core 30C is shorter, towards the blower 20 side, where the distance is longer. This tendency is particularly likely to occur when the plate fins 314 extend parallel to the direction from the first surface 30A to the second surface 30B and are aligned horizontally, as in the configuration of this modified example. In this case, the proportion of the air component that is inclined relative to the impeller 21 in the air drawn in by the blower 20 becomes large, and there is a risk that the smooth flow of air may be impaired.

[0112] Therefore, in this modified example, for example, the airflow rate of the blower 20 may be set such that the relationship is as follows: airflow rate of blower 20 when the distance to the heat exchange core 30C is L1' < airflow rate of blower 20 when the distance to the heat exchange core 30C is L2' < airflow rate of blower 20 when the distance to the heat exchange core 30C is L3' < airflow rate of blower 20 when the distance to the heat exchange core 30C is L4'. In other words, the rotational speed of blower 20 may be set such that the relationship is as follows: rotational speed of blower 20 when the distance to the heat exchange core 30C is L1' < rotational speed of blower 20 when the distance to the heat exchange core 30C is L2' < rotational speed of blower 20 when the distance to the heat exchange core 30C is L3' < rotational speed of blower 20 when the distance to the heat exchange core 30C is L4'. In this case, the same effect as described in the third modified example can be obtained.

[0113] (Fifth variation) Figures 15 and 16 show a heat dissipation device according to the fifth modified example. Specifically, Figure 15 shows the external appearance of the heat dissipation device according to the fifth modified example, and Figure 16 is a cross-sectional view along the line XVI-XVI in Figure 15. The heat dissipation device according to the fifth modified example comprises a first heat exchanger 30-1 and a second heat exchanger 30-2 arranged to form a V-shape when viewed from above, similar to the fourth modified example. However, it differs from the fourth modified example in that the first heat exchanger 30-1 and the second heat exchanger 30-2 are arranged to form an acute-angled V-shape.

[0114] In this modified configuration, 40 blowers 20 arranged in 20 rows and 2 columns are positioned adjacent to the first heat exchanger 30-1, and 40 blowers 20 arranged in 20 rows and 2 columns are positioned adjacent to the second heat exchanger 30-2. More specifically, 40 blowers 20 arranged in 20 rows and 2 columns, which are part of a group of blowers 20, are positioned adjacent to the first heat exchanger 30-1 such that the extension of the rotation axis Ax of each impeller 21 intersects with the second surface 30B of the heat exchange core 30C of the first heat exchanger 30-1. Forty fans 20, arranged in 20 rows and 2 columns, which are part of the other half of the multiple fans 20, are positioned adjacent to the second heat exchanger 30-2, such that the extension of the rotation axis Ax of each impeller 21 intersects with the second surface 30B of the heat exchange core 30C of the second heat exchanger 30-2. Each fan 20 is arranged on the same plane and held in the housing 10. There is no particular limit to the number of fans 20 used, but it is preferable to provide fans arranged in multiple rows and multiple columns for a single heat exchanger.

[0115] In Figure 16, the symbols L1'' and L2'' indicate the distance from each blower 20 to the first heat exchanger 30-1 (its heat exchange core 30C), where multiple (two) blowers 20 are arranged horizontally. The closer to the bottom of the V-shape, the longer the distance from the blower 20 to the heat exchange core 30C, resulting in the relationship L1'' > L2''. In the fifth modified example, the setting of the airflow rate of the gas flowed by the multiple blowers 20 and / or the setting of the rotation speed of the multiple blowers 20 differs depending on the distance between each blower 20 and the adjacent first heat exchanger 30-1.

[0116] Specifically, the airflow of the blower 20 is set such that the airflow of the blower 20 at which the distance to the heat exchange core 30C is L1'' is less than the airflow of the blower 20 at which the distance to the heat exchange core 30C is L2''. In other words, the rotational speed of the blower 20 is set such that the rotational speed of the blower 20 at which the distance to the heat exchange core 30C is L1'' is less than the rotational speed of the blower 20 at which the distance to the heat exchange core 30C is L2''.

[0117] In other words, in this modified example as well, by setting the airflow rate or rotational speed of the blower 20 whose distance to the heat exchange core 30C is relatively shorter than that of the blower 20 whose distance to the heat exchange core 30C is longer, air can flow more smoothly. This setting of airflow rate or rotational speed can be particularly effective when the first heat exchanger 30-1 and the second heat exchanger 30-2 are arranged to form an acute-angled V-shape.

[0118] In the third to fifth modified examples, the first heat exchanger 30-1 and the second heat exchanger 30-2, which are arranged to form a V-shape, are positioned so that the bottom portion of the V-shape faces away from the blower 20. Alternatively, the first heat exchanger 30-1 and the second heat exchanger 30-2 may be positioned so that the bottom portion of the V-shape faces towards the blower 20.

[0119] The embodiments and modifications described above are merely examples of how to embody the present invention, and it is possible to implement the present invention in various other forms. For example, various modifications, substitutions, omissions, or combinations thereof are possible without departing from the spirit of the present invention. Such modified, substituted, or omission forms are also included within the scope of the present invention and the invention described in the claims and its equivalents. [Explanation of symbols]

[0120] S...Server cooling system, 1...Heat dissipation device, 10...Housing, 20...Blower, 21...Impeller, 22...Casing, 30...Heat exchanger, 30-1...First heat exchanger, 30-2...Second heat exchanger, 30A...First surface, 30B...Second surface, 30C...Heat exchange core, 310...Upper heat exchange core, 310A...Upper first surface, 310B...Upper second surface, 311...Upper frame, 313...Tube, 313a...Main flow path element, 313b...Reverse flow path element, 314...Plate fin, 315...Upper inlet (inlet section), 315a...Inlet, 315P...Upper inlet pipe, 315b...Upper first relay pipe, 316...Upper outlet (Outlet section), 316a...Upper second relay pipe, 316b...Outlet, 316P...Upper outlet pipe, 320...Lower heat exchange core, 320A...Lower first surface, 320B...Lower second surface, 321...Lower frame, 323...Tube, 324...Plate fin, 325...Lower inlet section (inlet section), 325a...Inlet, 325P...Lower inlet pipe, 325b...Lower first relay pipe, 326...Lower outlet section (outlet section), 326a...Lower second relay pipe, 326b...Outlet, 326P...Lower outlet pipe, 41...First pump, 42...Second pump, 100...Server rack, 101...Rack body, 102...Server, 110...Refrigerant flow path

Claims

1. An air-cooled heat exchanger having a heat exchange core including a first surface and a second surface opposite the first surface, The system comprises a plurality of blowers that cause the gas to flow from the first surface to the second surface by the rotation of an impeller, Multiple blowers are arranged such that the extension of the rotation axis of the impeller intersects the second surface. The heat exchange core has a plurality of tubes through which a heat transfer medium to be exchanged with the gas flows. A heat dissipation device wherein each of the tubes extends in a meandering manner from the second surface to the first surface, and the heat transfer medium flows in each of the tubes from the second surface to the first surface.

2. The heat dissipation device according to claim 1, wherein the plurality of blowers are arranged such that the extension of the rotation axis of the impeller is perpendicular to the second surface.

3. The heat dissipation device according to claim 1 or 2, wherein the multiple blowers are arranged in multiple rows and multiple columns.

4. The heat dissipation device according to claim 3, wherein the multiple blowers are arranged in four or more rows and four or more cases.

5. The heat dissipation device according to claim 1, The server rack is supplied with the heat transfer medium from the heat dissipation device, The server rack has a cooling channel that receives and circulates the heat transfer medium after heat exchange with the gas, and the server cooling system returns the heat transfer medium flowing out of the cooling channel to the heat dissipation device.

6. Even an air-cooled heat exchanger having a heat exchange core including a first surface and a second surface opposite the first surface, The heat exchange core has a plurality of tubes through which a heat transfer medium to be exchanged with the gas flows. A heat exchanger in which each of the tubes extends in a meandering manner from the second surface to the first surface, and the heat transfer medium flows in each of the tubes from the second surface to the first surface.

7. The present invention further comprises a plurality of plate fins extending parallel to the direction from the first surface to the second surface and arranged in a direction perpendicular to the direction from the first surface to the second surface, The heat exchanger according to claim 6, wherein the tube extends in a meandering manner from the second surface side toward the first surface side while penetrating the plurality of plate fins and is in contact with the plate fins.

8. The system further includes an inlet that receives the heat transfer medium from the outside and allows it to flow into the tube, Each of the aforementioned tubes branches in parallel from the inlet, The heat exchange core includes a first heat exchange core and a second heat exchange core, and the first heat exchange core and the second heat exchange core are arranged adjacent to each other. The inlet portion includes a separate inlet portion connected to the tube of the first heat exchange core and an inlet portion connected to the tube of the second heat exchange core, The inlet connected to the tube of the first heat exchange core and the inlet connected to the tube of the second heat exchange core each extend in a direction in which the first heat exchange core and the second heat exchange core are adjacent to each other. The heat exchanger according to claim 6, wherein the inlet connected to the tube of the first heat exchange core and the inlet connected to the tube of the second heat exchange core are arranged such that they are offset in the direction from the first surface to the second surface, and when viewed in the direction from the first surface to the second surface, the end of the inlet connected to the tube of the first heat exchange core on the second heat exchange core side overlaps the end of the inlet connected to the tube of the second heat exchange core on the first heat exchange core side.

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