Cooling system and method of cooling assembly

Abstract

To provide an improved cooling system and cooling method.SOLUTION: A cooling system for cooling an assembly including at least one heat-generating electronic device includes a heat spreader thermally coupled to the at least one heat-generating electronic device, and a heat removal device having a surface that is thermally coupled to the at least one heat-generating electronic device via the heat spreader. The heat removal device includes an inlet area and at least one jet impingement feature fluidly coupled to the inlet area. The at least one jet impingement feature is positioned to direct a primary cooling fluid toward the surface that is thermally coupled to the at least one heat-generating electronic device.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] Exemplary embodiments relate to the art of thermal management, and more particularly, to thermal management of servers in data centers. [Background technology]

[0002] A "data center" refers to the physical location of one or more servers. Data centers and the servers housed therein typically consume a significant amount of power. Existing servers are designed to be at least partially cooled by airflow. Such servers typically include one or more printed circuit boards with multiple operable heat-producing devices attached. The printed circuit boards are typically housed in an enclosure with vents configured to direct outside air from the data center into, through, and out of the enclosure. The air absorbs heat dissipated by the components and mixes with the surrounding air after being exhausted from the enclosure. Air conditioners are then used to cool the heated air in the data center, and the air is recirculated to repeat the cooling process.

[0003] Typically, more powerful server components consume more power. However, the amount of heat that a conventional cooling system can remove from a server is limited in part by the extent of the air conditioning available in the data center. In general, the lower the air temperature in the data center, the more power each server component that is cooled by the airflow can consume, and therefore each server can operate at a correspondingly higher level of performance. Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE PRESENT EMBODIMENT It is therefore an object of the present invention to provide an improved cooling system and method. [Means for solving the problem]

[0005] According to one embodiment, a cooling system for cooling an assembly including at least one heat-generating electronic device includes a heat spreader thermally coupled to the at least one heat-generating electronic device and a heat removal device having a surface thermally coupled to the at least one heat-generating electronic device through the heat spreader. The heat removal device includes an inlet region and at least one jet impingement feature fluidically coupled to the inlet region. The at least one jet impingement feature is positioned to direct a primary cooling fluid toward the surface thermally coupled to the at least one heat-generating electronic device.

[0006] In addition to or as an alternative to one or more of the features described herein, further embodiments may include a heat removal device including a heat exchanger having an outlet header, a surface thermally coupled to at least one heat-generating electronic device disposed within the outlet header, and a primary cooling fluid and a secondary cooling fluid disposed in heat transfer relationship within the at least one heat exchanger.

[0007] In addition to or as an alternative to one or more of the features described herein, further embodiments may include a heat exchanger having an inlet header, the inlet region being defined by the inlet header. A plurality of heat exchange tubes extend between the inlet header and the outlet header. At least one jet impingement feature is separated from and fluidly coupled to the plurality of heat exchange tubes.

[0008] In addition to or as an alternative to one or more of the features described herein, further embodiments may include a heat exchanger having an inlet header, the inlet region being defined by the inlet header. A plurality of heat exchange tubes extend between the inlet header and the outlet header. At least one jet impingement feature is integrated with at least one of the plurality of heat exchange tubes.

[0009] In addition to or as an alternative to one or more of the features described herein, further embodiments may include a fluid movement device operable to move a secondary cooling fluid through the heat removal device.

[0010] In addition to or as an alternative to one or more of the features described herein, further embodiments may include the fluid movement device being a fan and the secondary cooling fluid being air.

[0011] In addition to or as an alternative to one or more of the features described herein, further embodiments may include that the heat removal device includes a plurality of heat exchangers, each of the plurality of heat exchangers being disposed and thermally coupled to a respective heat-generating electronic device.

[0012] In addition to or as an alternative to one or more of the features described herein, further embodiments may include at least some of the multiple heat exchangers being arranged in series with respect to the flow of the primary cooling fluid.

[0013] In addition to or as an alternative to one or more of the features described herein, further embodiments may include at least some of the multiple heat exchangers being arranged in parallel with respect to the flow of the primary cooling fluid.

[0014] In addition to or as an alternative to one or more of the features described herein, further embodiments may include a secondary heat exchanger disposed upstream of the heat removal device relative to the flow of the primary cooling fluid.

[0015] In addition to or as an alternative to one or more of the features described herein, further embodiments may include a secondary heat exchanger disposed upstream of the heat removal device relative to the flow of the secondary cooling fluid.

[0016] In addition to or as an alternative to one or more of the features described herein, further embodiments may include that the primary cooling fluid supplied to the heat removal device is a single-phase liquid.

[0017] According to one embodiment, a method of cooling an assembly including at least one heat-generating electronic device and at least one peripheral heat-generating device includes cooling a secondary cooling fluid via a primary cooling fluid, flowing the cooled secondary cooling fluid over the at least one peripheral heat-generating device, and ejecting the primary cooling fluid onto a surface of a heat removal device thermally coupled to the at least one heat-generating electronic device via at least one jet impingement feature to cool the at least one heat-generating electronic device.

[0018] In addition to or as an alternative to one or more of the features described herein, further embodiments may include the heat removal device being a heat exchanger and the cooling of the secondary cooling fluid via the primary cooling fluid occurs within a plurality of heat exchange tubes of the heat exchanger.

[0019] In addition to or as an alternative to one or more of the features described herein, further embodiments may include providing a secondary cooling fluid to the heat exchanger via a fluid transfer device.

[0020] In addition to or as an alternative to one or more of the features described herein, further embodiments may include supplying the primary cooling fluid to a secondary heat exchanger, the secondary heat exchanger being positioned upstream of the heat exchanger with respect to the flow of the primary cooling fluid.

[0021] In addition to or as an alternative to one or more of the features described herein, further embodiments may include cooling the primary cooling fluid in a secondary heat exchanger.

[0022] In addition to or as an alternative to one or more of the features described herein, further embodiments may include providing the primary cooling fluid to a separate heat removal device disposed in and thermally coupled to the at least one heat-generating electronic device, the separate heat removal device being disposed in series downstream of the heat removal device with respect to the flow of the primary cooling fluid.

[0023] In addition to or as an alternative to one or more of the features described herein, further embodiments may include providing the primary cooling fluid to a separate heat removal device disposed in and thermally coupled to the at least one heat-generating electronic device, the separate heat removal device being disposed in parallel with the heat removal device relative to the flow of the primary cooling fluid.

[0024] The following description should not be construed as limiting in any sense.With reference to the accompanying drawings, like elements are numbered the same, and in which: [Brief description of the drawings]

[0025] [Figure 1] FIG. 1 is a front view of a data center rack equipped with multiple servers. [Diagram 2] FIG. 1 illustrates a perspective view of a server, according to one embodiment. [Figure 3A] FIG. 2 is a top view of a server, according to one embodiment. [Figure 3B] FIG. 3B is a cross-sectional side view of the server of FIG. 3A, according to one embodiment. [Figure 4] 1 illustrates a cross-sectional view of a heat exchanger of a cooling system suitable for use in a server, according to one embodiment. [Diagram 5] 1 illustrates a cross-sectional view of a heat spreader with integrated fluid circuitry according to one embodiment. [Figure 6A] FIG. 2 is a schematic diagram of a primary cooling fluid circuit of a cooling system according to one embodiment. [Figure 6B] FIG. 2 is a schematic diagram of a primary cooling fluid circuit of a cooling system according to one embodiment. [Figure 7] FIG. 2 is a schematic diagram illustrating a portion of a primary cooling fluid circuit of a cooling system according to one embodiment. [Figure 8] FIG. 2 is a schematic diagram illustrating a portion of a primary cooling fluid circuit of a cooling system according to another embodiment. [Figure 9] FIG. 2 is a schematic diagram illustrating a portion of a primary cooling fluid circuit of a cooling system according to yet another embodiment. [Figure 10]1 is a schematic diagram of a heat removal device of a cooling system suitable for use in a server, according to one embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] A detailed description of one or more embodiments of the disclosed apparatus and methods is presented herein by way of example, and not by way of limitation, with reference to the drawings.

[0027] Referring now to FIG. 1, an example of a data center 20 is shown. As shown, the data center 20 includes a cabinet 22 having at least one slot, and in some embodiments, multiple slots (not shown) formed therein. One or more server rack subassemblies, also referred to herein as servers 30, may be permanently or removably mounted within the cabinet 22, such as within one or more slots formed within the cabinet 22. The multiple slots and the at least one server 30 receivable therein may be arranged in a generally vertical orientation (as shown) or, alternatively, may be arranged in a horizontal orientation. In some embodiments, the data center 20 may include a combination of both horizontal and vertical slots. Additionally, while only a single cabinet 22 is shown in the figures, it should be understood that the data center 20 may include multiple cabinets 22. In embodiments including multiple cabinets 22, the multiple cabinets 22 may be located in the same location within a building, or, alternatively, one or more of the cabinets 22 may be located in different locations within a single building or multiple buildings.

[0028] 2 and 3A, an example of a server 30 receivable within a slot of the cabinet 22 is shown. As shown, the server 30 may include a frame or chassis 32 having at least one printed circuit board 34 mounted to the frame. Although only a single printed circuit board 34 is shown, it should be understood that in some embodiments, multiple printed circuit boards may be mounted to the chassis 32. The chassis 32 is designed to be insertable, e.g., slidably insertable, into a slot of the server rack and to connect to power, data, and / or other connection cables provided at or by the cabinet 22.

[0029] The chassis 32 may include a number of walls 36, 38, 39, and 40 oriented at an angle to the printed circuit board 34 and extending around all or at least a portion of the perimeter of the printed circuit board 34. In one embodiment, the chassis 32 includes at least one flat, generally planar panel connected to one or more of the perimeter walls 36, 38, 40 of the chassis 32. At least one flat panel 42 may be disposed on either a first side or a second side of the printed circuit board 34. As shown, such a flat panel 42 may be vertically offset from the printed circuit board 34, either above or below the printed circuit board 34, when the server 30 is in a horizontal orientation. In some embodiments, the flat panel 42 is disposed both above and below the printed circuit board, as best shown in FIG. 3B. In one embodiment, the chassis 32 in combination with the flat panel 42 forms an airtight container surrounding the server 30. However, embodiments in which a separate jacket or container is disposed around the server 30 to form an airtight assembly are also contemplated herein. Additionally, embodiments involving air exchange with the surroundings are also within the realm of ambient air being drawn into the server, extracting heat from heat generating components, and then expelled with or without thermal management.

[0030] At least one heat-generating electronic device 50 may be mounted or electrically connected to the printed circuit board 34. Examples of heat-generating electronic devices 50 include, but are not limited to, a processor, such as a central processing unit and / or a graphics processing unit, memory, a hard drive, and a power supply module. The server 30 may also include one or more components that are not mounted or electrically connected to the printed circuit board 34. In embodiments in which the server 30 includes two or more components of the same type, such as, for example, a central processing unit, the components may be aligned along an axis extending between the sides 36, 38 of the chassis 32, aligned along an axis extending between the front and rear of the chassis 32, or offset from one another in one or more directions. It should be understood that any heat-generating electronic device 50 may be located anywhere within the chassis 32 or around the circuit board 34.

[0031] In one embodiment, one or more fluid movement devices 52 are mounted to the printed circuit board 34 and are operable to move a flow of fluid, such as air, over the heat-generating electronic device 50. In the illustrated non-limiting embodiment, the at least one fluid movement device is a fan 52 located near a first end 54 of the printed circuit board 34 such that when the server 30 is installed within the cabinet 22, the at least one fan 52 is located closer to a front of the cabinet 22 than the heat-generating electronic device 50. However, embodiments in which the one or more fluid movement devices 52 are located in another suitable location, such as, for example, near a second end 56 of the chassis 32 associated with the printed circuit board 34 or the rear of the cabinet 22, are also within the scope of this disclosure. It should be understood that any suitable configuration of server 30 is within the scope of this disclosure, including servers having full-width or half-width or sled configurations.

[0032] In one embodiment, the fluid moved by the at least one fluid moving device 52 is configured to make one pass over the heat generating electronic device 50. For example, cool air may be drawn into the fan 52 from a location adjacent the front of the chassis 32 and exhausted out the rear of the chassis 32 after removing heat from the heat generating electronic device 50. It should be understood that the air exhausted out the rear of the cabinet 22 may be at the same temperature as the surrounding environment, warmer than the surrounding environment, or cooler than the surrounding environment. In other embodiments, such as when the chassis 32 includes at least one flat panel 42, the fluid may be configured to circulate continuously within the server 30. For example, as best shown in FIG. 3B, the fluid moving device 52 may push a flow of fluid over the heat generating electronic device 50 disposed on the first surface 58 of the printed circuit board 34. Upon reaching the second end 56 of the printed circuit board 34, the fluid may change direction through one or more openings to make a second pass along the second opposite surface 60 of the printed circuit board 34. Upon reaching the first end 54 of the printed circuit board 34 , the fluid may change direction again and be drawn back to the inlet of the at least one fluid transfer device 52 .

[0033] The server 30 may include a cooling system 100 for removing heat from one or more of the heat-generating electronic devices 50. In one embodiment, the cooling system 100 is operable to cool at least one heat-generating electronic device 50 using a primary cooling fluid C1. Other heat-generating electronic devices 50 mounted on the printed circuit board 34 and not directly cooled via the primary cooling fluid C1 may be considered "peripheral" heat-generating devices. Although in the illustrated non-limiting embodiment, the selected heat-generating electronic device is described as a central processing unit or a graphics processing unit, and the at least one peripheral heat-generating device is described as including other components such as memory, hard drives, or power supply modules, it should be understood that any component of the server 30 may be designed as at least one selected heat-generating electronic device that is directly cooled by the primary cooling fluid C1, and any component of the server 30 may be designed as a peripheral heat-generating device.

[0034] In one embodiment, the cooling system 100 includes a heat removal device 102, such as a heat exchanger, mounted in an axially overlapping relationship and thermally coupled to at least one heat generating electronic device. With reference to the cross-sectional view of the cooling system 100 shown in FIG. 4, the heat exchanger 102 may be a heat exchanger, such as a microchannel heat exchanger having a plurality of substantially parallel microchannel heat exchanger tubes 104 extending between an inlet header 106 and an outlet header 108, each of the plurality of heat exchanger tubes 104 defining a plurality of fluid flow paths (not shown). However, examples of other types of heat exchangers that may be used may include, but are not limited to, microtube, double tube, shell-and-tube, tube-and-fin, plate, plate-and-shell, adiabatic shell, plate-fin, pillow plate, and fluid heat exchangers. The type of heat exchanger 102 selected may depend, at least in part, on the type of fluid supplied thereto.

[0035] The primary cooling fluid C1 and the secondary cooling fluid C2 are disposed in a heat transfer relationship in the heat exchanger 102. In the non-limiting embodiment shown in FIG. 4, the heat exchanger 102 has a single path configuration for both the primary cooling fluid C1 and the secondary cooling fluid C2. However, in other embodiments, at least one of the primary cooling fluid C1 and the secondary cooling fluid C2 may pass through the heat exchanger 102 multiple times. Furthermore, the primary cooling fluid C1 and the secondary cooling fluid C2 may be arranged in any suitable flow configuration in the heat exchanger, such as cross-flow, parallel flow, counter-flow, or any combination thereof.

[0036] In one embodiment, at least one jet impingement feature, such as a nozzle, jet or mouth, hole or opening, is formed in the plate 110, and in some embodiments, multiple jet impingement features 110 are disposed in the outlet header 108, with each nozzle 110 fluidly coupled to at least one fluid flow path of one or more heat exchanger tubes 104. The outlet end of the jet impingement feature 110 is directed to a surface of the outlet header 108 that is thermally coupled to at least one selected heat-generating electronic device 50, for example, a bottom surface of the outlet header 108. Although the one or more jet impingement features 110 are illustrated and described herein as being separate from the heat exchange tubes 104, in one embodiment, the outlet end of the heat exchange tubes 104 may be contoured such that the one or more jet impingement features 110 are integral therewith. The jet impingement configuration may be of a free surface type, or a submerged type, or a confined submerged type. Additionally, the jets emitted from the jet impingement features 110 may be of any geometric shape in cross section, such as circular, polygonal, star-shaped, etc.

[0037] In some embodiments, the heat exchanger 102 is directly coupled to a surface of the at least one selected heat generating electronic device 50. However, in other embodiments, as shown in FIG. 4, the heat exchanger 102 is indirectly coupled to the at least one selected heat generating electronic device 50. In server applications, the surface area of ​​the heat generating electronic devices (i.e., CPU, GPU, etc.) available is very small. The amount of heat dissipated from such heat generating devices 50 is usually so large that the surface area available to interface with a heat removal device is not sufficient to meet the cooling demand of the heat generating electronic devices. Thus, in the illustrated non-limiting embodiment, a heat spreader 120, such as formed from a conductive material, such as sheet metal, is attached to the printed circuit board 34 adjacent to the selected heat generating electronic device 50. Although the heat spreader 120 is shown axially overlapping both the at least one selected heat generating electronic device 50 and the printed circuit board 34, embodiments in which the heat spreader 120 is located in another position relative to the at least one selected heat generating electronic device 50 are also contemplated herein.

[0038] To facilitate the transfer of heat from the at least one selected heat-generating electronic device 50 to the heat spreader 120, a thermal interface material 122 may be disposed between a surface 124 of the at least one selected heat-generating electronic device and an adjacent surface 126 of the heat spreader 120. The surface area of ​​the surface 126 of the heat spreader 120 facing the at least one selected heat-generating electronic device 50 may be greater than, equal to, or, in some embodiments, less than the surface area of ​​the surface 124 of the at least one selected heat-generating electronic device 50.

[0039] The heat exchanger 102 is thermally coupled to a second opposite surface 128 of the heat spreader 120. In one embodiment, the second opposite surface 128 of the heat spreader 120 is larger than the surface 124 of the at least one selected heat-generating electronic device 50 to facilitate the transfer of heat from the heat spreader 120 to a fluid in the heat exchanger 102, such as, for example, the primary cooling fluid C1. For example, the surface area of ​​the surface 128 of the heat spreader 120 is at least 30% larger than the surface area of ​​the surface 124 of the at least one selected heat-generating electronic device 50, and in some embodiments, is at least 40%, 50%, 60%, 70%, 80%, 90%, 100%, or more than 100% larger than the surface 124 of the at least one selected heat-generating electronic device 50. However, in other embodiments, the surface area of ​​the second surface 128 of the heat spreader 120 may be the same as or smaller than the surface area of ​​the at least one selected heat-generating electronic device 50. In the illustrated non-limiting embodiment, the outlet header 108 may be disposed directly adjacent to the heat spreader 120 and thermally coupled to the heat spreader 120 via a thermal interface material 130 .

[0040] The inlet header 106 of the heat exchanger 102 may be fluidly connected to the first fluid inlet 132, and the outlet header 108 may be fluidly connected to the first fluid outlet 134 to form a first flow path of a primary cooling fluid C1. During operation, a primary cooling fluid C1, such as, for example, a refrigerant, is supplied from the first fluid inlet 132 to the inlet header 106 of the heat exchanger 102. The primary cooling fluid C1 supplied to the inlet header 106 may be single-phase, such as, for example, a cryogenic liquid or a cooling liquid. The primary cooling fluid C1 flows from the inlet header 106 through the multiple heat exchange tubes 104 of the heat exchanger 102 toward the outlet header 108.

[0041] The secondary cooling fluid C2 is configured to flow through gaps 136 defined between adjacent heat exchanger tubes 104. In the illustrated non-limiting embodiment, the secondary cooling fluid C2 is a flow of air moved (in a direction extending into the plane of the page) by at least one fluid moving device 52 associated with the server 30. However, it should be understood that any fluid, including a liquid, may be used as the secondary cooling fluid. In the illustrated non-limiting embodiment, a plurality of fins are disposed within the gaps 136 defined between adjacent heat exchanger tubes 104, although embodiments that do not include such fins are also contemplated herein. Within the multiple passages of the heat exchange tubes 104, heat from the secondary cooling fluid C2 is transferred to the primary cooling fluid C1. As a result, the cooled secondary cooling fluid C2 provided to the outlet of the heat exchanger 102 may be configured to flow over heat generating devices in the periphery of the server 30.

[0042] At least a portion of the slightly warmed primary cooling fluid C1 is now output from the plurality of heat exchange tubes 104 to one or more jet impingement features 110 disposed in the outlet header 108. In one embodiment, the primary cooling fluid C1 may be single-phase when it is fed to the one or more jet impingement features 110. In the jet impingement feature 110, the flow rate of the primary cooling fluid C1 is increased, so that the primary cooling fluid C1 is discharged from the outlet of the jet impingement feature at the surface of the outlet header 108 vertically aligned with the selected heat-generating electronic device 50. At least a portion of the heat transferred from the at least one selected heat-generating electronic device 50 to the first surface 126 of the heat spreader 120 is transferred from the second surface 128 of the heat spreader 120 to the primary cooling fluid C1. The primary cooling fluid C1 continuously impinges on the surface of the outlet header 108, thereby transferring heat from the surface of the outlet header 108 to the primary cooling fluid C1, thereby cooling the at least one selected heat-generating electronic device 50. After contacting the surfaces of the outlet manifold, the resulting warmer primary cooling fluid C1 exits the outlet header 108 of the heat exchanger 102 and flows towards the first fluid outlet 134.

[0043] As best shown in FIG. 4 , at least one valve may be disposed in the first fluid inlet 132 and / or the first fluid outlet 134 to control the flow of the primary cooling fluid C1 to or from the heat exchanger 102. In one embodiment, the position of the valve(s) V, and therefore the flow rate through the heat exchanger 102, is actively managed based on the thermal load at the heat exchanger 102. In the illustrated non-limiting embodiment, a first sensor is operable to monitor the temperature of the heat spreader 120 and a second sensor is operable to monitor the temperature of the primary cooling fluid C1 at the outlet header 108. The at least one sensor T may be operable to measure the temperature directly or may be configured to monitor another parameter that correlates with or can be used to derive the temperature therefrom.

[0044] In one embodiment, the heat spreader 120 of the cooling system 100 is a cooling plate having an internal fluid circuit. An example of an internal fluid circuit 200 of the heat spreader 120 is shown in the cross-sectional view of the heat spreader shown in FIG. 5. As shown, the fluid circuit 200 includes a fluid inlet 202 and a fluid outlet 204 formed in the body of the heat spreader 120. The fluid inlet 202 and the fluid outlet 204 can be of any shape, including a circle, an ellipse, a triangle, a square, a rectangle, or any simple polygon or part of a polygon in the depth direction (e.g., ZX plane in the accompanying figures). Also, in one embodiment, the fluid outlet 204 can have a much larger diameter than the fluid inlet 202, thereby helping to reduce the pressure drop of the cooling medium passing through the fluid outlet 204.

[0045] In one embodiment, the fluid circuit includes a single continuous flow path extending between the fluid inlet 202 and the fluid outlet 204. However, in other embodiments, the fluid circuit 200 includes a first or inlet manifold 206, a second or outlet manifold 208, and at least one fluid passage 210 connecting the first manifold 206 and the second manifold 208. In one embodiment, the at least one fluid passage 210 includes multiple fluid passages 210. The fluid inlet 202 may be configured to connect a source of the third cooling medium C3 to the inlet manifold 206 using any suitable mechanical connection. The third cooling medium C3 may be the same as either the primary cooling fluid C1 or the secondary cooling fluid C2, or may be separate or different from them.

[0046] In one embodiment, one or more fluid passages 210 of the fluid circuit 200 may be positioned to provide localized cooling in areas of the heat spreader where the heat flux is greatest, such as in areas of the heat spreader that are directly aligned or in an overlapping arrangement with a heat-generating electronic module. Thus, at least one fluid passage 210 may be associated with a heat-generating electronic module 50. In an embodiment in which the heat spreader is associated with multiple heat-generating electronic modules, one or more fluid passages 210 may be associated with each heat-generating electronic module and configured to remove heat from each heat-generating electronic module. More specifically, at least one fluid passage 210 associated with each heat-generating electronic module 50 may be physically positioned within the heat spreader 120 in alignment with the heat-generating electronic module 50. Including the fluid circuit 200 within the heat spreader 120 may reduce the size of the heat removal device 102 of the cooling system 100.

[0047] 6A, an example of a circuit 150 of the primary cooling fluid C1 of the cooling system 100 is shown. In the illustrated non-limiting embodiment, the circuit 150 of the primary cooling fluid C1 of the cooling system 100 is a closed loop and includes a pump 152 for moving the primary cooling fluid C1 therethrough. A filter 154 may be disposed upstream of at least one heat removal device 102 arranged to directly cool a corresponding heat-generating electronic device 50. Downstream of the one or more heat removal devices 102 is a cooling heat exchanger 156 configured to remove heat from the primary cooling fluid C1. The circuit 150 may further include a reservoir or accumulator 158 in which excess primary cooling fluid C1 is stored. As shown, the circuit 150 may include multiple valves positioned immediately upstream of the heat removal device 102 (VC1), immediately downstream of the heat exchanger 102 (VC2), and associated with a bypass conduit 160 for bypassing the cooling heat exchanger 156 (VC3), and another bypass conduit 162 for bypassing both the heat removal device 102 and the cooling heat exchanger 156 (VC4).

[0048] 6B, another circuit similar to that of FIG. 6A is shown. However, the circuit shown in FIG. 6B includes multiple heat exchangers 102 arranged in series with respect to the flow of primary cooling fluid C1. Fluid transfer devices 52 are shown diagrammatically as being associated with respective heat removal devices 102. It should be understood that in one embodiment, each heat removal device 102 is configured to receive a flow of secondary cooling fluid C2 from all fluid transfer devices 52. However, embodiments in which each heat removal device 102 is fluidly coupled to and configured to receive a flow of secondary cooling fluid C2 from a respective fluid transfer device 52 are also contemplated herein.

[0049] With reference to FIGS. 7-9, it will be appreciated that in some embodiments, the cooling system 100 may include a plurality of heat removal devices 102, each arranged to directly cool a respective heat-generating electronic device 50. In such embodiments, the primary cooling fluid C1 may flow to the plurality of heat removal devices 102 in any suitable manner. For example, as shown in FIG. 7, each of the plurality of heat exchangers 102 may be fluidly connected in parallel to the flow of the primary cooling fluid C1 between the first fluid inlet 132 and the first fluid outlet 134. In another embodiment, shown in FIG. 8, the plurality of heat removal devices 102 may be fluidly connected in series to the flow of the primary cooling fluid C1 between the first fluid inlet 132 and the first fluid outlet 134. In yet another embodiment, the plurality of heat removal devices 102 may be fluidly connected both in parallel and in series to the flow of the primary cooling fluid C1 between the first fluid inlet 132 and the first fluid outlet 134. As shown, multiple flow paths extend between the first fluid inlet 132 and the first fluid outlet 134, and at least one of the flow paths, and in some embodiments, each flow path, includes multiple heat exchangers 102.

[0050] As shown in FIGS. 7-9, in one embodiment, the cooling system 100 further includes a secondary heat exchanger 170 used to condition or cool another medium, such as, for example, a secondary cooling fluid C2. The secondary heat exchanger 170 may be mounted to the chassis 32 and / or the printed circuit board 34 and located at a location remote from both the selected one or more heat-generating electronic devices 50 and the one or more peripheral heat-generating devices. In the illustrated non-limiting embodiment, the secondary heat exchanger 170 is located upstream of at least one heat removal device 102 mounted in an overlapping arrangement with at least one selected heat-generating electronic device 50, relative to the flow of the primary cooling fluid C1, and in some embodiments, relative to the flow of the secondary cooling fluid C2. For example, the secondary heat exchanger 170 may be mounted near the first end 54 of the printed circuit board 34, in a position between the at least one selected heat-generating electronic device 50 and the at least one fan 52. However, embodiments in which the secondary heat exchanger 170 is located at another location are also contemplated herein.

[0051] The secondary heat exchanger 170 may be any suitable type of heat exchanger. In one embodiment, the secondary heat exchanger 170 is a microchannel heat exchanger having a plurality of substantially parallel microchannel heat exchange tubes, each defining a plurality of fluid flow paths (not shown). However, examples of other types of heat exchangers that may be used may include, but are not limited to, microtube, double tube, shell-and-tube, tube-and-fin, plate, plate-and-shell, adiabatic shell, plate-fin, pillow plate, and fluid heat exchangers.

[0052] In the illustrated non-limiting embodiment, the secondary heat exchanger 170 has a primary inlet 172 and a primary outlet 174 defining a flow path for the primary cooling fluid C1, and a secondary inlet 176 and a secondary outlet 178 defining a flow path for the secondary cooling fluid C2. The primary cooling fluid C1 and the secondary cooling fluid C2 may each pass through the secondary heat exchanger 170 once. However, in other embodiments, at least one of the primary cooling fluid C1 and the secondary cooling fluid C2 may pass through the heat exchanger 102 multiple times. Additionally, the primary cooling fluid C1 and the secondary cooling fluid C2 may be arranged in any suitable flow configuration in the heat exchanger, such as cross-flow, parallel flow, counter-flow, or any combination thereof.

[0053] In one embodiment, the secondary heat exchanger 170 is configured as a cooling coil, and the primary cooling fluid C1 supplied to the secondary heat exchanger 170 is configured to absorb heat from the secondary cooling fluid C2. During operation, at least one fan 52 supplies a flow of the secondary cooling fluid C2, such as, for example, ambient air, to the secondary heat exchanger 170. Within the secondary heat exchanger 170, the low-temperature or cooled primary cooling fluid C1 absorbs heat from the secondary cooling fluid C2. The primary cooling fluid C1 at both the primary inlet 172 and the primary outlet 174 may be single-phase, such as, for example, liquid, such that the primary cooling fluid C1 supplied to the heat exchanger 102 is single-phase and at a temperature capable of absorbing heat from the selected one or more heat-generating electronic devices 50. It should be understood that the secondary cooling fluid C2 output from the outlet 178 of the secondary heat exchanger 170 may pass through, and thus absorb heat from, one or more surrounding heat-generating electronic devices 50 before reaching the heat removal device 102.

[0054] In embodiments of the cooling system 100 including a secondary heat exchanger 170 mounted upstream of a plurality of heat-generating devices, cooling of the secondary cooling fluid C2 need not be performed in the heat removal device 102. Thus, a heat removal device 102 mounted in an overlapping arrangement with at least one selected heat-generating electronic device 50 need not be a heat exchanger. In such embodiments, cooling of the selected heat-generating device 50 may be performed primarily by flow of the primary cooling fluid C1 through the heat removal device 102.

[0055] 10, an example of another heat removal device 102 suitable for use in the cooling system 100 in combination with the secondary heat exchanger 170 is shown. As shown, the heat removal device 102 includes an inlet region 300 and at least one jet impingement feature 310, and in some embodiments, multiple jet impingement features 310 fluidly coupled to the inlet region 300. Similar to the heat exchanger 102 previously described herein, the outlet end of the jet impingement feature 310 is directed to a surface of the heat removal device 102 that is thermally coupled to at least one selected heat generating electronic device 50, such as, for example, the bottom surface 312 of the heat removal device 102. The jet impingement configuration can be of a free surface type, or a submerged type, or a confined submerged type. Additionally, the jet issuing from the jet impingement feature 310 can be of any geometric shape in cross section, such as a circle, a polygon, a star, etc.

[0056] The cooling system 100 shown and described herein provides an easily scalable solution for cooling heat generating components. Such a cooling solution can improve the sustainability and efficiency of the heat generating components by rejecting heat absorbed from the heat generating components to downstream heating applications. Additionally, air conditioning loads for cooling areas including data centers are reduced. The cooling system 100 can reduce costs compared to existing single phase liquid cooling systems.

[0057] The term "about" is intended to include the degree of error associated with measurement of the particular quantity with the equipment available at the time of application.

[0058] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms unless the context clearly indicates otherwise. It will be further understood that the terms "comprise" and / or "comprising", as used herein, specify the presence of stated features, integers, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components and / or groups thereof.

[0059] Although the present disclosure has been described with reference to one or more exemplary embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for the elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope of the present disclosure. Therefore, it is not intended that the present disclosure be limited to the particular embodiment disclosed as the best mode contemplated for carrying out the disclosure, but rather, the present disclosure is intended to include all embodiments falling within the scope of the appended claims.

Claims

1. 1. A cooling system for cooling an assembly including at least one heat-generating electronic device, comprising: a heat spreader thermally coupled to the at least one heat-generating electronic device; a heat removal device including a surface thermally coupled to the at least one heat-generating electronic device through the heat spreader, the heat removal device including an inlet region and at least one jet impingement feature fluidly coupled to the inlet region, the at least one jet impingement feature positioned to direct a primary cooling fluid toward the surface thermally coupled to the at least one heat-generating electronic device; The cooling system comprising:

2. 2. The cooling system of claim 1, wherein the heat removal device includes a heat exchanger having an outlet header, the surface thermally coupled to the at least one heat-generating electronic device being disposed within the outlet header, and the primary and secondary cooling fluids being disposed in heat transfer relationship within the at least one heat exchanger.

3. The heat exchanger includes: an inlet header, the inlet region being defined by the inlet header; 3. The cooling system of claim 2, further comprising a plurality of heat exchange tubes extending between the inlet header and the outlet header, the at least one jet impingement feature being separate from and fluidly coupled to the plurality of heat exchange tubes.

4. The heat exchanger includes: an inlet header, the inlet region being defined by the inlet header; 3. The cooling system of claim 2, further comprising a plurality of heat exchange tubes extending between the inlet header and the outlet header, the at least one jet impingement feature being integral with at least one of the plurality of heat exchange tubes.

5. 2. A cooling system according to any one of the preceding claims, further comprising a fluid movement device operable to move the secondary cooling fluid through the heat removal device.

6. The cooling system of claim 5 , wherein the fluid movement device is a fan and the secondary cooling fluid is air.

7. 2. The cooling system of claim 1, wherein the heat removal device further comprises a plurality of heat exchangers, each of the plurality of heat exchangers disposed and thermally coupled to a respective heat-generating electronic device.

8. The cooling system of claim 7 , wherein at least some of the plurality of heat exchangers are disposed in series with respect to the flow of the primary cooling fluid.

9. The cooling system of claim 7 , wherein at least some of the plurality of heat exchangers are arranged in parallel with respect to the flow of the primary cooling fluid.

10. 10. A cooling system according to any one of the preceding claims, further comprising a secondary heat exchanger arranged upstream of the heat removal device relative to the flow of the primary cooling fluid.

11. The cooling system of claim 10 , wherein the secondary heat exchanger is disposed upstream of the heat removal device relative to the flow of the secondary cooling fluid.

12. The cooling system of claim 1 , wherein the primary cooling fluid supplied to the heat removal device is a single-phase liquid.

13. 1. A method of cooling an assembly including at least one heat-generating electronic device and at least one peripheral heat-generating device, comprising: cooling a secondary cooling fluid via a primary cooling fluid; flowing the cooled secondary cooling fluid over the at least one peripheral heat-generating device; projecting the primary cooling fluid via at least one jet impingement feature onto a surface of a heat removal device thermally coupled to the at least one heat-generating electronic device to cool the at least one heat-generating electronic device; The method comprising:

14. The method of claim 13 , wherein the heat removal device is a heat exchanger, and the cooling of the secondary cooling fluid via the primary cooling fluid occurs within a plurality of heat exchange tubes of the heat exchanger.

15. The method of claim 14 further comprising supplying the secondary cooling fluid to the heat exchanger through a fluid transfer device.

16. 16. The method of any one of claims 13 to 15, further comprising supplying the primary cooling fluid to a secondary heat exchanger, the secondary heat exchanger being positioned upstream of the heat exchanger with respect to the flow of the primary cooling fluid.

17. The method of claim 16 further comprising cooling the primary cooling fluid in the secondary heat exchanger.

18. 18. The method of claim 13, further comprising supplying the primary cooling fluid to a further heat removal device disposed and thermally coupled to the at least one heat-generating electronic device, the further heat removal device being disposed in series downstream of the heat removal device with respect to the flow of the primary cooling fluid.

19. 19. The method of any one of claims 13 to 18, further comprising supplying the primary cooling fluid to a further heat removal device disposed on and thermally coupled to the at least one heat-generating electronic device, the further heat removal device being disposed in parallel with the heat removal device with respect to the flow of the primary cooling fluid.

20. 1. A cooling system for cooling an assembly including at least one heat-generating electronic device, the cooling system comprising: a heat removal device including a surface thermally coupled to the at least one heat-generating electronic device, the heat removal device including an inlet region and at least one jet impingement feature fluidly coupled to the inlet region, the at least one jet impingement feature positioned to direct a primary cooling fluid toward the surface thermally coupled to the at least one heat-generating electronic device; The refrigeration system, wherein the primary refrigeration fluid is single phase when delivered to the inlet region.

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