Two-stage cooling of heat-generating components

Abstract

A module for use in cooling one or more heat generating components, the module comprising: a heat exchanger having a plurality of ports for a primary coolant flow and a secondary coolant flow carrying heat from the one or more heat generating components, the heat exchanger configured to transfer heat from the primary coolant to the secondary coolant, and a volume compensator fluidly coupled to the heat exchanger through one of the plurality of ports. The volume compensator has an internal volume configured to increase and decrease in size in response to pressure. A cooled electronics system comprising one such module is also provided.

Description

[Technical field]

[0001] Technical Field The present disclosure relates to modules for use in cooling heat-generating components. [Background technology]

[0002] Background of the disclosure Computers, servers, disk drives, and other devices used in data processing (also called Information Technology or IT) are typically housed in a case, enclosure, or housing. For example, in a server, the enclosure is sometimes called a server chassis, although the term "chassis" is used herein to refer to the entire housing of any type used for electronic components. Server chassis conform to several industry standards that specify the height of each chassis, usually referred to as 1RU (one rack unit) or 1OU (one open unit), also abbreviated as 1U or 1OU. The smaller of the two main standards is 1RU / 1U, which is 44.45mm or 1.75 inches in height. Such units are sometimes called "blade" servers in terms of shape and style, although such server chassis may not necessarily be inserted or plugged into a backplane.

[0003] Different server products can utilize more than one RU / OU at a time for a chassis, for example a 2U chassis uses two rack units. The size of each server chassis is typically kept to a minimum to maximize the amount of computing power per server rack (the server rack is the main housing to which the server chassis are added).

[0004] Liquid cooling is increasingly being used to remove heat from IT components. In one type of system, the electrical components are immersed in the coolant to provide a large surface area for heat exchange between the heat-generating electrical components and the coolant liquid. Such systems may use single-phase coolants, where the coolant remains in the liquid phase, or they may use phase-change coolants, where the liquid coolant evaporates and must condense for continued, effective cooling.

[0005] Additionally or alternatively, a cold plate is used, where liquid coolant flows through the cold plate, which is typically in direct thermal contact with the one or more IT components. For example, a closed-loop cold plate can receive the coolant, transfer heat from the one or more IT components to the coolant without the coolant directly contacting the one or more IT components, and direct the coolant to a heat exchanger. In some implementations, heat is transferred from the liquid coolant flowing through the cold plate to a secondary liquid coolant.

[0006] WO 2018 / 096362 (commonly assigned with the present disclosure) describes a cooling system in which a primary dielectric coolant liquid is provided within a chassis and used to cool electronic components housed therein. The primary dielectric coolant liquid is pumped to a heat exchanger where heat is transferred to a secondary liquid coolant. The heat exchanger is provided within the chassis and a secondary liquid coolant, typically water or water-based (advantageous as it has a high specific heat capacity), is pumped to the chassis and the heat exchanger within the chassis, and may then be pumped out of the chassis and shared among multiple chassis. A pipe terminating in a nozzle is provided to transport the primary dielectric coolant from the heat exchanger to the electronic components to be cooled.

[0007] WO 2019 / 048864 (also commonly assigned with the present disclosure) describes heat sinks and heat sink arrangements for electronic devices. Such heat sinks can accumulate a primary dielectric coolant adjacent to a particular electronic component, effectively cooling the electronic component. The coolant can flow out of the heat sink by overflowing the heat sink and / or through one or more openings in the heat sink to join the remainder of the coolant in the chassis that cools other electronic components therein. In this manner, multiple levels of coolant can be provided, minimizing the total amount of coolant required. Pipes terminating in nozzles are provided to convey the primary dielectric coolant from the heat exchanger to each heat sink.

[0008] WO 2020 / 178579 (also commonly assigned with the present disclosure) relates to the adaptation of a modular chassis for housing liquid-cooled IT and a rack in which multiple such modules can be mounted.

[0009] WO 2020 / 234600 (also commonly assigned with the present disclosure) contemplates the possibility of using immersion cooling within a chassis (of the type described above, having a primary dielectric coolant) with one or more closed-loop cold plates within the same chassis. The coolant used for the closed-loop cold plate, received from outside the chassis, may also act as a secondary coolant to receive heat from the primary dielectric coolant. This is typically done with a heat exchanger that is also within the chassis. Such an approach can provide high cooling performance and high efficiency.

[0010] The heat exchanger between the primary and secondary coolants is therefore a critical part in all of these systems. Constraints may be placed on the implementation of the heat exchanger. For example, the heat exchanger may be desirably small, especially if mounted in a chassis. For this reason, plate heat exchangers are preferred. It is also often desirable to allow for a disconnection between the heat exchanger and the secondary coolant circuit without difficulty. For example (and especially if the heat exchanger is mounted in the chassis), quick disconnect fittings to the heat exchanger for the secondary coolant can be provided. These allow for the chassis to be directly removed from its mounting (e.g. in a rack). Summary of the Invention [Problem to be solved by the invention]

[0011] In this type of configuration, the flow of secondary coolant through the heat exchanger may be interrupted during operation. It would be desirable to mitigate problems that may arise in such implementations. [Means for solving the problem]

[0012] Disclosure Summary Against this background, there is provided a module for use in cooling one or more heat-generating components according to claim 1. There is also provided a cooled electronics system according to claim 18. The other claims define advantageous and / or more detailed features.

[0013] The volume compensator is connected to one port of the heat exchanger used to transfer heat from the primary coolant to the secondary coolant. The volume compensator has an internal volume that increases or decreases in size depending on the pressure. For example, a form of pressure regulator may be used for this purpose, including an oil-pneumatic device such as a water hammer arrester. Other options may include an elastically biased mechanism (e.g., a spring-loaded device) or a volume with a diaphragm (e.g., made from a flexible material such as rubber). Both the primary and secondary coolants are typically liquids, and advantageously the coolants and / or the module are designed for single-phase use.

[0014] It is understood that an accidental closed loop may form within the module, especially if the secondary coolant inlet and outlet of the module are isolated (from the supply and exhaust or loop). In that case, the secondary coolant may continue to heat up, although no secondary coolant will flow. As a result, pressure may build up within the accidental closed loop, which may cause significant problems to the module or external equipment when the module is connected (or reconnected) to an external device. Such problems may include connector failure, leaks, and other damage. By providing a volumetric compensator, such problems may be mitigated.

[0015] The volume compensator is generally connected to the port of the heat exchanger configured for the secondary coolant flow, but may also be connected to the port of the heat exchanger configured for the primary coolant flow. Advantageously, the volume compensator is connected to the port configured for the coolant flow from the heat exchanger. A quick disconnect fitting (fitting with a non-return valve) is usually connected to at least some ports of the heat exchanger, generally the port for the secondary coolant flow. Accidental closed loops may be formed in particular when quick disconnect fittings are used.

[0016] The volume compensator and the heat exchanger may define a module, but more typically, the module may be defined by additional components. Thus, the module may be a single unit for holding the heat generating components and the primary coolant. A server blade or other IT unit (whether mounted in a rack or not) is an example of such a module. For example, the heat exchanger is preferably in and / or mounted to the housing (chassis) of the module in which the heat generating components and the primary coolant are housed. Typically, the primary coolant reaches the heat exchanger from within the housing (e.g., a dielectric coolant that can remain in the chassis), and at least a portion of the secondary coolant reaches from outside the housing and / or is led from the heat exchanger to outside the housing (e.g., a facility coolant that may be water or water-based).

[0017] The volume compensator may be connected to the heat exchanger via a T-connector, which may be space-efficient in certain designs. The T-connector may have three ports: a first port connected to the heat exchanger, a second port connected to the volume compensator, and a third port for coolant flow to and / or from the heat exchanger. Thus, the three ports are typically arranged in a T-shape.

[0018] In one implementation, the volume compensator is located on the outside of the chassis and / or on a quick disconnect fitting coupled to the heat exchanger. Additionally or alternatively, the heat exchanger has only two ports for secondary coolant flow, and the volume compensator is connected to one of these ports (e.g., via a quick disconnect fitting).

[0019] In another implementation, the heat exchanger has two ports for the primary coolant flow and four ports for the secondary coolant flow. In other words, the heat exchanger has a total of six ports. Nevertheless, it is advantageous for the primary and secondary coolants to remain isolated within the heat exchanger. For example, two of the four ports for the secondary coolant flow may be located on the same side of the heat exchanger as the two ports for the primary coolant flow, and the other two of the four ports for the secondary coolant flow may be located on the opposite side. The volume compensator may be connected to the first port of the four ports for the secondary coolant flow (typically the port configured to flow out of the heat exchanger). The second port of the four ports for the secondary coolant flow may be blocked. These first and second ports may be associated with each side and / or the same side of the heat exchanger. The third of the four ports (typically opposite the heat exchanger) is for receiving secondary coolant to the heat exchanger (from outside the chassis), and the fourth of the four ports is for flow of secondary coolant from the heat exchanger (to outside the chassis).

[0020] Optionally, two or more volume compensators may be provided, each connected to a different port of the heat exchanger. For example, a first volume compensator may be connected to a port for coolant flow from the heat exchanger, and a second volume compensator may be connected to a port for coolant flow to the heat exchanger. Such a configuration may be used to provide additional volume compensation as needed.

[0021] A coolant flow device may also be provided with the module for directing the primary coolant to the heat exchanger and / or from the heat exchanger to one or more heat generating components. The coolant flow device generally comprises one or more pumps disposed within the housing and may further include piping (for directing the coolant from the one or more pumps to the heat exchanger and / or from the heat exchanger to the heat generating components). The coolant flow device may also comprise a manifold for splitting the primary coolant from the heat exchanger into multiple coolant streams for the different heat generating components.

[0022] One or more heat sink devices may be provided within the module. Each heat sink device has an internal volume in which coolant is received and stored from a heat exchanger. Heat is then transferred to the stored coolant from a heat generating component that may be mounted within the internal volume and to which the heat sink device may be attached. The heat sink devices may take a variety of forms. In one form, the heat sink device may be a closed loop cold plate configured to receive a secondary coolant, for example, from a heat exchanger. An alternative form of heat sink device stores a primary coolant within the internal volume and allows the stored coolant to flow out of the internal volume (e.g., by overflowing). The flowing coolant is then used to cool other heat generating components (e.g., by providing multiple coolants to multiple levels within the module).

[0023] A cooled electronics system may include one or more modules (which may be mounted, for example, in a rack) having a secondary heat exchanger for transferring heat from a secondary coolant to a heat sink (thereby providing a secondary coolant loop in which cooled secondary coolant is returned to one or more modules). The secondary heat exchanger may be provided in the rack or externally. One example of a secondary heat exchanger is a heat rejection unit. The secondary coolant from and / or to each module may be combined in series or parallel via a secondary coolant piping arrangement.

[0024] BRIEF DESCRIPTION OF THE DRAWINGS The present disclosure can be put into practice in a number of ways and preferred embodiments will now be described, by way of example only, with reference to the accompanying drawings, in which: [Brief description of the drawings]

[0025] [Figure 1] FIG. 2 is a plan view of a liquid cooling module with an external volume compensator according to a first embodiment. [Figure 2A] FIG. 2 is a rear isometric view of the embodiment of FIG. 1. [Figure 2B] FIG. 2 is a front isometric view of the embodiment of FIG. 1. [Figure 3A] FIG. 2 is a rear isometric view of a heat exchanger with a volume compensator for use in the embodiment of FIG. 1. [Figure 3B] FIG. 3B is a front isometric view of a heat exchanger having a volumetric compensator as shown in FIG. 3A. [Figure 4] FIG. 13 is a plan view of a liquid cooling module with an internal volume compensator according to a second embodiment. [Figure 5A] FIG. 5 is a rear isometric view of the embodiment of FIG. 4. [Figure 5B] FIG. 5 is a front isometric view of the embodiment of FIG. [Figure 6A] FIG. 5 is a rear isometric view of a heat exchanger with a volume compensator for use in the embodiment of FIG. [Figure 6B] FIG. 6B is a front isometric view of a heat exchanger having a volumetric compensator as shown in FIG. 6A. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0026] Like features are designated with the same reference numerals throughout.All drawings may be understood to be schematic in nature.

[0027] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring initially to Figure 1, a plan view of a liquid cooling module (e.g., a blade server) with an external volume compensator is shown. See also Figure 2A, which shows a rear isometric view of the embodiment of Figure 1, and Figure 2B, which shows a front isometric view of the embodiment of Figure 1.

[0028] In all these figures, the entire chassis of the module is shown, but without the lid (which is normally provided on the assembled module). It comprises a chassis 1 defining a volume 2 in which a dielectric coolant can be placed, a motherboard 3, a chip or integrated circuit (which may include any type of processor, CPU, GPU, or other) mounted with a heat sink 4 on the motherboard 3, a DIMM (or ancillary electronics) 5 also mounted on the motherboard 3, a pump 6, a first connecting tube 7, a plate heat exchanger 8, a second connecting tube 9, a primary coolant manifold 10, a hose tube connection 11, and a nozzle 12. The plate heat exchanger 8 is within the chassis 1, and the module further comprises quick disconnect fittings 13, 14 on the exterior of the chassis 1 to receive a secondary coolant (facility coolant, which may be water or water-based) to enter and exit the heat exchanger 8. The secondary coolant is received from and returned to a secondary coolant loop (not shown) external to the module chassis 1. The secondary coolant loop comprises a further heat exchanger (not shown) that cools the secondary coolant and transfers heat to a downstream heat sink (not shown). For example, a heat rejection unit may be suitable. All these features are known to provide a primary (dielectric) cooling circuit and a second stage of liquid cooling, as described in WO 2018 / 096362 and WO 2019 / 048864. In particular, the configuration of the processor with the heat sink 4, the first connecting tube 7 (connecting the pump 6 to the plate heat exchanger 8) and the second connecting tube 9 (connecting the plate heat exchanger 8 to the primary coolant manifold 10) is as described in WO 2019 / 048864. The flow rates of the primary and / or secondary coolant can be set (or adjusted) to keep the primary and / or secondary coolant as liquid.

[0029] Additionally, there is a "T" piece connector 15 and a volume compensator 16 mounted between the plate heat exchanger 8 and the quick disconnect fittings 14. The volume compensator 16 takes the form of a water hammer arrestor in this example. When the module chassis 1 is disconnected from the secondary (facility) coolant loop via the quick disconnect fittings 13, 14, some of the facility coolant can become trapped in the accidental closed circuit formed by the plate heat exchanger 8 and the quick disconnect fittings 13, 14. This accidental closed circuit can be, for example, about 70 cm 3 It may have a small amount of secondary (facility) coolant, ~1 liter (in some specific examples, e.g. for a 10 kW system, ~30 cm for a relatively small module). 3 ~100cm 3 , 250cm for larger modules 3 , 1200 cm for significantly larger modules 3 The volume of the spleen was measured.

[0030] A typical installation coolant circuit is 1.5 to 4 bar (1.5 x 10 5 From 4 × 10 5 This secondary coolant is usually already pressurized, since the main cooling system operates at a pressure of 1000 Pa. This pressure is often the weakest point of the closed circuit, which is the quick disconnect fitting 13, 14, and can be up to 4 bar (4 × 10 Pa), depending on the equipment used. 5 Pa) ~ 20 bar (2 × 10 6 Pa), for example about 7 or 8 bar (7 or 8×10 5 Pa) or 16 bar (1.6×10 6 This is manageable as it can operate at 100 MPa (300 psi) per minute. Nevertheless, there are two issues that can increase the pressure significantly and therefore cause problems:

[0031] First, in some cases, the quick disconnect fittings 13, 14 can be disconnected from the secondary coolant loop, but the chassis 1 may still be powered. For example, a power cable may be used in the harness chain that provides power to the chassis 1 when the module is pulled out of the rack. In fact, this continued power may be intentional, so that the electronics in the module continue to operate during servicing of the chassis 1. When the fittings 13, 14 are disconnected, the electronics on the motherboard 3 continue to generate heat, and the pump 6 continues to circulate the dielectric coolant. This heats up the dielectric coolant in the plate heat exchanger 8, which in turn heats up the remaining secondary (equipment) coolant in the plate heat exchanger 8. In one example, this can cause the secondary coolant in an accidental closed circuit to rise from 20°C to 60°C, i.e., a temperature rise of 40°C (typically, the ambient temperature can be 10°C to 20°C, and the temperature can rise to 80°C, so the temperature rise can be up to 60°C or 70°C). This causes the secondary coolant to expand in the accidental closed circuit. The accidental closed circuit has a relatively small volume (compared to the secondary coolant loop) and does not have any air. As a result, the pressure can increase significantly, and modelling has shown that in larger modules, the pressure can reach 30-40 bar (3 x 10 6 ~4×10 6 Pa), and even 300 bar (3 × 10 7 Such pressures are significantly higher than the rated limits of the quick disconnect fittings 13, 14 and may cause them to fail.

[0032] Secondly, even if the pressure rise in the accidental closed loop is manageable, problems can still occur when the quick-disconnect fittings 13, 14 are reconnected to the secondary coolant loop. At this time, the valves in the quick-disconnect fittings 13, 14 may move slightly backwards, reducing the volume in the accidental closed circuit. Even a small reduction in volume can cause a significant increase in pressure. In systems where the coupling to the quick-disconnect fittings 13, 14 is manual, this pressure rise may simply make it difficult to refit the fittings. Furthermore, the reduction in volume is only per fitting, since one fitting is fitted at a time. In contrast, the chassis 1 may be provided on slide rails with blind-fitting fittings, in which case the volume reduction and resulting pressure rise are much more substantial. The chassis 1 and the components mounted therein are typically heavy (up to 150 kg in known designs), and the engagement forces and velocities on the fittings can be high when the chassis 1 is pushed back into the rack. Furthermore, both fittings are engaged at the same time, significantly reducing the volume. Thus, the quick disconnect fittings 13, 14 and associated fittings on the secondary coolant loop may be damaged and other failures may follow.

[0033] Both of these problems can cause significant damage to the quick-disconnect fittings 13, 14 on the chassis 1 and the mating fittings on the equipment cooling side. Even without the use of quick-disconnect fittings, in certain configurations the fittings on the equipment cooling side can fail. Failure of the equipment side fittings can result in significant coolant leakage.

[0034] The volume compensator 16 increases the volume in the accidental closed loop, reducing the pressure in this accidental closed loop. Only a small amount of additional volume can eliminate the pressure problem. In one example, a water hammer arrester commercially available under product designation 660 series by Sioux Chief Manufacturing Company can be used. These components are specifically designed to operate on water hammer, by displacing a piston to provide additional volume. A pressurized chamber behind the piston provides compression resistance. For example, such a water hammer arrester can be used to reduce the pressure of the typically used quick disconnect fittings 13, 14 at approximately 7 bar (7 x 10 5 Approximately 3 bar (3×10 Pa) below the operating limit 5 It can operate at a pressure of 1000 psi (Pa).

[0035] Referring now to FIG. 3A, a rear isometric view of a heat exchanger with a volume compensator for use in the embodiment of FIG. 1 is shown. Referring also to FIG. 3B, a front isometric view of a heat exchanger with the volume compensator shown in FIG. 3A is shown. These views show the circuit of a closed cold plate heat exchanger 8 without the chassis and the primary coolant circuit. This is a circuit that can reach high pressure. The inlet port 17 and outlet port 18 of the plate heat exchanger 8 are also shown, with the "T" piece connector 15 and the volume compensator 16 connected to the outlet port 18. Note that these components may alternatively be connected to the inlet port 17. The "T" piece connector 15 can be rotated so that the volume compensator 16 is mounted in a different position depending on the configuration. Optionally, if more volume compensation is desired, a second additional volume compensator (not shown) can be added to the inlet port 17 of the plate heat exchanger port 8.

[0036] Thus, in a general sense, a module for use in cooling one or more heat generating components may be conceived. In its most basic form, such a module may comprise a heat exchanger (e.g., a plate heat exchanger) having a plurality of ports for a primary coolant flow and a secondary coolant flow carrying heat from one or more heat generating components, configured to transfer heat from the primary coolant to the secondary coolant, and a volume compensator connected to one of the ports (or fluidically coupled to the heat exchanger via one of the ports). Advantageously, the internal volume of the volume compensator (which may be fluidically coupled to the heat exchanger via one port) is configured to increase or decrease in size depending on the pressure (within the internal volume). The heat exchanger (and preferably the entire module) is advantageously configured to keep the secondary coolant and the primary coolant isolated from each other, for example by using isolated chambers for the two coolants.

[0037] In a typical embodiment, a quick disconnect fitting (or a fitting with a check valve) is connected to each of at least one (or more commonly two, e.g., an inlet and an outlet) of the ports, typically for secondary coolant flow.

[0038] More typically, the module further comprises a housing for containing the heat generating components and the primary coolant. The heat exchanger is then generally within the housing and / or attached to the housing. An external heat exchanger is possible, but should at least be fixed to the chassis. Thus, in either case, the primary coolant can be received at the heat exchanger from within the housing (as the primary coolant is typically confined within the housing and does not exit the housing). At least a portion of the secondary coolant is then received at the heat exchanger from outside the housing and / or conducted from the heat exchanger to outside the housing.

[0039] The volume compensator may comprise (or be) a hydro-pneumatic device, such as, for example, a water hammer arrestor. Advantageously, the port to which the volume compensator is connected is configured for secondary coolant flow. Additionally or alternatively, the port to which the volume compensator is connected is configured for coolant flow from the heat exchanger (i.e., outlet). In some implementations, the volume compensator is connected to a port of the heat exchanger via a T-connector. This allows the coolant to flow out of (or into) the heat exchanger through the same port to which the volume compensator is connected.

[0040] In one embodiment, the volume compensator is located outside the chassis. Additionally or alternatively, the volume compensator is connected to a quick disconnect fitting that is connected to a port of the heat exchanger (typically again via a T-connector).

[0041] Optionally, the volume compensator is a first volume compensator connected to a first port of the plurality of ports. The module may then further comprise a second volume compensator connected to a second port of the plurality of ports. For example, the first port may be configured for the flow of a coolant (e.g., a secondary coolant) from the heat exchanger. The second port may then be configured for the flow of a coolant to the heat exchanger. Each of the first and second volume compensators may be connected to a respective port of the heat exchanger via a respective different T-connector.

[0042] The module may also be provided with a coolant flow device configured to direct the primary coolant to the heat exchanger and / or from the heat exchanger to one or more heat generating components. For example, the coolant flow device may comprise at least one pump (in some implementations, two or more pumps) disposed within the housing. The coolant flow device may further comprise a piping device. The piping device may be configured to transfer the primary coolant from the pump to the heat exchanger and / or from the heat exchanger to one or more heat generating components. Optionally, the coolant flow device comprises a manifold configured to receive a portion of the primary coolant from the heat exchanger and provide a plurality of coolant streams, each coolant stream corresponding to a respective heat generating component. In this case, the piping device may be configured to transfer the primary coolant from each of the plurality of coolant streams provided by the manifold to a respective one of the plurality of heat generating components.

[0043] In one implementation, the heat sink device may be configured to receive a portion of the primary coolant from the heat exchanger and accumulate the received coolant in an internal volume of the heat sink device. This can be achieved such that heat is transferred from one of the heat generating components thermally (conductively) coupled to the heat sink device to the accumulated and received coolant. For example, one of the heat generating components may be disposed within the internal volume of the heat sink device, or the heat sink device may be attached to one of the heat generating components such that heat is transferred from the heat generating component to the internal volume of the heat sink device. Advantageously, the heat sink device is configured such that the coolant accumulated in the internal volume of the heat sink device flows out of the internal volume of the heat sink device (through an opening and / or by overflowing) and is used to cool at least one other of the heat generating components (not thermally and / or conductively coupled to the heat sink device). Multiple heat sink devices may be used in the housing, each heat sink device for cooling a respective one or more of the heat generating components. Further details of such heat sink devices can be found in WO 2019 / 048864.

[0044] In another aspect, a cooled electronics system may be considered that includes one or more modules, each as described herein (e.g., that are mountable or mounted in a rack), and a secondary heat exchanger configured to receive a secondary coolant from the one or more modules, cool the received secondary coolant by transferring heat from the received secondary coolant to a heat sink (e.g., air or another liquid or gas coolant), and return the cooled secondary coolant to the one or more modules. In this manner, a secondary coolant loop may be provided.

[0045] The cooled electronics system may further include a secondary coolant piping arrangement configured to transport the secondary coolant between the one or more modules and the secondary heat exchanger such that the secondary coolant from each of the one or more modules is combined. The secondary coolants may be combined in series (i.e., the secondary coolant flows from one module to the next before flowing through the heat exchanger) and / or in parallel (i.e., the secondary coolant flow is split between two or more modules before recombining upstream of the heat exchanger).

[0046] Advantageously, the heat exchanger and / or module and / or system may be configured to maintain the primary coolant and / or the secondary coolant in liquid form (i.e., single-phase coolant).

[0047] Reference will now be made to more specific implementations, however further discussion in accordance with these general terms of the disclosure is provided below.

[0048] Referring now to Figure 4, there is shown a plan view of a liquid cooling module with an internal volume compensator according to a second embodiment. See also Figure 5A, which shows a rear isometric view of the embodiment of Figure 4, and Figure 5B, which shows a front isometric view of the embodiment of Figure 4. In all of these figures, the entire chassis is shown, but without the (usually additional) lid. As mentioned above, where the same parts are shown in different figures, the same reference numbers are used.

[0049] In this alternative configuration, the "T" piece connector 15 and the volume compensator 16 are inside the chassis 1. This is advantageously possible by using a six-port plate heat exchanger 8b. Such a heat exchanger is described in co-pending international patent application PCT / EP2021 / 082224 (commonly assigned with the present disclosure), however, a brief description of this device is provided for completeness.

[0050] The heat exchanger has two isolated chambers, a first chamber for a primary coolant and a second chamber for a secondary coolant. A thermally conductive interface (e.g., a wall made of a thermally conductive material) separates the two chambers and allows heat to be transferred without exchanging coolants. The second chamber has two inlets (inlet ports) and two outputs (outlet ports), and at least two paths through them (i.e., each path provides a path from the inlet to the outlet). Each path provides a path for liquid coolant between a different combination of inlet and outlet ports, and at least one of the paths does not pass through or come into contact with a thermally conductive interface through which heat can pass to other chambers of the heat exchanger. All paths are fluidly connected and are within the same chamber of the heat exchanger that is fluidly isolated from any other chambers of the heat exchanger.

[0051] Thus, one inlet and one outlet for the secondary coolant, hereinafter referred to as the main secondary coolant inlet and main secondary coolant outlet, respectively, are provided on one side of the heat exchanger 8b (the same side as the quick disconnect fittings 13, 14). One inlet and one outlet for the secondary coolant are provided on the other side of the heat exchanger 8b (together with the inlet and outlet for the primary coolant), hereinafter referred to as the auxiliary secondary coolant inlet and auxiliary secondary coolant outlet, respectively. In this configuration, the secondary coolant can pass from the outside of the chassis to the inside of the chassis and can be used, for example, in one or more cold plates. Furthermore, the secondary coolant can receive heat from the primary coolant in the heat exchanger 8b. A "T" piece connector 15 and a volume compensator 16 are connected to the auxiliary secondary coolant outlet. The auxiliary secondary coolant inlet is provided with a plug 19. The advantage of this configuration is a better utilization of space. The length of the module in the front-to-rear direction including the volume compensator 16 is reduced.

[0052] See also Figure 6A, which shows a rear isometric view of a heat exchanger 8b having a volume compensator 16 for use in the embodiment of Figure 4, and Figure 6B, which shows a front isometric view of the heat exchanger having the volume compensator shown in Figure 6A. The quick disconnect fittings 13, 14 are directly connected to the respective main secondary coolant inlet and outlet ports 17, 18 of the plate heat exchanger 8b. The primary coolant inlet 20 and primary coolant outlet 21 are also visible.

[0053] In an alternative version of this configuration, the "T" piece connector 15 can be removed and the volume compensator can be screwed directly onto the plate heat exchanger 8b. This may be a better use of space in some configurations.

[0054] As with the external volume compensator described above, if more volume compensation is required, plug 19 can be removed and an additional volume compensator (not shown) can be added to this port. In fact, four volume compensators can be implemented if needed, each connected to a respective one of the ports for secondary coolant flow. T-connectors are then required on at least some of the ports to allow secondary coolant flow to and from the heat exchanger. For example, a double T-joint can be used to attach two volume compensators to one port.

[0055] In a further alternative, the auxiliary secondary coolant inlet and auxiliary secondary coolant outlet can be used to transport the secondary coolant to one or more cold plates provided within the chassis. Each cold plate may be attached to a respective heat generating component (or components) to transfer heat from the respective one or more heat generating components to the secondary coolant flowing through the cold plate. The secondary coolant then flows back through the heat exchanger and back into the secondary coolant loop via the main secondary coolant outlet. This describes a closed loop cold plate implementation.

[0056] Returning to the general sense of the present disclosure above, further optional features may be considered. For example, in one implementation, the heat exchanger may have two ports (e.g., one inlet and one outlet) for the primary coolant flow and four ports (e.g., two inlets and two outlets) for the secondary coolant flow. For example, two of the four ports for the secondary coolant flow may be provided on one side of the heat exchanger. And the two ports for the primary coolant flow and the other two of the four ports for the secondary coolant flow may be provided on the other side of the heat exchanger.

[0057] In this case, the volume compensator is advantageously connected to a first port of the four ports for the secondary coolant flow. Typically, this is one of two of the four ports for the secondary coolant flow (e.g., outlet) provided on the opposite side of the heat exchanger. Optionally, the second port of the four ports for the secondary coolant flow is blocked. The second port may also be one of two of the four ports for the secondary coolant flow (e.g., inlet) provided on the opposite side of the heat exchanger. More generally, the first port may be associated with the second port and / or may be on the same side of the heat exchanger as the second port. The third port of the four ports for the secondary coolant flow may be configured for a secondary coolant flow to the heat exchanger (from outside the chassis), and the fourth port of the four ports for the primary coolant flow may be configured for a secondary coolant flow from the heat exchanger (from outside the chassis). The third and fourth ports are typically located on the same side of the heat exchanger, opposite the first and second ports.

[0058] In one implementation, the heat sink device may be configured to receive a portion of the secondary coolant from the heat exchanger and store the received coolant in an interior volume of the heat sink device, such that heat is transferred from one of the heat generating components thermally (conductively) coupled to the heat sink device to the received and stored coolant. For example, the heat sink device may comprise a closed-loop cold plate.

[0059] While specific embodiments have been described herein, those skilled in the art will appreciate that various modifications and variations are possible. As discussed above, the arrangement of components, heat sinks, support structures, and other components can be modified, combined, or configured in a variety of different ways, of which those disclosed herein are merely examples. The configuration of the electronic device cooled by the heat sink and / or other electronic device can vary significantly. The exact shape and / or size of the heat sink device can also be changed. The configuration of the heat sink device may also vary, for example, using other multi-part assemblies or as an integrally configured device. The volumetric compensator can be connected in some configurations to a port of a heat exchanger configured for primary coolant flow.

[0060] Other options for the volume compensator may be considered. One example could use an elastically biased mechanism (e.g. with a spring) rather than a hydro-pneumatic approach. Such a device could be similar to a radiator cap on an automobile, for example. Another possibility could use a volume with a diaphragm. On one side of the diaphragm, a reference pressure may be set. Thus, the volume on the other side of the diaphragm changes depending on the pressure difference across the diaphragm (which is typically made from a flexible material, such as rubber, for example).

[0061] Further possible alternative configurations can include the use of quick disconnect fittings in the primary coolant circuit. For example, these may be connected to one or both ports of the heat exchanger used for the primary coolant. Such quick disconnect fittings can, for example, allow for the quick removal of heat-generating components (e.g., electronics or server boards) from the chassis. Similar to the use of quick disconnect fittings in the secondary coolant circuit, the presence of a check valve between the pump and the heat exchanger can result in an accidental closed loop. In this case, the use of a volume compensator connected to one of the heat exchanger ports for the flow of the primary coolant can be beneficial. The likelihood of a continued temperature rise in this case is lower than an accidental closed loop in the secondary coolant circuit, since the heat-generating component (e.g., server board) may have been removed from the chassis.

[0062] All of the features disclosed herein may be combined in any combination, except combinations in which at least some of such features and / or steps are mutually exclusive. In particular, the preferred features of the invention are applicable to all aspects of the invention and may be used in any combination. Similarly, features described in non-essential combinations may be used separately (not in combination).

Claims

1. 1. A module for use in cooling one or more heat generating components, comprising: a heat exchanger having a plurality of ports for a primary coolant flow and a secondary coolant flow carrying heat from one or more of the heat generating components, the heat exchanger being configured to transfer heat from the primary coolant to the secondary coolant; a volume compensator fluidly coupled to the heat exchanger via one of the plurality of ports, the volume compensator having an interior volume configured to increase or decrease in size in response to pressure; A module comprising:

2. a housing for containing the heat generating component and the primary coolant; the heat exchanger is within and / or attached to the housing, the primary coolant being received at the heat exchanger from within the housing, and at least a portion of the secondary coolant being received at the heat exchanger from outside the housing and / or being conducted from the heat exchanger to outside the housing. The module of claim 1 .

3. The module of claim 1 or 2, wherein the volume compensator comprises one of a hydro-pneumatic device, a resiliently biased mechanism, and a volume having a diaphragm.

4. a quick disconnect coupling connected to each of at least one of the ports; the one port is configured for flow of the secondary coolant; and the one port is configured for flow of coolant from the heat exchanger; 13. A module according to any preceding claim, which is one or more of:

5. 10. The module of any preceding claim, wherein the volume compensator is connected to the one port via a T-connector.

6. the volume compensator is disposed outside the chassis; and the volume compensator is connected to a quick disconnect coupling connected to the one port; 13. A module according to any preceding claim, wherein either or both of

7. 10. The module of any preceding claim, wherein the volume compensator is a first volume compensator connected to a first port of the plurality of ports, and the module further comprises a second volume compensator connected to a second port of the plurality of ports.

8. 8. The module of claim 7, wherein the first port is configured for flow of coolant from the heat exchanger and the second port is configured for flow of the coolant to the heat exchanger.

9. 10. A module according to any preceding claim, wherein the heat exchanger has two ports for the primary coolant flow and four ports for the secondary coolant flow.

10. 10. The module of claim 9, wherein the one port is a first of the four ports for the flow of the secondary coolant.

11. The module of claim 10 , wherein a second of the four ports for the flow of the secondary coolant is plugged.

12. 12. The module of claim 10 or 11, wherein a third port of the four ports for the secondary coolant flow is configured for the secondary coolant flow to the heat exchanger and a fourth port of the four ports for the primary coolant flow is configured for the secondary coolant flow from the heat exchanger.

13. a coolant flow device configured to direct the primary coolant to the heat exchanger and / or from the heat exchanger to the one or more heat generating components. A module according to any preceding claim.

14. The module of claim 13 , wherein the coolant flow device comprises at least one pump disposed within the housing.

15. 15. The module of claim 13 or 14, wherein the coolant flow device comprises a manifold configured to receive a portion of the primary coolant from the heat exchanger and provide a plurality of coolant flows, each coolant flow corresponding to a respective heat generating component.

16. a heat sink device configured to receive a portion of the primary coolant or the secondary coolant from the heat exchanger and to store the received coolant in an interior volume of the heat sink device, such that heat is transferred from one of the heat generating components thermally coupled to the heat sink device to the received and stored coolant. A module according to any preceding claim.

17. 17. The module of claim 16, wherein the heat sink apparatus comprises a closed-loop cold plate or the heat sink apparatus is configured such that coolant stored within the internal volume of the heat sink apparatus flows out of the internal volume of the heat sink apparatus and is used to cool at least one other of the heat generating components.

18. 1. A cooled electronics system comprising: One or more modules, each according to any of the preceding claims; a secondary heat exchanger configured to receive the secondary coolant from the one or more modules, cool the received secondary coolant by transferring heat from the received secondary coolant to a heat sink, and return the cooled secondary coolant to the one or more modules; 1. A cooled electronics system comprising:

19. and a secondary coolant piping system configured to transport the secondary coolant between the one or more modules and the secondary heat exchanger such that the secondary coolant from each of the one or more modules is combined.

20. The cooled electronics system of claim 18.

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