Multi-circuit cooling configuration for high-density server racks

Abstract

Embodiments of a cooling unit are disclosed herein. The cooling unit includes a unit inlet, an open-loop outlet, and a closed-loop outlet. A fluid bypass line having a first three-way valve and a second three-way valve is fluidly coupled to the unit inlet, and is fluidly coupled to the open-loop outlet and the closed-loop outlet through the second three-way valve. A main cooling circuit is fluidly coupled to the fluid bypass line. The main cooling circuit includes a heat exchanger having an inlet and an outlet. The inlet of the heat exchanger is fluidly coupled to the fluid bypass line through a supply line at or near the unit inlet, and the outlet of the heat exchanger is coupled to the fluid bypass line through a return line between the first three-way valve and the second three-way valve. A pump is fluidly connected in the return line, and a two-way line is fluidly coupled to the return line upstream of the first three-way valve and the pump. Different system circuit designs and operating modes are configured by adjusting the three-way valve and the two-way circuit.

Description

Technical Field

[0001] The disclosed embodiments relate generally to liquid cooling systems for temperature control of electronic equipment, and particularly, but not exclusively, to multi-circuit cooling configurations for high-density server racks. Background Art

[0002] Many modern information technology (IT) devices, such as servers, blade servers, routers, edge servers, etc., generate a lot of heat during operation. The heat generated by individual components, especially high-power components such as processors, makes many of these individual components impossible or difficult to cool effectively with air cooling systems. Therefore, modern IT equipment requires liquid cooling or liquid-air hybrid cooling.

[0003] Because of the need for liquid cooling, some IT equipment has on-board liquid cooling systems that are thermally coupled to the individual components that require cooling. However, these on-board liquid cooling systems are generally not able to operate independently. They are generally coupled to at least one larger cooling system, such as a liquid cooling system in an electronics rack, and the rack's cooling system may also be coupled to a liquid cooling system of a larger facility, such as a data center. In such a system, the data center's cooling system circulates a working fluid through the rack cooling system, which in turn circulates a working fluid through the cooling system on the IT equipment.

[0004] One challenge in designing data centers and data center racks is the mismatch between the life of the data center and the life of the IT equipment housed in the rack or data center. Data centers and their facilities, electrical systems, cooling systems, etc. change more slowly than the electronic equipment housed in the data center. In general, electronic devices change rapidly and become more customized, including their form factors, packaging methods, system designs, mechanical / thermal (air cooling and liquid cooling) / structural solutions. This rapid change leads to several related problems. For example, different operating conditions can result in different rack powers in different situations. Data center design and corresponding cooling and power availability may lag behind. For example, some data centers only provide cooling air, which may be insufficient considering the increase in power and heat loads generated and changes in cooling design in IT equipment. Summary of the invention

[0005] According to one aspect of the present application, a cooling unit is provided, which may include:

[0006] Unit inlet, open loop outlet and closed loop outlet;

[0007] a fluid bypass line having a first three-way valve and a second three-way valve coupled therein, wherein the fluid bypass line is fluidly coupled to the cell inlet and fluidly coupled to the open-loop outlet and the closed-loop outlet through the second three-way valve;

[0008] A main cooling circuit, fluidly coupled to the fluid bypass line, the main cooling circuit comprising:

[0009] a heat exchanger having an inlet and an outlet, the inlet of the heat exchanger being fluidly coupled to the fluid bypass line through a supply line at or near the unit inlet, and the outlet of the heat exchanger being coupled to the fluid bypass line through a return line between the first three-way valve and the second three-way valve;

[0010] a pump fluidly coupled in the return line; and

[0011] A two-way line is fluidly coupled to the first three-way valve and the return line upstream of the pump.

[0012] According to another aspect of the present application, a cooling system is provided, which may include:

[0013] An information technology (IT) container comprising a container inlet, a container outlet, and a container flow path, the container flow path being fluidly coupled between the container inlet and the container outlet for cooling heat generating components within the IT container, and the IT container comprising a closed-loop container inlet, the closed-loop container inlet being fluidly coupled to an inlet of the container flow path via a closed-loop flow path;

[0014] A cooling unit is fluidly coupled to the IT container, the cooling unit comprising:

[0015] Unit inlet, open loop outlet and closed loop outlet,

[0016] a fluid bypass line having a first three-way valve and a second three-way valve coupled therein, wherein the fluid bypass line is fluidly coupled to the unit inlet and is fluidly coupled to the open-loop outlet and the closed-loop outlet through the second three-way valve, and

[0017] A main cooling circuit, fluidly coupled to the fluid bypass line, the main cooling circuit comprising:

[0018] a heat exchanger having an inlet and an outlet, the inlet of the heat exchanger being fluidly coupled to the fluid bypass line through a supply line at or near the unit inlet, and the outlet of the heat exchanger being coupled to the fluid bypass line through a return line between the first three-way valve and the second three-way valve;

[0019] a pump fluidly coupled in the return line; and

[0020] a two-way line fluidly coupled to the first three-way valve and the return line upstream of the pump;

[0021] wherein the IT container is located downstream of the cooling unit, wherein the container inlet is fluidly connected to the open-loop outlet, or wherein the IT container is located upstream of the cooling unit, wherein the container outlet is fluidly connected to the unit inlet, and the closed-loop outlet is fluidly connected to the closed-loop container inlet.

[0022] According to another aspect of the present application, a method is provided, which may include:

[0023] The cooling unit is fluidly coupled to an upstream information technology (IT) container, a downstream IT container, or both the upstream IT container and the downstream IT container, wherein:

[0024] Each IT container includes a container inlet, a container outlet, and a container flow path, the container flow path being fluidly coupled between the container inlet and the container outlet for cooling heat generating components within the IT container, and the IT container includes a closed-loop container inlet, the closed-loop container inlet being fluidly coupled to an inlet of the container flow path via a flow path;

[0025] The cooling unit may include:

[0026] Unit inlet, open loop outlet and closed loop outlet,

[0027] a fluid bypass line having a first three-way valve and a second three-way valve coupled therein, wherein the fluid bypass line is fluidly coupled to the unit inlet and is fluidly coupled to the open-loop outlet and the closed-loop outlet through the second three-way valve, and

[0028] A main cooling circuit, fluidly coupled to the fluid bypass line, the main cooling circuit comprising:

[0029] a heat exchanger having an inlet and an outlet, the inlet of the heat exchanger being fluidly coupled to the fluid bypass line through a supply line at or near the unit inlet, and the outlet of the heat exchanger being coupled to the fluid bypass line through a return line between the first three-way valve and the second three-way valve;

[0030] a pump fluidly coupled in the return line; and

[0031] a two-way line fluidly coupled to the first three-way valve and the return line upstream of the pump;

[0032] wherein an inlet of a downstream IT container is fluidly coupled to said open-loop outlet, and wherein an outlet of an upstream IT container is fluidly coupled to said unit inlet, and a closed-loop container inlet of said upstream IT container is fluidly coupled to said closed-loop outlet;

[0033] The second three-way valve is configured to direct cooling fluid to the downstream IT container, the upstream IT container, or both the upstream IT container and the downstream IT container. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Non-limiting and non-exhaustive embodiments of the present invention are described with reference to the following figures, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified.

[0035] Figure 1 is a block diagram of one embodiment of an IT container including an electronics rack having electronic equipment and a cooling system housed therein.

[0036] Figure 2 is a block diagram of an embodiment of a cooling unit.

[0037] Figure 3 is a block diagram of another embodiment of a cooling unit.

[0038] Figure 4 is a block diagram of an embodiment of a system having a cooling unit coupled to an IT container.

[0039] Figure 5 is a block diagram of another embodiment of a system having a cooling unit coupled to a pair of IT containers.

[0040] 6A to 6F It is available Figure 5 A diagram of an embodiment of a flow path implemented by a cooling unit in a system embodiment.

[0041] FIG. 7A to FIG. 7B Together they are used to control Figure 5 Flow chart of an embodiment of a process of a cooling unit in an embodiment of a system. DETAILED DESCRIPTION

[0042] The following describes an embodiment of a multi-circuit cooling configuration for a high-density server rack. Specific details are described to provide an understanding of the embodiments, but a person skilled in the relevant art will recognize that the invention can be practiced without one or more of the described details or with other methods, components, materials, etc. In some cases, well-known structures, materials, or operations are not shown or described in detail, but are still included in the scope of the invention.

[0043] Reference throughout the specification to "one embodiment" or "an embodiment" means that the described features, structures, or characteristics may be included in at least one embodiment of the present invention, so that appearances of the phrases "in one embodiment" or "in an embodiment" do not necessarily all refer to the same embodiment. In addition, in one or more embodiments, the particular features, structures, or characteristics may be combined in any suitable manner.

[0044] Described below are implementations of high-level designs for servers and rack cabinets and their associated thermal management hardware. The described implementations provide a method for more efficiently deploying servers and IT equipment in a data center with little or no reliance on connectivity to the facility, thereby mitigating the impact of some of the design challenges discussed above.

[0045] Existing solutions do not provide the multi-loop configuration described below. In addition, the described embodiments may include the following advantageous features: overall architecture of hardware and IT cabinet combination design; multi-loop operation mode; use of multiple valves / three-way valves to configure loop control of different cooling loops; system layout mechanism; system modular design concept using core units; sensor system implementation and corresponding control design; and closed-loop and open-loop operation modes.

[0046] In the described embodiments, the IT enclosure is combined and / or assembled with the cooling hardware in the cooling unit to form a complete system, and the IT enclosure and the cooling unit can together achieve several cooling circuit configurations. The cooling hardware design enables the system to be controlled and configured in a closed loop or an open loop, and to switch between closed loop and open loop. The sensing system and system hardware devices enable the loop to operate at high efficiency, and enable switching between loops without significant impact on normal operation or with minimal impact on operation. The embodiments can be suitable for different types of IT enclosures and most data center systems. In addition, the embodiments can adapt to different IT containers, PoDs, and cluster requirements in a shared environment.

[0047] Figure 11 is a block diagram showing a side view of an embodiment of an electronics rack, which is a type of IT container commonly used in data centers. In one embodiment, the electronics rack 100 includes a CDU 101, a rack management unit (RMU) 102, and one or more blade servers 103A-103D, which are collectively referred to as blade servers 103. The blade servers 103 can be inserted into the server slot array from the front end 104 of the electronics rack 100, respectively. Note that although only four blade servers 103A-103D are shown, more or fewer blade servers can be maintained within the electronics rack 100. It should also be noted that the specific locations of the CDU 101, CMU 102, and blade servers 103 are shown only for illustrative purposes; other arrangements or configurations of the CDU 101, CMU 102, and blade servers 103 can also be implemented. In addition, the front door provided on the front end 104 and the rear door provided on the rear end 105 are optional. In some embodiments, there are no doors on the front end 104 and / or the back end 105 .

[0048] In one embodiment, the CDU 101 includes a heat exchanger 111, a liquid pump 112, and a pump controller 110. The heat exchanger 111 may be a liquid-to-liquid heat exchanger. The heat exchanger 111 includes a first tube having a first pair of liquid connectors coupled to external liquid supply / return lines 131-132 to form a main loop, wherein the connectors coupled to the external liquid supply / return lines 131-132 may be disposed or mounted on the rear end 105 of the electronic rack 100. In addition, the heat exchanger 111 also includes a second tube having a second pair of liquid connectors coupled to a liquid manifold 125, which may include a supply manifold and a return manifold, the supply manifold being used to supply cooling liquid to the blade servers 103, and the return manifold being used to return warmer liquid to the CDU 101. The processor may be mounted on a cold plate, wherein the cold plate includes a liquid distribution channel embedded therein to receive cooling liquid from the liquid manifold 125 and return cooling liquid carrying heat exchanged from the processor to the liquid manifold 125. Rack 100 is an example of an IT container, whose supply / return lines 131-132 can be fluidly coupled to a cooling unit of rack 100 (see Figure 2 wait).

[0049] Each blade server 103 may include one or more IT components (e.g., CPU, GPU, memory and / or storage device). Each IT component may perform data processing tasks, wherein the IT component may include software installed in a storage device, loaded into a memory and executed by one or more processors to perform data processing tasks. The blade server 103 may include a host server (referred to as a host node) connected to one or more computing servers (also referred to as computing nodes). The host server (having one or more CPUs) typically interacts with a client over a network (e.g., the Internet) to receive requests for specific services, such as storage services (e.g., cloud-based storage services such as backup and / or recovery), executing applications to perform certain operations (e.g., image processing, deep data learning algorithms or modeling, etc., as part of a service software or SaaS platform). In response to the request, the host server assigns the task to one or more of the computing servers (having one or more GPUs) managed by the host server. The computing server performs the actual task, which may generate heat during operation.

[0050] The electronics rack 100 also includes an RMU 102 configured to provide and manage power to the blade servers 103 and the CDU 101. The RMU 102 may be coupled to a power supply unit (not shown) to manage the power consumption of the power supply unit and other thermal management of the power supply unit (e.g., cooling fans). The power supply unit may include necessary circuitry (e.g., alternating current (AC) to direct current (DC) or DC to DC power converters, batteries, transformers or regulators, etc.) to provide power to the remaining components of the electronics rack 100.

[0051] In one embodiment, the RMU 102 includes an optimal control logic 111 and a rack management controller (RMC) 122. The optimal control logic 111 is connected to at least some of the blade servers 103 to receive the operating status of each of the blade servers 103, such as the processor temperature of the processor, the current pump speed of the liquid pump 112, and the liquid temperature of the coolant. Based on this information, the optimal control logic 111 determines the optimal pump speed of the liquid pump 112 by optimizing a predetermined objective function so that the output of the objective function reaches a maximum value while satisfying a set of predetermined constraints. Based on the optimal pump speed, the RMC 122 is configured to send a signal to the pump controller 110 to control the pump speed of the liquid pump 112 based on the optimal pump speed.

[0052] Figure 2 An embodiment of a cooling unit 200 that can be coupled to one or more IT containers to cool electronic devices within the containers is shown (see, e.g., Figures 4 to 5). The cooling unit 200 includes a housing 202 having a unit inlet 204 and two cooling outlets, the two cooling outlets being an open loop outlet 206 and a closed loop outlet 208. Within the cooling unit 200, a bypass line B fluidly couples the inlet 204 to a second three-way valve V2. Valve V2 in turn fluidly couples the bypass line B to the open loop outlet 206 and the closed loop outlet 208, so that valve V2 can be used to switch between an open loop and a closed loop configuration. A first three-way valve V1 is also fluidly coupled to the bypass line B between the inlet 204 and valve V2. Both three-way valves V1 and V2 have three fluid ports, numbered #1-#3 in the figure. In both three-way valves V1 and V2, fluid can be directed from any port to one or two of the other ports; when a three-way valve directs flow from one port to two other ports, the valve can also change the proportion of flow entering each output port. Additionally, in each valve V1 and V2, fluid flow from each port to the other port can be adjusted independently without affecting the other port, and in one operating mode, all three ports in the valve can be closed.

[0053] The cooling unit 200 also includes a main loop or cooling loop that is fluidly coupled to the bypass line B. The main loop includes a heat exchanger (HX) 210 having an inlet that is fluidly coupled to the bypass line B through a supply line S at or near the inlet 204. A return line R fluidly couples the outlet of the heat exchanger 210 to the bypass line B between the first valve V1 and the second valve V2; with this arrangement, the supply line S, the heat exchanger 210, the return line R, and a portion of the bypass line B form a main cooling loop. A pump 212 is fluidly coupled to the return line R to circulate the cooling fluid through at least a portion of the main loop and the bypass line. In the illustrated embodiment, the heat exchanger 210 also includes an external inlet and an external outlet. The external outlet may include a valve 211 to open and close the external outlet. In addition, the valve 211 may be used to adjust the flow rate. In another embodiment, a pump may be used to adjust the fluid flow rate. Both the external outlet and the external inlet can be coupled to a data center cooling system to supply cooling fluid to the heat exchanger 210, with the external inlet coupled to a facility supply source and the external outlet coupled to a facility return source. Other embodiments of the cooling unit 200 can be completely self-contained and do not require the use of an external inlet or an external outlet.

[0054] The two-way line 214 is fluidly coupled to the three-way valve V1 and to the return line R upstream of the pump 212. Fluid can flow through the two-way line 214 in both directions: from the return line R to the valve V1, or from the valve V1 to the return line R, depending on the operating mode of the unit. The bypass line B, together with the two-way line 214 and the three-way valve V1, is designed to address abnormal operating modes, thereby improving the robustness, maintainability and flexibility of the system. The two-way line 214, as well as the bypass line B, the supply line S and the return line R can all be made of flexible pipes, rigid pipes, or some combination of rigid and flexible pipes.

[0055] In addition to the flow hardware described above, the cooling unit 200 may include various sensors to monitor conditions within the unit. The cooling unit 200 includes a flow meter M1, a pressure sensor P1, and a temperature sensor T, although other embodiments may include additional or different sensors for measuring these or other quantities within the unit. In the illustrated embodiment, the flow meter M1 is positioned near the inlet 204, while the pressure sensor P1 and the temperature sensor T are positioned in the bypass line B downstream of the connection between the return line R and the bypass line, specifically, in this embodiment, between the fluid connection between the return line R and the bypass line B and the three-way valve V2. In other embodiments, the sensors may be positioned differently (see, e.g. Figure 3 ). Various sensors in the unit 200 are communicatively coupled to the control system 216, and the control system 216 is also communicatively coupled to flow hardware within the unit 200 that can be controlled during operation - in this embodiment, the flow hardware is the pump 212 and the three-way valves V1 and V2. The dashed lines in the figure show the signal connections between the sensors, the control system, and the flow hardware. Thus, in the illustrated embodiment, the control system 216 can change the speed of the pump 212 and the position of the three-way valves V1 and V2 based on inputs from the flow meter M1, the pressure sensor P1, and the temperature sensor T, as well as any additional or different sensors that may be present.

[0056] For ease and flexibility in product design, as well as system assembly, availability, and maintenance, in some embodiments, the components within the cooling unit 200 may be grouped into modules that can be manufactured and assembled separately. In the illustrated embodiment, the components are grouped into three modules, shown by the double dashed lines. Module 1 includes the heat exchanger 210, the flow meter M1, and associated fluid connections. Module 2 includes the pumping system and associated fluid connections, and module 3 includes the remaining components in the system and their associated fluid connections. In other embodiments, the components within the unit 200 may be modularized (i.e., grouped into modules) differently than shown (see, e.g., Figure 3 ).

[0057] In operation, the cooling unit 200 can be operated in a closed loop mode, an open loop mode, or a mixed closed loop / open loop mode, mainly depending on the setting of the three-way valve V2. Figures 4 to 5 The three-way valve V1 together with the two-way pipeline 214 is mainly used to adjust the internal operation of the cooling unit 200, as described below in conjunction with FIG. 7A to FIG. 7B described.

[0058] Figure 3 An embodiment of a cooling unit 300 that can be coupled to one or more IT containers is shown (see, e.g., Figures 4 to 5 ). Cooling unit 300 is similar to cooling unit 200 in most respects, with substantially the same components and the same variations in different embodiments. The main difference between cooling units 200 and 300 is that in unit 300, the components are positioned differently and are also modularized differently. In unit 300, instead of being located near inlet 204, flow meter M1 is connected to bypass line B between three-way valves V1 and V2, downstream of which return line R is fluidly connected to bypass line B (i.e., downstream of pump discharge). Positioning flow rate sensor M1 here allows the main control elements of unit 300 - sensors M1, P1 and T, three-way valves V1 and V2, and associated signal connections - to be combined together in module 3, rather than positioning flow meter M1 in module 1 as in unit 200. This modularization introduces more compact system packaging and integration methods for better and more efficient products and design methods. In addition to product design, this also provides other important benefits, such as for system integrators, component providers, and end users.

[0059] Figure 4 An embodiment of a system 400 is shown in which a cooling unit 404 is coupled to an information technology (IT) container 402. In the illustrated embodiment, the cooling unit 404 corresponds to Figure 2 Cooling unit 200 is shown, but other embodiments of system 400 may of course use cooling unit embodiments different than that shown.

[0060] IT container 402, as its name implies, houses IT components that generate heat, and includes container flow path 403, through which cooling fluid entering IT container 402 is transported to the heat generating components. Container flow path 403 can be understood as a cooling fluid management design for an IT container. Figure 1An embodiment of a container flow path 403 in a data center rack is shown, but other embodiments of the IT container 402 may have a container flow path different from that shown. The cooling unit 404 is not limited to any particular container flow path, but may be used with any flow path within the IT container 402. The container 402 also includes an inlet 406 and an outlet 408, and the container flow path 403 is fluidly coupled to both the inlet 406 and the outlet 408 via a fluid pipeline. The IT container 402 also includes another closed-loop container inlet 410, which is fluidly coupled between the closed-loop container inlet 410 and a location upstream of the container flow path 403, between the container inlet 406 and the container flow path inlet. The cooling unit 404 similarly includes an inlet 204 coupled to the bypass line B, and includes an outlet 412 fluidly coupled to the closed-loop outlet 208. The fluid lines within the IT container 402 may be made of rigid pipes, flexible pipes, or both, and may be pre-installed within the IT container to make it more modular.

[0061] The container 402 is located upstream of the cooling unit 404, with its container outlet 408 fluidly coupled to the unit inlet 204 and its closed-loop container inlet 410 fluidly coupled to the outlet 412. In one embodiment, at the container inlet 406, the fluid couplings between the container outlet 408 and the unit inlet 204, and between the outlet 412 and the closed-loop container inlet 410 may be achieved using quick disconnect fittings or blind-mate fittings, although other embodiments may of course use different fluid couplings.

[0062] In the configuration shown, the system 400 operates in a closed loop mode, where it cools the upstream IT container 402. When valve V2 directs fluid from port #1 to port #2, a closed loop is formed for the IT enclosure; when V2 directs fluid from port #1 to port #3, an open loop is formed that couples the unit to a larger recirculation system.

[0063] The cooling fluid enters the IT container 402 through the inlet 406, for example, from another cooling unit (not shown) located upstream. The cooling fluid flows through the container flow path 403, where the cooling fluid absorbs heat from the IT components and electronic equipment, and the now hot cooling fluid exits the IT container through the outlet 408. When exiting the outlet 408, the now hot cooling fluid enters the cooling unit 404 through the inlet 204 and flows into the heat exchanger 210 through the supply line S, where the fluid is cooled. After exiting the heat exchanger through the return line R and the pump 212 and the bypass line B, the now cooled fluid flows to the valve V2, which is configured to direct the fluid through port #2 into the closed loop outlet 208. The closed loop outlet 208 is fluidly coupled to the cooling unit outlet 412, so that the now cooled fluid flows through the closed loop outlet to the unit outlet 412. The fluid flows to the unit outlet 412 and is received into the IT container 402 through the inlet 410 and then directed back into the container flow path 403. Then, in this closed loop mode, the cooling unit 404 recirculates the cooling fluid to cool the upstream IT container 402. The fluid line connecting the inlet 410 and the container flow path 403 can be assembled separately, or considered as part of the container flow path 403. The function of this fluid line is similar to that of the closed loop outlet 208: completing the closed loop of the IT container and the cooling unit.

[0064] Figure 5 1 shows an embodiment of system 500. The figure shows how the system can be arranged in a cluster or data center. System 500 is similar to system 400 in most respects. The main difference between system 500 and 400 is that in system 500, cooling unit 404 is coupled to both upstream IT container 402 and downstream IT container 502. As in system 400, in system 500, cooling unit 404 corresponds to Figure 2 200 is shown in FIG. 4 , but other embodiments of system 400 may of course use cooling units different than those shown.

[0065] Both IT containers 402 and 502 house IT components that generate heat. Container 402 includes container flow path 403 that delivers cooling fluid that enters IT container 402 through container flow path 403 to its heat generating components, and similarly, container 502 includes container flow path 503 that delivers cooling fluid to its heat generating components through container flow path 503. As previously described, cooling unit 404 is not limited to any particular container flow path, but can be used with any container flow path. IT container 402 includes inlets 408 and 410 and outlet 408, as described above with respect to Figure 4IT container 502 similarly includes an inlet 504, an outlet 506, and a container flow path 503 fluidly coupled to both the inlet 504 and the outlet 506. IT container 502 also includes a closed-loop container inlet 508, which is fluidly coupled between the closed-loop container inlet 508 and a location upstream of the container flow path 503, between the inlet 504 and the inlet of the container flow path, via a closed-loop flow path 510. The fluid coupling within IT container 502 is the same as described above for IT container 402.

[0066] IT container 402 is located upstream of cooling unit 404 and is fluidly coupled to the cooling unit, as described above with respect to Figure 4 As described. On the other hand, IT container 502 is located downstream of cooling unit 404, and its inlet 504 is fluidly coupled to open-loop outlet 206. Outlet 506 and inlet 508 can be coupled to another cooling unit (not shown) downstream. In one embodiment, the fluid couplings between open-loop outlet 206 and inlet 504, between outlet 506 and any downstream device, and between inlet 508 and any downstream device can use quick disconnect fittings or blind-mate fittings, but of course other embodiments can use different fluid couplings.

[0067] In the configuration shown, the system 500 can operate in a closed loop mode, an open loop mode, or a combination of the two, depending on how the three-way valve V2 is set. If the three-way valve V2 only directs fluid into port #2, the system 500 operates in a closed loop mode to cool the upstream IT container 402, as described above for Figure 4As described. However, if the three-way valve V2 is set to direct flow into port #3, it operates in open-loop mode to cool the downstream IT container 502. In this case, when the system 500 operates in closed-loop mode, the IT container 402 and the cooling unit 404 may form one closed loop, while the IT container 502 and its downstream cooling unit may form another loop. When operating in open-loop mode, fluid reaching the three-way valve V2, whether it is uncooled fluid received through the bypass line B or cooled fluid traveling through the cooling circuit, which includes the supply line S, the heat exchanger 210, and the return line R, is directed to the open-loop outlet 206, which then directs the fluid into the inlet 504, through the container flow path 503, and through the outlet 506 to any device downstream of the IT container 502. If there is another cooling unit 404 downstream of the IT container 502, whether the inlet 508 receives any fluid will depend on whether the downstream cooling unit is operating in open-loop mode or closed-loop mode. If in cooling unit 404 , valve V2 is set to direct fluid partially into port # 2 and partially into port # 3 , cooling unit 404 may operate in a hybrid open-loop / closed-loop mode, where cooling unit 404 provides partial cooling for upstream IT container 402 and downstream IT container 502 .

[0068] 6A to 6F In simplified form, embodiments of flow paths that may be implemented by the cooling unit 200 or 300 when coupled to upstream and / or downstream IT containers are shown, for example, as shown in FIG. Figures 4 to 5 . In each figure, cooling unit 604 is fluidly coupled to upstream IT container 602 and downstream IT container 606. Downstream IT container 606 may be coupled to another cooling unit 608 and other further downstream IT containers and cooling units, and IT container 602 may be similarly coupled to upstream IT containers and cooling units. In each figure, flow paths are shown by dashed lines. For the following description, it is assumed that system 600 is configured similar to system 500, upstream IT container 602 is configured similar to IT container 402, and downstream IT container 606 is configured similar to IT container 502, and cooling unit 604 is configured similar to cooling unit 404. However, other embodiments may of course have other configurations.

[0069] FIG. 6A to FIG. 6C Open loop operation is shown. Fig. 6AAn open loop operation with cooling is shown. Fluid enters the upstream IT container 602 and flows through the container flow path into the cooling unit 604. Once inside the cooling unit 604, the fluid flows through the cooling circuit (e.g., through the supply line S, the heat exchanger 210, and the return line R), then flows out of the cooling unit 604 and into the downstream IT container 606. For example, this flow configuration can be achieved by closing all three ports of the three-way valve V1 and by setting the three-way valve V2 to direct all flow from port #1 through port #3 into the open loop outlet.

[0070] Figure 6B An open loop operation with cooling and bypass is shown. Fluid enters the upstream IT container 602 and flows through the container flow path into the cooling unit 604. Once inside the cooling unit 604, the fluid simultaneously flows through the bypass line B and through the cooling circuit (e.g., through the supply line S, the heat exchanger 210, and the return line R), then flows out of the cooling unit 604 and into the downstream IT container 606. For example, this flow configuration can be achieved by setting the ports of the three-way valve V1 to direct all flow from port #1 to port #3, while also setting the three-way valve V2 to direct all flow from port #1 through port #3 to the open loop outlet.

[0071] Figure 6C An open loop operation with bypass is shown. Fluid enters the upstream IT container 602 and flows through the container flow path into the cooling unit 604. Once inside the cooling unit 604, the fluid flows only through the bypass line B and then flows out of the cooling unit 604 and into the downstream IT container 606. For example, this flow configuration can be achieved by setting the ports of the three-way valve V1 to direct all flow from port #1 to port #3, setting the three-way valve V2 to direct all flow from port #1 through port #3 to the open loop outlet, and shutting off the pump 212.

[0072] FIG. 6D to FIG. 6E Closed loop operation is shown. Fig.6DAn open loop operation with cooling is shown. The fluid enters the upstream IT container 602 and flows through the container flow path into the cooling unit 604. Once inside the cooling unit 604, the fluid flows through the cooling circuit (e.g., through the supply line S, the heat exchanger 210, and the return line R), and then flows out of the cooling unit 604 and back to the upstream IT container 602, reconnecting the flow path upstream of the container flow path. Thus, this flow configuration establishes a loop and can be achieved, for example, by closing all three ports of the three-way valve V1 and by setting the three-way valve V2 to direct all flows from port #1 to a closed loop outlet through port #2. If in the cooling unit 604, the valve V2 is set to partially direct the fluid into port #2 and partially direct the fluid into port #3, the cooling unit 604 can operate in a hybrid open loop / closed loop mode, in which the cooling unit 604 provides partial cooling for both the upstream IT container 602 and the downstream IT container 608, as shown.

[0073] Fig. 6E A closed loop operation with cooling and bypass is shown. Fluid enters the upstream IT container 602 and flows through the container flow path into the cooling unit 604. Once inside the cooling unit 604, the fluid flows through the bypass line B and the cooling loop (e.g., through the supply line S, the heat exchanger 210, and the return line R) simultaneously, and then flows out of the cooling unit 604 and into the upstream IT container 602. For example, this flow configuration can be achieved by setting the ports of the three-way valve V1 to direct all flow from port #1 to port #3 (i.e., closing port #2), while also setting the three-way valve V2 to direct all flow from port #1 through port #2 (i.e., closing port #3) to the closed loop outlet. If in cooling unit 604, valve V2 is set to partially direct fluid into port #2 and partially direct fluid into port #3, cooling unit 604 can operate in a hybrid open-loop / closed-loop mode, in which cooling unit 604 provides partial cooling for both the upstream IT container 602 and the downstream IT container 608, as shown.

[0074] Fig. 6FA flow path is shown that can be used to completely bypass the cooling unit 604 and IT container 602. This may occur, for example, if the unit or certain components within the unit need to be repaired or replaced, and the components in the IT container 606 may be operating at a higher temperature during the repair or replacement, or the IT container is in use. Fluid enters the upstream IT container 602, but instead of entering the container flow path, the fluid flows into the closed loop outlet in the opposite direction of normal operation. The fluid flows through the closed loop outlet to three-way valve V2, where the fluid is directed into the IT container 606, thereby almost completely bypassing the cooling unit 604. For example, this flow configuration can be achieved by closing outlet 408 and setting three-way valve V2 to direct all flow entering the closed loop outlet at port #2 to the open loop outlet through port #3 (i.e., closing port #1).

[0075] FIG. 7A to FIG. 7B Together, they show that the control system 216 (see Figures 2 to 5 ) An embodiment of a process for controlling operation of a cooling unit in both an open loop mode and a closed loop mode is used. Fig. 7A shows the open loop mode, Figure 7B A closed loop mode is shown. The method is described with reference to cooling unit 200, but the method is also applicable to other cooling unit embodiments. The figures only show pure open loop or pure closed loop operation; hybrid open loop / closed loop operation is not explicitly discussed, but in one embodiment, hybrid open loop / closed loop operation will be a combination of the disclosed open loop and closed loop processes.

[0076] The process starts at box 702. At box 704, the process checks whether the system is ready for operation, that is, whether the control system 216 has been initialized, whether all sensors (M1, P1 and T) are operating properly, and whether all mechanical elements such as valves V1 and V2 and pump 212 are operating properly. If the system is not ready for operation at box 704, the process waits until the system is ready. However, if at box 704, the system is ready, the process moves to box 706. At box 706, the process determines whether the system operation is open loop or closed loop. If at box 706, the process determines that the operation will be open loop, it moves to the open loop process, starting with box 708 and including boxes 708-724.

[0077] At box 710, the process checks whether the pressure sensor P1 indicates an increase in pressure. This is to measure whether there are any upstream changes that affect the pressure. If at box 710, the process detects an increase in pressure, it means that there is a pressure pulse or otherwise increased pressure in the system. Generally, it is not desirable to propagate a pressure pulse downstream or increase a pressure pulse, so when the three-way valve V1 partially switches from port #1 to port #2 by increasing the opening ratio (i.e., by directing more fluid flow from port #1 to port #2), the process moves to box 712, which prevents the pressure increase from propagating downstream by directing some pressure to the closed loop outlet. In another embodiment, to address the increase in P1, V2 can be used by reducing the opening ratio of V2 from #1 to #2 (i.e., by directing less fluid flow from port #1 to port #2).

[0078] The process then moves to box 718 where it is checked whether the flow rate measured by flow meter M1 has decreased due to the adjustment of valve V1. If at box 718, the flow rate has not decreased, then at box 708, the process returns to the beginning of the open loop process. This is to ensure that the appropriate flow rates are maintained for the outlet and inlet. At box 710, an increase in flow rate will cause P1 to increase. However, if at box 718, the flow rate has decreased, then the process moves to box 720 where the three-way valve V1 is adjusted to increase the ratio of port #1 to port #3, i.e., the three-way valve V1 is adjusted to direct more flow from bypass line B to three-way valve V2 and less to bidirectional line 214, thereby attempting to increase the flow rate. The process then moves to box 722 where it is checked whether pump 212 is operating properly. If at box 722, the pump is operating properly, then the process returns to box 708. However, if at block 722 the pump is not operating correctly, meaning the pump is not able to deliver the desired flow rate, to compensate for the pump not being able to deliver the desired flow rate, the process moves to block 724 where three-way valve V1 fully opens ports #1 and #3, thereby directing all flow to three-way valve V2 for distribution into the downstream IT container 606 or closed loop outlet 208.

[0079] If at box 710 sensor P1 does not indicate an increase in pressure, the process moves to box 714 where it is checked whether the pressure is decreasing. If at box 714 there is no decrease in pressure (i.e., the pressure is stable because it is neither increasing at box 710 nor decreasing at box 714), the process returns to box 708. However, if at box 714 the pressure is decreasing, the process moves to box 716 where three-way valve V1 is adjusted to increase the ratio of fluid flowing from port #1 to port #2, i.e., V1 is adjusted to direct more fluid from port #1 to port #2, thereby directing more fluid to pump 212 where its pressure can be increased. The process then moves to box 718 and continues through boxes 720-724 as described above.

[0080] Figure 7B The closed loop operation of the system is shown. If in block 706 ( Fig. 7A ), the process determines that the system will operate in closed-loop mode, then in box 726, move to the start of the closed-loop process, in box 726, set the three-way valve V2 so that only ports #1 and #2 are open, thereby directing all fluid flow to the closed-loop outlet, and proceed to box 728.

[0081] At box 728, the process checks whether the pressure determined by sensor P1 has increased. If the pressure has increased at box 728, the process moves to box 730, where it checks whether the flow rate measured by flow rate sensor M1 has increased. If the flow rate has increased at box 730, the process moves to box 732, where the speed of pump 212 is reduced, and then returns to box 726. However, if the flow rate has not increased at box 730 (i.e., the pressure has increased but the flow rate has not increased at box 728), the process moves to box 736, where V1 is adjusted to reduce the opening ratio of port #1 to port #2, i.e., to direct more fluid from port #1 to port #2. The process then returns to box 726.

[0082] If there is no pressure increase at box 728, the process moves to box 738 where it is checked whether the pressure is decreasing rather than increasing. If there is no pressure decrease at box 738 (i.e., the pressure is stable because the pressure is neither increasing at box 728 nor decreasing at box 738), the process returns to box 726. However, if there is a pressure decrease at box 738, the process moves to box 740.

[0083] At block 740, the process determines whether the flow rate is decreasing. If at block 740, despite the pressure drop at block 738, there is no decrease in flow rate, the process moves to block 746, where the three-way valve V1 is adjusted to increase the flow rate ratio from port #1 to port #2 (i.e., increase the amount of fluid directed from port #1 to port #2) and / or the three-way valve V1 is adjusted to increase the flow rate ratio from port #1 to port #3 (i.e., increase the amount of fluid directed from port #1 to port #3). After V1 is adjusted at block 746, the process returns to block 726.

[0084] However, if at box 740, in addition to the pressure drop at box 738, the process determines that there is a reduction in flow rate at box 740, the process moves to box 742, where it is checked whether pump 212 is operating properly. If the pump is operating properly at box 742, the process moves to box 744, where the pump speed is increased, and then returns to box 726. However, if the pump is not operating properly at box 742, the process moves to box 748, where the three-way valve V1 is adjusted to open only ports #1 and #3, that is, V1 is adjusted to direct all flow from port #1 to port #3 and not to port #2. After valve V1 has been adjusted at box 748, the process returns to box 704.

[0085] In addition to the above embodiments, other embodiments of the cooling system are also possible. For example:

[0086] Cooling hardware system layout can be modularized and arranged in different ways.

[0087] Cooling hardware modules can be connected in different ways.

[0088] Additional sensors may be used in the system to add additional features.

[0089] The above description of embodiments is not intended to be exhaustive or to limit the invention to the form described. Specific embodiments and examples of the invention are described herein for purposes of illustration, but various modifications are possible.

Claims

1. A cooling unit, comprising: Unit inlet, open loop outlet and closed loop outlet; a fluid bypass line having a first three-way valve and a second three-way valve coupled therein, wherein the fluid bypass line is fluidly coupled to the cell inlet and fluidly coupled to the open-loop outlet and the closed-loop outlet through the second three-way valve; A main cooling circuit, fluidly coupled to the fluid bypass line, the main cooling circuit comprising: a heat exchanger having an inlet and an outlet, the inlet of the heat exchanger being fluidly coupled to the fluid bypass line through a supply line at or near the unit inlet, and the outlet of the heat exchanger being coupled to the fluid bypass line through a return line between the first three-way valve and the second three-way valve; a pump fluidly coupled in the return line; and A two-way line is fluidly coupled to the first three-way valve and the return line upstream of the pump.

2. The cooling unit according to claim 1, wherein: The heat exchanger also includes an external inlet coupled to a facility cooling fluid source and an external outlet fluidly coupled to a facility hot fluid return through a control valve. 3 . The cooling unit of claim 2 , further comprising a temperature sensor, a flow rate sensor, and a pressure sensor coupled to the bypass line.

4. The cooling unit of claim 3, further comprising a control system communicatively coupled to the flow rate sensor, the pressure sensor, and the temperature sensor, and further communicatively coupled to the control valve, the pump, the first three-way valve, and the second three-way valve.

5. The cooling unit according to claim 4, wherein: the flow rate sensor being located in the bypass line upstream of where the heat exchanger inlet is fluidly coupled to the bypass line; the pressure sensor being fluidly coupled to the bypass line between the second three-way valve and where the pump is fluidly coupled to the bypass line; The temperature sensor is fluidly coupled to the bypass line between the second three-way valve and where the pump is fluidly coupled to the bypass line.

6. The cooling unit according to claim 4, wherein: the flow rate sensor being located in the bypass line between the second three-way valve and where the pump is fluidly coupled to the bypass line; the pressure sensor being fluidly coupled to the bypass line between the second three-way valve and where the pump is fluidly coupled to the bypass line; The temperature sensor is fluidly coupled to the bypass line between the second three-way valve and where the pump is fluidly coupled to the bypass line.

7. A cooling system comprising: An information technology container comprising a container inlet, a container outlet, and a container flow path, the container flow path being fluidly coupled between the container inlet and the container outlet for cooling heat generating components within the information technology container, and the information technology container comprising a closed-loop container inlet, the closed-loop container inlet being fluidly coupled to an inlet of the container flow path via a closed-loop flow path; A cooling unit fluidly coupled to the information technology container, the cooling unit comprising: Unit inlet, open loop outlet and closed loop outlet, a fluid bypass line having a first three-way valve and a second three-way valve coupled therein, wherein the fluid bypass line is fluidly coupled to the unit inlet and is fluidly coupled to the open-loop outlet and the closed-loop outlet through the second three-way valve, and A main cooling circuit, fluidly coupled to the fluid bypass line, the main cooling circuit comprising: a heat exchanger having an inlet and an outlet, the inlet of the heat exchanger being fluidly coupled to the fluid bypass line through a supply line at or near the unit inlet, and the outlet of the heat exchanger being coupled to the fluid bypass line through a return line between the first three-way valve and the second three-way valve; a pump fluidly coupled in the return line; and a two-way line fluidly coupled to the first three-way valve and the return line upstream of the pump; wherein the information technology container is located downstream of the cooling unit, wherein the container inlet is coupled to the open-loop outlet fluid, or wherein the information technology container is located upstream of the cooling unit, wherein the container outlet is coupled to the unit inlet fluid, and the closed-loop outlet is coupled to the closed-loop container inlet fluid.

8. The cooling system according to claim 7, wherein: The heat exchanger also includes an external inlet coupled to a facility cooling fluid source and an external outlet fluidly coupled to a facility hot fluid return through a control valve. 9 . The cooling system of claim 8 , further comprising a temperature sensor, a flow rate sensor, and a pressure sensor coupled to the bypass line.

10. The cooling system of claim 9, further comprising a control system communicatively coupled to the flow rate sensor, the pressure sensor, and the temperature sensor, and further communicatively coupled to the control valve, the pump, the first three-way valve, and the second three-way valve.

11. The cooling system of claim 10, wherein: the flow rate sensor being located in the bypass line upstream of where the heat exchanger inlet is fluidly coupled to the bypass line; the pressure sensor being fluidly coupled to the bypass line between the second three-way valve and where the pump is fluidly coupled to the bypass line; The temperature sensor is fluidly coupled to the bypass line between the second three-way valve and where the pump is fluidly coupled to the bypass line.

12. The cooling system of claim 10, wherein: the flow rate sensor being located in the bypass line between the second three-way valve and where the pump is fluidly coupled to the bypass line; the pressure sensor being fluidly coupled to the bypass line between the second three-way valve and where the pump is fluidly coupled to the bypass line; as well as The temperature sensor is fluidly coupled to the bypass line between the second three-way valve and where the pump is fluidly coupled to the bypass line.

13. The cooling system according to claim 7, wherein: In the information technology container, the closed-loop container inlet and the closed-loop flow path are bidirectional.

14. The cooling system according to claim 13, wherein: The closed-loop outlet is bi-directional such that when operated in one direction with the closed-loop container inlet and the closed-loop flow path, the closed-loop outlet functions as part of a closed loop, and when operated in another direction with the closed-loop container inlet and the closed-loop flow path, the closed-loop outlet functions as a bypass to bypass the information technology container and the cooling unit.

15. A cooling method comprising: A cooling unit is fluidly coupled to an upstream information technology container, a downstream information technology container, or both the upstream information technology container and the downstream information technology container, wherein: Each information technology container includes a container inlet, a container outlet, and a container flow path, the container flow path being fluidly coupled between the container inlet and the container outlet for cooling heat generating components within the information technology container, and the information technology container includes a closed-loop container inlet, the closed-loop container inlet being fluidly coupled to an inlet of the container flow path via a closed-loop flow path; The cooling unit comprises: Unit inlet, open loop outlet and closed loop outlet, a fluid bypass line having a first three-way valve and a second three-way valve coupled therein, wherein the fluid bypass line is fluidly coupled to the unit inlet and is fluidly coupled to the open-loop outlet and the closed-loop outlet through the second three-way valve, and A main cooling circuit, fluidly coupled to the fluid bypass line, the main cooling circuit comprising: a heat exchanger having an inlet and an outlet, the inlet of the heat exchanger being fluidly coupled to the fluid bypass line through a supply line at or near the unit inlet, and the outlet of the heat exchanger being coupled to the fluid bypass line through a return line between the first three-way valve and the second three-way valve; a pump fluidly coupled in the return line; and a two-way line fluidly coupled to the first three-way valve and the return line upstream of the pump; wherein the inlet of the downstream information technology container is fluidly coupled to the open loop outlet, and wherein the outlet of the upstream information technology container is fluidly coupled to the cell inlet, and wherein the closed loop container inlet of the upstream information technology container is fluidly coupled to the closed loop outlet; The second three-way valve is configured to direct cooling fluid to the downstream information technology container, the upstream information technology container, or both the upstream information technology container and the downstream information technology container.

16. The cooling method of claim 15, further comprising regulating operation of the cooling unit using the first three-way valve.

17. The cooling method of claim 15, further comprising a control system communicatively coupled to a flow rate sensor, a pressure sensor, and a temperature sensor, and further communicatively coupled to the pump, the first three-way valve, and the second three-way valve.

18. The cooling method of claim 17, further comprising regulating a flow path within the cooling unit using the control system, the first three-way valve, the second three-way valve, and the pump.

19. The cooling method according to claim 18, wherein: The flow path within the cooling unit includes the bypass line, the main cooling circuit, or both the bypass line and the main cooling circuit.

20. The cooling method according to claim 18, wherein: The closed loop flow path in the IT container, the closed loop container inlet, and the closed loop outlet and the closed loop flow path in the cooling unit are bidirectional and further comprises bypassing the cooling unit by: reversing flow through the closed-loop flow path, the closed-loop vessel inlet, and the closed-loop outlet; and The second three-way valve is arranged to direct fluid received through the closed-loop outlet only into the open-loop outlet.

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