Two-Phase System Design Based on High Power Density

Abstract

A cooling system can include an input channel through which fluid enters the cooling system and an output channel through which fluid exits the cooling system. The cooling system can include a vapor buffer and a liquid buffer, as well as a connection between the two buffers. A vapor buffer valve disposed in the fluid channel of the cooling system can be controlled to: disconnect the vapor buffer from the input channel in a first mode, and connect the vapor buffer to the input channel and disconnect the vapor buffer from the input end of the condenser or a port capable of being attached to the input end of the condenser in a second mode.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to cooling systems for data centers or information technology (IT) equipment. The cooling system may utilize the phase change of a fluid for cooling. Background Art

[0002] Information technology (IT) includes technologies such as computers that can be accessed via the Internet or a local network, which provide storage or access to data, websites, computer programs, etc. The thermal environment required to maintain various IT devices (e.g., servers, power supplies, etc.) is crucial. For high power density racks, the management of thermal requirements may be particularly important and challenging because, if not properly cooled, an unacceptable amount of thermal energy can accumulate in a short period of time and damage the system.

[0003] In a two-phase cooling system, a cooling fluid changes its phase (e.g., from liquid to vapor or from vapor to liquid) to extract latent heat energy from a heat energy source (e.g., IT equipment). Using a two-phase cooling system can be efficient; however, due to the nature of the phase change, the control of such a cooling system can be critical and challenging. Temperature is a poor feedback parameter because a change in latent heat energy does not necessarily change the temperature. In addition, changes such as the workload of IT equipment and / or the condenser capacity can significantly affect the evaporation and condensation rates of the cooling fluid. Both the pressure and flow rate of the cooling fluid are difficult to measure and use as control parameters.

[0004] The variation in thermal load can be different among IT devices. In addition, the same IT device can also have a varying thermal load depending on the time of day, the active services being executed, etc. Therefore, there is a need for a cooling system that can cope with large variations in cooling demand, e.g., a single cooling system that can be adjusted between a large heat transfer load and a small heat transfer load.

[0005] In addition, considering the nature of the phase change process, the efficient use of the condenser may be important. The amount of vaporized fluid can vary according to the workload; however, the condenser should be able to condense the vaporized cooling fluid at a higher load. In addition, abnormal situations may also occur in the IT environment.

[0006] Some existing cooling systems may not be able to support large variations in evaporation and condensation in an efficient manner, especially in high density applications that may have a high thermal load. A significant change in power density can lead to complex changes in vapor generation rate (evaporation), condensation, liquid return, and liquid demand. Summary of the Invention

[0007] An embodiment of the present invention provides a cooling system, comprising: an input channel and an output channel, a fluid enters the cooling system from the input channel, and the fluid leaves the cooling system from the output channel; a vapor buffer; a liquid buffer, the liquid buffer is connected to the input channel and the output end of the condenser or a port capable of being attached to the output end of the condenser; and a plurality of vapor buffer valves, the plurality of vapor buffer valves are arranged in one or more fluid channels, the one or more fluid channels are located between the vapor buffer and the input channel, and between the vapor buffer and the input end of the condenser or a port capable of being attached to the input end of the condenser, the plurality of vapor buffer valves are controlled to disconnect the vapor buffer from the input channel in a first mode, and to connect the vapor buffer to the input channel and disconnect the vapor buffer from the input end of the condenser or the port capable of being attached to the input end of the condenser in a second mode.

[0008] An embodiment of the present invention further provides an electronic rack of a data center, comprising: a plurality of information technology (IT) devices; and a cooling system, the cooling system is coupled to the IT devices to provide cooling to the IT devices. Wherein, the cooling system comprises: an input channel and an output channel, a fluid enters the cooling system from the input channel, and the fluid leaves the cooling system from the output channel; a vapor buffer; a liquid buffer, the liquid buffer is connected to the input channel and the output end of the condenser or a port capable of being attached to the output end of the condenser; and a plurality of vapor buffer valves, the plurality of vapor buffer valves are arranged in a fluid channel, the fluid channel is located between the vapor buffer and the input channel, and between the vapor buffer and the input end of the condenser or a port capable of being attached to the input end of the condenser, the plurality of vapor buffer valves are controlled to disconnect the vapor buffer from the input channel in a first mode, and to connect the vapor buffer to the input channel and disconnect the vapor buffer from the input end of the condenser or the port capable of being attached to the input end of the condenser in a second mode.

[0009] An embodiment of the present invention further provides a data center, including: a plurality of electronic racks, each electronic rack including one or more information technology (IT) devices; and a cooling system coupled to at least one of the electronic racks to provide cooling to the electronic racks. Wherein, the cooling system includes: an input channel and an output channel, fluid enters the cooling system from the input channel, and the fluid leaves the cooling system from the output channel; a vapor buffer; a liquid buffer connected to the input channel and the output end of the condenser or a port capable of being attached to the output end of the condenser; and a plurality of vapor buffer valves arranged in a fluid channel located between the vapor buffer and the input channel, and between the vapor buffer and the input end of the condenser or a port capable of being attached to the input end of the condenser, the plurality of vapor buffer valves being controlled to disconnect the vapor buffer from the input channel in a first mode, and connect the vapor buffer to the input channel and disconnect the vapor buffer from the input end of the condenser or the port capable of being attached to the input end of the condenser in a second mode. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In the figures of the drawings, aspects are shown by way of example and not by way of limitation, in which like reference numerals indicate like elements. It should be noted that a reference to "one" or "an" aspect of the present disclosure does not necessarily refer to the same aspect, and they mean at least one aspect. Additionally, for the sake of brevity and reducing the total number of figures, a given figure may be used to illustrate features of more than one aspect, and not all elements in the figure are necessary for a given aspect.

[0011] Figure 1 An example cooling system according to some embodiments is shown.

[0012] Figure 2 An example cooling system operating in a normal mode according to some embodiments is shown.

[0013] Figure 3 An example cooling system operating in a vapor buffer mode according to some embodiments is shown.

[0014] Figure 4 An example cooling system operating in a vapor discharge mode according to some embodiments is shown.

[0015] Figure 5 and Figure 6 An example of one or more cooling systems according to some embodiments is shown, the one or more cooling systems being arranged with IT racks in an open-loop arrangement.

[0016] Figure 7 FIG. Figure 7 shows an example of a cooling system according to some embodiments, the cooling system being arranged with an IT rack in a closed-loop arrangement.

[0017] Figure 8 FIG. Figure 8 shows an example of a cooling system connected to an external condenser according to some embodiments.

[0018] Figure 9 FIG. Figure 9 shows an example of an IT rack having a cooling system according to some embodiments. DETAILED DESCRIPTION

[0019] Several aspects of the present disclosure will now be explained with reference to the accompanying drawings. As long as the shape, relative position, and other aspects of the parts described in a given aspect are not explicitly defined, the scope disclosed herein is not limited solely to the parts shown, which are merely for illustrative purposes. Additionally, although many details are set forth, it should be understood that some aspects may be practiced without these details. In other instances, well-known circuits, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification. Further, unless the meaning is clearly contrary, all ranges set forth herein are considered to include the endpoints of each range.

[0020] References in the specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present disclosure. The phrase "in one embodiment" appearing in different places in the specification does not necessarily refer to the same embodiment.

[0021] As described, there are some problems with two-phase cooling systems that can be improved. A complete architecture design of the cooling system can be implemented for deploying a two-phase cooling solution for high-density racks for high-performance computing (HPC) workloads and artificial intelligence (AI) workloads.

[0022] The cooling system can have a multi-buffer system including a vapor buffer and a liquid buffer. The full-system buffer design accommodates variations in power load and cooling capacity, as well as variations caused by abnormal operating conditions. In some embodiments, the cooling system is integrated with the architecture of an IT facility (e.g., an IT room). The cooling system can include multiple operable loops of a cooling fluid and / or separation of a two-phase coolant to improve system efficiency.

[0023] In some embodiments of the present disclosure, the cooling system includes two buffer units for cooling a high power density rack. The first buffer unit is a vapor buffer, while the second buffer unit is a liquid buffer. These two buffer units are used to store and buffer changes in the evaporation and condensation rates of the cooling fluid, especially when they are unbalanced (e.g., one is greater than the other). The operation of the buffer units in the cooling system constrains the liquid supply and return of the system to remain at ideal parameters, even in the case of changes in the power generation of IT equipment and the external cooling capacity of different condensers.

[0024] The connection and design of the fluid channels connecting the components of the cooling system enable the two-phase fluid to operate efficiently. The fluid is either directed to the load (in liquid form) or to the condenser (in vapor form). The unit can be integrated with the IT rack in a closed-loop or open-loop manner to adapt to different data center facility-level architectures.

[0025] In some embodiments, the cooling system includes an input channel through which fluid enters the cooling system and an output channel through which fluid exits the cooling system. The system fluidly includes a vapor buffer and a liquid buffer. The liquid buffer is connected to i) the input channel, and ii) the output end of the condenser (or, in the case where the condenser is external to the cooling system, a port capable of being attached to the output end of the condenser). A plurality of vapor buffer valves are arranged in the fluid channels located between i1) the vapor buffer and the input channel, and ii1) the vapor buffer and the input end of the condenser (or, in the case where the condenser is external to the cooling system, a port capable of being attached to the input end of the condenser).

[0026] The plurality of vapor buffer valves can be controlled to i2) fluidly disconnect the vapor buffer from the input channel in a first mode, and ii2) connect the vapor buffer to the input channel and disconnect the vapor buffer from the input end of the condenser or a port capable of being attached to the input end of the condenser in a second mode.

[0027] In this way, under normal operation, the fluid can be separated into a liquid loop and a vapor loop. Depending on the current heat load and / or the condensation capacity of the condenser, the system can operate in different modes to direct vapor to the vapor buffer when needed. In some embodiments, the system can operate in two modes (normal mode and vapor buffer mode), while in other embodiments, the system can operate in three modes (normal mode, vapor buffer mode, and vapor discharge mode).

[0028] In the case where the system operates in two modes, the first mode is the normal mode and also the vapor buffer discharge mode, in which the vapor buffer does not absorb any vapor but can discharge vapor to the condenser. In the second mode, which is the vapor buffer mode, the vapor buffer absorbs vapor but does not discharge vapor to the condenser.

[0029] In the case where the system operates in three modes, in the first mode, which is the normal mode, the vapor buffer is isolated from the input channel and the condenser. In the second mode, which is the vapor buffer mode, the vapor buffer is filled with vapor. In the third mode, which is the vapor buffer discharge mode, the vapor buffer discharges vapor into the condenser but does not absorb vapor.

[0030] Figure 1 A cooling system 100 according to some embodiments is shown. The cooling system can be encapsulated within a housing 141 to share a common portable body. The system includes a vapor buffer 112 and a liquid buffer 114. The vapor buffer can be a chamber for holding vapor. Similarly, the liquid buffer can be a chamber for holding liquid. Either buffer can have various three-dimensional shapes, such as, for example, bean-shaped, spherical, cubic, or rectangular parallelepiped-shaped. The volume of the buffer can vary according to the application but should have sufficient capacity to provide buffering for the system, e.g., hold more fluid than standard conduit and plumbing fitting components. In some embodiments, the capacity of the liquid buffer and / or the vapor buffer is greater than 1 liter (L), 2L, 5L, 10L, or 100L. In some embodiments, the buffer is an enclosed box rather than a standard plumbing fitting or tube.

[0031] Two-phase fluid enters the cooling system through an input channel 101. In some embodiments, an input valve 120 is located in the input channel such that it is in line with the input channel and can allow or block fluid flow through the input channel. The input valve 120 can be open under normal operating conditions and closed under maintenance or fault conditions. The valve state (open or closed) can be manual and / or controlled by a controller.

[0032] At the input channel, the fluid is part liquid and part vapor. Fluid channels such as 107, 103, and 102 separate the fluid and direct the fluid to separate components. The liquid travels through the liquid section 107 of the fluid channel to the liquid buffer 114, and the liquid section 107 directly fluid-connects the input channel to the liquid buffer 114. The fluid channel can be inclined downward relative to gravity (e.g., straight down as shown, or at an angle). The liquid section can be valve-less such that the liquid buffer is always operational and receives liquid from the input channel as the liquid is pumped from the liquid buffer to the load.

[0033] The vaporized fluid (vapor) can rise directly to the condenser through the vapor section 102 of the fluid channel. The vapor section 102 of the fluid channel can extend upward (e.g., vertically or inclined) from the input channel to receive vapor rather than liquid, thus separating the vapor from the liquid. In addition, the vapor can travel through the vapor buffer section 103 of the fluid channel to the vapor buffer 112. The vapor buffer section can also extend upward from the input channel (e.g., vertically or inclined) to facilitate the separation of vapor and liquid. The input channel can be horizontal or flat (e.g., substantially perpendicular to gravity). A valve 121 can be arranged in section 103 to allow or block the vapor flow to the vapor buffer 112. In the figure, the dashed line shows the mixing of vapor and fluid, the dash line shows the vapor flow, and the solid line shows the liquid flow. In some embodiments, the input end 132 of the vapor buffer is located below the output end 131 of the vapor buffer to facilitate the circulation of vapor from the vapor input channel into the vapor buffer and out of the vapor buffer into the condenser.

[0034] The vapor can flow from the vapor buffer to the condenser 110, thus discharging the buffered vapor through the second vapor buffer section 104 that connects the vapor buffer to the input end of the condenser (or, when the condenser is outside the cooling system, a port capable of being attached to the input end of the condenser). The inflow through this second vapor buffer section can be controlled by the vapor buffer discharge valve 122.

[0035] The fluid in liquid form flows through the buffer channel 106 that fluidly connects the vapor buffer 112 to the liquid buffer 114. In this way, the liquid inadvertently accumulated in the vapor buffer can be discharged into the liquid buffer. In some embodiments, a buffer valve 124 is located in the buffer channel to regulate the flow between the vapor buffer and the liquid buffer. In some embodiments, the valve remains open during normal operation and closes when the vapor in the vapor buffer reaches a threshold such that there is a risk of the vapor flowing downward into the liquid buffer. In some embodiments, the buffer channel does not include a valve.

[0036] The liquid buffer is fluidly connected to the output end of the condenser (or a port capable of being attached to the output end of the condenser) through the condenser output channel 105. A valve 123 can be located in the output channel 105 to regulate the fluid flow from the condenser to the liquid buffer. The fluid has been condensed by the condenser at this time, such that it is in liquid form. In some embodiments, a pump 130 is connected to the output channel 108. The pump draws the fluid out of the liquid buffer to leave the cooling system through the output channel. Thus, a pump can be used on the liquid supply side to pump the liquid fluid to the load.

[0037] It should be understood that in some embodiments, the cooling system shows a representation of the relative positions of components with respect to gravity. The liquid buffer can be located below the vapor buffer and the input channel to facilitate the separation of fluids and receive the fluid in liquid form from the input channel. The vapor buffer can be located above the liquid buffer and is connected to the input channel through an ascending and / or inclined fluid channel (e.g., section 103) to facilitate the separation of fluids and receive the fluid in vapor form. The ascending and / or inclined fluid section 102 can direct the fluid in vapor form to the condenser 110, which is also at least partially above the input channel and the liquid buffer. The annular section 104 can also be implemented as an inclined channel. The channels 106 and 105 connect the vapor buffer and the condenser to the liquid buffer with a downward and / or inclined fluid channel respectively to facilitate the separation of liquid from the fluid in the vapor buffer and the condenser and bring the liquid from the condenser and the vapor buffer into the liquid buffer. Thus, the system components are arranged and interconnected to facilitate the natural separation and re - fusion of fluids in vapor and liquid forms by utilizing gravity.

[0038] Figure 2 The normal operating mode of the cooling system according to some embodiments is shown. The thick black solid lines with arrows show which fluid channels are operating and the flow of fluid through the cooling system. In this normal mode, the vapor travels directly upward to the condenser and the liquid falls into the liquid buffer. The liquid - state fluid is contained in the liquid buffer and the pump 130 can be used to pump the fluid out of the buffer unit to a load (e.g., an IT rack). In this normal mode, the valve 121 is closed to prevent the vapor flow to the vapor buffer. This is because the condenser is considered capable of condensing the amount of vapor currently received by the cooling system. If any vapor is stored in the vapor buffer 112, the valve 122 can be closed to prevent the vapor from flowing from the vapor buffer to the condenser. Additionally, unless otherwise stated, the valves 120 and 123 are in the open position (in different modes) to allow fluid to enter the cooling system and let the liquid flow from the condenser to the liquid buffer. Further, in some embodiments (e.g., in the case where the system operates in two modes), the valve 122 can be open in the normal mode to discharge vapor from the vapor buffer, or when the vapor is completely discharged from the vapor buffer, the valve 121 is closed. This can simplify the operation such that the system operates in two modes instead of three modes.

[0039] Figure 3A system in vapor buffer mode is shown, where vapor is partially directed into a vapor buffer and stored in a buffer unit. In response to an imbalance in fluid evaporation and condensation, the vapor buffer participates in the cooling process. This imbalance can be determined based on changes in the cooling capacity of the condenser and / or heat generation in the load. In vapor buffer mode, the vaporized fluid enters both the condenser and the vapor buffer. The vapor buffer stores some of the vapor in the cooling system to compensate for the condenser's inability to condense all of the vaporized fluid entering the cooling system through the input channel. In this mode, valve 121 is opened to allow vapor to flow into the vapor buffer. Valve 122 is closed to isolate the vapor buffer from the condenser. It should be noted that in the context of the connections between the condenser, vapor buffer, liquid buffer, and other system components, the terms "connected" and "disconnected" refer to the connection and isolation of the cooling fluid used by the cooling system.

[0040] Figure 4 The vapor discharge mode in some embodiments is shown. The vapor stored in the vapor buffer is released to the condenser. The condenser condenses the vaporized fluid into liquid form. In this mode, valve 121 is closed to prevent vapor from entering the buffer from the input channel. Valve 122 is opened to allow the vapor stored in the vapor buffer to rise to the condenser. Thus, when the condenser capacity is considered to be greater than the current vapor load, the system can discharge vapor to better utilize the condenser.

[0041] Therefore, based on the buffer and discharge modes of the cooling system, it can be seen that the cooling system uses a buffer to improve the utilization rate of the condenser. A smaller condenser can handle a larger heat load because when the heat load evaporates more fluid than the condenser can handle, the vapor is buffered. When the heat load decreases or the cooling capacity increases, the buffered vapor can be directed to the condenser and condensed by the condenser. The liquid buffer accommodates changes in the liquid returning from the condenser and provides a discharge point for the vapor buffer to drain any liquid inadvertently collected in the vapor buffer into the liquid buffer.

[0042] In some embodiments, when a) the evaporation rate of the fluid (e.g., in the input channel) and / or b) the condensation rate of the fluid do not meet a threshold, multiple vapor buffer valves are controlled to be in a normal mode (e.g., a first mode). In some embodiments, the threshold can be based on the evaporation rate of the fluid and / or the condensation capacity of the condenser. For example, the threshold can be the ratio or difference between the evaporation rate of the fluid and the condensation rate of the condenser.

[0043] In some embodiments, when the evaporation rate of the fluid exceeds the condensation rate of the condenser, a threshold can be met, which can be expressed mathematically as, for example, evaporation rate / condensation rate. Thus, in this example, when the condensation capacity of the condenser is greater than the evaporation rate of the fluid, the threshold is not met, and multiple vapor buffer valves are controlled to place the cooling system in the normal mode. In some embodiments, the threshold can be a range “a”, e.g., (evaporation rate ± a / 2) / condensation rate.

[0044] When a) the evaporation rate of the fluid in the input channel and / or b) the condensation rate of the fluid meets the threshold, multiple vapor buffer valves (e.g., valves 121 and 122) are controlled to be in the vapor buffer mode (e.g., the second mode). This threshold can be the same as the threshold used in the normal mode or a different threshold.

[0045] The evaporation rate of the fluid can be determined based on one or more sensed pressures in the fluid channels. Pressure sensors located in the input channel of the cooling system and / or other fluid channels can be used to sense the pressure in the fluid channels, and the evaporation rate of the fluid can be derived from this pressure by known means (e.g., through a look-up table and / or a mathematical formula that correlates pressure with evaporation rate). The cooling system can measure one or more pressures because changes in the evaporation rate and condensation rate affect the static pressure in a given channel. The derivation of the evaporation rate and / or condensation rate can be based on one or more calculations that are based on system specifications and / or collected test data, where the collected test data correlates pressure with evaporation rate and / or condensation rate under different conditions. These calculations and test data can be determined based on tests and experiments. In some aspects, one or more reference values representing one or more thresholds can be preset in the system.

[0046] In some embodiments, as Figures 1 to 4 shown, the controller 140 can control the states of the valves (e.g., valves 120, 121, 122, 123, and 124). These valves can have motors, solenoids, or other known actuation mechanisms that can be commanded by the controller to open, close, or open / close partially.

[0047] In some embodiments, the controller can include a computer configured to perform logical operations to open and close the valves. Alternatively or additionally, the controller can include analog and digital electronic circuits that can perform logical operations. The controller can receive sensed inputs from which the evaporation rate and condensation rate of the fluid can be derived. The controller can then determine whether one or more thresholds are met such that the controller can command the valves to open or close according to the mode, as described above. The control of the valves can be performed by commands transmitted from the controller to each valve via an electrical signal (e.g., the output of the controller) and / or a known communication protocol (e.g., RS232, CAN bus, ModBus, etc.).

[0048] Figure 5 Illustrates how in some embodiments a cooling system can be connected to other IT devices such as a host IT rack 502 and a downstream IT rack 503. The input channel of the cooling system can be connected to the output of the host IT rack. The fluid received from the host IT rack can be in both liquid and vapor forms as the fluid has extracted thermal energy from the host IT rack. The cooling system can cool the fluid in normal mode, vapor buffer mode, or vapor discharge mode as described in other sections. The vapor condenses into liquid and then cycles out to the downstream IT rack (which is separate from the host IT rack). In this way, the first IT rack is fluidly connected to the input channel of the cooling system, and the second IT rack is fluidly connected to the output channel of the same cooling system. This IT rack to cooling system to IT rack to cooling system approach can be repeated to create a chain of serially connected IT racks and cooling systems. This configuration can be described as an open-loop configuration.

[0049] For example, Figure 6 Shows a side view of IT racks and cooling systems connected in an open-loop configuration. A cooling fluid loop is used to distribute external cooling fluid to the condensers of each cooling system. The fluid of IT rack A (which can be a mixture of liquid and vapor) is directed to cooling system A. The cooling system cools the fluid and directs the fluid in liquid form and directs the fluid to IT rack B. The fluid extracts thermal energy from IT rack B and, in the process, some of the fluid can vaporize. The fluid then is directed along the chain to cooling system B, and so on. It should be understood that in some embodiments, the "open-loop" configuration can form a complete loop. For example, the output channel of cooling system D can be connected to the inlet of IT rack A, although not shown in the figure.

[0050] Alternatively, as Figure 7 shown, each cooling system can be connected to a dedicated IT device. In this case, the same IT rack is fluidly connected to the input channel and the output channel of the cooling system. The IT room can have multiple cooling systems connected to various other IT devices. It should be understood that the arrangement of the IT racks as well as each cooling system can vary according to the application, including a mix of open-loop and closed-loop connections. The cooling system can be integrated into the rack as part of the rack or be a partial unit of the rack. Some drawings may show the cooling system having a larger footprint and form factor than the IT rack for illustrative purposes only.

[0051] In some embodiments, as Figure 8As shown, the condenser unit is separated from the cooling system and can be described as being integrated with the cooling facility unit. In this embodiment, the input channel, the vapor buffer, the liquid buffer, the plurality of vapor buffer valves, port 602 that can be attached to the output port of the condenser, and port 603 that can be attached to the input port of the condenser are housed in or on the common housing 601 of the cooling system. The condenser is located outside the cooling system and its housing. In such an arrangement, the cooling system can be located on the IT cluster side, and the condenser unit can be implemented on the cooling facility side. The IT cluster side can be understood as being integrated within the housing 601, which is located near the rack, as Figure 5 shown. The cooling facility side can refer to the top section above the housing.

[0052] In Figure 8 , the condensation unit (condenser) is located above the housing in the cooling facility section. In such a design, the two-phase fluid will pass through both the IT cluster and the facility side. In an embodiment where the condenser is encapsulated in the housing, the two-phase fluid will only recirculate within the IT cluster, and the external fluid will pass through both the facility side and the IT cluster because the condenser is in the housing. In the cooling facility side, the architecture is simple. The cooling fluid can be used as an external cooling source to cool the fluid passing through the condenser. The external fluid and the cooling fluid can be isolated within the condenser. Connection lines such as ducts and / or hoses can be used to connect the condenser to ports 603 and 602 of the cooling system, thereby supplying a vapor stream to the condenser and providing a liquid stream from the condenser to the liquid buffer. In some embodiments, the cooling unit including the condenser can be one module, and the IT cluster can be a separate module.

[0053] Figure 9 is a block diagram showing an example of an IT rack with an integrated cooling system according to some embodiments. However, it should be understood that different variations can be implemented. The IT rack 900 can include one or more servers, each server having one or more processing units attached to the bottom of any of the above-described cooling devices. The rack 900 includes, but is not limited to, a cooling system 901, a rack management unit (RMU) 902 (optional), and one or more server blades 903A - 903D (collectively referred to as server blades 903). The cooling system 901 can be any embodiment of the cooling system described herein.

[0054] The server blades 903 can be inserted into the array of server slots from the front end 904 or the rear end 905 of the IT rack 900, respectively. Note that although only five server blades 903A-903E are shown here, more or fewer server blades can be held within the IT rack 900. Also note that the specific locations of the cooling system 901, RMU 902, and server blades 903 are shown for illustrative purposes only; other arrangements or configurations can also be implemented. Note that the rack 900 can be open to the environment or partially contained by a rack container, as long as the cooling fans can generate airflow from the front to the rear.

[0055] In addition, for each of the server blades 903, a fan module is associated with the server blade. In this embodiment, the fan modules 931A-931E are collectively referred to as fan modules 931 and are associated with the server blades 903A-903E, respectively. Each of the fan modules 931 includes one or more cooling fans. The fan modules 931 can be mounted on the rear end of the server blade 903 to generate an airflow that flows from the front end 904, travels through the air space of the server blade 903, and exits at the rear end 905 of the rack 900.

[0056] The condenser of the cooling system 901 can be connected to the external liquid supply / return lines 931-932 to form a main loop. In some embodiments, if the condenser is outside the IT rack, the external fluid supply / return lines can be connected to the ports of the cooling system 901 (e.g., Figure 8 901). Connectors connected to external liquid supply / return lines 931-932 can be provided or mounted on the rear end 905 of the rack 900. In some embodiments, the liquid supply / return lines 931-932 are connected to a set of room manifolds that are connected to an external heat removal system or an external cooling loop. The input and output channels of the cooling system can be connected to the liquid manifold 925 to form a secondary loop, which can include a supply manifold that supplies cooling liquid to the server blades 903 and a return manifold that returns the hotter liquid to the cooling system 901.

[0057] Each of the server blades 903 may include one or more IT components (e.g., a central processing unit or CPU, a graphics processing unit (GPU), memory, and / or a storage device). Each IT component may perform data processing tasks, where the IT component may include software installed in a storage device, loaded into memory, and executed by one or more processors to perform the data processing tasks. At least some of these IT components may be attached to the bottom of any of the cooling devices described above. The server blade 903 may include a host server (referred to as a host node) coupled to one or more compute servers (also referred to as compute nodes, e.g., a CPU server and a GPU server).

[0058] The host server (having one or more CPUs) typically docks with clients via 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), and requests to execute applications to perform certain operations (e.g., image processing, deep data learning algorithms, or modeling, etc., as part of a software as a service or SaaS platform). In response to the request, the host server assigns tasks to one or more of the performance compute nodes or compute servers (having one or more GPUs) managed by the host server. The performance compute servers perform the actual tasks and may generate heat during operation.

[0059] The IT rack 900 may also include an optional RMU 902, which is configured to provide and manage the power supplied to the servers 903, the fan module 931, and the cooling system 901. The RMU 902 may be coupled to a power supply unit (not shown) to manage the power consumption of the power supply unit. The power supply unit may include the necessary circuitry (e.g., an alternating current (AC) to direct current (DC) or DC to DC power converter, a backup battery, a transformer, or a regulator, etc.) to supply power to the rest of the IT rack 900.

[0060] In one embodiment, the RMU 902 includes an optimization module 921 and a Rack Management Controller (RMC) 922. The RMC 922 may include a monitor to monitor the operating states of various components within the rack 900 such as, for example, the compute nodes 903, the cooling system 901, and the fan modules 931. Specifically, the monitor receives operating data representing the operating environment of the IT rack 900 from various sensors. For example, the monitor may receive operating data representing the temperatures of the processors, the cooling liquid, and the air flow, which may be captured and collected via various temperature sensors. The monitor may also receive data representing the fan power and the pump power generated by the fan modules 931 and the liquid pumps 912, which may be proportional to their respective speeds. This operating data is referred to as real-time operating data. Note that the monitor may be implemented as a separate module within the RMU 902.

[0061] Based on the operating data, the optimization module 921 performs optimization using a predetermined optimization function or optimization model to derive a set of optimal fan speeds for the fan modules 931 and an optimal pump speed for the liquid pumps 912 such that the total power consumption of the liquid pumps 912 and the fan modules 931 is minimized while the operating data associated with the cooling fans of the liquid pumps 912 and the fan modules 931 is within their respective design specifications. Once the optimal pump speed and the optimal fan speeds have been determined, the RMC 922 configures the cooling fans of the liquid pumps 912 and the fan modules 931 based on the optimal pump speed and the fan speeds.

[0062] As an example, based on the optimal pump speed, the RMC 922 communicates with the pump controller of the cooling system 901 to control the speed of the liquid pump 912, which in turn controls the liquid flow rate of the cooling liquid supplied to the liquid manifold 925 for distribution to at least some of the server blades 903. Thus, the operating conditions and the corresponding cooling device performance are regulated. Similarly, based on the optimal fan speeds, the RMC 922 communicates with each of the fan modules 931 to control the speed of each cooling fan of the fan modules 931, which in turn controls the air flow rate of the fan modules 931. Note that each of the fan modules 931 can be individually controlled with its specific optimal fan speed, and different fan modules and / or different cooling fans within the same fan module may have different optimal fan speeds.

[0063] Note that some or all of the IT components of the server 903 can be attached to any of the above cooling devices via air cooling using radiators or liquid cooling using cold plates. One server can utilize air cooling while another server can utilize liquid cooling. Alternatively, one IT component of a server can utilize air cooling while another IT component of the same server can utilize liquid cooling.

[0064] It should be understood that some features described and shown in the drawings may vary without departing from the scope of the present disclosure. For example, the cooling loop design of the cooling facility is different from that shown in the drawings. In addition, additional valves or auxiliary units may be added to the cooling system for additional features. Further, different types of valves, such as three-way valves, may be implemented in the cooling system to achieve the same result. In some embodiments, the controller may adjust the opening ratio between fully closed (0%) and fully open (100%) of any valve as described herein.

[0065] Some embodiments may include a non-transitory machine-readable medium (such as a microelectronic memory) storing instructions that program one or more data processing components (collectively referred to herein as "processors") to perform valve control operations, such as determining in which mode to operate and / or deriving an evaporation rate and / or a condensation rate. In some aspects, the condensation rate is configurable (e.g., it is stored as a setting in a computer-readable memory). In some embodiments, some of these operations may be performed by specific hardware components including hardwired logic. These operations may alternatively be performed by any combination of programmed data processing components and fixed hardwired circuit components.

[0066] In the foregoing specification, embodiments of the present disclosure have been described with reference to their specific exemplary embodiments. It is apparent that various modifications can be made thereto without departing from the broader spirit and scope of the present disclosure as set forth in the appended claims. Accordingly, the specification and drawings are to be regarded as illustrative rather than restrictive.

[0067] Although certain aspects have been described and shown in the drawings, it should be understood that these aspects are merely illustrative and not a limitation on the broad disclosure, and the present disclosure is not limited to the specific constructions and arrangements shown and described, as various other modifications may be contemplated by those of ordinary skill in the art. Accordingly, the description is to be regarded as illustrative rather than restrictive.

[0068] In some aspects, the present disclosure may include language such as "at least one of [element A] and [element B]". Such language may refer to one or more of the elements. For example, "at least one of A and B" may refer to "A", "B", or "A and B". Specifically, "at least one of A and B" may refer to "at least one of A and at least one of B", or "at least one of A or B". In some aspects, the present disclosure may include language such as "[element A], [element B], and / or [element C]". Such language may refer to any one of the elements or any combination thereof. For example, "A, B, and / or C" may refer to "A", "B", "C", "A and B", "A and C", "B and C", or "A, B, and C".

Claims

1. A cooling system, comprising: An input channel and an output channel, with fluid entering the cooling system through the input channel and leaving the cooling system through the output channel; A vapor buffer; A liquid buffer, the liquid buffer being connected to the input channel and the output of the condenser or a port capable of being attached to the output of the condenser; And A plurality of vapor buffer valves, the plurality of vapor buffer valves being arranged in one or more fluid channels, the one or more fluid channels being located between the vapor buffer and the input channel, and between the vapor buffer and the input of the condenser or a port capable of being attached to the input of the condenser, the plurality of vapor buffer valves being controlled to disconnect the vapor buffer from the input channel in a first mode, and to connect the vapor buffer to the input channel and disconnect the vapor buffer from the input of the condenser or the port capable of being attached to the input of the condenser in a second mode.

2. The cooling system according to claim 1, wherein, The fluid channel includes a first section that fluidly connects the input channel to the vapor buffer through an inclined channel, and the plurality of vapor buffer valves includes a first valve arranged in the first section.

3. The cooling system according to claim 2, wherein, The fluid channel includes a second section that fluidly connects the vapor buffer to the input of the condenser or the port capable of being attached to the input of the condenser through an inclined channel, and the plurality of vapor buffer valves includes a second valve arranged in the second section.

4. The cooling system according to claim 1, wherein, The liquid buffer is fluidly connected to the input channel without regulation from a valve.

5. The cooling system according to claim 1, wherein, The fluid travels directly from the liquid buffer to the output channel.

6. The cooling system according to claim 1, wherein, In the first mode, the plurality of vapor buffer valves are controlled to disconnect the vapor buffer from the condenser.

7. The cooling system according to claim 1, wherein, It further includes a third mode, in which the plurality of vapor buffer valves are controlled to disconnect the vapor buffer valves from the input channel and connect the vapor buffer to the input of the condenser or the port capable of being attached to the input of the condenser.

8. The cooling system according to claim 1, wherein, When the evaporation amount of the fluid in the input channel meets a threshold, the plurality of vapor buffer valves are controlled to be in the second mode.

9. The cooling system according to claim 8, wherein, When the evaporation amount of the fluid does not meet the threshold, the plurality of vapor buffer valves are controlled to be in the first mode.

10. The cooling system according to claim 8, wherein, The threshold is a ratio or difference between the evaporation amount of the fluid and the condensation amount of the fluid by the condenser.

11. The cooling system according to claim 8, wherein, The evaporation amount of the fluid is determined based on the sensed pressure in the input channel or the fluid channel.

12. The cooling system according to claim 1 further includes a pump connected to the output channel, wherein, The pump pumps the fluid out of the liquid buffer to leave the cooling system through the output channel.

13. The cooling system according to claim 1, further comprising an input valve arranged in a straight line with the input channel.

14. The cooling system according to claim 1 further includes a buffer passage that fluidly connects the vapor buffer to the liquid buffer when a buffer valve located in the buffer passage is opened.

15. The cooling system according to claim 1, wherein, The cooling system including the condenser is housed in a common enclosure.

16. The cooling system according to claim 1, wherein, The input passage, the vapor buffer, the liquid buffer, the plurality of vapor buffer valves, the port capable of being attached to the output end of the condenser, and the port capable of being attached to the input end of the condenser are housed in or on the enclosure of the cooling system, and the condenser is located outside the enclosure.

17. The cooling system according to claim 1, wherein, An information technology (IT) rack is fluidly connected to the input passage and the output passage of the cooling system.

18. The cooling system according to claim 1, wherein, A first information technology (IT) rack is fluidly connected to the input passage, and a second IT rack is fluidly connected to the output passage of the cooling system.

19. An electronic rack for a data center, comprising: a plurality of information technology (IT) devices; and a cooling system coupled to the IT devices to provide cooling to the IT devices, wherein the cooling system includes: an input passage and an output passage, fluid enters the cooling system from the input passage and the fluid exits the cooling system from the output passage; a vapor buffer; a liquid buffer connected to the input passage and the output end of the condenser or a port capable of being attached to the output end of the condenser; and a plurality of vapor buffer valves arranged in a fluid passage located between the vapor buffer and the input passage and between the vapor buffer and the input end of the condenser or a port capable of being attached to the input end of the condenser, the plurality of vapor buffer valves being controlled to disconnect the vapor buffer from the input passage in a first mode and to connect the vapor buffer to the input passage and disconnect the vapor buffer from the input end of the condenser or the port capable of being attached to the input end of the condenser in a second mode.

20. A data center, comprising: a plurality of electronic racks, each electronic rack including one or more information technology (IT) devices; and a cooling system coupled to at least one of the electronic racks to provide cooling to the electronic racks, wherein the cooling system includes: an input passage and an output passage, fluid enters the cooling system from the input passage and the fluid exits the cooling system from the output passage; a vapor buffer; a liquid buffer connected to the input passage and the output end of the condenser or a port capable of being attached to the output end of the condenser; and A plurality of vapor buffer valves, the plurality of vapor buffer valves being arranged in a fluid passage that is located between the vapor buffer and the input passage, and between the vapor buffer and the input end of the condenser or a port that can be attached to the input end of the condenser, the plurality of vapor buffer valves being controlled to disconnect the vapor buffer from the input passage in a first mode and to connect the vapor buffer to the input passage and disconnect the vapor buffer from the input end of the condenser or the port that can be attached to the input end of the condenser in a second mode.

Images