Cooling circuit to buffer cooling capacity changes

Abstract

A cooling system for buffering changes in cooling capacity and heat load includes a buffer unit having a fluid container and a gas container; and a multi-way valve positioned between a fluid inlet and the buffer unit. The multi-way valve is operable to form multiple fluid loops, including a fluid loop passing through the fluid container. When the cooling system is in an undersupply period, the buffer unit can store a portion of the fluid in the fluid container. When the cooling system is in an oversupply period, the fluid stored during the undersupply period can be discharged from the fluid container due to the gas pressure in the gas container reaching a threshold.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to airflow management in data centers. More specifically, embodiments of the present disclosure relate to a buffer unit for buffering cooling capacity variations in a cooling system used with information technology (IT) servers or IT racks. Background Art

[0002] With the booming adoption of artificial intelligence (AI), high-performance computing (HPC), cloud computing, and data-driven applications, data centers and their computing and storage infrastructure are becoming increasingly important for companies to maintain a competitive advantage. Maintaining data centers and their computing and storage infrastructure is expensive, and part of that expense is related to cooling the data centers.

[0003] One of the main challenges in cooling a data center is maintaining a balance between the cooling capacity of the cooling system and the heat removal requirements of the data center. If the cooling capacity exceeds the heat removal requirements, some of the cooling capacity will be wasted, thereby increasing cooling costs and reducing cooling efficiency. On the other hand, if the cooling capacity is less than the heat removal requirements, the data center may not be adequately cooled. Designing a cooling system that provides just the right amount of cooling capacity to meet the heat removal requirements is difficult because the heat load in a data center can vary based on factors that are difficult to predict, such as sudden and unexpected spikes in workload. This situation becomes even more critical as the power density of electronic components deployed in data centers increases. Summary of the Invention

[0004] A cooling system in a data center includes: a buffer unit, which includes a fluid container; and a first valve, which is positioned between a fluid inlet and the buffer unit, the first valve operates to form a plurality of fluid loops, the plurality of fluid loops including a first fluid loop passing through the fluid container; wherein the buffer unit stores a portion of the fluid in the first fluid loop to the fluid container when the cooling system is in an undersupply period, and discharges the previously stored fluid from the fluid container when the cooling system is in an oversupply period.

[0005] According to some embodiments, the buffer unit further comprises a gas container separated from the fluid container by a physical divider, wherein the physical divider is adjustable such that both the gas container and the fluid container are expandable in size.

[0006] According to some embodiments, the gas container includes a first heat exchanger integrated therewith, and wherein the plurality of fluid loops includes a second medium loop passing through the first heat exchanger.

[0007] According to some embodiments, the cooling system further includes: a second heat exchanger; and a second valve positioned between the buffer unit and the second heat exchanger; wherein the buffer unit discharges the stored fluid to the second heat exchanger via the second valve.

[0008] According to some embodiments, the plurality of fluid loops further include a second fluid loop and a third fluid loop, wherein the second fluid loop passes through the first heat exchanger, and wherein the third fluid loop directly connects the fluid inlet and the second heat exchanger.

[0009] According to some embodiments, during the starvation, the first fluid loop is opened to the second valve, the second fluid loop is closed, and the third fluid loop is opened to form a complete fluid circuit.

[0010] According to some embodiments, the portion of fluid stored to the fluid container is added to existing fluid in the fluid container, resulting in an increase in the volume of the fluid in the fluid container.

[0011] According to some embodiments, the increased volume pushes the physical divider toward the gas container acting as a collapsible buffer unit, causing the pressure of the gas in the gas container to increase.

[0012] According to some embodiments, when the pressure of the gas in the gas container reaches a first threshold, the first valve closes the first fluid circuit.

[0013] According to some embodiments, the fluid in the third fluid loop flows to the second heat exchanger where it is cooled by the primary loop and then returned to the IT servers or IT racks.

[0014] According to some embodiments, during the oversupply period, the first fluid loop is opened to the second valve, the second fluid loop is opened to form a complete fluid circuit, and the third fluid loop is closed.

[0015] According to some embodiments, the fluid in the second fluid loop heats the gas in the gas container to increase the pressure of the gas in the gas container to a second threshold.

[0016] According to some embodiments, in response to the pressure of the gas reaching the second threshold, the buffer unit opens the second valve and pushes toward the fluid container to squeeze out a portion of the stored fluid.

[0017] According to some embodiments, the squeezed fluid passes through the opened second valve and merges with the fluid from the second fluid loop, wherein the merged fluid passes through the second heat exchanger and returns to the IT server or IT rack.

[0018] According to some embodiments, the fluid entering the cooling system from the IT servers or IT racks is steam, wherein at least a portion of the steam will rise to the second heat exchanger, and the second heat exchanger will condense the at least a portion of the steam into a cooling liquid, and the cooling liquid will fall into the IT servers or the IT racks due to gravity.

[0019] According to some embodiments, the fluid entering the cooling system from the IT servers or IT racks is a cooling liquid, wherein at least a portion of the cooling liquid will be pushed upward by a pump to the second heat exchanger, where the at least a portion of the cooling liquid is cooled by the main loop and falls into the IT servers or the IT racks due to gravity.

[0020] According to some embodiments, one or more pumps will be positioned on either side of the second heat exchanger to move fluid through the second heat exchanger.

[0021] According to some embodiments, the discharge section of the first fluid loop has a larger diameter than the remaining portion of the first fluid loop, or is positioned in an inclined manner to facilitate discharge of the fluid stored in the fluid container.

[0022] According to some embodiments, the buffer unit comprises a pressure sensor for measuring the pressure of the gas in the buffer unit.

[0023] A method for cooling a data center includes: providing a buffer unit in a cooling system, wherein the buffer unit includes a fluid container; positioning a first valve between a fluid inlet and the buffer unit, wherein the first valve operates to form a plurality of fluid loops, wherein the plurality of fluid loops include a first fluid loop passing through the fluid container; and storing a portion of the fluid in the first fluid loop to the fluid container, or discharging previously stored fluid from the fluid container, based on whether the cooling system is in an undersupply period or an oversupply period. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Embodiments of the invention are illustrated by way of example, and not by way of limitation, in the figures of the accompanying drawings and in which like references indicate similar elements.

[0025] Figure 1 A cooling system with a buffer unit according to one embodiment is shown.

[0026] Figure 2 A cooling system with multiple pumps according to one embodiment is shown.

[0027] Figure 3 A cooling system with a multiphase fluid according to one embodiment is shown.

[0028] Figure 4 A cooling system with a single-phase fluid is shown according to one embodiment.

[0029] Figure 5 FIG. 1 is a schematic diagram illustrating a process of cooling capacity change in a buffer cooling system according to one embodiment.

[0030] Figure 6 A process of cooling capacity change in a buffer cooling system according to one embodiment is shown. DETAILED DESCRIPTION

[0031] Various embodiments and aspects of the present invention will be described with reference to the details discussed below, and the accompanying drawings will illustrate various embodiments. The following description and drawings are illustrative of the present invention and should not be construed as limiting the present invention. Many specific details are described to provide a thorough understanding of the various embodiments of the present invention. However, in some cases, well-known or conventional details are not described in order to provide a concise discussion of embodiments of the present invention.

[0032] Reference in the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the present invention. The appearances of the phrase "in one embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

[0033] According to various embodiments, systems and methods for buffering cooling capacity changes in a cooling system are described herein. In one embodiment, a cooling system for buffering cooling capacity changes includes: a buffer unit having a fluid container; and a multi-way valve positioned between a fluid inlet and the buffer unit. The multi-way valve is operable to form a plurality of fluid loops, including a buffer fluid loop passing through the fluid container. When the cooling system is in an undersupply period, the buffer unit may store cooling fluid in the buffer fluid loop leading to the fluid container. When the cooling system is in an oversupply period, the fluid previously stored during the undersupply period may be discharged.

[0034] In one embodiment, the buffer unit is fully sealed and may also include a gas container separated from a fluid container by a physical divider. The physical divider is a physical layer that can move vertically or horizontally, but not both, under pressure to expand the size of either the gas container or the fluid container. The gas container may include an integrated heat exchanger.

[0035] In one embodiment, the cooling system may further include a heat exchanger external to the buffer unit. The heat exchanger may function as a liquid-liquid exchanger, a liquid-gas exchanger, or a fluid phase condenser. A discharge valve may be positioned between the heat exchanger and the buffer unit. The discharge valve may be opened or closed based on the gas pressure in the gas container. When the discharge valve is open, fluid may be discharged through the discharge valve to the heat exchanger external to the buffer unit.

[0036] In one embodiment, the cooling system may further include a fluid loop for heating gas through a heat exchanger in the buffer unit, and a direct fluid loop extending from the multi-way valve to a heat exchanger outside the buffer unit. The direct fluid loop may further pass through information technology (IT) servers or IT racks and return to the multi-way valve to form a complete fluid circuit. The heated fluid loop is also a complete fluid circuit and can be used to heat gas in the gas container to change the gas pressure in the gas container.

[0037] In one embodiment, when the cooling system is in an underprovision period, the cooling capacity configured for the cooling system is insufficient to remove the desired amount of heat from the IT servers or IT racks. When the cooling system is in an overprovision period, the cooling capacity provided exceeds the capacity required to remove the desired amount of heat from the IT servers or IT racks. One or more sensors and one or more system functions may be used to determine whether the cooling system is in an underprovision period or an overprovision period.

[0038] In one embodiment, when the cooling system is in a supply shortage period, the buffer fluid loop is opened to the discharge valve, the heating fluid loop is closed, and the direct fluid loop is opened to form a complete fluid circuit. The fluid stored in the fluid container can be added to the existing fluid in the fluid container and cause the total volume of the fluid in the fluid container to increase. The increased volume can push the physical divider toward the gas container, causing the gas pressure in the gas container to increase. When the gas pressure reaches a threshold, the control valve can close the buffer fluid loop, and thus no more fluid is stored in the fluid container. The fluid in the direct fluid loop can flow to a heat exchanger outside the buffer unit. At the heat exchanger, the fluid is cooled by the main loop and then returned to the information technology (IT) server or IT rack.

[0039] In one embodiment, when the cooling system is in an oversupply period, the buffer fluid loop is opened to the discharge valve, the heating fluid loop is opened to form a complete fluid circuit, and the direct fluid loop is closed or partially opened. The fluid in the heating fluid loop can heat the gas in the gas container so that the pressure of the gas in the gas container increases to a threshold value that is higher than the threshold value for closing the buffer fluid loop. The increased gas pressure can cause the discharge valve to open, while pushing the physical divider toward the fluid container to squeeze out a portion of the stored fluid. The squeezed fluid can pass through the open discharge valve and merge with the fluid from the heating fluid loop. The merged fluid can pass through a heat exchanger outside the buffer unit and return to the information technology (IT) server or IT rack.

[0040] In one embodiment, a heat exchanger external to the buffer unit can be positioned at a predetermined height above the buffer unit. If the fluid entering the cooling system from the IT servers or IT racks is steam, at least a portion of the steam can pass through the buffer unit to merge with a portion of the steam in the direct fluid loop. The merged steam can rise to the heat exchanger, which condenses the merged steam into a cooling liquid. The cooling liquid can then fall into the IT servers or IT racks due to gravity.

[0041] In one embodiment, if the fluid entering the cooling system from the servers or IT racks is cooling liquid, at least a portion of the cooling liquid can pass through a buffer unit and merge with a portion of the cooling liquid draining from the fluid reservoir. This merged cooling liquid can be pumped upward to a heat exchanger outside the buffer unit. At this heat exchanger, the merged cooling liquid can be cooled through the main loop and fall into the IT servers or IT racks due to gravity.

[0042] In one embodiment, the buffer fluid loop may have a discharge section that may have a larger diameter than the rest of the loop or may be positioned in an inclined manner to facilitate discharge of stored fluid.The buffer unit may include a pressure sensor for measuring the gas pressure in the buffer unit.

[0043] Compared to existing cooling systems, the above cooling system can handle variations in cooling capacity when using multiphase fluids. Furthermore, the cooling system can use different types of fluids for cooling and can utilize physical properties / gravity to regulate the fluid flow in the system, rather than relying on pumps. In the above embodiment, pressure-based fluid valves are used for system control.

[0044] Thus, the cooling system described in the present disclosure can use multiphase fluids, including liquids, gases, and phase-changing fluids. Advantages of the cooling system include improving cooling efficiency for IT racks that experience variations in heat load and / or cooling capacity, IT load, and cooling conditions; simplifying the design of the cooling system using multiple fluid loops; and enabling the cooling system to be self-regulating, thereby reducing design capital costs.

[0045] The above description does not include an exhaustive list of all embodiments of the present disclosure. All systems and methods can be practiced from all suitable combinations of the various aspects and embodiments described in this disclosure.

[0046] The following description and drawings are illustrative and should not be construed as limiting. Numerous specific details are described to provide a thorough understanding of various embodiments. However, in some cases, well-known or conventional details are not described in order to provide a concise discussion of the embodiments.

[0047] Figure 1 A cooling system 100 with a buffer unit 106 according to one embodiment is shown. As shown, cooling system 100 includes heat exchanger A 101 and heat exchanger B 117. Heat exchanger A 101 may be embedded in a gas container 105, which is part of buffer unit 106. Heat exchanger A 101 may be a heating / cooling coil compressed within gas container 105, containing a gas whose pressure is highly sensitive to temperature changes. An example of the gas may be nitrogen. In one embodiment, heat exchanger A 101 functions as a heating unit to heat the gas to a higher temperature, thereby increasing its pressure.

[0048] In one embodiment, the buffer unit may also include a fluid container 103. The buffer unit itself may be a completely sealed container, separated into a gas container 105 and a fluid container 103 by a physical layer. In one embodiment, the physical layer may be understood as a flexible physical layer of the gas container. The physical layer may serve as a movable physical separator that can be moved vertically or horizontally upwards depending on the orientation of the buffer unit, but not both horizontally and vertically. The movable physical layer enables the volume / area of both the gas container 105 and the fluid container 103 to be adjusted.

[0049] For example, in one embodiment, if the physical layer moves upward, the size of the gas container 105 will decrease, and correspondingly, the size of the fluid container 103 will increase. As the gas container shrinks, one of its boundaries (i.e., the physical layer) moves upward. When the physical layer moves downward, the size of the gas container 105 will increase, and the size of the fluid container 103 will decrease.

[0050] In one embodiment, cooling system 100 may further include valve A 109 and valve B 112. Valve A 109 may be a multi-way control valve, such as a three-way valve or a two-way valve, depending on the number of fluid circuits required for cooling system 100. Valve B 112 is a two-way valve connected to fluid container 103 and serves as a drain valve for draining a portion of the fluid stored in fluid container 103. The fluid in fluid container 103 may be a liquid, a vapor, or a combination of a liquid and a vapor.

[0051] In one embodiment, valve A 109 is a three-way valve that operates to create three separate fluid loops 111, 113, and 115. Loop A 111 connects inlet 107 to heat exchanger B 117, which allows fluid (e.g., cooling liquid or vapor, or a combination thereof) from IT servers or IT racks to enter cooling system 100. Heat exchanger B can be a liquid-to-liquid exchanger where the fluid releases heat to main loop 119, an air-cooled exchanger, or a condenser that can condense vapor into cooling liquid.

[0052] In one embodiment, fluid loop A 111 is a direct fluid loop that provides a direct connection between inlet 107 and heat exchanger B 117 without using any additional components. In this way, fluid loop A 111 can have a low resistance to the fluid, so that fluid loop A 111 can transfer the fluid faster.

[0053] In one embodiment, fluid loop B 113 is a heating fluid loop that connects inlet 107, heat exchanger A 101, and heat exchanger B 117. One of the functions of loop B 113 is to direct fluid from inlet 107 to heat exchanger A 101, where a portion of the heat in the fluid is transferred to the gas in gas container 105, thereby heating the gas. The fluid in fluid loop B 113 can then flow to heat exchanger B 117, where the heat in the fluid is released to main loop 119.

[0054] In one embodiment, fluid loop C 115 is a buffer fluid loop connecting fluid inlet 107, fluid container 103, valve B 112, and heat exchanger B 117. The discharge section 114 of fluid loop C 115 may have a larger diameter than the remainder of the loop 115 or be positioned in an inclined manner 116 to facilitate draining fluid from fluid container 103.

[0055] In one embodiment, a pressure sensor 124 may be used to measure the pressure of the gas in the gas container 105. The gas pressure may be used to control valve A 109 and valve B 112. For example, the cooling system may use two thresholds to control valve A 109 and valve B, respectively, with one of the thresholds being higher than the other.

[0056] In one embodiment, when the cooling system is in an undersupply period, which means that the cooling capacity of the cooling system 100 is insufficient to remove the heat load in the cooling system 100 to reduce its temperature to a predetermined level, the buffer unit 106 can be used to store a portion of the fluid and the corresponding thermal energy contained in the fluid to buffer the change.

[0057] As an exemplary embodiment, cooling system 100 may periodically check the gas pressure in gas container 105 and maintain valve B 112 closed, while maintaining valve A 109 open until the gas pressure reaches a lower threshold, allowing fluid in fluid container 103 to be stored in fluid container 103. During periods of low supply, fluid loop B 113 is closed and fluid loop A is opened to form a complete fluid loop. In this disclosure, a complete cooling loop means a fluid loop connecting inlet 107 and heat exchanger B 119, and then connecting back to inlet 107 after passing through the IT servers or IT racks. In some embodiments, the complete fluid loop may also pass through buffer unit 106.

[0058] In one embodiment, during the starvation period, as more fluid is stored in the fluid container, the volume of fluid in the fluid container 104 continues to increase, and the increased volume may exert a pushing force on the physical layer separating the gas container 105 and the fluid container 103. The pushing force may reduce the size of the gas container 103 and thereby increase the gas pressure in the gas container 105. When the gas pressure reaches a lower threshold, the cooling system 100 may close the fluid loop C 115 at valve A 109, which will prevent additional fluid from being stored in the fluid container 103.

[0059] In one embodiment, when the cooling system is in an overprovisioning period, meaning that the cooling capacity configured for cooling system 100 is higher than the heat removal requirement, cooling system 100, fluid loop A 111, may be completely closed, fluid loop B 113 may be opened, and fluid loop C 115 may be opened to the point of valve B 112. Heat in fluid loop B 113 may be partially transferred to the gas in gas container 105, causing the gas pressure in gas container 105 to increase. The increased pressure 124 in gas container 105 triggers the opening of valve B 113, for example, by reducing the opening pressure of valve B 112. The reduced opening pressure of valve B 112 may make valve B 112 easier to open, and the increased pressure of the gas in the gas container may push the physical layer in buffer unit 106 toward fluid container 103, causing a portion of the fluid therein to be discharged through valve B 112.

[0060] like Figure 1 As further shown in FIG, a pump 121 may be used in some cases to pump fluid in the cooling system 100 to an outlet 123 or the main loop 119. The pump 121 may be located between the heat exchanger B 117 and the outlet 113, or between the heat exchanger B 117 and the point 122.

[0061] Figure 2 FIG. 2 shows a cooling system 200 having multiple pumps according to one embodiment. Figure 2As shown, pump A 201 and pump B 203 are used in the cooling system. Pump A 201 has less power than pump B 203 and can be used primarily by fluid loop A 111, where the fluid may encounter lower resistance due to the lack of physical components in fluid loop A 111. On the other hand, pump B 203 has greater power than pump A 201 and is used primarily by fluid loop B 113 and fluid loop C 115 to overcome higher resistance. The higher resistance in these loops is due to buffer unit 106. The two pumps 201 and 203 can be arranged in a distributed redundant mode or a reserve mode. In another embodiment, the two pumps can be operated in a combined mode to maximize energy efficiency.

[0062] In one embodiment, in distributed redundancy mode, both pumps 201 and 203 can be used in parallel, and failure of either pump forces the active pump to take over the entire pumping load. In reserve mode, only one pump is in use at any given time. Only if the active pump fails will the other pump be activated.

[0063] Figure 3 A cooling system 300 with a multiphase fluid is shown according to one embodiment. More specifically, this embodiment utilizes thermosiphoning to regulate the temperature of IT servers / racks 301.

[0064] In one embodiment, the phase-change cooling fluid from IT servers / racks 301 is heated to steam 303. When the cooling system is undersupplied, a portion of the steam can be temporarily stored in fluid container 103, while a portion of the steam can rise to heat exchanger B 117. When the cooling system is oversupplied, the previously stored steam can be discharged via valve B 112 and loop C and merged with the steam in fluid loop 113. The merged steam can rise to heat exchanger B 117.

[0065] In one embodiment, heat exchanger B 117 may function as a condenser to condense the vapor reaching heat exchanger B 117 into a liquid phase as cooling liquid 305 , which falls into the IT servers / racks 303 due to gravity.

[0066] Figure 4 A cooling system 400 with a single-phase fluid is shown according to one embodiment. In this embodiment, the cooling system 400 uses a single-phase fluid 403 to cool the IT servers / racks 301. In this embodiment, a pump 422 is used to pump the cooling liquid from one or more of the fluid loops 111, 113, and 115 upward to the heat exchanger B 117 because the cooling liquid cannot rise like vapor.

[0067] Heat exchanger B 117 can be used as a liquid-liquid heat exchanger or a heat exchanger cooled by cooling air. After passing through heat exchanger B 117, the temperature of the liquid is reduced with the additional cooling from the main loop 119. The cooled liquid 405 is then pumped back to the IT servers / racks 301.

[0068] Figure 5 FIG. 1 is a schematic diagram illustrating a process of cooling capacity change in a buffer cooling system according to an embodiment. Figure 5 As shown, one or more sensors and / or system functions are used to determine whether the cooling system is in an under-provision period or an over-provision period in block 501. The sensors may collect data for the system function to make the determination based on some predetermined rules.

[0069] In block 503, the cooling system makes a determination based on the collected data. In block 505, the cooling system determines that there is an undersupply of cooling capacity (i.e., the cooling system is in an undersupply period). In this case, fluid loop A forms a complete fluid circuit, fluid loop B is closed, and fluid loop C is used to store a portion of the heat load in the buffer unit.

[0070] In block 509, while a portion of the heat load is being stored in the buffer unit, a portion of the fluid may flow through fluid loop A to heat exchanger B, and the heat in the fluid may then be transferred to heat exchanger B. When the gas pressure in the buffer unit reaches a lower threshold due to the increased volume of fluid in the buffer unit, storage of the fluid may be stopped.

[0071] In block 507 , if the cooling system is not in an underprovision period, the cooling system may determine whether it is in an overprovision period or a period where cooling capacity and heat rejection requirements are balanced.

[0072] In block 511, when a balance exists between cooling capacity and heat removal requirements, only fluid loop A is opened to form a complete fluid circuit, while fluid loops B and C are closed, because the cooling system does not require a buffer unit during this period. The cooling system then begins collecting sensor data 501 again in a new cycle to detect whether the balance between cooling capacity and heat removal requirements has been broken.

[0073] In block 513 , the cooling system is in an overprovision period during which fluid loop B is opened to complete the fluid circuit, fluid loop A is closed, and fluid loop C is opened to valve B.

[0074] In block 515, as the fluid passes through heat exchanger A in the gas container, the gas in the gas container may be heated, causing the gas pressure in the gas container to increase to a higher threshold. When the higher threshold is reached, the fluid stored in the fluid container during the low supply period may be squeezed out due to the increased pressure from the gas container. Simultaneously, valve B may open to allow the squeezed-out fluid to be discharged.

[0075] In block 517 , the fluid squeezed out of the fluid container may merge with the fluid in fluid loop B, and the merged fluid may flow toward heat exchanger B.

[0076] In block 519, the cooling system may determine if the gas pressure has dropped below a lower threshold, at which point venting will cease and valve B will close. However, if the gas pressure remains at the lower threshold, a balance between cooling capacity and heat removal requirements has been achieved.

[0077] Figure 6 A process for buffering cooling capacity changes in a cooling system according to one embodiment is shown. In block 601, a buffer unit is provided in a cooling system. The buffer unit includes a fluid container and a gas container. The fluid container and the gas container are separated by an adjustable physical layer, which makes both containers expandable. In block 603, a first valve is positioned between a fluid inlet and the buffer unit. The first valve operates to form a plurality of fluid loops, including a first fluid loop passing through the fluid container. In block 505, a portion of the fluid in the first fluid loop is stored in the fluid container, or a portion of the fluid previously stored in the fluid container is discharged, based on whether the cooling system is in an undersupply period or an oversupply period.

[0078] In the foregoing description, embodiments of the present disclosure have been described with reference to specific exemplary embodiments thereof. It will be apparent that various modifications may be made thereto without departing from the broader spirit and scope of the present disclosure as set forth in the appended claims. The description and drawings are, therefore, to be regarded in an illustrative rather than a restrictive sense.

[0079] As previously explained, embodiments of the present disclosure may be (or include) a non-transitory machine-readable medium (such as a microelectronic memory) having stored thereon instructions that program one or more data processing components (collectively referred to herein as "processors") to perform airflow management operations, such as controlling the fan speed of one or more fans of a battery module (and / or BBU shelf). In other embodiments, some of these operations may be performed by specific hardware components containing hardwired logic. These operations may alternatively be performed by any combination of programmed data processing components and fixed hardwired circuit components of any of the battery modules described herein.

[0080] Although certain aspects have been described and illustrated in the drawings, it should be understood that these aspects are merely illustrative and not restrictive of the broader disclosure, and that the disclosure is not limited to the exact constructions and arrangements shown and described, as various other modifications may occur to those skilled in the art. Accordingly, the description is to be regarded as illustrative and not restrictive.

[0081] In some aspects, the present disclosure will include statements such as "at least one of [element A] and [element B]." Such statements 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 will include statements such as "[element A], [element B], and / or [element C]." Such statements 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 in a data center, comprising: a buffer unit comprising a fluid container; and a first valve positioned between a fluid inlet and the buffer unit, the first valve being operative to form a plurality of fluid loops including a first fluid loop passing through the fluid container; wherein the buffer unit stores a portion of the fluid in the first fluid loop in the fluid container when the cooling system is in an undersupply period, and discharges the previously stored fluid from the fluid container when the cooling system is in an oversupply period; The buffer unit further comprises a gas container separated from the fluid container by a physical divider, the gas container including a first heat exchanger integrated therewith, and wherein the plurality of fluid loops includes a second medium loop passing through the first heat exchanger; Also includes: a second heat exchanger; a second valve positioned between the buffer unit and the second heat exchanger; wherein the buffer unit discharges the stored fluid to the second heat exchanger via the second valve; The plurality of fluid loops further include a second fluid loop and a third fluid loop, wherein the second fluid loop passes through the first heat exchanger, and wherein the third fluid loop directly connects the fluid inlet and the second heat exchanger; During the starvation period, the first fluid loop is opened to the second valve, the second fluid loop is closed, and the third fluid loop is opened to form a complete fluid circuit; During the oversupply period, the first fluid loop is opened to the second valve, the second fluid loop is opened to form a complete fluid circuit, and the third fluid loop is closed.

2. The cooling system according to claim 1, wherein: The physical divider is adjustable such that both the gas container and the fluid container are expandable in size.

3. The cooling system according to claim 2, wherein: The portion of fluid stored in the fluid container is added to the existing fluid in the fluid container, resulting in an increase in the volume of the fluid in the fluid container.

4. The cooling system according to claim 3, wherein: The increased volume pushes the physical divider toward the gas container, which acts as a collapsible buffer unit, causing the pressure of the gas in the gas container to increase.

5. The cooling system according to claim 4, wherein: When the pressure of the gas in the gas container reaches a first threshold, the first valve will close the first fluid loop.

6. The cooling system according to claim 2, wherein: The fluid in the third fluid loop flows to the second heat exchanger where it is cooled by the primary loop and then returned to the IT servers or IT racks.

7. The cooling system according to claim 2, wherein: The fluid in the second fluid loop heats the gas in the gas container to increase the pressure of the gas in the gas container to a second threshold.

8. The cooling system according to claim 7, wherein: In response to the pressure of the gas reaching the second threshold, the buffer unit opens the second valve and pushes toward the fluid container to squeeze out a portion of the stored fluid.

9. The cooling system according to claim 8, wherein: The squeezed fluid passes through the opened second valve and merges with the fluid from the second fluid loop, wherein the merged fluid passes through the second heat exchanger and returns to the IT server or IT rack.

10. The cooling system according to claim 9, wherein: The fluid entering the cooling system from the IT servers or IT racks is steam, wherein at least a portion of the steam will rise to the second heat exchanger, and the second heat exchanger will condense the at least a portion of the steam into cooling liquid, and the cooling liquid will fall into the IT servers or the IT racks due to gravity.

11. The cooling system according to claim 9, wherein: The fluid entering the cooling system from the IT servers or IT racks is a cooling liquid, wherein at least a portion of the cooling liquid will be pushed upward by the pump to the second heat exchanger, where the at least a portion of the cooling liquid is cooled by the primary loop and falls into the IT servers or the IT racks due to gravity.

12. The cooling system according to claim 1, wherein: One or more pumps will be positioned on either side of the second heat exchanger to move fluid through the second heat exchanger.

13. The cooling system according to claim 1, wherein: The discharge section of the first fluid loop has a larger diameter than the remaining portion of the first fluid loop or is positioned in an inclined manner to facilitate discharge of the fluid stored in the fluid container.

14. The cooling system according to claim 1, wherein: The buffer unit includes a pressure sensor for measuring the pressure of gas in the buffer unit.

15. A method for cooling a data center, using the cooling system according to any one of claims 1 to 14, comprising: Providing a buffer unit in a cooling system, wherein the buffer unit includes a fluid container; positioning a first valve between a fluid inlet and the buffer unit, wherein the first valve operates to form a plurality of fluid loops including a first fluid loop through the fluid reservoir; Based on whether the cooling system is in an undersupply period or an oversupply period, a portion of the fluid in the first fluid loop is stored in the fluid container, or previously stored fluid is discharged from the fluid container.

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