Server Cooling System

Abstract

We provide server cooling systems that cool servers with less energy. [Solution] One aspect of the server cooling system of the present invention includes a liquid cooling unit (1) that cools a server using a coolant, a coolant circulation unit (2) that circulates the coolant, and an adsorption heat pump (3) for performing a first cooling to cool the coolant after the server has been cooled by the liquid cooling unit (1).

Description

Technical Field

[0001] The present invention relates to a server cooling system.

Background Art

[0002] Patent Document 1 describes a system for cooling a server using a liquid such as water or fluorinate as a refrigerant.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the future, it is expected that the amount of data processing in data centers and the like will increase. Therefore, from the viewpoints of reducing power costs and environmental problems such as global warming, technologies for cooling servers with less energy are required. One aspect of the present invention aims to cool a server with less energy.

Means for Solving the Problems

[0005] As one means for solving the above problems, the present invention provides aspects according to the following [1] to [3]. 〔1〕A liquid cooling unit that cools a server using a coolant, a coolant circulation unit that circulates the coolant, and at least one of an adsorption heat pump and an absorption heat pump for performing a first cooling to cool the coolant after the server is cooled in the liquid cooling unit. A server cooling system including a first cooling unit. [2] A server cooling system according to [1], further comprising a second cooling unit that performs a second cooling to further cool the coolant after the first cooling has been performed, wherein the first cooling unit cools a first heat medium using the thermal energy contained in the coolant that is the target of the first cooling and supplies the first heat medium to the second cooling unit, and the second cooling unit performs the second cooling using the first heat medium. [3] The server cooling system according to [1] or [2], wherein the coolant circulation unit further has the function of further cooling the coolant after the first cooling by heat exchange using a second heat transfer medium, and further comprises a third cooling unit that supplies the second heat transfer medium for cooling the coolant to the coolant circulation unit and cools the second heat transfer medium, which has been used to cool the coolant supplied from the coolant circulation unit, using a third heat transfer medium, wherein the first cooling unit supplies the third cooling unit a first heat transfer medium, which is a heat transfer medium cooled using the thermal energy of the coolant that is the target of the first cooling, and the third cooling unit performs a third cooling by cooling the third heat transfer medium using the first heat transfer medium. [Effects of the Invention]

[0006] According to one aspect of the present invention, the server can be cooled with less energy. [Brief explanation of the drawing]

[0007] [Figure 1] This diagram schematically shows the configuration of a server cooling system according to one embodiment of the present invention. [Figure 2] This diagram schematically shows the configuration of a server cooling system according to one embodiment of the present invention. [Modes for carrying out the invention]

[0008] One embodiment of the present invention is described below. In this specification, unless otherwise specified, "~" means a range including both ends.

[0009] [Embodiment 1] (Configuration of server cooling system 10) One embodiment of the present invention will be described below with reference to Figure 1 and other figures. Figure 1 is a schematic diagram showing the configuration of a server cooling system 10 according to one embodiment of the present invention.

[0010] The server cooling system 10 is a system for cooling servers equipped with GPUs (Graphics Processing Units), CPUs (Central Processing Units), etc.

[0011] A server may be located, for example, in a data center. Furthermore, a so-called supercomputer is also considered a form of server in this specification.

[0012] The server cooling system 10 includes a liquid cooling unit 1, a coolant circulation unit 2, an adsorption heat pump 3 (first cooling unit), a cooling tower 4, a heat exchanger 5 (second cooling unit), and a chiller 6 (third cooling unit).

[0013] (Liquid-type cooling unit 1) The liquid cooling unit 1 is a unit that cools a server (not shown) using a coolant. The liquid cooling unit 1 cools heat-generating components such as GPUs mounted on the server by bringing the coolant into thermal contact with them using a cold plate or the like, thereby removing the heat energy from the components. A specific configuration of the liquid cooling unit 1 could be, for example, a DLC (Direct Liquid Cooling) type cooling unit.

[0014] In the present invention, the coolant can be a liquid at a temperature lower than the temperature of the server to be cooled. For example, conventionally known coolants for server cooling can be used, such as water, an aqueous solution of ethylene glycol, or an aqueous solution of propylene glycol.

[0015] (Coolant circulation unit 2) The coolant circulation unit 2 is a unit that circulates the coolant. The coolant circulation unit 2 pressurizes and pumps the coolant so that it circulates through the coolant circulation path within the server cooling system 10.

[0016] Furthermore, the coolant circulation unit 2 also has a function to cool the coolant. This function may include, for example, heat exchange with another heat transfer medium. In this embodiment, we will describe a case in which the coolant circulation unit 2 further has a function to cool the coolant after the first cooling described later by heat exchange using a second heat transfer medium. An example of a unit having such a cooling function and for circulating the coolant is a conventionally known CDU (Coolant Distributing Unit).

[0017] (Adsorption-type heat pump 3) The adsorption heat pump 3 is one embodiment of the first cooling unit in the present invention. The adsorption heat pump 3 cools the coolant after the server has been cooled in the liquid cooling unit 1. This cooling is one embodiment of the first cooling in the present invention and is simply referred to as the first cooling in this embodiment as well. The first cooling unit in the present invention is not limited to an adsorption heat pump, but may also be an absorption heat pump, or both an adsorption heat pump and an absorption heat pump may be used. As the adsorption heat pump, any adsorption heat pump that can be driven at the coolant temperature of the liquid cooling unit 1 is acceptable, for example, the one described in International Publication No. 2004 / 090458 can be used.

[0018] The adsorption heat pump 3 can cool the first heat transfer medium using the thermal energy contained in the coolant, which is the target of the first cooling. In other words, in this embodiment, the adsorption heat pump 3 cools the first heat transfer medium using the thermal energy of the coolant, and also cools the coolant (first cooling). The first heat transfer medium cooled in this way is supplied to the heat exchanger 5, which will be described later. As will be described later, the heat exchanger 5 performs a second cooling using the first heat transfer medium. Examples of the first heat transfer medium include water, an aqueous solution of ethylene glycol, an aqueous solution of propylene glycol, and the like.

[0019] The cooling tower 4 further cools the coolant that has been first cooled by the adsorption heat pump 3. The cooling tower 4 is installed outdoors, for example, and uses the outside air to cool the coolant. The specific form of the cooling tower 4 is not particularly limited, and a conventionally known cooling tower can be adopted, or a cooling tower installed in an existing data center or the like may be used. Further, in one aspect of the present invention, instead of or in addition to the cooling tower, a unit for cooling the coolant may be included other than the heat exchanger 5 described later. Further, in the present embodiment, a form including a unit for cooling the coolant between the first cooling and the second cooling described later, such as the cooling tower 4, will be described, but the present invention is not limited to such a form, and the unit may or may not be included.

[0020] (Heat exchanger 5) The heat exchanger 5 is an aspect of the second cooling unit in the present invention. The heat exchanger 5 further cools the coolant that has been first cooled by the adsorption heat pump 3. This cooling is an aspect of the second cooling in the present invention, and is simply referred to as the second cooling in the present embodiment. The heat exchanger 5 performs the second cooling using the first heat medium supplied from the adsorption heat pump 3. The specific form of the heat exchanger 5 may be any form in which the first heat medium and the coolant can be thermally contacted, and a conventionally known heat exchanger can be used.

[0021] (Chiller 6) The chiller 6 is an aspect of the third cooling unit in the present invention. The chiller 6 supplies the second heat medium used for heat exchange in the coolant circulation unit 2 to the coolant circulation unit 2. The coolant circulation unit 2 supplies the second heat medium after being used in the coolant to the chiller 6, and the chiller 6 cools the second heat medium supplied from the coolant circulation unit 2 using the third heat medium. The chiller 6 cools the second heat medium by heat exchange with the third heat medium and supplies it again to the coolant circulation unit 2.

[0022] Examples of the second heat transfer medium include water and / or refrigerants used in conventional server cooling systems such as DCUs to cool the server's cooling fluid in a CDU. Examples of the third heat transfer medium include synthetic refrigerants such as fluorocarbons and their substitutes, and natural refrigerants such as propane and ammonia.

[0023] (Operation of server cooling system 10) Next, we will describe the operation of the server cooling system 10. First, we will describe the cooling of the server by the liquid cooling unit 1.

[0024] The liquid cooling unit 1 cools the server using coolant supplied from the coolant circulation unit 2. Here, the coolant is supplied to the liquid cooling unit 1 at, for example, about 25°C, and after cooling the server, it reaches about 65°C before being supplied to the adsorption heat pump 3.

[0025] The adsorption heat pump 3 cools the coolant after the server has been cooled in the liquid cooling unit 1 (first cooling). During the first cooling, the adsorption heat pump 3 uses the thermal energy contained in the coolant that is the target of the first cooling to cool the first heat transfer medium. As a result, for example, the coolant becomes approximately 55°C, and the first heat transfer medium, which was supplied at approximately 25°C, is cooled to approximately 20°C. The temperature of the cooled first heat transfer medium is preferably 25°C or lower, more preferably 20°C or lower, and even more preferably 15°C or lower. This cooled first heat transfer medium is preferably input to the heat exchanger 5 described later. The temperature of the coolant that can be used as a heat source from which the adsorption heat pump 3 extracts thermal energy is preferably 55°C or higher, more preferably 65°C or higher, and even more preferably 70°C or higher. The temperature of the coolant that can be used as a heat source from which the absorption heat pump extracts thermal energy is preferably 80°C or higher, and more preferably 85°C or higher.

[0026] The adsorption heat pump 3 supplies cooled coolant to the cooling tower 4 and cools the first heat transfer medium to the heat exchanger 5. The coolant output from the adsorption heat pump 3 to the cooling tower 4 is preferably 60°C or lower, and more preferably 55°C or lower.

[0027] The cooling tower 4 further cools the coolant supplied from the adsorption heat pump 3. Here, the coolant is preferably at a temperature of approximately 45°C or lower, and more preferably at 40°C or lower. The cooling tower 4 supplies the coolant to the heat exchanger 5.

[0028] The heat exchanger 5 cools the coolant supplied from the cooling tower 4 using the first heat transfer medium supplied from the adsorption heat pump 3 (second cooling). Here, the coolant is preferably at about 40°C or lower, more preferably at 30°C or lower, more preferably at 25°C or lower, and even more preferably at 20°C or lower. On the other hand, the first heat transfer medium is at about 25°C. The heat exchanger 5 supplies the coolant to the coolant circulation unit 2 and supplies the first heat transfer medium to the adsorption heat pump 3.

[0029] The coolant circulation unit 2 further cools the coolant through heat exchange. Therefore, the coolant output from the coolant circulation unit 2 to the liquid-type cooling unit 1 is not particularly limited as long as it is lower in temperature than the coolant supplied to the coolant circulation unit 2, but the preferred range for the temperature of the output coolant is 40°C or lower, more preferably 35°C or lower, and even more preferably 32°C or lower. In this heat exchange, a second heat transfer medium supplied from the chiller 6 is used. Here, the coolant is cooled to approximately 25°C. The second heat transfer medium is supplied from the chiller 6 at approximately 7°C and is used to cool the coolant by the coolant circulation unit 2, bringing it down to approximately 12°C.

[0030] The coolant circulation unit 2 supplies the cooled coolant to the liquid cooling unit 1 and supplies the second heat transfer medium used to cool the coolant to the chiller 6.

[0031] The chiller 6 cools the second heat transfer medium supplied from the coolant circulation unit 2 using the third heat transfer medium. This reduces the temperature of the second heat transfer medium from approximately 12°C to approximately 7°C. The chiller 6 then supplies this second heat transfer medium back to the coolant circulation unit 2. The chiller 6 also cools the third heat transfer medium and uses it again to cool the second heat transfer medium.

[0032] (Main effects of this embodiment) As mentioned above, the adsorption heat pump 3 included in the server cooling system 10 is a heat pump that can cool liquids such as coolant with less energy. Therefore, the server can be cooled with less energy. In addition, the adsorption heat pump 3 can use the thermal energy of the coolant after cooling the server to cool the first heat transfer medium, and furthermore, this first heat transfer medium can also be used to cool the coolant. Therefore, the coolant can be cooled with less energy, and consequently, the server can be cooled with less energy.

[0033] Furthermore, although this embodiment describes an embodiment using an adsorption type heat pump, the same effect can be obtained when using an absorption type heat pump that can be driven by the coolant temperature of the liquid cooling unit 1. This is because an absorption type heat pump can also generate cooling using the thermal energy contained in the coolant after the server has been cooled. In addition, in one embodiment of the present invention, an absorption type heat pump and / or an adsorption type heat pump may be used in combination.

[0034] Furthermore, one aspect of the present invention that uses an adsorption heat pump and / or an absorption heat pump has the effect of improving the energy efficiency required for cooling as the heat of the server to be cooled increases. In other words, since adsorption heat pumps and absorption heat pumps cool the first heat medium using the thermal energy of the coolant, the more thermal energy increases, the more energy can be used to cool the first heat medium. Therefore, in the future, when the processing load of servers in data centers and the like increases and generates more heat (for example, when the temperature of the coolant becomes 70°C or higher, or around 95°C), one aspect of the present invention will be more advantageous.

[0035] More specifically, as a server cooling system according to one aspect of the present invention, the amount of power consumption required for server cooling can be reduced by 10% to 30% compared to conventional systems.

[0036] [Embodiment 2] (Configuration of server cooling system 20) Another embodiment of the present invention will be described with reference to Figure 2. Figure 2 is a schematic diagram showing the configuration of a server cooling system 20 according to one embodiment of the present invention. Components having the same function as those described in the above-mentioned embodiments are denoted by the same reference numerals, and their descriptions will not be repeated.

[0037] This embodiment differs from Embodiment 1 in that the adsorption heat pump 3 supplies the first heat transfer medium, which has been cooled using the thermal energy of the coolant during the first cooling process, to the chiller 6, and the chiller 6 uses the first heat transfer medium to cool the third heat transfer medium. This cooling is one aspect of the third cooling process in the present invention and is simply referred to as the third cooling process in this embodiment as well.

[0038] As shown in Figure 2, the adsorption heat pump 3 supplies the first heat transfer medium, which has been cooled during the first cooling process, to the chiller 6.

[0039] The chiller 6 cools the second heat transfer medium supplied from the coolant circulation unit 2 by heat exchange with the third heat transfer medium. The chiller 6 also cools the third heat transfer medium after it has been used to cool the second heat transfer medium. The mechanism by which the chiller 6 cools the third heat transfer medium includes a process of compression, condensation, and then expansion (vaporization), similar to conventionally known chillers. In this embodiment, the third heat transfer medium, after compression and condensation, is cooled using the first heat transfer medium supplied from the adsorption heat pump 3 (third cooling). Subsequently, the third heat transfer medium is expanded to generate a low-temperature third heat transfer medium.

[0040] (Main effects of this embodiment) The adsorption heat pump 3 can cool the first heat transfer medium using the thermal energy of the coolant after cooling the server. Then, it can use this first heat transfer medium to cool the third heat transfer medium before it vaporizes. By further lowering the temperature of the third heat transfer medium before it vaporizes, the energy required by the chiller 6 to lower the temperature of the third heat transfer medium can be reduced. Consequently, the server can be cooled with less energy. Therefore, the coolant can be cooled with less energy, and consequently, the server can be cooled with less energy.

[0041] For example, conventionally, the refrigerant after condensation is approximately 45°C, and it is expanded to become a refrigerant at approximately 0°C. However, according to one aspect of the present invention, the refrigerant after condensation, which is 45°C, can be reduced to, for example, 35°C. Subsequently, to reduce the refrigerant to approximately 0°C, the energy required can be reduced compared to the case of reducing from 45°C to 0°C. As described above, the first heat transfer medium is cooled by the adsorption heat pump 3 using the thermal energy of the coolant supplied from the liquid cooling unit 1. Therefore, the energy required to cool the server can be reduced for the entire server cooling system 10.

[0042] More specifically, as a server cooling system according to one aspect of the present invention, the amount of power consumption required for server cooling can be reduced by 10% to 30% compared to conventional systems.

[0043] Furthermore, although this embodiment describes an embodiment using an adsorption type heat pump, the same effect can be obtained when using an absorption type heat pump. This is because an absorption type heat pump can also generate cooling using the thermal energy contained in the coolant after the server has been cooled.

[0044] The present invention is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present invention.

[0045] For example, regarding the use of the first heat transfer medium cooled by the first cooling unit using the thermal energy of the coolant after cooling the server, Embodiment 1 described a configuration in which it is used to recool the coolant, and Embodiment 2 described a configuration in which it is used to cool the third heat transfer medium in the third cooling unit. However, the present invention is not limited to configurations in which it is used for only one of these purposes. For example, a portion of the first heat transfer medium may be used to recool the coolant, and the remainder may be used to cool the third heat transfer medium. [Explanation of Symbols]

[0046] 1. Liquid cooling unit, 2. Coolant circulation unit, 3. Adsorption heat pump (first cooling unit), 4. Cooling tower, 5. Heat exchanger (second cooling unit), 6. Chiller (third cooling unit), 10. 20. Server cooling system

Claims

1. A liquid cooling unit that cools servers using a coolant, A coolant circulation unit that circulates the aforementioned coolant, A first cooling unit, which is at least one of an adsorption heat pump and an absorption heat pump, for performing a first cooling to cool the cooling liquid after the server has been cooled in the liquid cooling unit, including, Server cooling system.

2. The system further includes a second cooling unit that performs a second cooling to further cool the coolant after the first cooling has been performed, The first cooling unit cools the first heat transfer medium using the thermal energy contained in the cooling liquid that is the target of the first cooling, and supplies the first heat transfer medium to the second cooling unit. The second cooling unit performs the second cooling using the first heat transfer medium. The server cooling system according to claim 1.

3. The coolant circulation unit further has the function of further cooling the coolant after the first cooling by heat exchange using a second heat transfer medium. The system further comprises a third cooling unit that supplies the second heat transfer medium for cooling the coolant to the coolant circulation unit, and cools the second heat transfer medium, after it has been used to cool the coolant supplied from the coolant circulation unit, using a third heat transfer medium. The first cooling unit supplies the third cooling unit with a first heat transfer medium, which is a heat transfer medium cooled using the thermal energy of the coolant that was the target of the first cooling. The server cooling system according to claim 1 or 2, wherein the third cooling unit performs a third cooling by using the first heat transfer medium to cool the third heat transfer medium.

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