JP-7856690-B2 - Server System

Inventors

• 加藤 真人
• 谷岡 功基
• 北山 真太郎

Assignees

• ＫＤＤＩ株式会社

Dates

Publication Date

20260511

Application Date

20240312

Claims (15)

1. A liquid immersion device containing at least a part of a server device and a cooling liquid for cooling at least a part of the server device, A cooling water circulation device that circulates cooling water that exchanges heat with the aforementioned cooling liquid, A heat exchanger in which the cooling water, while in liquid state, exchanges heat between the cooling water and the outside air, It has, The aforementioned immersion apparatus is The cooling liquid flows into an inlet from the cooling water circulation device, An outlet section through which the cooling liquid, after heat exchange with the server device, flows out to the cooling water circulation device, It has, The heat resistance temperature of the server device is 75°C or higher. A server system in which, even if the temperature of the cooling liquid flowing into the inlet is 45°C or higher and 60°C or lower, the temperature of the cooling liquid flowing out from the outlet is 60°C or higher and less than 75°C.
2. The amount of evaporation of the cooling liquid when maintained at 120°C for 24 hours is 5% by mass or less. The server system according to claim 1.
3. The cooling liquid contains an antioxidant, The server system according to claim 1.
4. The cooling liquid contains an additive that suppresses the odor of the oil. The server system according to claim 1.
5. The server device is A server device main unit having a processing unit with a processor and a storage device without a processor, A network device for connecting the main body of the server device to an external device, It has, The cable connecting the server unit and the network device is heat-resistant and oil-resistant. The server system according to claim 1.
6. Within the immersion apparatus, the server unit and the network device are connected by a cable other than an optical cable. The server system according to claim 5.
7. The material of the cable does not contain any of styrene rubber, ethylene propylene rubber, butyl rubber, or polyvinyl chloride. The server system according to claim 5.
8. The flash point of the cooling liquid is 250°C or higher. The server system according to any one of claims 1 to 7.
9. The cooling liquid is an oil with a higher kinematic viscosity than the cooling water. The server system according to any one of claims 1 to 7.
10. The kinematic viscosity of the cooling liquid is 50 mm² /s or less. The server system according to claim 9.
11. The kinematic viscosity of the cooling liquid is 35 mm² /s or less. The server system according to claim 10.
12. The thermal conductivity of the cooling liquid is 0.13 W/(m·K) or higher. The server system according to any one of claims 1 to 7.
13. The thermal conductivity of the cooling liquid is 0.15 W/(m·K) or higher. The server system according to claim 12.
14. Pigment ink is used for printing on the cable and the server device. The server system according to claim 5.
15. The server device body further includes a heat sink for cooling the processing unit, and the processing unit and the heat sink are connected via an iron bonding material. The server system according to claim 5.

Description

Article 30, Paragraph 2 of the Patent Law applies. See https://biz.kddi.com/beconnected/feature/2022/220119/ for details. (Published: January 19, 2022) Article 30, Paragraph 2 of the Patent Law applies. Published in the Nikkei Shimbun online edition. (Published: March 18, 2022) (URL: https://www.nikkei.com/article/DGXZQOUC24BTP0U2A120C2000000/) Article 30, Paragraph 2 of the Patent Law applies. Published in the Nikkei Shimbun online edition. (Published: May 30, 2022) (URL: https://www.nikkei.com/telling/DGXZTS00001540X20C22A5000000/) Article 30, Paragraph 2 of the Patent Law applies. Published in the Nikkei Shimbun. (Publication date: June 20, 2022) Applicable to Article 30, Paragraph 2 of the Patent Law. Disclosed to our business partner, SK hynix NAND Product Solutions Japan LLC (Solidigm Japan). (Date of public disclosure: February 16, 2022) This invention relates to a server system. Conventionally, techniques for cooling server equipment by immersing it in liquid are known. Patent Document 1 discloses an immersion cooling system in which ICT equipment inside a liquid immersion tank is cooled by the liquid immersion tank coolant, which is cooled by heat exchange between the primary cooling system refrigerant (whose heat is dissipated to the outside air by a chiller) and the immersion tank coolant via a heat exchanger. Patent No. 6919442 The configuration of the server system according to this embodiment is schematically shown.The physical properties of PAO 8 cSt, the liquid used in the prototype server system, are shown. [Server System S Configuration] Figure 1 is a schematic diagram showing the configuration of the server system S according to this embodiment. The server system S comprises an immersion device 1, a liquid flow path 2, a cooling water circulation device 3, a cooling water flow path 4, and a heat exchanger 5. The immersion device 1 is a device that houses at least a portion of the server device 6 and liquid L. Liquid L is a liquid that cools at least a portion of the server device 6. Liquid L is, for example, oil. Liquid L includes, for example, polyalphaolefin. As will be explained in detail later, the server system S is configured such that when the temperature of the liquid L flowing into the inlet 11 of the immersion device 1 is between 45°C and 60°C, the temperature of the liquid L flowing out from the outlet 12 of the immersion device 1 is between 60°C and 75°C. By setting the heat resistance temperature and operating temperature of the server device 6 to 75°C, the temperature of the liquid L surrounding the server device 6 can be kept below 60°C, thereby bringing the temperature of the server device 6 inside the immersion device 1 to an operating temperature. Therefore, the server system S can be operated without operating a special device for forced cooling. Specifically, by keeping the temperature of the liquid L below 60°C, it becomes possible to efficiently cool the liquid L to around 45°C using cooling water directly cooled at an ambient temperature of around 40°C or less, without operating a special device for forced cooling. As a result, the server system S can be operated continuously without the need to install special equipment for forced cooling. In other words, by raising the operating temperature of the server device 6, it becomes possible to eliminate the use of server room air conditioning and cooling water/refrigerant refrigeration systems, which were almost commonplace in the server technology field, thereby achieving the remarkable effect of significantly reducing total power consumption. The configuration of server device 6 will be described in detail below. The server device 6 comprises a server device main unit 61 and a network device 62. The server device main unit 61 includes an arithmetic processing unit 611, a storage device 612, and a communication device 613 connected to the network device 62. The arithmetic processing unit 611 is a device having a processor. The arithmetic processing unit 611 is, for example, a CPU (Central Processing Unit) and executes programs stored in the storage device 612. The storage device 612 is a device without a processor. The storage device 612 includes, for example, ROM (Read Only Memory), RAM (Random Access Memory), and SSD (Solid State Drive). The storage device 612 stores the program executed by the arithmetic processing unit 611. The communication device 613 is a device for electrically connecting the server unit 61 to the network device 62 using an electrical cable 63. The communication device 613 includes, for example, a LAN card. The network device 62 is a device for connecting the server unit 61 to an external device. The network device 62 may be, for example, a repeater hub, a switching hub, or a router. The immersion device 1 has an inlet 11 and an outlet 12. The inlet 11 has an opening through which liquid L flows in from the cooling water circulation device 3. The outlet 12 has an opening through which the liquid