UBM Technology｜Air cooling? Liquid cooling? Come and see the new changes in the data center!

Latest update time：2023-11-15

Reads：

Wind chill? Liquid cooling?

New changes in data centers

With the development of science and technology, "data" is becoming more and more, and the safe preservation of data is an extremely important issue that almost all Internet companies and even companies that apply digitalization for business need to solve.

In addition to data stored locally, data on the network generally needs to be stored in rows of servers in the data center. A typical air-cooled supercomputer uses 30% to 35% of its energy just to keep the temperature low. A large number of servers consume a lot of power and dissipate an incredible amount of heat to the outside.

The "National Data Center Application Development Guidelines (2020)" report released by the Information and Communications Development Department of the Ministry of Industry and Information Technology shows that as of the end of 2019, the total number of data center racks in use in my country exceeded 3 million, with an average annual growth rate of more than 30% in the past five years. According to a special article in the People's Daily, the total electricity consumption of data centers across the country in 2020 accounted for approximately 1.5%-1.9% of the electricity consumption of the entire society in the same period. CCID Consulting predicts that with the rapid popularity of high-power single cabinets brought about by the rapid improvement of data center computing power, the average power of a single cabinet in global data centers is expected to reach 25kW in 2025.

Therefore, how to effectively cool down the data center is one of the key issues that needs to be solved in the future. In this issue of UBM Technology, Xiaoou takes everyone to understand the new applications of data center cooling.

air cooling

Conventional data center cooling is mainly based on air cooling technology. The basic principle is to transfer the heat generated by the internal components of the server to the air inside the computer room, through the cooling equipment in the building (such as air conditioners, etc.) or by introducing outdoor low-temperature air to the indoor hot air. Cool down. However, with the rapid increase in the scale of data centers and the introduction of a series of national policy requirements for green energy, shortcomings such as high energy consumption and poor stability of air cooling have caused everyone to begin to seek new technology applications.

liquid cooling

Liquid cooling, as the name suggests, uses liquid as the cooling medium to cool down the equipment. From common car engine coolants, to liquid cooling radiators in high-performance desktop computers, and even VC liquid cooling in newly released high-performance mobile phones, this technology is not unfamiliar to most people. But how does it apply to the data center?

Source: Xiaomi mobile phone official website

Liquid cooling servers are mainly divided into two types: direct cooling and indirect cooling. Direct cooling is mainly immersion liquid cooling, which can also be divided into phase change immersion liquid cooling and non-phase change immersion liquid cooling; indirect cooling is mainly cold plate liquid cooling. cold.

Immersion liquid cooling

Schematic diagram of the basic principle of immersed liquid cooling

The cooling technology that immerses the server in liquid and uses liquid as the heat transfer medium is called immersion liquid cooling. The entire system is divided into two parts: indoor and outdoor. In the indoor part, the heat emitted by the server is taken away by the low-temperature coolant. After the coolant heats up, it exchanges heat with the low-temperature water in the outdoor cooling tower in the liquid cooling heat exchange module and becomes low-temperature coolant again. The return flow continues to absorb the heat of the server. .

Cold plate liquid cooling

In cold plate liquid cooling, the server and the coolant are not in direct contact. The coolant is arranged in a radiator (cold plate) made of metal with good thermal conductivity. The heat of the server is conducted to the radiator, thereby achieving a cooling effect. Since cold plate liquid cooling has little impact on the structural design of existing servers, this technology is an early and relatively mature liquid cooling solution. According to the "2022-2023 Global Computing Power Index Assessment Report" data, in the incremental market in 2022, cold plate servers will account for 94.9%.

Spray liquid cooling

The "White Paper on Liquid Cooling Technology for Telecom Operators" released by China Mobile, China Telecom and China Unicom mentioned the third liquid cooling technology - spray liquid cooling. This is a technology that sprays insulating coolant directly onto the heating unit and achieves heat dissipation through convection heat transfer.

Liquid cooling has many advantages over air cooling, and industry development and innovation are also extremely active. Companies such as Huawei and Alibaba have also entered this track and launched a variety of products. However, in actual applications, since the initial construction cost of liquid-cooled data centers is about 10% higher than that using air-cooling technology, and the industry's standardization and standardization need to be strengthened, the product ecology is still in its infancy, which makes liquid cooling technology promotion faces some difficulties.

Alibaba Cloud liquid cooling products. Source: Intel official website

However, with the promotion of national policies, the continuous development of technology, and the vision given by the three major telecom operators in the white paper, it is expected that large-scale application of liquid-cooled data centers will be carried out in 2025, which will help promote the high-quality development of the industry as a whole. Pattern plays a crucial role.