Low carbon data center construction ideas and future trends

In recent years , With IT The rapid development of Technology , The demand for data processing capability is getting higher and higher , The demand for infrastructure services such as data centers has increased dramatically . At the same time, green development 、 The concept of energy conservation and environmental protection has gradually penetrated and developed in many industries , Become an important way to improve the comprehensive benefits of development . In China, carbon dioxide emissions will strive to 2030 Reach the peak of carbon by 2000 、 stay 2060 Under the vision of achieving carbon neutrality and energy efficiency dual control by , green 、 Energy saving 、 Low carbon data center development has become the focus . Relevant research shows that , The cooling system of the data center is the most power consuming part of the entire data center , Of total data center energy consumption 30%~50%. This paper analyzes the current situation of HVAC system in data center , Discuss the development path of low carbon data center , by “ Double carbon ” Provide suggestions on the planning and construction of the data center under the target .

Data center low carbon policy

At present , China has issued a series of policies to promote the green development of data centers .2020 year 12 month , National Development and Reform Commission 、 Central network information office 、 Ministry of industry and information technology 、 Jointly issued by the national energy administration and other four ministries and commissions 《 Guiding opinions on accelerating the construction of collaborative innovation system of national integrated big data center 》 It is proposed that , To 2025 year , The eastern and Western data centers achieve structural balance , large 、 Very large data centers run PUE No more than 1.3.2021 year 7 month , Issued by the ministry of industry and information technology 《 Three year action plan for new data center development （2021—2023 year ）》, Make it clear to 2023 year , New large and above data centers PUE Down to 1.3 following . Since the energy consumption of HVAC system accounts for a relatively high proportion of the total energy consumption of the data center , To make the data center PUE Compliance with policy limits , Reducing the energy consumption of HVAC system is the focus of the current data center .

Combined with the data center refrigeration system, this paper describes the green data center 、 Low carbon 、 modularization 、 The development direction of intelligent technology .

Status quo of data center refrigeration system

At present, China's data center refrigeration system is mainly divided into the following types ： Water cooling 、 The wind is cold 、 Indirect evaporation 、 Magnetic levitation phase change refrigeration and liquid cooling .

Water cooling system is the most commonly used cooling system in the data center at present , The comprehensive heat of the room is transferred to the outdoor cooling tower through the end air conditioner through primary and secondary heat exchange , The heat is transferred to the outdoor through the fan , More heat exchange losses lead to high energy consumption in system operation , And the water system pipeline is complex , There are many valves , Extremely unfavorable to operation and maintenance . At present, more and more users begin to pay attention to the energy-saving problems caused by the high energy consumption in the data center , The operating water temperature of the refrigerator in the water cooling system is directly related to the refrigeration energy consumption , Relevant research shows that , The average outlet temperature of chilled water increases every 1℃,COP Ascension approx 3.8%, The temperature of chilled water in the new data center is also gradually planned to 18/24 degree , The existing water-cooled data center can be optimized and transformed according to the actual situation , Save energy consumption in operation , With the water chiller and cooling tower 、 Improvement of plate material exchange process and heat exchange efficiency , At present, the average annual operation of the water cooling system is PUE Some areas can be lower than 1.3.

The air cooling system is mainly in the following four forms ：

• System 1. Air cooled chiller + Terminal precision air conditioner ;

  System 2. Direct expansion precision air conditioner + Outdoor unit ;

  System 3. Indirect evaporative cooling air conditioning ;
  

chart 1 Indirect evaporation unit and heat exchange principle

System 4. Magnetic levitation phase change refrigeration air conditioning ;

chart 2 Magnetic levitation phase change refrigeration system

According to previous data center planning and design experience , When the construction of data center is restricted by the impact of water resources , Will consider the system 1 And system 2 Air cooled form , However, high energy consumption has always been the focus of attention , The two air-cooled systems operate annually PUE Even as high as 2.0 above , Not in line with the current society “ Double carbon ” Data center construction requirements . With the increasing demand for energy conservation , Indirect evaporative cooling system 、 Magnetic levitation phase change refrigeration system has gradually replaced the traditional form of air conditioning , In terms of system form , By reducing the number of heat exchange links 、 Add energy-saving modules , Increased heat exchange efficiency , Extended free cooling service time , It solves the problem of traditional air cooling system PUE Too high a problem ; On system architecture , The refrigeration system is becoming more and more modular , Users can flexibly configure refrigeration power according to their own construction needs , On demand refrigeration , Reduced inefficient energy consumption . These refrigeration systems are gradually applied on a large scale with the construction of the national low-carbon data center .

Data center low carbon route development

Now ,“ Carbon reaches its peak 、 Carbon neutralization ” It has become a green energy-saving modern data center 、 Important guiding principles for ecological civilization planning , It poses more severe challenges to the development of the data center .

l Location of data center
Energy efficiency level and location of data center 、 technology 、 Management and other aspects are closely related . The location of the data center should consider the climate and regional factors as much as possible , Superior geographical location is a prerequisite for solving the high energy consumption of the data center . chart 3 yes GB50176 Five zones divided according to domestic climate parameters , At present, the data center is mainly clustered in , Annual average temperature in Guiyang 15.3 degree , The annual average temperature in Zhangbei and Wulanchabu areas is less than 10℃. Secondly, it is equipped with efficient power supply and distribution equipment 、 refrigeration unit 、 Intelligent control system, etc , Create powerful conditions for extremely low-power data centers .

In addition, the location of the data center can give priority to areas rich in renewable energy , Realize local consumption of renewable energy . Take Zhangbei area as an example , Relevant data show that the average annual utilization hours of wind energy in Zhangbei are 2400 hours , The average annual sunshine hours of solar energy are about 3000 Hours . During the Beijing East Olympic Games , Zhangbei renewable energy has realized all competition venues for the first time in history 100% Green power supply , For data centers , Not IT The priority of green power supply can be increased for the distribution of key facilities , Access to green energy , Green data center . Wind power 、 Photovoltaic 、 Energy storage 、 Pumping and storage and other forms of energy will be greatly developed in the future , In the future, the site selection of data center should include green and sustainable energy utilization into the measurement index .

l Data center liquid cooling

“ Low carbon ” The construction requirements of the centralized data center show that the traditional air-cooled direct expansion 、 High energy consumption refrigeration systems such as air-cooled chillers can no longer meet the current policy and market requirements , With cloud computing 、5G、 Big data network construction , The power of a single cabinet can reach 20kw、30kw, More and more attention has been paid to the cooling of server chips , Compared to air with low thermal conductivity , The cooling capacity of liquid is that of air 1000~3500 times , Liquid cooling has the advantage of ultra-high heat conduction , It has become one of the refrigeration systems in the data center .

There are three main forms of liquid cooling ： Submerged 、 Cold plate and back plate ;

Submerged liquid cooling can be divided into single-phase submerged type and two-phase submerged type according to whether there is phase change in heat exchange , In the single-phase immersion type, the device and the refrigerant always maintain the liquid state during the heat exchange process , Use the temperature difference of the refrigerant itself for convection or increase the power to strengthen convection ; Phase change refrigerant is used in two-phase immersion type , The refrigerant is vaporized after heating , Condense at the top of the cabinet and then flow back to the cabinet .

chart 4 Schematic diagram of submerged liquid cooling

In the cold plate liquid cooling, the working liquid is separated from the cooled object , The working fluid is not in direct contact with electronic devices , The heat of the cooled object is transferred to the refrigerant through high-efficiency heat transfer components such as liquid cooling plate . Some scholars have conducted energy-saving analysis on the adaptability of cold plate liquid cooling in different thermal zones in China , It is found that the plate liquid system PUE All are lower than 1.13, It has remarkable energy saving effect . The first batch of industrial standards for liquid cooling series in China, which was formulated by Xinhua Group III under Ziguang Co., Ltd., has been officially released , meanwhile , Xinhua III participated in the industry （ such as CCSA、ODCC And the Electronics Association ） Almost all liquid cooling standards are formulated . At present, we can provide customers with customized cold plate liquid cooling server .

The back plate liquid cooling also separates the working liquid from the cooled object , The working fluid is not in direct contact with electronic devices , Transfer heat to the cooling medium through the server fan .

chart 5 Schematic diagram of cold plate liquid cooling

chart 6 Schematic diagram of back plate liquid cooling

surface 1 Advantages and disadvantages of liquid cooling system

l Data center modularity

In recent years, the pace of data center construction and delivery has accelerated , modularization 、 Low granularity has become one of the mainstream demands of data center construction . The modular machine room has high flexibility , Users can purchase the data center by stages according to their own construction or lease 、 The construction of the , Each sub unit is relatively independent , It can adapt to a variety of scenarios , In the modular deployment mode ,UPS、IT equipment 、 Air conditioner 、 distribution 、 fire 、 lighting 、 Subsystem modules such as generic cabling can be stacked and deployed in the main production area of the machine room .

Modularity indicates high product integration to a certain extent , From the perspective of refrigeration, heat exchange and electrical transmission , More efficient conversion , Lower PUE, Meet the construction requirements of low-carbon data center , This is also the indirect evaporation of the current data center 、 Liquid cooling 、 The main reason why the form of high-voltage DC is favored .

l Intelligent data center

Data center intelligence means transforming the data center “ The brain ”, take AI Technology applied in data center , Build a neural network model through big data , Depth adaptive logic control , Establish energy consumption and IT load 、 Climatic conditions 、 Machine learning models such as the number of equipment running , Linkage control the operation mode of each subsystem , Accurately infer and configure the optimal control logic of the data center , Adjust parameters in real time , Lower data center PUE.

At present, the control unit area division in the data center is quite obvious , The control logic is relatively simple , Take the refrigeration system as an example , In order to make full use of natural cold source , Reduce the energy consumption of system operation , Set up the unit “ Dry condition ” Pattern , When the outdoor wet bulb temperature 、 When the water temperature under the cooling tower reaches a certain value , The cold mechanism stops , The end return water transfers heat to the cooling side through the plate exchanger . At present, the water cooling system of most domestic data centers is dry 、 The temperature and humidity during wet condition switching are at a fixed adjustment value , The temperature and humidity are actually disturbed by many factors , Outdoor parameters can be comprehensively considered , Modeling based on the measured data of the data center's perennial operation , To realize the dynamic intelligent control of the refrigeration system , Reasonably optimize the setting parameters , Maximize the use of natural cold sources .

chart 7 Xinhua 3 micro module data center

Sum up , With the country's low-carbon 、 The requirements of energy conservation are becoming more and more strict and people's awareness of environmental protection is improving , The green energy-saving rating of data centers is becoming more and more regular , In particular, high energy consumption in HVAC has always been the focus of social attention , This paper analyzes the main refrigeration systems used in domestic data centers , Let readers have an intuitive understanding of the energy consumption and development of the existing refrigeration system .

future , Under the new target, the construction of data center will start from site selection planning , Green solutions 、 Low energy technology products will play an important role , modularization + Intelligent data center will become the mainstream , Equipped with advanced liquid cooling system and efficient power transmission system , Intelligent tuning control will cover every corner of the data center , Realize green high technology to fill the entire life cycle of the data center . At the time , We will usher in the real era of low-carbon data center .

Data center is a big energy consumer , The transition to low carbon and energy conservation is an inevitable trend , Various low-carbon energy-saving technologies focusing on the cooling system of the data center will “ Double carbon ” Play a complementary role in the process , Drive the data center to gradually realize “ Carbon neutralization ” The goal is .