With the acceleration of digital transformation and the rapid development of technologies such as artificial intelligence and cloud computing, the construction of computing power infrastructure with data centers as the core has become the core link in the development of the digital economy. According to the "2022-2023 China IDC Industry Development Research Report", in 2022, China's overall IDC business market will reach 397.56 billion yuan, a year-on-year increase of 32%. It is predicted that in the next three years, China's overall IDC business market will continue to grow at a rate of more than 35%. The Guangdong-Hong Kong-Macao Greater Bay Area is an important platform for my country to build a world-class urban agglomeration and participate in global competition and cooperation. It has strong economic strength, technological innovation capabilities and market potential. Under the guidance of the "Guangdong-Hong Kong-Macao Greater Bay Area Development Plan", continuously optimize and upgrade information infrastructure, actively develop the digital economy, and promote the application of digital technology in various fields. In February 2022, the National Development and Reform Commission and other departments agreed that the Guangdong-Hong Kong-Macao Greater Bay Area will start the construction of a national hub node of a national integrated computing power network, and the construction of the Guangdong-Hong Kong-Macao Greater Bay Area's computing power industry has entered a new stage. In this context, the 18th China IDC Industry (Great Bay Area) Annual Ceremony, sponsored by the China IDC Industry Annual Ceremony Organizing Committee and the Guangdong Data Center Industry Alliance and undertaken by the China IDC Circle, is scheduled for July 5, 2023 - Held in Shenzhen on the 6th. The theme of this conference is "Green Digital Intelligence Ecological Co-construction", inviting relevant government departments, industry associations, well-known enterprises, experts and scholars to discuss the development trend of computing power infrastructure in the Greater Bay Area, AI innovation, green development, and achievements Applications and other topics, share the latest technological achievements and lessons learned, promote the interconnection and innovative development of the computing power industry, and provide solid support for building a sustainable digital future. The conference set up a main forum and multiple sub-forums, covering hot topics such as data center construction layout, industrial development trend, artificial intelligence innovation and application, computing power infrastructure application in government affairs, finance, games, intelligent manufacturing, intelligent transportation and many other fields . As the largest, most representative and guiding industry event in the domestic data center industry, the China IDC Industry Annual Ceremony has been successfully held for 17 sessions. The previous conferences have accurately grasped the development trend of the industry, and have been highly recognized by the relevant departments of the Ministry of Industry and Information Technology of China and the industry, providing a platform for the industry to exchange technology and business.

Data centers are essential components of modern businesses, providing the backbone for many of the services and operations that keep companies running. As such, it is critical that data centers be designed and managed in a way that ensures maximum efficiency and reliability. One of the most important aspects of data center design is the use of Power Distribution Units (PDUs). PDUs (Power Distribution Units) are used in data centers to provide power distribution and management. They are used to distribute power from a central source, such as a UPS or generator, to multiple devices in the data center. PDUs also provide remote monitoring and control of the power distribution system, allowing administrators to monitor power usage and adjust settings remotely. This helps to ensure that all connected devices are receiving the correct amount of power, while also reducing energy costs by eliminating wasted electricity.PDUs provide a reliable source of power to all devices in the data center, helping to ensure that they remain operational at all times. A PDU is an electrical device used to distribute power from a main source to multiple outlets or devices. It typically consists of a metal box with several outlets on one side and a power cord on the other. The PDU can be mounted directly onto a wall or rack, or it can be connected via cables to other equipment in the data center. In addition to providing power distribution, PDUs also offer protection against overloads and surges, as well as remote monitoring capabilities. The use of PDUs in data centers has become increasingly important over time due to their ability to provide reliable power distribution and protection from electrical problems. This is especially true for larger data centers, where there may be hundreds or even thousands of devices requiring power at any given time. By using PDUs, these devices can be powered reliably without having to worry about potential problems caused by overloaded circuits or surges in voltage. Additionally, since many PDUs come with remote monitoring capabilities, administrators can easily keep track of their power usage and make adjustments as needed. In addition to providing reliable power distribution and protection from electrical problems, using PDUs in data centers also helps improve energy efficiency. By distributing power more efficiently through the use of multiple outlets on each unit rather than relying on one large circuit breaker panel, less energy is wasted during transmission and cooling costs are reduced due to lower temperatures in the server room. Additionally, since many PDUs come with advanced features such as metering capabilities which allow administrators to monitor energy usage more closely, they can identify areas where energy savings could be made and take steps accordingly. Using PDUs also helps improve safety within the data center environment by reducing risks associated with overloaded circuits or surges in voltage which could potentially cause fires or other damage if left unchecked. Since most PDUs come with circuit breakers built-in which automatically shut off when an overload occurs, this helps protect both personnel and equipment from harm’s way while still allowing for reliable operation when needed. Finally, using PDUs helps reduce downtime by ensuring that all devices remain operational even if one outlet fails due to an overload or surge in voltage thus avoiding costly downtime for businesses relying on these systems for their operations.

A few days ago, our company has successfully become a precision air conditioning supplier of Georgia HVAC Company, exporting 28 precision air conditioners, and its innovative strength has been affirmed again. We will continue to rely on precision air conditioners to escort relevant projects of the HVAC Company. The data center is one of the local pillar industries and plays an important role in the development of the national economy. Due to the special application environment of the industry, precision air conditioners must operate 24 hours without interruption to ensure a continuous cooling supply and avoid data loss, major environmental pollution, and huge economic loss caused by sudden power failure. At the same time, with the current deepening of global industrial upgrading and technological innovation, the HVAC industry has put forward stricter requirements and higher standards for industrial precision air conditioning systems. In this bidding, detailed evaluation rules have been set up for the production and manufacturing qualification, product comprehensive performance, after-sales service capacity, etc. of suppliers. In this regard, COOLNET actively organized a professional team to participate in the preliminary market research, product research and online technical exchange, mobilize all staff to respond and cooperate with relevant work, and finally become the precision air conditioning supplier of the project again with the advantages of high reliability, high customization, high service.

Micro-module refers to the micro-module data room, which is a product integrating power distribution, air conditioning, wiring, cabinets, fire protection, monitoring, and lighting systems of traditional server rooms into an integrated product, which can realize rapid and flexible deployment of the system, not only reduce the construction period but also comply with the policy in saving energy consumption, which is now a systematic way that people are more concerned about. Micro-modular data centers are designed to cope with changes in servers such as cloud computing, virtualization, centralization, and high density, improve the operational efficiency of data centers, reduce energy consumption, and achieve rapid expansion without affecting each other. Nowadays, the modular data center is one of the hottest concepts in data center construction. The modular construction method can significantly shorten the construction cycle of data centers, save the time cost that Internet companies value most, and make data center construction easy and fast. Among the various modular data center products, the miniature modular data center is the premier product. By 2013, Tencent completed the initial exploratory accumulation of micro-modular landing and began to prepare for the large-scale landing of micro-modular data centers. At the same time, many domestic companies also started to make attempts to build micro-modular data centers. Since 2013, new micro-module solutions have started to be deployed and applied nationwide one after another. As of the end of September 2015, the total number of micro-module data centers that have been landed in China has reached about 1,100 sets, with more than 400,000 servers built, which is nearly twice as much as in 2014, a very encouraging growth.

Spring Festival, commonly known as "New Year", "New Year", "New Year's Day" and so on, is a folkloric festival that integrates the removal of the old and the new, worship of gods and ancestors, praying for blessings and warding off evil spirits, family and friends reunion, celebration and entertainment, and food. Spring Festival", also known as "New Year", is a folk festival that integrates the removal of the old and the new, worshiping the gods and ancestors, praying for blessings and warding off evil spirits, family and friends reunion, celebration and entertainment, and food. Spring Festival has a long history and evolved from the ancient era of the first year of praying for the year's sacrifice. All things are originally from the sky, people are originally from the ancestors, pray for the year rituals, respect for the sky and the ancestors, and the beginning of the rewards. The origin of the Spring Festival contains a profound cultural connotation and carries a rich historical and cultural heritage in the inheritance and development. During the Spring Festival, various activities are held all over the country to celebrate the New Year, with strong local characteristics. In traditional agrarian societies, the Chinese New Year is of great significance and has given rise to a large number of folk cultures related to it. Although the calendar is different, the festive framework and many folk customs have been passed down throughout history. In modern times, people set the Spring Festival on the first day of the first month of the lunar calendar, but generally, the New Year does not end until at least the 15th day of the first month. The Chinese New Year is the first of all festivals and is the grandest traditional festival of the Chinese people. Influenced by Chinese culture, some countries and regions around the world also have the custom of celebrating Chinese New Year. According to incomplete statistics, nearly 20 countries and regions have designated the Chinese Spring Festival as a legal holiday for the whole or some cities under their jurisdiction. Spring Festival is one of the four traditional Chinese holidays, along with the Qingming Festival, the Dragon Boat Festival, and the Mid-Autumn Festival. The Spring Festival is a time to get rid of the old and bring in the new. Although the Spring Festival is scheduled for the first day of the first month of the lunar calendar, the activities of the Spring Festival do not stop on the first day of the first month. From the end of the year, people start to "busy New Year": sacrificing stoves, sweeping dust, buying New Year's goods, posting New Year's red, washing hair and bathing, decorating with lights, etc. All these activities have a common theme, namely "resigning the old and welcoming the new". Spring Festival is a joyful and peaceful, family reunion festival, but also a carnival of people to express their desire for happiness and freedom and the eternal spiritual pillar. Spring Festival is also a day to worship ancestors and pray for the New Year. Rituals are a kind of faith activities, which are created by human beings in ancient times to survive and expect a harmonious coexistence with heaven, earth, and nature. Coolnet team will be celebrating the Chinese New Year holiday from January 19 to January 28, 2023. We sincerely wish all our customers good health and all the best.

Recently, our company successfully became a UPS supplier of Saudi Aramco. The first batch of 100 UPS were exported, and our innovation strength was recognized again. We will continue to rely on UPS power supply to protect Saudi Aramco's related projects. Petrochemical industry is one of the pillar industries in Saudi Arabia and plays an important role in the development of national economy. Due to the special application environment of the industry and its dangerous characteristics such as high temperature, high pressure, flammability and explosiveness, industrial UPS power supply products must be configured for important loads such as instruments, industrial computers and displays, PLC cabinets, excitation cabinets and fire fighting instruments and meters to ensure continuous power supply and avoid personal injury, major environmental pollution and huge economic losses caused by sudden power failure. At the same time, with the continuous deepening of the current global industrial upgrading and technological innovation, the petrochemical industry has put forward stricter requirements and higher standards for industrial UPS power system. In this bidding, Saudi Aramco has set detailed evaluation rules for suppliers' manufacturing qualification, comprehensive product performance, after-sales service capacity, etc. In this regard, COOLNET actively formed a professional team, participated in the preliminary market research, product research and online technical exchange, mobilized all the staff to respond and cooperate with the relevant work, and finally became the uninterrupted power supply supplier of the project again with the advantages of high reliability, high customization, high service capacity, etc. In the future, we will continue to forge ahead and make every effort to provide more professional and high-quality services to our cooperative customers.

Sustainability Trends in Data Centers Although more and more data centers have become more conscious of sustainability over the past decade, data centers remain one of the world's largest consumers of electricity as data demand is growing exponentially. According to the EU JRC, the information and communication technology (ICT) sector, including data centers, generates 2% of global CO2 emissions. According to the Mandipiai (MDPI) journal, its share of CO2 emissions is expected to rise to 8 percent by 2030 if no further measures are taken. For data centers, the electricity used to operate equipment and cool facilities accounts for about 86% of the total data center energy consumption, with cooling alone accounting for 40%. According to Hong Kong IDC New Horizon Interconnection, under pressure from multiple sources including regulators, investors and consumers, the data center industry has taken action to study and adopt sustainable operating models in an attempt to limit its impact on climate change. Many data center companies, led by massive corporations such as Google, Microsoft and Amazon, have also made commitments to operate data centers with renewable or carbon-free energy by 2025 and plan to achieve climate neutrality by 2030. According to a recent study by Global Market Insights, the green data center market is expected to be valued at more than $175 billion (approximately RMB 1.2 trillion) by 2030. Data centers reflect the ratio of total data center energy consumption to IT load energy consumption through the energy efficiency index (PUE), and the closer the PUE value is to 1, the more efficient the energy use is. Data centers take up 3% of the world's electricity, how should the energy problem be solved? In order to bring data center PUE closer to 1 and move closer to sustainable data centers, whether building new data centers or converting old buildings into data centers, there may be PUE requirements for data centers around the world in recent years to design data centers from the perspective of energy saving and using renewable energy. Singapore, for example, has thus implemented a data center ban from 2019 and did not open its green data center pilot program until July this year, with new data centers required to meet sustainability regulations to keep PUE below 1.3. Data Center Sustainability Trends 1. Finding Alternative Alternatives to Diesel Fuel Data centers need to be equipped with backup diesel generators to deal with unexpected situations such as power outages. Today, many data center operators are trying to reduce their reliance on diesel and looking for greener alternatives. Many data centers today are exploring hydrogen-powered fuel cells as an alternative to backup generators. While current technology does not yet guarantee the reliability of hydrogen fuel cells as a complete replacement for diesel generators, it is still worthwhile to continue research and development of the technology because hydrogen fuel cells produce zero emissions and its only byproduct as a fuel is water. As many as 37 percent of data center managers are currently considering implementing this technology in the coming year. In September, Equinix partnered with the Centre for Energy Research and Technology (CERT) at the National University of Singapore's (NUS) School of Design and Engineering to test hydrogen fuel cell power for a local data center, and in December, Dutch data center company NorthC developed the Eindhoven data center in the Netherlands, a facility that will use natural gas or hydrogen as an alternative to traditional diesel power generation. The facility will use natural gas or hydrogen as an alternative to traditional diesel power generation. 2. Renewable Energy The use of renewable energy sources is not only beneficial to the sustainability of data centers, but can also help them overcome the challenges posed by the energy crisis, with solar and wind power being more commonly adopted in data centers. Some hyper-scale enterprises have also started to purchase renewable energy to power their data centers. In September, Digital Realty signed a 650 GWh wind-based renewable energy deal with a Spanish renewable energy company, and in November, Google signed power purchase agreements (PPAs) in Texas and Spain, acquiring 942 MW and 149 MW of solar energy, respectively, to power local data centers. In the same month, Microsoft signed an agreement in Canada to purchase 543 GWh of wind power per year. 3. More Efficient Airflow Management While data centers cool equipment through air-cooled systems, airflow management means maximizing cooling efficiency and energy savings by minimizing contact between the cold air used to cool the server room and the waste heat in the facility. Therefore, it is a higher requirement for data center design to enable the facility to better manage the heating, ventilation and air conditioning systems so that airflow management becomes a virtuous cycle. 4. Cooling technologies for high-density computing As applications such as artificial intelligence and cryptographic computing that require large amounts of high-density computing become more popular, this means that traditional cooling methods in data centers may no longer be efficient. According to Gartner, a global consulting firm, liquid cooling is 3,000 times more efficient than air cooling. According to marketsandmarkets' forecast for the data center liquid cooling market, the market has grown rapidly in recent years and is expected to grow at an even higher rate in the coming years, from $2.1 billion (about RMB 14.6 billion) in 2022 to $6.4 billion (about RMB 44.6 billion) in 2027, a compound annual growth rate of 24.8%. 5. Saving Data Center Energy Costs with AI Identifying energy waste through smart sensors and deploying software to manage energy consumption will be more effective than manually monitoring power and can minimize PUE. There are already cases of using AI to assist data centers in reducing energy consumption today. Google saved 40% of energy for its data center in 2016 through its AI DeepMind. 6. Waste heat utilization Data centers hosting more powerful and intensive computing means more heat will be emitted, and how to deal with this waste heat is a challenge for data centers to consider. In the current case of data center waste heat utilization, using the waste heat for district heating for the local area or using the heat for crop farming nearby is a good direction. For example, QTS recently chose to connect its Groningen data center in the Netherlands to a local heating project, providing 2.5MW of waste heat generated by the data center. In addition, there is also the Hokkaido Mizaka Data Center in Japan, which heats air and water with heat generated by servers in order to try to grow food such as mushrooms, Japanese mustard spinach, coffee beans, abalone and sea urchin. Overall, while data centers continue to have significant power consumption problems, it's easy to see that in recent years, major data center operators have been making efforts to meet their climate and carbon neutrality commitments by trying to operate in a more sustainable manner.

As the world becomes more and more accustomed to digital remote means to meet the demands of work and life, we need to keep upgrading IT and network capacity, which means building more data centers. As the core of the future digital world, the number and scale of data centers have been growing rapidly. National and local governments are also intensively introducing relevant policies to regulate their construction and operation in order to achieve the goal of efficient and sustainable development. I. Data Center Industry Continues to Grow Steadily The fourth industrial revolution driven by digital technology is bringing profound changes to human production and life, and data centers, as the physical base for carrying various digital technology applications, are gradually highlighting their industry-enabling value. Internationally, major countries around the world are actively guiding the development of data center industry, and the scale of data center market is expanding, with active investment and mergers and acquisitions, and increasingly fierce competition. Domestically, the development of the "new infrastructure" and the construction target of Digital China in the 14th Five-Year Plan have provided important guidance for the construction of China's digital infrastructure, and the development of China's data center industry has entered a new stage, with the scale of data centers steadily increasing and the pattern of low-carbon, high-quality and coordinated development. The scale of data center industry in China has steadily increased, and a pattern of low-carbon, high-quality and coordinated development is gradually taking shape. (1) In terms of scale, the number of new data centers worldwide is relatively stable, while China maintains rapid growth. Global data center additions are relatively stable. According to the annual increase of global servers, the scale of new servers put into use from 2015 to 2021 is relatively stable, and the net added value is also relatively stable, and the scale of data centers is expected to maintain steady growth in the next few years, as shown in Figure 1. China's data center rack scale continues to grow steadily, and the scale of data centers above large scale is growing rapidly. In recent years, the scale of data center racks in China has been growing steadily. According to the standard rack 2.5kW, by the end of 2021, the scale of data center racks in use in China will reach 5.2 million racks, with an average annual compound growth rate of over 30% in the past five years. Among them, the rack size of data centers above large scale is growing more rapidly, with 4.2 million racks according to the standard rack 2.5kW, accounting for 80% of the rack size. (2) Revenue, the global market is growing steadily, and China maintains a high growth rate In terms of data center market revenue, the global data center market size will exceed US$67.9 billion1 in 2021, up 9.8% from 2020. The market revenue is expected to reach $74.6 billion in 2022, with an overall stable growth rate, as shown in Figure 3. Driven by national policies such as new infrastructure, digital transformation and Digital China Vision, as well as enterprise demand for cost reduction and efficiency improvement, China's data center business revenue continues to grow at a high rate. In 2021, the market revenue of China's data center industry will reach about 150 billion RMB2, with an average annual compound growth rate of 30.69% in the past three years. (3) Demand, strong demand in emerging markets and diverse application scenarios in China The "Digital India" plan launched in 2015 provides a continuous boost to India's digital development, and the construction of large data centers is an important part of the plan. In 2021, South Africa's Department of Communications and Digital Technology released a draft National Data and Cloud Policy, which provides guidelines for the construction of a National High Performance Computing and Data Processing Center, which will be a merger of the existing Sentech and Broadband Infraco data centers, and will provide cloud services to all levels of government, enterprises and universities. These data centers will provide cloud services to all levels of government, enterprises and universities. The government-led data center construction will lay a solid foundation for the development of South Africa's digital economy. In terms of market, India is becoming increasingly rich in smart devices and digital consumption scenarios, with a surge in demand for data reckoning and storage, while the intensification of the new crown epidemic has shifted more offline business activities to online. Multinational companies remain optimistic about the development of India's digital economy and are strengthening their digital service capabilities through data center construction. Amazon is investing $2.8 billion in 2020 to establish a new service area in Telangana, India, which will be Amazon's second cloud computing region in India. (4) Competition, Expanding Arena, M&A to Drive Stronger Players In order to enrich business sources, the top data center operators are actively expanding outside their home markets and expanding their industrial footprints. Basic telecom operators, such as China Telecom, China Mobile, CenturyLink and NTT Communications, and third-party data center operators, such as Equinix, Digital Reality Trust and Universal Data, have already held large-scale data center resources in the local market by virtue of their early start in construction. In the course of their development, basic telecom operators and third-party data center operators have relied on their resources, capital and technological R&D advantages to accelerate their data center deployment globally by cultivating their own brands, expanding international marketing channels and providing a full range of data center services. For example, Equinix, the world's leading data center operator, has data centers in Singapore, Hong Kong, Tokyo, Sydney, and Jakarta; UP Data will have a preliminary market presence in Southeast Asia by 2021 and will invest in mega data center parks in Malaysia and Indonesia; and China Mobile International Limited (CMI) will commission its data center in Frankfurt, Germany, by 2021. The global data center arena will further expand as more and more giant companies move beyond their local markets and actively expand their data center footprints.

Reviewing 2021, along with the digital economy, the explosive growth of data volume is driving the expansion of the data center industry, and at the same time, data centers are developing in a more energy-efficient and low-carbon direction. 2022 has already started, what kind of changes will happen in the development of data centers? What aspects will undergo more in-depth innovative changes? Which technologies will reach wider application popularity? And what will be the overall development trend? 1.Data center will be green and integrated Looking back on the past 2021, it was really an extraordinary year, especially for the IDC industry, we saw that the epidemic was still raging around the world, and the sharp rise in coal costs caused an unprecedented power shortage, which in turn led to a significant increase in electricity prices. At the same time, the country released the "East is West" plan, and China announced to the world an epic energy revolution policy: carbon neutral and carbon peak, 2021, these drastic changes bring huge challenges to the IDC industry. At the same time, change also means opportunity, and IDC companies need to dynamically adapt to the external environment and policies to begin with the end in mind and seek a path to long-term stable development. For the coming 22 years, the IDC industry is mainly adapting to changes and constantly adjusting its own strategy for the year, and needs to continuously create value for customers with its own advantages and continuous innovation. In 2022, the digital economy will become the main line of global economic development. As the infrastructure of the digital economy, data centers play a fundamental role in supporting the take-off of the digital economy, and with the further development of the digital economy, the growth of data center demand is bound to be driven. However, while growing, we also need to pay attention to our national guidance on the healthy development of the data center industry. 2022, green, low-carbon and energy-saving will become the most core keywords for the sustainable development of data centers. 2.Data centers will develop rapidly and comprehensively, and continue to change and innovate Looking back to 2021, driven by both policy and demand, the industrial scale of China's IDC has approached 100 billion, the market investment scale has rapidly increased, and China's data center has officially stepped into the era of traffic enhancement. meta-universe is also exceptionally hot in 2021, and major central enterprises, unicorns and head Internet enterprises have entered meta-universe, and the importance of data assets and data center has been significantly increased again. Then, 2022 will be a year when the digital economy is riding high and the IDC industry will develop rapidly. In 2022, the whole data center industry will move from resource-driven to innovation-driven, and the data center market will enter the value competition stage. Medium and high density cabinets, elastic architecture, low carbon and energy saving, rapid deployment, AI intelligent operation and maintenance, security and trustworthiness will also be the main trends in the evolution of data center technology.

Characteristics of liquid cooling method 3.1 Make full use of the natural cooling source, energy-saving effect is obvious Liquid-cooled cabinet can make full use of the outdoor cooling source. Liquid-cooled cabinets in addition to cold plate liquid cooling, general spray and submerged liquid cooling of the server side in and out of the coolant temperature of 40 ℃ ~ 45 ℃, while the ambient temperature of the outside of the room can generally meet the requirements of the coolant cooling, spray and submerged liquid cooling can all use outdoor cold sources for server cooling, the overall PUE effect to improve significantly, and can make full use of natural cold sources, energy-saving effect is extremely The overall PUE is significantly improved, and natural cooling sources can be fully utilized, resulting in significant energy savings. The PUE of all three liquid cooling methods can reach below 1.2, especially the spray and submerged liquid cooling system is more obvious, saving about 20% of air conditioning power compared to air cooling, plus the elimination of the internal fan of the server, the IT part of the power can save 13% to 25%, the overall energy saving effect is more than 40%. For the current carbon emission, submerged and sprayed liquid cooling has a high temperature on its output water side, which has the value of waste heat recovery and utilization. If combined with partial waste heat utilization, the energy saving effect will have a significant space for improvement, and also can reduce the carbon emission intensity of the overall data center. 3.2 Low noise can be achieved in the server room The noise in the server room mainly comes from the server fans. According to the current national regulations, the noise value measured at the main operator position in the manned mainframe room and auxiliary area should be less than 65dB(A) when the electronic information equipment is down. As large data centers continue to emerge, it is becoming common for data centers with host rooms containing hundreds of network devices in size. When these devices are working at the same time, most of the noise is close to or exceeds 65dB, which is the noise value tested under normal operation and 50% to 60% load of the equipment, and can only be higher if working at full speed with adjustable fan speed. When the environmental noise exceeds 80dB, personnel have been unable to work in the environment for a long time, and the laws of Europe and the United States also provide that if the noise in the workplace reaches 80dB to 85dB, the corresponding occupational protection must be provided. Even if the cold plate type liquid cooling is used, the general fan works at a lower speed and the noise is lower than the conventional air-cooled form, so the noise value is greatly improved. In addition, due to its own characteristics, the liquid cooling system reduces the part of conventional cold sources (such as chillers, air conditioning outdoor units, etc.), which can also largely reduce the noise impact on the environment, and is relatively easy and friendly for the arrangement of the data center and the surrounding environment. 3.3 Small footprint Due to the simple structure of liquid cooling system, it can make full use of natural cooling source and reduce the layout of conventional data center's cooling source and ancillary equipment and pipeline, the system is simple and occupies a small area, plus the general liquid cooling cabinet can achieve high power density, which can realize 10~50kW power, saving a larger area than conventional. 3.4 Flexible system layout transformation Due to the small footprint of liquid cooling system, the simplicity of the system, the advantage of using natural cooling source, and the possibility of achieving high power density, the convenience can be greatly improved for the transformation or expansion of the data center. 3.5 Low environmental requirements for server rooms For submerged and cold plate type liquid cooling system server room, there is no positive pressure requirement for the server room, and there is no additional requirement for the neatness of the server room, and the requirement for the decoration of the server room such as wall and floor is low. Moreover, as the environment of the server room is mainly to meet the needs of personnel maintenance. The number of precision air conditioners and the arrangement of air conditioning rooms are reduced, and conventional air-cooled ends can be used, and the overall reliability of the server room's cold source needs are reduced. 3.6 Server reliability is improved and life span is extended 3.6.1 Low chip operating temperature and reduced energy consumption Since the conversion efficiency of liquid energy efficiency far exceeds that of air, and the liquid cooling system can directly dissipate heat to the chips and other key components of the server, the heat dissipation is precise and efficient, so the operating temperature of the key components of the server is significantly lower than the conventional air cooling heat dissipation temperature, and the temperature is constant, and the system can continue to run at high load, doubling the efficiency; and since the spray liquid cooling and submerged liquid cooling remove the server system fan, they can directly The energy consumption of the server is reduced by about 15% to 25%, while the cold plate type is reduced by about 5% to 10%. 3.6.2 Improved server lifetime The increase of server life is mainly reflected in two aspects. ① As the chip works mainly at a lower temperature and at a constant temperature, when reducing the vibration of the fan work (spray and submerged liquid cooling), it can significantly improve the life of the chip. ②Since the spray and submerged liquid-cooled server room is submerged in the coolant, the server does not need to be in contact with the air in the room, avoiding the accumulation of airborne dust and other particles in the server that can cause equipment failure. In addition, it also directly reduces the corrosion of the servers by moisture and dust in the environment, which improves the reliability and extends the service life of the equipment. 3.7 Low equipment maintenance expenses Compared with the spray and submerged liquid cooling, cold plate type liquid cooling system operation and maintenance costs are high, even more than the air-cooled system, mainly because of its use of pure water equipment operation and maintenance expenses are relatively high, and with the use of years of growth in costs almost doubled. Spray and submerged liquid cooling system has a simple structure, the number of components of the equipment is small, such as the number of equipment that eliminates the refrigeration host, air-cooled air conditioning, the probability of equipment failure will be reduced. In terms of the whole life cycle of the equipment, on the one hand, it reduces the spare parts of the equipment, and on the other hand, it can also reduce the manpower expenditure of the maintenance part at a later stage. The cold plate type is an additional set of liquid cooling pipes compared to the air-cooled system, and the system is more complicated. However, the coolant of partial immersion liquid cooling system uses fluorinated liquid phase change method, which requires overall shutdown for maintenance, and there is difficulty in maintenance, and the filling volume of liquid cooling coolant is the largest. From the three forms, the spray liquid cooling system, in addition to having a simple system, can do online maintenance, maintenance costs in the three for the lowest, overall in the later equipment life-cycle management, the overall maintenance costs of expenditure is the simplest, is the best one of the three ways. 3.8 Large upfront investment in equipment As liquid-cooled equipment is still in its infancy, the current liquid-cooled form is extremely small compared to traditional air-cooled rooms, coupled with some key materials such as coolant and other temporary monopoly by some companies, compared to conventional rooms, the initial investment in equipment is larger, and because some of the equipment needs to be customized, such as servers, when the required number of small cases, the cost is higher, the general initial investment for the traditional room 3 times More than. When the single cabinet management equipment density in more than 20kW and more than 500 cabinets, the cost will have a greater reduction. 3.9 Customer acceptance needs to be improved Liquid-cooled cabinets belong to a newer way, at present, customer acceptance is not as good as the acceptance of conventional air-cooled cabinets; because of the current investment in liquid-cooled rooms and the power density of the cabinets is greater, but with reference to the current social molding cases, the general power of liquid-cooled cabinets in 10 to 20kW or more, it is difficult to reach customer acceptance, the current basic use or transformation for own users, I believe that later with the liquid-cooled It is believed that with the promotion of liquid-cooled cabinets, the acceptance level of customers will be improved. Conclusion In summary, the advantages of spray liquid cooling compared with the other two liquid cooling methods are mainly reflected in the low weight of the server room, less coolant filling, simple system and low noise in the server room. Combined with the current characteristics of data scaling, there is a large utilization space in the application of server room renovation, upgrade of enterprise self-use server rooms, BBU small units in the communication industry, and there is a huge energy-saving potential in the use of natural energy, which is a new data center cooling method worth recommending.

This paper introduces the traditional heat exchange methods in data centers and the three liquid cooling methods commonly used at present, and describes the composition forms of the three liquid cooling methods, compares the advantages and disadvantages of each of the three liquid cooling methods, and introduces them in a targeted manner in terms of energy saving, noise, land occupation, arrangement methods, environmental requirements, server reliability, maintenance expenditures and customer acceptance, respectively. Keywords: data center; liquid cooling; cold plate; spraying; submersion 1 Introduction of liquid cooling system The traditional data center cooling method is air cooling, i.e., using air as the refrigerant to transfer heat to the heat-generating parts of the server and take away the heat. The IDC liquid cooling system is a technology that uses liquid instead of air as the refrigerant to heat the heated parts and take away the heat. When using liquid cooling method, it is necessary to use liquid cooling server. This server refers to a server that injects liquid into the server to take away heat from the server through cold and heat exchange. The composition of the liquid cooling system mainly contains the primary side heat exchange part and the secondary side heat exchange part. The primary side refers to the loop that takes away heat from the server and carries out the loop medium for heat dissipation on the secondary side, and the secondary side refers to the loop that discharges heat from the primary side to the outdoor environment or other heat recovery units. 2 The main forms of liquid cooling methods Liquid cooling forms are mainly divided into spray type, cold plate type and submerged type, the main difference between the three is reflected in the different ways of heat dissipation to the server. Spray liquid cooling is the coolant through the spray on the server cooling components to take away the heat generated by the server; cold plate liquid cooling is in the server CPU and other large power consumption components using liquid cooling plate cooling, other small number of heat generating devices (such as hard disk, interface cards, etc.) still using air cooling cooling system; submerged liquid cooling refers to the server's heat generating components completely submerged in the coolant, through the coolant of the convection or phase change of the coolant to remove the heat of the server cooling system. Secondly, spray submerged servers do not have fans, while fans exist in cold plate servers. The details are described as follows. 2.1 Sprayed liquid cooling system Spray direct liquid cooling is a precise spraying, direct contact liquid cooling technology for electronic equipment devices. Coolant can be sprayed directly onto the heat-generating devices of IT equipment or the solid heat-conducting materials connected to them through gravity or system pressure, and heat exchange with them to achieve thermal management of IT equipment. In the process of heat exchange, the free liquid level of the coolant in the IT equipment is lower than the heat generating device or the solid heat-conducting material connected to it, and the system can exchange heat to the coolant through the heat exchange unit outside the IT equipment to meet the requirement of recycling. 2.2 Cold plate type liquid cooling system The basic working principle of cold plate type liquid cooling cabinet is described as follows: using cold plate assembly and high heat flow density components contact, heat generation through the cooling media in the cold plate assembly export, and then through one or more cooling circuit heat exchange transfer, and finally the equipment heat will be distributed to the external environment or recycling a liquid cooling realization method. 2.3 Submerged liquid cooling system The basic working principle of submerged liquid cooling cabinet is described as follows: a form of heat dissipation by submerging the electronic information equipment in the coolant and taking away the heat by the coolant. According to the different forms of coolant heat dissipation process, it is divided into phase change and and single-phase liquid cooling.

The stable equipment in the computer room is based on stable environmental factors such as normal temperature, no water leakage, and no fire hazard. The premise of determining whether these factors are stable is to have a set of environmental parameters monitoring system in the computer room configured according to the conventional configuration, so as to realize the environmental management before, during and after the event. What are the functional characteristics of the conventional computer room environmental monitoring system? 1. Monitor environmental parameters such as temperature change value, relative humidity percentage, presence or absence of smoke, infrared monitoring status, water immersion, air-conditioning outlet temperature, and computer room set temperature. 2. It can count a large amount of measurement information, and use logic programs to analyze the dynamic changes of temperature control equipment and environmental parameters. 3. In case of unbalanced temperature, accumulated water, etc. monitored by the system, an alarm message can be sent to the person in charge of the computer room by text message or phone immediately, and the abnormal environment can be dealt with in time. 4. Monitor the status of multiple devices in real time and support the query of detailed device information 5. You can use IE, Google, QQ and other browsers to log in to the system, remotely and instantly understand environmental information, and support advanced equipment linkage control. 6. The software is based on an efficient, convenient and highly distributed B/S architecture, and adopts the mainstream ARM chip for embedded computer room environment monitoring. The program is written and implemented in rigorous and accurate C++ programming language, which can prevent viruses and intrusions, and ensure the stability and reliability of system operation to the greatest extent. After using the enterprise computer room environmental parameter monitoring system, the pressure and difficulty of the staff are reduced, and the essential improvement has been seen from the perspective of long-term maintenance and safety. At present, the system has been applied in computer rooms in different industries in China, and has become a key factor in maintaining the stability of the computer room environment.