It is worth mentioning that in order to transmit data with high bandwidth, data centers now generally use optical fiber instead of network cables. Therefore, optical fibers, optical modules and optical communication equipment (OTN, etc.) have become important components of the data center.

 

Especially for optical modules, high-speed optical modules (such as 400G) are very expensive and account for a large part of the cost of the data center, which restricts development.

There is also a popular optical communication term called DCI, which is Data Center Inter-connect. Nowadays, distributed deployment is popular, and the data traffic between data centers is very large, which requires high bandwidth.

 

Therefore, operators and cloud service providers engage in DCI and build specialized optical communication backbone networks between data centers, which is a large market.

 

The "digital calculation in the east and in the west" that our country engages in involves the interconnection of data centers, which has a stimulating effect on the DCI-related market that cannot be ignored.

Grouped equipment

 

Next, let’s look at the supporting supporting equipment and facilities of the data center.

 

Let’s look at power supply and distribution first.

 

Power supply is the basis for the normal operation of the data center. Without electricity, data centers are scrap metal.

 

The main function of the power distribution equipment in the data center is to switch on and off, control and protect electric energy. The most important power distribution equipment is the power distribution cabinet.

 

Data center power distribution cabinets are divided into medium voltage power distribution cabinets and low voltage power distribution cabinets. The medium-voltage distribution cabinet is mainly of 10kV voltage level. It is connected to the mains power upward and the low-voltage distribution cabinet downward. Low-voltage distribution cabinets are mainly 400V voltage level, which further converts, distributes, controls, protects and monitors electric energy.

In addition to power distribution cabinets, in order to ensure normal power supply in emergencies, data centers are also equipped with a large number of UPS (uninterruptible power supplies) and even diesel generator sets.

 

"UPS + mains power" is a traditional power supply solution. Nowadays, the more popular solution is the "HVDC+mains power" solution.

 

HVDC is High Voltage Direct Current, high voltage direct current transmission. The difference between it and UPS involves relatively complex knowledge of strong electricity, which will be introduced later when I have the opportunity.

 

In short, "HVDC + mains power" is more reliable and safer, and its power supply efficiency is stronger than "UPS + mains power". It is the mainstream development trend of uninterruptible power supplies.

 

Let‘s talk briefly - 48V and 220V.

 

Students who have practical experience in the ICT industry know that IT equipment such as servers usually use 220V AC, while core network, wireless and other communication equipment mostly use -48V DC.

 

Mains power supply is usually AC. Data centers generally provide both -48V DC and 220V AC (through AC-DC conversion and DC-AC inverter conversion).

 

In fact, DC is now becoming the choice of more data centers (such as Google) because DC has smaller losses and higher utilization of power energy, which is in line with the current trend of high energy consumption in data centers with high computing power.

 

Let’s take a look at cooling.

 

The refrigeration system is the second largest energy consumer in the data center after the main equipment. Regarding the power consumption data of the data center, I have introduced it in detail in the article "Counting the East and Counting the West", so I won‘t go into details here.

 

Currently, data center cooling mainly includes two methods, one is air cooling and the other is liquid cooling.

 

Air cooling generally uses air-cooled air conditioning systems. Like our home air conditioners, data center air-cooled air conditioners are also divided into indoor units and outdoor units. Relatively speaking, the technology is mature, the structure is simple, and it is easy to maintain.

 

Liquid cooling uses liquid as a refrigerant to cool down and dissipate heat.

 

The thermal conductivity of liquid is 25 times that of air. Under the same volume, the heat carried away by liquid is nearly 3,000 times that of air. From a noise perspective, at the same heat dissipation level, the noise of liquid cooling is 20-35 decibels lower than that of air cooling. From the perspective of energy consumption, liquid cooling saves 30%-50% of electricity than air cooling.

 

At present, liquid cooling technology is generally optimistic about the industry, but it is still in the exploratory stage. Overall, the market prospects for liquid cooling are very broad, and it is said that the market size exceeds 100 billion.

Regarding cooling and heat dissipation, it is worth mentioning that near-end cooling methods such as cabinet pool level, row level and cabinet level are emerging and becoming the mainstream choice for new data centers.

 

Traditional refrigeration is at the room level, where the entire computer room is air-conditioned and refrigerated. This method has a too long cooling path and is too inefficient. It cannot meet the cooling needs of high-power-consuming equipment and consumes a lot of energy.

 

Cabinet pool level, row level and cabinet level are based on a cabinet pool, a row of cabinets or a single cabinet as the center for heat dissipation design.

In this way, the airflow path is significantly shortened and the heat dissipation efficiency is very high.

 

In addition to power distribution and heat dissipation and refrigeration, the data center also has some equipment and facilities related to management and operation and maintenance, such as dynamic environment monitoring systems, building automatic control systems, fire protection systems, etc.

 

Dynamic environment monitoring refers to power and environment monitoring, which monitors and manages the operating status of the data center in real time.

 

In recent years, based on the traditional dynamic environment monitoring system, DCIM has begun to evolve.

 

The full name of DCIM is Data Center Infrastructure Management, which was proposed by Garter, a well-known consulting company. Its management scope is more comprehensive, using tools to monitor, manage and control all IT main equipment and supporting infrastructure in the data center.

The fire protection system in the data center is quite interesting. Because the computer room is full of electronic equipment, if a fire occurs, you must not spray water, foam or dust directly.

 

then what should we do? Gas fire extinguishing.

 

After a fire occurs, the fire and smoke sensor alarm sounds, and then the computer room area can release inert gases such as argon and nitrogen to deprive the flame of oxygen and extinguish the fire (it can be done in about tens of seconds).

 

Modular data center

 

The data center is a huge system, the construction process is very complicated and cumbersome, and the construction period is also very long. In recent years, in order to deploy data centers more quickly and flexibly, manufacturers have introduced the concept of modular data centers.

 

To put it bluntly, it is to integrate the data center‘s structural system, power supply and distribution system, HVAC system, fire protection system, lighting system, integrated wiring, etc. into "building blocks" one by one. Then, after transporting the "building blocks" to the site, they can be simply hoisted and set up to complete the construction and deployment.

 

Using this method, the construction cycle of large data centers is reduced from 18-24 months to about 6 months, and the economic benefits are obvious.

 

3. Conclusion

 

Okay, the above is an introduction to the data center.

 

As I said before, data centers are an important information infrastructure in the digital era and an important carrier of computing power, which directly determines the country‘s digital competitiveness.

 

Driven by the “digitize in the east and calculate in the west” strategy, domestic data centers will usher in another wave of development boom. According to statistics, my country‘s data center business market size will reach 320.05 billion yuan in 2022, with an average annual compound growth rate of as high as 27.0%. In 2025, the scale of domestic data center IT investment is expected to reach 707.09 billion yuan.

 

In addition to the surge in number, data centers are developing in a green and intelligent direction, actively introducing AI to improve energy efficiency and reduce operational complexity.

 

Let us wait and see whether there will be new changes in the form of data centers in the future!