Data center, that is, the building site where centrally placed electronic information equipment provides the operating environment, including the main computer room, auxiliary area, support area and administrative area. This paper mainly introduces the scheme layout, fire protection design, mechanical and electrical scheme architecture-related design, etc., and analyzes the key points of conventional architectural design of data centers for reference by design peers.

1. Introduction

With the deepening of digital transformation in our country's regions and industries, our country's data center market size will maintain a continuous growth trend, and the data center projects contacted by our institute are mainly about 6kW per rack, and in the future, with technological progress and the owner's acceptance of new technology applications, there will be more and larger single-power racks put into the market. This paper mainly takes the case of single-rack power design projects based on 6kW as the main analysis object, focusing on the analysis of the problems encountered in the process of data center architectural design and the summary of engineering experience, for the reference of the same industry.

2. Determination of early demand and scale

In the early stage of building the data center, the owner needs to have a professional pre-development team evaluate the feasibility of the project, select the development city and pre-selected project land, and track the development land of the pre-selected project in a timely manner with the land and resources management department.

If an enterprise needs to determine an investment project, it should go to the National Development and Reform Commission or the management department of the Economic and Information Commission to file and approve the project, and at the same time follow the following steps to hire a unit with relevant qualifications to cooperate in the preparation of the corresponding application documents:

1.1 Hire a professional energy-saving company to prepare a project energy-saving report and submit it to the management department of the National Development and Reform Commission for review and approval.

1.2 Submit environmental impact assessment materials to the management department of the Environmental Protection Bureau for review and approval;

1.3 Submit traffic impact assessment materials to the management department of the Transportation Bureau for review and approval;

1.4 Submit the power supply scheme design documents and requirements to the management department of the power bureau for review and approval;

1.5 Submit the design documents and requirements of the water supply plan to the management department of the Water Affairs Bureau for review and approval.

At the same time, it is necessary to track and confirm the relevant processes of land bidding, auction and listing, and do a good job in signing the state-owned land transaction contract, do a good job in approving the relevant construction land use conditions by the planning bureau, provide the design institute with architectural planning and planning documents in a timely manner, provide them to the planning department for review and confirmation, and approve the construction project planning permit.

This part belongs to the civil engineering application stage, generally the new data center project development process is in accordance with the large open space Class C plant application regulations, to the subsequent construction drawing design qualification, the civil engineering development and construction stage, this stage of civil engineering construction drawings should implement the civil engineering related conditions of mechanical and electrical process design, so as to avoid subsequent mechanical and electrical deepening to increase unnecessary construction costs.

After the approval of energy conservation and the approval of the regulations, the construction scale of the construction project, the number of total racks, the total electricity consumption and other indicators will be determined, and the deepening of mechanical and electrical engineering should also be carried out before the civil engineering declaration, so as not to affect the revision of the subsequent mechanical and electrical declaration documents.

Figure 1

3. Data center classification

The construction scale and requirements of various types of data centers vary greatly, so the data center should confirm the level requirements of the data center of the project with the owner before construction.

According to the Data Center Design Code (GB50174-2017), data centers are mainly divided into three levels: A, B, and C:

During operation, the site equipment should not be interrupted due to operation errors, equipment failures, external power supply interruptions, maintenance and overhaul.

The B-level electronic information system computer room should be set up in accordance with the redundancy requirements, and the site equipment should not cause the electronic information system to operate due to equipment failure within the redundancy capacity.

The C-level electronic information system computer room should be configured according to basic needs to ensure that the operation of the electronic information system is not interrupted.

4. Data center site selection and general plan planning

4.1 Data center site selection

The specific demand area should be considered first, and it should be as close as possible to the main application city, and at the same time, issues such as electricity, communication, transportation, water sources, and natural environment should be considered:

4.1.1 Electricity

The electricity consumption of data centers is generally relatively large, and the power supply and stability of electricity consumption in construction sites should be examined.

4.1.2 Communications

Data centers should be close to core network nodes to reduce network latency;

4.1.3 Transportation

There are as many roads as possible and smooth to meet the needs of timely support;

4.1.4 Water sources

The heat dissipation of the data center is mainly solved by the air conditioning system, of which there are two main ways, the first is air cooling and heat dissipation, the second is water evaporation heat dissipation, the water consumption per kilowatt of IT equipment per day is about 100L, the following formula: circulating cooling water (m³/h) = IT load (KW) x (0.25~0.30), hourly water replenishment is: circulating water (m³/h) x 1.4%, a day is 24h; For example: 6000kw IT equipment, the daily water consumption is: 6000x0.25x0.014x24=504 tons, a year needs 504x365=183960 tons, therefore, the water source of the refrigeration data center using water evaporative cooling method should be sufficient;

4.1.5 Natural environment

The construction of data centers in different regions will cause different costs due to different indicators such as ambient temperature and air cleanliness, and the choice of areas that are as conducive to energy conservation as possible will be selected.

4.2 Master plan planning

For the selected construction land plots, the main content design should be mainly considered when meeting the planning technical conditions:

4.2.1 Vertical design

The absolute elevation of the first floor of the newly built A-level data center should be more than 1.0m higher than the water level line of the local flood century-old return period, and should be more than 0.6m higher than the outdoor floor, and should be higher than the absolute elevation of the surrounding roads to prevent waterlogging.

 4.2.2 Phased planning

The general data center is divided into civil construction stage and mechanical and electrical stage, and the owner will generally implement it in stages in order to control the investment to meet the needs of capital and customer changes; The civil engineering development stage is mainly declared as a large open Class C workshop, and after completion and acceptance, mechanical and electrical construction is carried out, which may involve demolition and structural reinforcement for large changes in customer demand.

4.3 Building layout

The layout of each building in the general plan should also consider the fire spacing requirements, fire lane layout, diesel steel platform, cold storage tank layout, oil storage tank location, sunlight on surrounding plots, noise impact, truck transportation path and turning radius loading and unloading operation distance, rainwater collection pond, underground pipe ditch location, etc.

Figure 2 The layout of the general drawing of the project case

5. Data center architectural design

5.1 Layout

5.1.1 Installment requirements

The graphic design of the data center should also be planned in phases according to the owner's operational needs, such as by floor or by computer room. The owner of the same data center building may lease to N tenants, but each lessee has different requirements for data cabinets due to different business needs.

5.1.2 Rack size and spacing

Among them, the conventional size of the rack (width mm× depth mm× height mm) IT equipment: 600×1200×2200;

Transmission equipment: 600×600×2200.

When the length of the racks arranged in rows does not exceed 15m; The spacing between the racks in the communication room is 1200mm; The width of the main transportation and handling channel in the computer room is 1.5m, and the width of the secondary channel is not less than 1m. The above dimensions are mainly relative to 6KW cabinets, but for single cabinets higher than 6kw, such as 8KW or 10kw, their direct arrangement spacing may be larger, from the original 1.2m to 1.5m or even 1.8m, mainly to meet the ventilation and heat dissipation needs of the cabinet.

5.1.3 Functional Streamline

The flow line of the data center is mainly divided into the operation flow line, the equipment transportation flow line, the computer room visit flow line, each flow line should avoid crossing, the flow line of the computer room is mainly designed around the data computer room, among them, the high-voltage computer room, the boundary room, the parallel machine room, the refrigeration station, the ECC monitoring room, the communication computer room, etc. are mainly arranged in the first floor, and the second floor and above are arranged according to the layout of the data computer room, the corresponding low-voltage computer room, battery room, UPS room, etc.;

5.1.4 Fire prevention and energy saving

Data centers are generally based on industrial buildings or civil buildings as the main declaration type, whether industrial or civil use is mainly based on the type of land, general industrial land, data center buildings are characterized according to Class C factories, such as multi-functional land or other types of land, data center buildings are characterized according to civil buildings; For specific fire protection requirements, it can be characterized according to whether the data center itself is based on civil buildings or industrial buildings, and you can refer to the "Building Design Fire Protection Code" GB50016-2014 and other relevant fire prevention chapters for in-depth design. For the energy conservation of the data center, some places do not have energy conservation requirements, some places declare that need energy conservation calculation books, energy conservation special articles and other content, specifically to the requirements of the local government review functional department, energy conservation is also similar to fire prevention, the specific data center is to industrial buildings or civil buildings to declare, respectively consult the energy conservation specifications are different, of which the energy conservation of industrial buildings is mainly based on the "Unified Standard for Energy Conservation Design of Industrial Buildings" GB51245-2017, and the energy conservation of civil buildings is subject to the "Energy Conservation Design Standards for Public Buildings" GB50189-2015 and local specifications.

5.2 Vertical section design

The profile height of the data center generally needs to be combined with the equipment size in the specific HVAC technical requirements, generally the common height is 5m, 5.5m, 6m, of which there are also projects designed less than 5m, but the specific project implementation due to the different size of the equipment manufacturers, the required building height is also different, such as the owner has determined the equipment manufacturer, should meet the equipment requirements as much as possible, to save the project civil construction cost with a reasonable floor height, but not only to consider the cost savings as much as possible without considering the later equipment manufacturer replacement, the civil cost is simply a drop in the bucket for the cost of mechanical and electrical, or to focus on the mechanical and electrical process needs, colleagues also consider the later change needs. The façade design of the data center is generally based on the introduction of industrial style, because the façade window opening requirements of the data center are less, as much as possible to reduce the impact on the computer room and other electrical rooms, due to the lack of façade windows, colleagues also improve the challenge of fire protection façade rescue windows, smoke prevention and exhaust requirements, façade effect design, etc. For example, some data centers have no windows on the entire surface, so some fire rescue windows can only be opened in the four corner stairwells, although the fire prevention regulations do not specify whether they can be opened in the stairwell, but from the perspective of the escape streamline, the stairwell is the main escape route after a fire, and the firefighters break the window in the stairwell at the same time, which will definitely cause a flow of people and is not conducive to fire fighting (the actual number of operation and maintenance personnel in the data center is very small, and it can also be implemented).

Figure 3 Schematic diagram of the layout of the floor space

6. Key points of mechanical and electrical design technology

6.1 Key points of water supply and drainage technology

The influence of water supply and drainage of the data center on the building layout is mainly the cylinder room and high-level water tank room on the ground, and the fire pump room and pool, water replenishment machine room and pool, domestic water pump room and pool underground, etc. Some projects may require reclaimed water treatment room and other needs due to municipal conditions. The layout of the building also has some impact, and the municipal conditions should be confirmed with the owner in this early stage, so as not to affect the time schedule of the entire project. For the fire end water supply and drainage, it is mainly divided into gas extinguishing and spraying areas, which are mainly used in electric rooms, and spraying is mainly used in non-electrical rooms such as corridors. On the whole, water supply and drainage majors have relatively little impact on the layout of buildings in the design of data centers.

6.2 Key points of HVAC technology

For different project requirements in different regions, PUE is also different, PUE index requirements, mainly rely on HVAC technical solutions to meet, different PUE requirements may affect the entire HVAC mechanical and electrical scheme, and at the same time affect the layout of the building, the lower the PUE requirements, the current matching conventional technical solutions are indirect evaporation systems, new magnetic levitation integral fluorine pump systems, liquid cooling technology is also used to meet the high power of a single cabinet, lower energy consumption projects, but liquid cooling technology is currently implemented less by the owner, As the technology becomes more and more mature in the future, it may also be implemented on a large scale. At present, the design field of data centers is mainly indirect evaporation, fluorine pump system, water cooling system, etc., and the terminal mainly uses inter-column air conditioning, air conditioning room, etc. For the building layout, the largest construction area of the HVAC major is the refrigeration station, which generally needs about 1,000 square meters, and some other projects may involve air conditioning in the machine room, fresh air room room, roof cooling tower, smoke exhaust machine room, replenishment machine room, etc.

6.3 Key points of electrical technology

The electrical major of the data center is mainly divided into power supply major, electric lighting major, and weak current intelligent major, which is more detailed than the electrical major of civil buildings, because the data center is mainly in the power supply and distribution area, which is also a more important professional content of the mechanical and electrical major. Weak current intelligence mainly designs some fire alarms, security, intelligence, communication rooms, etc., which have a great impact on the building layout, mainly involving weak current rooms such as communication rooms, ECC, and fire control rooms. For the building layout has a greater impact on power supply and distribution, different data center level requirements are different, A-level data room needs a fault-tolerant 2N system, which requires more building area than B-level and C-level computer rooms, because not only do two sets of system rooms, but also involve diesel generator rooms.

There are three main architectures for A-level data center power supply and distribution systems: 2N system, DR system, and RR system.

The 2N system is mainly composed of 2 power supply and distribution units (in the professional understanding of architecture, that is, two identical power supply and distribution rooms), each unit carries 50% of the load; One unit fails, the other is fully loaded at 100%.

DR system N ≥ composed of 3 power supply and distribution units, each unit bears 66% of the load, and 2 adjacent units supply power, and when one unit fails, the remaining unit continues to supply power to the other unit.

The RR system consists of multiple power supply and distribution units, one of which serves as a backup (also called backup redundancy) for other operating units, and when one operating unit fails, the backup unit continues to supply power to the load through the power switching device.

Among them, the 2N system is the best, not only reliable power supply but also simple system architecture, and domestic data centers also use 2N the most. For the building layout, the power supply and distribution major mainly includes high-voltage computer room, parallel machine room, diesel generator room, low-voltage power distribution room, battery room, etc., which is also the major occupying the most building area in data center design in addition to the data room room.

7. Conclusion

Data center design is different from civil buildings, no longer based on architecture, data centers tend to be dominated by power supply and supplemented by refrigeration solutions. As an architectural designer, if we want to do a good job in the data center project, we should understand more about the system principle of power supply and distribution and the detailed requirements of each electrical room plan, and at the same time, we should summarize and communicate more about the advantages and disadvantages of new technologies and principles of refrigeration, so as to prepare for the subsequent data center architectural design.

References:

[1] New Infrastructure: Data Center Planning and Design/Zhong Jinghua et al., eds.——Beijing: Electronics Industry Press, 2021.1 (New Infrastructure Series)

[2] GB50174-2017 Data Center Design Specification. Beijing: China Planning Press, 2017

[3] Data Center Power Supply and Distribution Technology and Design/Guo Wu, Editor-in-Chief—Beijing: Machinery Industry Press, 2022.5