How to calculate the power consumption of the data center

Time of issue:2021-12-25

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Everyone knows that the computer room has a high electricity consumption rate. As far as the current situation is concerned, the electricity consumption of the computer room of China's large data center is relatively large compared with that of developed countries. The electricity distribution of the computer room is: IT accounts for 44%, and cooling accounts for 38%. % Or more (some even up to 50%), and the remaining power supply and lighting account for about 18%. It can be seen that the cooling power consumption is the key to the PUE value, and the air-conditioning cooling is the main culprit in the power consumption of the computer room.

1. Calculation of the area occupied by computer room workstations, storage, etc.

Calculation formula for the area of the computer room:

A (main unit room area) = F single unit occupies an area of 3.5～5.5㎡/unit (take the middle value 4.5) * N total number of cabinets

Host room area = 4.5 (㎡/unit) * 30 units = 135㎡

2. UPS selection index

(1) Power consumption of equipment in the computer room. For example, the computer room plans to install 30 cabinets, and each cabinet is calculated according to the power consumption of 3KW, and the power consumption of the cabinet equipment in the computer room will be 3KW*30=90KW.

(2) The power consumption of other equipment (fire fighting, monitoring, emergency lighting) monitoring, emergency lighting and fire fighting equipment in the computer room is about 8000W. The basic capacity of the uninterruptible power supply system can be calculated as follows:

E≥1.2P

formula,

E-the basic capacity of the uninterruptible power supply system (not including redundant uninterruptible power supply equipment)
P——Calculated load of electronic information equipment [(KW/KVA)]

P=1)+2)=90KW+8KW=98KW
E≥1.2P
E≥1.2*98 KW
E≥110.4KVA

Considering that UPS running between 60% and 70% is the best state, it is recommended to divide the above calculation result by 0.7 to enlarge it again.

110.4KVA/0.6≈184KVA. Choose a model close to the power according to the model manual, so choose a 200KVA UPS. For the safety and reliability of the power supply side, it is recommended to use the UPS machine configuration 1+1 redundancy scheme, so two 200KVA UPSs are required.

So in the selection: choose two 200KVA UPS to do 1+1 parallel.

3. Air conditioner selection index

Experience adopts "power and area method" computer room cooling load.

Qt=Q1+Q2

Among them, Qt total cooling capacity (KW)

Q1 Indoor equipment load = UPS power consumption × 0.8
Q2 Environmental cooling load=0.12～0.18KW/㎡ × area of ​​computer room

Therefore, the cooling capacity of the computer room is:

Q1 Indoor equipment load=200KVA*0.8=160KW
Q2 Environmental cooling load=0.15KW/㎡ *251 ㎡=37.5KW

Qt=Q1+Q2=160KW+37.5KW=197.5KW

Therefore: the cooling capacity required in the computer room is 197.5KW, and it is recommended to do 40% redundancy in the cooling capacity. Use 320KW refrigeration air conditioner (4 sets of 80KW air conditioner with cooling power)

4. Total electricity consumption in the computer room

Actual total power consumption = UP power consumption + air conditioning power consumption + lighting + others

UPS equipment power consumption: 200KVA=200KW

Power consumption of precision air conditioner: cooling capacity/2.5=320KW/2.5=128KW

Lighting: P (lighting power per square meter) * S (machine room area)

20W*251 square meters=5KW Other equipment: 10KW

Actual total power consumption = (200KW) + (128KW) + 5KW + 10KW = 343KW

When building the computer room, the margin is generally 25%, and the actual total power distribution is 450KW

5. The overall area of the computer room

(1) The computer room, workstations, storage, etc. occupy an area of 135.5 square meters
(2) UPS, power distribution and battery area

The UPS system needs to use 32 12V-200AH batteries for a delay of 30 minutes for a single unit, and 64 batteries for two units.

The above data is 28 square meters in total. This data refers to the actual area occupied by the equipment without maintenance space. The area of the maintenance space is 2-3 times the actual area of the equipment. Therefore, UPS, power distribution and batteries cover an area of about 70 square meters.

(3) Air conditioner floor space The air conditioner chooses 4 air conditioners, a single air conditioner covers an area of 2.1 square meters, and the air conditioner is fully maintained. The actual area is about 4 square meters if the actual area is double the air conditioner itself. 4 air conditioners total 16 square meters.

(4) The total area of the computer room The area of the computer room, workstations, storage, etc., covers an area of 135 square meters + UPS, power distribution and battery area of ​​70 square meters + air conditioner area of 16 square meters = 221 square meters

The fire protection area is the area of the machine room: 30 square meters

The total area of the computer room is approximately: 251 square meters

Summarize:

To achieve energy-saving use of electricity, we must first do a good job in the detection of electricity in the computer room. Accurately grasping the electricity in the computer room is the first step in energy saving. Most mobile base stations are unattended, but the various electronic equipment in these communication rooms need to be in a certain temperature environment (the national standard for computer room environment GB50174-93 stipulates that the temperature of the computer room is 18 ℃ ~ 28 ℃ for many years) In order to reach the standard ambient temperature of the computer room, each communication computer room is equipped with about two air conditioners, and these air conditioners are turned on for many years, so the electricity consumption of the computer room is a big consumption. .

If you want to accurately count the power consumption of equipment in the computer room, you can use power measurement equipment or management software, just like using a power meter, UPS or PDU. For a single device, we can connect a three-phase power meter by ourselves, and P=I×V Formula to estimate the power consumption, but this can only measure the instantaneous power consumption. Once the power consumption of the device is not a fixed value, it cannot be counted, analyzed or converted into power consumption (kW × hour), and operation and connection The method is also more complicated.

It should be noted that the figures related to the power consumption of the equipment include effective power (watts) and total power consumption (volt-amperes). Usually we refer to power consumption, or the index used by Taipower to calculate electricity costs. The effective power is used, and the electricity consumption (kWh) calculated by the substation is also calculated using the effective power, so it can be directly converted into electricity bills. However, according to the data provided in the device manual, the error between the statistical results of the electricity consumption and the actual electricity bill is about 0.5% to 2%. However, this detection method is only suitable for one device to detect. It cannot be used with centralized management software for analysis and statistics. Therefore, if you want to know the power consumption of multiple machines at the same time, you must use special power management equipment for statistics, such as uninterruptible power systems (UPS) or PDU power distributors.

Utilization or equipment can fully grasp the power situation of equipment in the computer room, and management is also easy, but the one-time cost to be paid is relatively high, usually more than hundreds of thousands of yuan, which is more suitable for large computer rooms or environments with more equipment, but for single The power meter of the product design costs only a few thousand yuan. If there are fewer devices to be monitored, you can use this type of product and record the value manually.