Why are small computer rooms also using precision air conditioners for computer rooms
In recent years, there has been a trend of rapid growth in field computer rooms, network management centers, mobile base stations, and small computer rooms. The construction of computer rooms has also seen scattered small computer rooms. However, the development of small computer rooms has not brought correspondingly The refrigeration system of the environment has completely changed. In the past, small-scale computer room refrigeration has always been popular for general comfort air conditioners. Nowadays, small-scale computer rooms have begun to use precision air conditioners in computer rooms one after another.r
According to relevant statistics, there are about 100,000 new computer rooms in China each year, 80% of which are small and medium-sized computer rooms with an area of less than 100 square meters. Most of these computer rooms use general comfort air conditioners, and the computer rooms cannot use ordinary air conditioners. Because ordinary air conditioners only provide users with suitable temperature, and humidity cannot be controlled. The electronic equipment in the computer room usually mainly includes computer equipment such as servers, switches, optical transceivers, and uninterruptible power supply UPS. These equipment will transfer heat, convection, The way of radiation emits heat to the computer room, and this heat only forms an increase in the temperature in the computer room. If the humidity in the computer room is too humid or too dry, the impact on the electronic equipment in the computer room is extremely unfavorable. The heat dissipation of the equipment in the computer room is attributed to the steady-state heat source. Uninterrupted operation throughout the year requires an uninterrupted air-conditioning guarantee system. There are also higher requirements for the power supply of air-conditioning equipment. Not only is it necessary to have dual mains mutual investment, but also to ensure air-conditioning for important accounting equipment. The system should also have a generator set as a backup power source, so precision air conditioning must be installed to provide a constant temperature and humidity environment for the computer room. In addition to constant temperature and humidity, factors that require the use of precision air conditioners in computer rooms include:
Reason 1: High reliability
(1) The function of the control system is closely related to the overall function of the air conditioning system. The highly sophisticated control system can ensure the reliability of the computer room air conditioner
Many manufacturers of special air conditioners for computer rooms have specifically announced a series of controllers as part of the air conditioning system. The use of electronic controllers or microcomputer control is now very common. Some companies have now applied fuzzy control skills to special air conditioners for computer rooms. System. For example, you can record the operating time of each s* component and perform fault diagnosis;
Managers can also set parameters for active protection, even if the power is off, they can save operating parameters and alarm records. The system can store 30 historical alarms. In addition, the excellent human-computer interaction interface allows managers to quickly and easily use the system's functions. Play to best.
(2) The grid adaptability of precision air conditioners in computer rooms is also an important guideline for judging its functions
Take mobile base stations, field computer rooms and other small computer rooms as examples. They are generally in a harsh grid environment and the grid voltage fluctuates greatly. This requires the corresponding cooling system to have good grid adaptability. For example, the ultra-wide input voltage plan is selected, and the voltage fluctuation scale is allowed to be ±20; it has the same phase loss protection function and phase sequence detection function, high and low voltage active monitoring and protection functions; has the phase sequence misalignment active adjustment function, which can complete the active call . This kind of joint planning ensures that the refrigeration system operates efficiently and reliably in the harsh grid environment.
(3) The nature of the small computer room determines its high reliability requirements for the same air conditioning system
Cooling problems in general occasions have little impact, and the reliability of the computer room air conditioner is not high, which threatens the security of the entire computer room equipment and the entire network. Therefore, in terms of planning, the reliability of special air conditioners for computer rooms is much higher than that of general air conditioners. A series of guarantee methods are adopted in the planning and production of structure and control system, and the composition of air conditioning system. According to the plan of operating 24 hours a day, 365 days a year , And each product has passed rigorous factory tests, which can ensure that the equipment operates without failure all year round.
(4) A computer room attaches importance to reliability
For 8,760 hours of trouble-free operation throughout the year, reliable components and excellent control systems for computer room air conditioners are required. Usually the computer room is mostly N+1 backup. If one air conditioner has a problem, the other air conditioners can receive all the systems immediately.
Reason two: precise control
The small computer room, because of its small area, not much equipment, and low heat generation, it seems that the general comfort air conditioner can now control the temperature within a certain scale, which "reaches" the cooling effect, but in detail, the temperature control is only One aspect of computer room environment conditioning. In addition, temperature control accuracy, humidity conditioning, and air filtration are also important policy requirements for the computer room environment for the refrigeration system.
The planning of general comfort air-conditioning is aimed at home environment or general working environment, and cannot meet the above guidelines.
(1) Humidity
In terms of humidity control, the comfort air conditioner has no humidification function at all, it can only perform dehumidification, and therefore cannot perform humidity control. In the equipment room, if the humidity is too high, it will condense into water mist or even water droplets. If the humidity is too low, static electricity will occur. Both of these conditions are very unfavorable to the operation of the equipment. Regarding special air conditioners for computer rooms, humidity control is an important parameter, and its humidity control accuracy can generally reach ±5. The high ventilation power can also keep the humidity stable, and the relative humidity can be controlled within 50%±5%RH, ensuring the operation function of the equipment in the computer room.
（2）Temperature
In terms of temperature control accuracy, because the number of air changes of the comfort air conditioner is only 5-15 times per hour, the temperature adjustment accuracy is ±3-5℃, which can basically meet the temperature adjustment requirements of the general environment, but the temperature in the computer room The field is unevenly distributed. This adjustment accuracy can only ensure the temperature of the near-end equipment of the air conditioner. In comparison, the air exchange frequency of the precision air conditioner in the computer room is 30-60 times per hour. The high-power air exchange capacity makes the air-conditioning system possible Sensing the temperature fluctuation of the entire computer room to ensure that the temperature adjustment accuracy of the computer room is maintained at about 1 ℃, and then to ensure the overall cooling of the computer room.
(3) Cleanliness
In addition to temperature and humidity, the computer room also has strict requirements on the cleanliness of the air. Dust and corrosive gases in the air will severely damage the life of electronic components, causing problems such as poor contact and short circuits. The filter cannot meet the cleanliness requirements of the computer room, and the precision air conditioner of the computer room has efficient air filtration capacity, which can remove dust and filter the circulating air according to relevant specifications, so that the computer room can ensure the required cleanliness and then ensure the safe operation of the equipment.
(4) High-precision planning
The precision air conditioner in the computer room can not only adjust the temperature, but also the humidity, and the accuracy is very high. Computers, especially servers, have extremely high requirements for temperature and humidity. If the changes are too large, computer calculations may show errors, which is very unfavorable for service providers, especially for banking and communications professions. Nowadays, precision air conditioners in computer rooms usually require temperature accuracy of ±2°C and humidity accuracy of ±5%. High-precision computer room precision air conditioners can achieve temperature accuracy of ±0.5°C and humidity accuracy of ±2%.
Reason 3: High efficiency and energy saving
Because the computer room generates a lot of heat, and some IDC computer rooms generate more than 30kw/㎡, it is cooled all year round.
The point of demand here is that the precision air conditioner in the computer room also has a heater, but it is distributed during dehumidification. It should be that the temperature of the air outlet during dehumidification should be relatively low to prevent the room temperature from falling too fast (the computer room requests that the temperature change does not exceed 1 ℃ every 10 minutes, and the humidity does not exceed 5% per hour). In terms of high efficiency and energy saving, general comfort The air conditioner obviously cannot compare with the dedicated air conditioner for the computer room. From the perspective of sensible heat ratio, the sensible heat ratio of special air conditioners for computer rooms is as high as 80%-90%, which means that 90% of the power is used to effectively cool the equipment, and only about 10% of the energy consumption is used for moderate dehumidification;
The sensible heat ratio of the comfort air conditioner is 60%-70%, and 30%-40% of the power is used for excessive dehumidification. This situation simply leads to low humidity in the equipment room, not only the equipment is under the threat of static electricity, but also a great waste of electrical energy.
From the point of view of energy efficiency ratio, the energy efficiency ratio of industrial-grade compressors selected for computer room special air conditioners is as high as 3.3 or more, while the energy efficiency ratio of compressors currently used in the industry for comfort air conditioners is about 2.9, which is much lower than that of computer room special air conditioners.
Green environmental protection, energy saving and consumption reduction have now become the policies of various industries, and therefore are also an important consideration in the construction of data centers or computer rooms, and the refrigeration system in particular has received more attention. According to a research report submitted by the U.S. Environmental Protection Agency to the U.S. Congress, the refrigeration system accounts for about 40% of the total electricity consumption of data centers.
And IDC's research also shows that in data centers, the cooling system consumes more power than the server itself. When the server doubles, the supporting power consumption will increase exponentially. Therefore, the selection of high-efficiency and energy-saving products for the refrigeration system is of great significance for the energy saving and consumption reduction of data centers or computer rooms.
The query indicates that there are many problems in the computer room using comfort air conditioners, and s* should be manifested in the high failure rate of the electronic equipment in the computer room and the large amount of protection of the comfort air conditioner itself. The reason for these problems is that the planning specifications for comfort air conditioners do not meet the requirements of temperature and humidity in the computer room, and do not meet the requirements of high reliability and green efficiency. As a special environment, small computer rooms should be protected by professional air conditioners in the computer room. The specialized chemical smelting of refrigeration field should be completed.
Precision air conditioning in the computer room with cooling, heating, humidifying and dehumidifying functions
(1) Scale of use
Computer room precision air conditioners are widely used in high-precision environments such as computer rooms, program-controlled switch rooms, satellite mobile communication stations, large-scale medical equipment rooms, laboratories, testing rooms, and precision electronic instrument production workshops. Such environments affect the temperature and humidity of the air. , Cleanliness, air distribution and other goals have very high requirements, it is necessary to ensure that the special precision air-conditioning equipment in the special computer room operates safely and reliably 24 hours a day, 365 days a year.
(2) The heat is large
The host and peripherals, servers, switches, optical transceivers and other computing equipment in the computer room, as well as power assurance equipment, such as UPS power supplies, will emit heat into the computer room by means of heat transfer, convection, and radiation. These heat only constitute the computer room. The increase in temperature is attributed to sensible heat. The heat dissipation of a server cabinet is a few kilowatts to more than ten kilowatts per hour. If it is a blade server, the heat dissipation will be higher. The heat dissipation of equipment in large and medium-sized computer rooms is about 400W/m2, and the data center with higher installed density may reach more than 600W/m2. The sensible heat ratio in the machine room can be as high as 95%.
(3) Low latent heat
does not change the temperature in the computer room, but only changes the moisture content of the air in the computer room. This part of the heat is called latent heat. There is no humidity dissipating equipment in the computer room, and the latent heat s* must come from the operators and outdoor air, and the large and medium-sized computer room generally adopts the management mode of man-machine separation. The enclosure structure of the computer room is well sealed, and the fresh air is generally pretreated by temperature and humidity. Human computer room, so the latent heat of the computer room is small.
(4) Large air volume, small enthalpy difference
The heat of the equipment is transmitted to the computer room through conduction and radiation. The heat generated in the densely-equipped areas of the equipment is concentrated. In order to make the temperature and humidity of each area in the computer room uniform, and the control is within the agreed base and shaken scale, there is a greater demand The air volume will take away the residual heat. In addition, the latent heat in the computer room is small, and dehumidification is generally not required. When the air passes through the air conditioner evaporator, it does not need to drop below zero. Therefore, the temperature difference and enthalpy difference of the supply air are required to be small. Large air supply is required.
(5) Uninterrupted operation, cooling all year round
The heat dissipation of the equipment in the computer room is attributed to a steady-state heat source, and it operates continuously throughout the year. This requires an uninterrupted air-conditioning guarantee system. There are also higher requirements for the power supply of air-conditioning equipment. Not only is there a need for dual-channel city power mutual investment, In addition, the air conditioning system for ensuring important accounting equipment should also have a generator set as a backup power source. The long-term steady-state heat source composition requires cooling even in the winter machine room, especially in the southern area. In the northern region, if cooling is still required in winter, when selecting an air conditioning unit, the condensing pressure of the unit and other related issues need to be considered. Otherwise, the share of outdoor cold air intake can be increased to achieve energy saving.
