November 20, 2023
ForewordHi, I'm Mr. Lin, what air conditioners are commonly used in computer labs? We all know that precision air conditioners are commonly used in computer labs. What are functions of precision air conditioners? What are requirements for air conditioning in a computer room? TextWhat air conditioners are commonly used in computer rooms?
Computer Room Air Conditioner, as name suggests, is a precision air conditioner specially used for computer rooms. Because it can not only control temperature of computer room, but also control humidity at same time, it is also called special air conditioner for constant temperature and humidity air conditioners. The temperature and humidity control accuracy is very high, also known as computer room precision air conditioner.
The main maintenance object of air conditioner in computer room is computer. It provides a stable and reliable IDC for computer room, and detects operating temperature, relative humidity and air purity of computer room. It has characteristics of high sensible heat coefficient, high energy efficiency coefficient, high reliability and high precision.
Composition:
Computer room air conditioner mainly consists of six parts:
1. Control and monitoring system
The control system displays air temperature and humidity, as well as operating status of air conditioner through controller, analyzes signals from each sensor, and issues operating instructions for each function of device to achieve goal. temperature and humidity control.
2. Ventilation system
When various functions of device (cooling, dehumidifying, heating, humidifying, etc.) process air in engine room, airflow is required to complete exchange of heat and moisture, and air in engine room needs to maintain a certain flow rate to prevent dust deposition and timely filter out dust suspended in air.
3. Cooling cycle and dehumidification system
Using an evaporative-compression refrigeration cycle system, it uses latent heat of vaporization absorbed by refrigerant to cool it as it evaporates. The refrigerant is working fluid for refrigeration cycle in a refrigeration air conditioning system. feature, first compress refrigerant gas into a gas with high temperature and high pressure with a compressor, and then send it to condenser for high pressure cooling. The gas will dissipate heat and condense into a liquid at a higher temperature. High Pressure Cooling The liquid agent passes through a throttling device so that pressure drops rapidly and then reaches evaporator where it boils at a lower pressure and temperature.
The main refrigeration system consists of four main components: compressor, evaporator, condenser and expansion valve.
The dehumidification system usually uses its own refrigeration cycle system, which is reduced for same cooling capacity.
4. Humidification system
When using equipment such as electrode humidifiers or infrared humidifiers, this is achieved by heating water to form water vapor.
5. Heating system
Heat is used as heat compensation and most of them use electric heating tubes.
6. Water (ethylene glycol) circulation system of water cooling unit
The condenser of water-cooled unit is installed inside unit. The circulating water passes through heat exchanger to cool and condense refrigerant gas into liquid. Since specific heat of water is large, volume of condensing heat exchanger is small. Three-way return water temperature control valve (or electric control valve controls amount of water passing through heat exchanger to control condensation pressure.The power of circulating water is provided by a water pump, and heated water has several cooling methods that are more commonly used.It is cooled by a dry cooler, that is, water is directedIt flows into sealed dry cooler coil and then returns after being cooled by a fan. stable and high reliability, but it requires a larger cooling coil and fan. There is also an open cooling method, that is, water is sent to cooling tower for spraying, and water itself is evaporated and then returned. It will enter system and, in severe cases, block pipeline and affect heat transfer effect, so regular decontamination is required.
Features:
Functions that computer room air conditioners should have
Independent cooling system Independent heating system Independent humidification system
Independent dehumidification system
Air filtration system for machine room
Monitoring function
MTBF (Mean Time Between Failures)>100,000 hours
Features:
1. Year-round cooling
Since a computer room generates a lot of heat, overheating will cause a number of problems. Some IDC computer rooms generate over 300 W/m2 of heat, so they are cool all year round.
One point to mention here is that air conditioner in computer room also has a heater, but it is activated during dehumidification. This is because temperature of outlet air during dehumidification must be relatively low in order to avoid a too rapid drop in room temperature (the temperature change in machine room must not exceed 1°C every 10 minutes, and humidity must not exceed 5% per hour ).
2. High sensible heat coefficient
The sensible heat ratio is ratio of sensible cooling to total cooling. The total cooling capacity of air conditioner is sum of sensible cooling capacity and latent cooling capacity, with sensible cooling used for cooling and latent cooling used for dehumidification. The heat in a computer room is mostly sensible heat, so sensible heat of a computer room air conditioner is relatively high, usually above 0.9 (normal comfort air conditioners are only about 0.6). Large air volume and small enthalpy difference are essential differences between computer room air conditioners and other air conditioners. The use of a large volume of air can prevent outlet air temperature from being too low and increase amount of air exchange in machine room, which is useful for computing servers and computers. If temperature in computer room changes too much in a short period of time, it will cause server calculation errors, and if humidity in computer room is too low, it will cause static electricity (static electricity can reach 10,000 volts at 20% humidity).
3. High energy efficiency ratio
The Energy Efficiency Ratio (COP) is coefficient of conversion of energy into heat, 1 unit of energy is converted into 3 units of heat, COP=3. Since most computer room air conditioners use scroll compressors (the minimum power is also 2.75 kW), efficiency can reach a maximum of 5.6. The energy efficiency coefficient of whole machine reaches above 3.0.
4. Precision design
A computer room air conditioner can regulate not only temperature, but also humidity with very high accuracy. Computers, especially servers, have particularly high temperature and humidity requirements, and if temperature and humidity fluctuate too much, computer calculation errors can occur, which is very unfavorable for service providers, especially banking and communications industries. Computer room air conditioners generally require ±2°C temperature accuracy and ±5°C humidity accuracy. High-precision computer room air conditioners can achieve ±0.5° temperature accuracy.C and humidity accuracy ±2%.
5. High reliability
The most important thing for a computer room is reliability. For 8,760 hours of uptime throughout year, reliable components and excellent control systems for air conditioners in engine room are required. Typically, a computer room has an N+1 backup. If one air conditioner fails, other air conditioners can immediately take over entire system
