1. Direct natural cooling
(1) Fresh air natural cooling
Outdoor fresh air is directly introduced and combined with hot and cold aisle isolation to achieve cooling of the computer room. Depending on the climate conditions of different regions, the fresh air needs to undergo pretreatment such as filtration, humidification, dehumidification, and supply and return air mixing before entering the computer room.
(2) Chicken coop-style hot press natural circulation air cooling
No mechanical assistance is needed; the heat emitted by the server generates its own power for natural cooling. The heat emitted by the server is collected, and the upward force generated by the expansion of air is used to propel the hot air upward through a sufficiently tall chimney, creating airflow and completing the cooling cycle.
(3) Rotary heat exchanger with natural cooling
By utilizing the energy storage function of the packing material inside the rotor, the rotor rotates slowly within two enclosed air ducts, and the packing material, cooled by outdoor air, cools the indoor air.
2. Indirect natural cooling
(1) Air-cooled chiller unit with natural cooling energy-saving module
During the spring and autumn transition seasons and at night, when the ambient temperature is two degrees Celsius or more lower than the chilled water return temperature, the natural cooling module is activated for cooling, with no compressor power consumption. For any insufficient natural cooling, the compressor refrigeration module then takes over to provide the required cooling capacity. As the outdoor ambient temperature decreases, the proportion of natural cooling increases until it reaches 100%, achieving completely natural cooling with no compressor power consumption.
(2) Water-side plate heat exchanger energy-saving device
It consists of a large cooling tower, a water-cooled chiller unit, and a plate heat exchanger. In summer, the chiller unit and cooling tower are used for cooling, while in winter, the plate heat exchanger is used to convert the impurity cooling water into clean chilled water and send it to the indoor air conditioning unit, at which point the chiller unit is shut down.
(3) Dual-coil ethylene glycol natural cooling
A set of chilled water economy coils is connected in parallel to the direct expansion evaporator coils. Two sets of two-way valves are used to adjust whether the water flows through the condenser of the plate heat exchanger or through the chilled water coils. The outdoor dry cooler provides cooling water to the plate heat exchanger for direct expansion refrigeration in summer and chilled water to the economy coils for chilled water refrigeration in winter.
(4) Fluorine pump natural cooling
In summer, the refrigeration compressor operates; when the outdoor temperature drops below the set point, it automatically switches to the refrigerant pump energy-saving system, stopping the compressor and ensuring safe and reliable operation of the computer room air conditioning throughout the year. The refrigerant pump’s power consumption does not exceed 10% of the compressor’s operating power. Compared to water-cooled air conditioning systems, no antifreeze needs to be added, eliminating concerns about water-related issues.
(5) Assisted evaporation and natural cooling
The outdoor unit of the air conditioner uses a water atomizing spray system to pressurize softened water and then atomize it using a high-speed DC motor. Each drop of water is atomized to about 1/500th of its original volume and sprayed directly onto the condenser fins to assist evaporation, thereby increasing the overall heat dissipation of the condenser and reducing power consumption. This method of extending the natural cooling operation time through outdoor unit atomization spraying is most effective in dry climates, such as western and northeastern China.