Liquid cooling refers to

cooling Cooling is removal of heat, usually resulting in a lower temperature and/or Phase transition, phase change. Temperature lowering achieved by any other means may also be called cooling. The Heat transfer, transfer of Internal energy, thermal energ ...

by means of the

convection Convection is single or Multiphase flow, multiphase fluid flow that occurs Spontaneous process, spontaneously through the combined effects of material property heterogeneity and body forces on a fluid, most commonly density and gravity (see buoy ...

or circulation of a

liquid Liquid is a state of matter with a definite volume but no fixed shape. Liquids adapt to the shape of their container and are nearly incompressible, maintaining their volume even under pressure. The density of a liquid is usually close to th ...

. Examples of liquid cooling technologies include: * Cooling by convection or circulation of

coolant A coolant is a substance, typically liquid, that is used to reduce or regulate the temperature of a system. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-toxic, chemically inert and neither causes nor promotes corr ...

, including

water cooling file:KKP Auslauf.jpg, Cooling tower and water discharge of a nuclear power plant Water cooling is a method of heat removal from components and industrial equipment. Evaporative cooling using water is often more efficient than air cooling. Water i ...

* Liquid cooling and ventilation garments, worn by astronauts *

Liquid metal cooled reactor A liquid metal cooled nuclear reactor (LMR) is a type of nuclear reactor where the primary coolant is a liquid metal. Liquid metal cooled reactors were first adapted for breeder reactor power generation. They have also been used to power nuclear ...

s * Radiators (engine cooling) *

Cooling tower A cooling tower is a device that rejects waste heat to the atmosphere through the cooling of a coolant stream, usually a water stream, to a lower temperature. Cooling towers may either use the evaporation of water to remove heat and cool the ...

Applications

Computing

In computing and electronics, liquid cooling involves the technology that uses a special water block to conduct heat away from the processor as well as the chipset. This method can also be used in combination with other traditional cooling methods such as those that use air. The application to microelectronics is either indirect or direct. The former pertains to the category that utilizes cold plate cooling, which uses water as coolant while, in the latter (also referred to as liquid immersion cooling), the surface of the chips comes in contact with the liquid since there is no wall separating the heat source from the coolant. This immersion cooling also offer a higher transfer coefficient, although this depends on the specific coolant used and mode of convective heat transfer. One of the main benefits achieved is the reduction of noise and it is also more efficient. Some of the drawbacks include the risk entailed with the close proximity of liquid to electronics as well as its cost. Liquid cooling systems are more expensive than fan sets, which require fewer components such as reservoir, pump, water blocks, hose, and

radiator A radiator is a heat exchanger used to transfer thermal energy from one medium to another for the purpose of cooling and heating. The majority of radiators are constructed to function in cars, buildings, and electronics. A radiator is always a ...

HVAC

Liquid cooling is also used to remove heat from large buildings by using

chillers A chiller is a machine that removes heat from a liquid coolant via a vapor-compression, adsorption refrigeration, or absorption refrigeration cycles. This liquid can then be circulated through a heat exchanger to cool equipment, or another pr ...

which transfer the coolant from the evaporator to air handling units, chilled beams and fan coil units inside the building, and to the

cooling towers A cooling tower is a device that rejects waste heat to the atmosphere through the cooling of a coolant stream, usually a water stream, to a lower temperature. Cooling towers may either use the evaporation of water to remove heat and cool t ...

from the condenser if the condenser is liquid-cooled. Some buildings are directly cooled by the cooling towers using plate heat exchangers transferring the heat from the chiller condenser loop to the evaporator loop. Convective heat transfer is used to cool the coolant if the building uses dry or closed-circuit cooling towers.

Liquid cooling garments

Liquid Cooling Garments (LCG) are used to decrease the wearer’s bodily temperature and keep them comfortable. Generally, an LCG uses a series of coolant-filled tubes and a refrigeration unit and a pump to move the coolant throughout the system. These parts are usually encased inside of a normal garment, usually a vest. Since the coolant is so close to human skin, water tends to be the preferred coolant, as it is both safe for skin contact and effective at transferring heat. Due to their portable and versatile nature, LCGs have been proposed as a solution to overheating in areas where a standard air conditioning system would not be feasible or where the cooling would need to be under protective gear.

References

{{Tech-stub broad-concept articles Cooling technology