Liquid cooling

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Liquid cooling refers to cooling by means of the convection or circulation of a liquid.

Contents

Examples of liquid cooling technologies include:

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. [1] 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. [2] This immersion cooling also offer a higher transfer coefficient, although this depends on the specific coolant used and mode of convective heat transfer. [3] One of the main benefits achieved is the reduction of noise and it is also more efficient. [1] 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 less components such as reservoir, pump, water blocks, hose, and radiator. [1]

HVAC

Liquid cooling is also used to remove heat from large buildings by using chillers 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 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. [4] 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. [5] 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. [6]

Related Research Articles

<span class="mw-page-title-main">Radiator</span> Type of heat exchanger; radiant body through water or other liquids

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.

<span class="mw-page-title-main">Heat pipe</span> Heat-transfer device that employs phase transition

A heat pipe is a heat-transfer device that employs phase transition to transfer heat between two solid interfaces.

<span class="mw-page-title-main">Water cooling</span> Method of heat removal from components and industrial equipment

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 is inexpensive and non-toxic; however, it can contain impurities and cause corrosion.

<span class="mw-page-title-main">Cooling tower</span> Device which rejects waste heat to the atmosphere through the cooling of a water stream

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 working fluid to near the wet-bulb air temperature or, in the case of dry cooling towers, rely solely on air to cool the working fluid to near the dry-bulb air temperature using radiators.

<span class="mw-page-title-main">Chiller</span> Machine that removes heat from a liquid coolant via vapor compression

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 process stream. As a necessary by-product, refrigeration creates waste heat that must be exhausted to ambience, or for greater efficiency, recovered for heating purposes. Vapor compression chillers may use any of a number of different types of compressors. Most common today are the hermetic scroll, semi-hermetic screw, or centrifugal compressors. The condensing side of the chiller can be either air or water cooled. Even when liquid cooled, the chiller is often cooled by an induced or forced draft cooling tower. Absorption and adsorption chillers require a heat source to function.

<span class="mw-page-title-main">Computer cooling</span> The process of removing waste heat from a computer

Computer cooling is required to remove the waste heat produced by computer components, to keep components within permissible operating temperature limits. Components that are susceptible to temporary malfunction or permanent failure if overheated include integrated circuits such as central processing units (CPUs), chipsets, graphics cards, hard disk drives, and solid state drives.

<span class="mw-page-title-main">Cooling</span> The transfer of heat out of an object

Cooling is removal of heat, usually resulting in a lower temperature and/or phase change. Temperature lowering achieved by any other means may also be called cooling. The transfer of thermal energy may occur via thermal radiation, heat conduction or convection. Examples can be as simple as reducing temperature of a coffee.

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 corrosion of the cooling system. Some applications also require the coolant to be an electrical insulator.

<span class="mw-page-title-main">Thermosiphon</span> Method of heat exchange in which convection drives pumpless circulation

Thermosiphon is a method of passive heat exchange, based on natural convection, which circulates a fluid without the necessity of a mechanical pump. Thermosiphoning is used for circulation of liquids and volatile gases in heating and cooling applications such as heat pumps, water heaters, boilers and furnaces. Thermosiphoning also occurs across air temperature gradients such as those utilized in a wood fire chimney or solar chimney.

<span class="mw-page-title-main">Absorption refrigerator</span> Refrigerator that uses a heat source

An absorption refrigerator is a refrigerator that uses a heat source to provide the energy needed to drive the cooling process. Solar energy, burning a fossil fuel, waste heat from factories, and district heating systems are examples of convenient heat sources that can be used. An absorption refrigerator uses two coolants: the first coolant performs evaporative cooling and then is absorbed into the second coolant; heat is needed to reset the two coolants to their initial states. Absorption refrigerators are commonly used in recreational vehicles (RVs), campers, and caravans because the heat required to power them can be provided by a propane fuel burner, by a low-voltage DC electric heater or by a mains-powered electric heater. Absorption refrigerators can also be used to air-condition buildings using the waste heat from a gas turbine or water heater in the building. Using waste heat from a gas turbine makes the turbine very efficient because it first produces electricity, then hot water, and finally, air-conditioning—trigeneration.

<span class="mw-page-title-main">Electric heating</span> Process in which electrical energy is converted to heat

Electric heating is a process in which electrical energy is converted directly to heat energy. Common applications include space heating, cooking, water heating and industrial processes. An electric heater is an electrical device that converts an electric current into heat. The heating element inside every electric heater is an electrical resistor, and works on the principle of Joule heating: an electric current passing through a resistor will convert that electrical energy into heat energy. Most modern electric heating devices use nichrome wire as the active element; the heating element, depicted on the right, uses nichrome wire supported by ceramic insulators.

<span class="mw-page-title-main">Vapor-compression refrigeration</span> Refrigeration process

Vapour-compression refrigeration or vapor-compression refrigeration system (VCRS), in which the refrigerant undergoes phase changes, is one of the many refrigeration cycles and is the most widely used method for air conditioning of buildings and automobiles. It is also used in domestic and commercial refrigerators, large-scale warehouses for chilled or frozen storage of foods and meats, refrigerated trucks and railroad cars, and a host of other commercial and industrial services. Oil refineries, petrochemical and chemical processing plants, and natural gas processing plants are among the many types of industrial plants that often utilize large vapor-compression refrigeration systems. Cascade refrigeration systems may also be implemented using two compressors.

Solar air conditioning, or "solar-powered air conditioning", refers to any air conditioning (cooling) system that uses solar power.

<span class="mw-page-title-main">Liquid cooling and ventilation garment</span> Garment worn inside a spacesuit for cooling and ventilation

A liquid cooling garment (LCG) is a form-fitting garment that is used to remove body heat from the wearer. It is commonly used in environments where evaporative cooling from sweating and open-air convection cooling does not work or is insufficient, or the wearer has a biological problem that hinders self-regulation of body temperature.

<span class="mw-page-title-main">Evaporator</span> Machine transforming a liquid into a gas

An evaporator is a type of heat exchanger device that facilitates evaporation by utilizing conductive and convective heat transfer, which provides the necessary thermal energy for phase transition from liquid to vapour. Within evaporators, a circulating liquid is exposed to an atmospheric or reduced pressure environment causing it to boil at a lower temperature compared to normal atmospheric boiling.

Free cooling is an economical method of using low external air temperatures to assist in chilling water, which can then be used for industrial processes, or air conditioning systems. The chilled water can either be used immediately or be stored for the short- or long-term. When outdoor temperatures are lower relative to indoor temperatures, this system utilizes the cool outdoor air as a free cooling source. In this manner, the system replaces the chiller in traditional air conditioning systems while achieving the same cooling result. Such systems can be made for single buildings or district cooling networks.

<span class="mw-page-title-main">Radiator (engine cooling)</span> Heat exchangers used for cooling internal combustion engines

Radiators are heat exchangers used for cooling internal combustion engines, mainly in automobiles but also in piston-engined aircraft, railway locomotives, motorcycles, stationary generating plants or any similar use of such an engine.

HVAC is a major sub discipline of mechanical engineering. The goal of HVAC design is to balance indoor environmental comfort with other factors such as installation cost, ease of maintenance, and energy efficiency. The discipline of HVAC includes a large number of specialized terms and acronyms, many of which are summarized in this glossary.

<span class="mw-page-title-main">Pumpable ice technology</span> Type of technology to produce and use fluids or secondary refrigerants

Pumpable icetechnology (PIT) uses thin liquids, with the cooling capacity of ice. Pumpable ice is typically a slurry of ice crystals or particles ranging from 5 micrometers to 1 cm in diameter and transported in brine, seawater, food liquid, or gas bubbles of air, ozone, or carbon dioxide.

<span class="mw-page-title-main">Immersion cooling</span> IT cooling practice

Immersion cooling is an IT cooling practice by which complete servers are immersed in a dielectric, electrically non-conductive fluid that has significantly higher thermal conductivity than air. Heat is removed from a system by putting the coolant in direct contact with hot components, and circulating the heated liquid through heat exchangers. This practice is highly effective because liquid coolants can absorb more heat from the system, and are more easily circulated through the system, than air. Immersion cooling has many benefits, including but not limited to: sustainability, performance, reliability and cost.

References

  1. 1 2 3 Docter, Quentin; Dulaney, Emmett; Skandier, Toby (2012). CompTIA A+ Complete Deluxe Study Guide Recommended Courseware: Exams 220-801 and 220-802, Second Edition. Hoboken, NJ: John Wiley & Sons. p. 61. ISBN   9781118324066.
  2. Tong, Ho-Ming; Lai, Yi-Shao; Wong, C. P. (2013). Advanced Flip Chip Packaging . Dordrecht: Springer Science & Business Media. pp.  447. ISBN   9781441957689.
  3. Yarin, L. P.; Mosyak, A.; Hetsroni, G. (2008). Fluid Flow, Heat Transfer and Boiling in Micro-Channels . Berlin: Springer-Verlag. pp.  13. ISBN   9783540787549.
  4. Zhang, Mengsheng; Li, Zijun; Xu, Yu; Wang, Junjian (April 2022). "Design and research of liquid cooling garments in thermal environment". International Journal of Refrigeration. 139: 136–147. doi:10.1016/j.ijrefrig.2022.04.014. ISSN   0140-7007.
  5. Yu, Xu; Zijun, Li; Junjian, Wang; Mengsheng, Zhang; Mintao, Jia; Qiaoli, Wang (5 January 2022). "Man-portable cooling garment with cold liquid circulation based on thermoelectric refrigeration". Applied Thermal Engineering. 200 via Elsevier.
  6. Zhang, Yingshuai; Yang, Yiyong; Ji, Linhong; Cheng, Jia; Yao, Qi (2023). "Research and application of liquid cooling garment system based on human acupoints and meridians cooling stimulation in the high temperature environment". Thermal Science. 27 (2 Part B): 1687–1697. doi: 10.2298/tsci220702163z .