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{{short description|Method of heat removal from components and industrial equipment}}
{{Use dmy dates|date=June 2021}}
[[file:KKP Auslauf.jpg|thumb|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 is inexpensive and non-toxic; however, it can contain impurities and cause corrosion.
Water cooling is commonly used for cooling automobile [[internal combustion engine]]s and [[power stations]]. Water coolers utilising [[Convection (heat transfer)|convective heat transfer]] are used inside high-end [[personal computers]] to lower the temperature of [[CPU]]s and other components.
Other uses include the cooling of [[lubricant]] oil in [[pump]]s; for cooling purposes in [[heat exchanger]]s; for cooling [[building]]s in [[Heating, ventilation, and air conditioning|HVAC]] and in [[chiller]]s.
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==Mechanism==
=== Advantages ===
Water is inexpensive, [[non-toxic]], and available over most of the earth's surface. Liquid cooling offers higher thermal conductivity than air cooling. Water has unusually high specific heat capacity among commonly available liquids at room temperature and atmospheric pressure allowing efficient heat transfer over distance with low rates of mass transfer. Cooling water may be recycled through a ''recirculating'' system or used in a single
=== Disadvantages ===
Water accelerates the corrosion of metal parts and is a favorable medium for biological growth. Dissolved minerals in natural water supplies are concentrated by evaporation to leave deposits called scale. Cooling water often requires the addition of chemicals to minimize corrosion and insulating deposits of scale and biofouling.{{sfn|Betz|pages=183–184}}
Water contains varying amounts of impurities from contact with the atmosphere, soil, and containers.
[[Biofouling]] occurs because water is a favorable environment for many life forms. Flow characteristics of recirculating cooling water systems encourage colonization by [[Sessility (zoology)|sessile]] organisms
[[Chlorine]] may be added in the form of [[hypochlorite]] to decrease biofouling in cooling water systems, but is later reduced to [[chloride]] to minimize the toxicity of blowdown or OTC water returned to natural aquatic environments. Hypochlorite is increasingly destructive to wooden cooling towers as pH increases. Chlorinated phenols have been used as biocides or leached from preserved wood in cooling towers. Both hypochlorite and [[pentachlorophenol]] have reduced effectiveness at pH values greater than 8.{{sfn|Betz|pages=203–209}} Non-oxidizing biocides may be more difficult to detoxify prior to release of blowdown or OTC water to natural aquatic environments.<ref>{{cite web |url=https://www.evs.anl.gov/publications/doc/ANL-Biocide_Usage.pdf |title=Biocide Usage in Cooling Towers in the Electric Power and Petroleum Refining Industries |last1=Veil |first1=John A. |last2=Rice |first2=James K. |last3=Raivel |first3=Mary E.S. |website= |publisher=United States Department of Energy |accessdate=23 June 2021 }}</ref>
Concentrations of [[polyphosphate]]s or [[phosphonate]]s with zinc and chromates or similar compounds have been maintained in cooling systems to keep heat exchange surfaces clean
[[Total dissolved solids]] or TDS (sometimes called
Some groundwater contains very little oxygen when pumped from wells, but most natural water supplies include dissolved oxygen. Increasing
Water ionizes into [[hydronium]] (H<sub>3</sub>O<sup>+</sup>) [[cation]]s and [[hydroxide]] (OH<sup>−</sup>) [[anion]]s. The concentration of ionized [[hydrogen]] (as protonated water) in a cooling water system is
== Steam power stations ==
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}}</ref>]]
[[File:KKP Einlauf.jpg|thumb|Cooling water intake of a nuclear power plant]]
Few other cooling applications approach the large volumes of water required to condense low
|title=Profile of the Fossil Fuel Electric Power Generation Industry
|url=http://www.epa.gov/compliance/resources/publications/assistance/sectors/notebooks/fossil.html
|author=U.S. Environmental Protection Agency (EPA).
|year= 1997
|
}} Document No. EPA/310-R-97-007. p. 79.</ref> Many facilities, particularly electric power plants, use millions of gallons of water per day for cooling.<ref>EPA (2010). [http://www2.epa.gov/sites/production/files/2015-04/documents/partial-list-of-facilities-subject-to-cwa-316b_2010.pdf "Partial List of Facilities Subject to Clean Water Act 316(b)."]</ref> Water cooling on this scale may alter natural water environments and create new environments. [[Thermal pollution]] of rivers, estuaries and coastal waters is a consideration when siting such plants. Water returned to aquatic environments at temperatures higher than the ambient receiving water
'''Once-through cooling''' (OTC) systems may be used on very large rivers or at [[coastal]] and [[estuarine]] sites. These power stations put the [[waste heat]] into the river or coastal water. These OTC systems thus rely upon
The U.S. [[Clean Water Act]]
=== Cooling towers ===
[[File:A Marley industrial cooling tower.jpg|thumb|right|A Marley mechanical induced draft cooling tower]]
{{see also|Cooling tower}}
As an alternative to OTC, industrial cooling towers may use recirculated river water, coastal water ([[seawater]]), or well water. Large mechanical induced-draft or forced-draft cooling towers in industrial plants continuously circulate cooling water through heat exchangers and other equipment where the water absorbs heat. That heat is then rejected <!-- engineering term, although ejected makes more sense in regular English-->to the atmosphere by the
== Internal combustion engines ==
{{
The heated coolant mixture can be used to warm the air inside the car by means of the [[heater core]]. Also, the [[water jacket]] around an engine is very effective at deadening mechanical noises,
=== Open method ===
[[File:Moore-single-cylinder-gasoline-engine.jpg|thumb|An antique gasoline engine with an evaporative cooler and mesh screen to improve evaporation. Water is pumped up to the top and flows down the screen to the tank.]]
{{
An open water cooling system makes use of [[evaporative cooling]], lowering the temperature of the remaining (unevaporated) water. This method was common in early internal combustion engines
=== Pressurization ===
Water
|last=Nice|first=Karim|title=How Car Cooling Systems Work|url=http://auto.howstuffworks.com/cooling-system.htm|work=HowStuffWorks|publisher=HowStuffWorks, Inc|access-date=20 August 2012
|date=2000-11-22}}</ref>
=== Antifreeze ===
The use of water cooling carries the risk of damage from freezing. Automotive and many other engine cooling applications require the use of a water and [[antifreeze]] mixture to lower the freezing point to a temperature unlikely to be experienced. Antifreeze also inhibits corrosion from dissimilar metals and can increase the boiling point, allowing a wider range of water cooling temperatures.<ref name="HowStuffWorks"/> Its distinctive odor also alerts operators to cooling system leaks and problems that would go unnoticed in a water-only cooling system
=== Other additives ===
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== Power electronics and transmitters ==
Since approximately 1930 it is common to use water cooling for tubes of powerful transmitters. As these devices
Modern solid-state transmitters can be built so that even high
|reason=this section has no reference citations
|date=June 2013}}
=== Liquid cooling maintenance ===
{{unreferenced section|date=May 2024}}
[[File:© CoolIT Rack DCLC AHx Liquid Cooling Solution.jpg|thumb|CoolIT Rack DCLC AHx Liquid Cooling Solution]]
Liquid cooling techniques are increasingly being used for the thermal management of electronic components. This type of cooling is a solution to ensure the optimisation of energy efficiency while simultaneously minimising noise and space requirements. Especially useful in supercomputers or Data Centers
|reason=this section has no reference citations
|date=September 2018}} It is important in electronics technology to analyse the connection systems to ensure:
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== Computer usage ==
{{Redirect|T-Line|the rail line in San Francisco|T Third Street|the rail line in Tacoma|T Line (Sound Transit)|the planned transit line in Hamilton, Ontario|BLAST network|a shorthand system|Teeline Shorthand}}
{{see also|Computer cooling}}
[[File:Watercool Heatkiller IV waterblock for Titan X mounted on 1080 Ti.jpg|thumb|GPU waterblock on an Nvidia [[1080 Ti]]]]
[[
Water cooling often adds complexity and cost in comparison to air cooling design by requiring a pump, tubing or piping to transport the water, and a radiator, often with fans, to reject the heat to the atmosphere. Depending on the application, water cooling may create an additional element of risk where leakage from the water coolant recycle loop
The primary advantage of water cooling for cooling [[Central processing unit|CPU]] cores in computing equipment is transporting heat away from the source to a secondary cooling surface to allow for large, more optimally designed [[radiator]]s rather than small, relatively inefficient fins mounted directly on the heat source. Cooling hot computer components with various fluids has been in use since at least the [[Cray-2]] in 1982,
Water cooling can be used
Internal radiator size may vary: from
[[
A ''T-Line'' is used to remove trapped air bubbles from the circulating water. It is made with a t-connector and a capped-off length of tubing. The tube n acts as a mini-reservoir and allows air
Water coolers for desktop computers were, until the end of the 1990s, homemade. They were made from car [[radiator (engine cooling)|radiators]] (or more commonly, a car's [[heater core]]), [[aquarium]] pumps and home-made water blocks, laboratory-grade PVC and silicone tubing and various reservoirs (homemade using plastic bottles, or constructed using cylindrical acrylic or sheets of acrylic, usually clear) and or a [[T-Line]]. More recently{{when|date=May 2022}} a growing number of companies are manufacturing water-cooling components compact enough to fit inside a computer case.<ref>{{Cite web |date=2022-05-06 |title=Featured Projects – LiquidHaus |url=https://www.liquidhaus.com/pages/gallery |access-date=2022-05-06 |website= |archive-url=https://web.archive.org/web/20220506071434/https://www.liquidhaus.com/pages/gallery |archive-date=6 May 2022 |url-status=dead}}</ref> This, and the trend to CPUs of higher power dissipation, has greatly increased the popularity of water cooling.
Dedicated overclockers have occasionally
An alternative cooling
To avoid damage from condensation around the Peltier junction, a proper installation requires it to be "potted" with silicone epoxy. The epoxy is applied around the edges of the device, preventing air from entering or leaving the interior.{{Citation needed|date=February 2011}}
Apple's [[Power Mac G5]] was the first mainstream desktop computer to have water cooling as standard (although only on its fastest models). [[Dell]] followed suit by shipping their XPS computers with liquid cooling{{Citation needed|date=November 2009}}, using [[thermoelectric cooling]] to help cool the liquid. Currently, Dell's only computers to offer liquid cooling are their [[Alienware]] desktops.<ref>{{cite web|title=Alienware Desktops|url=http://www.dell.com/us/en/home/desktops/desktop-gaming/ct.aspx?refid=desktop-gaming&s=dhs&cs=19&~ck=mn|url-status=dead|archive-url=
Asus are the first and only mainstream brand to have put water
== Ships and boats ==
Water is an ideal cooling medium for vessels as they are constantly surrounded by water that generally remains at a low temperature throughout the year. Systems operating with
== Other applications ==
Plant [[transpiration]] and animal [[perspiration]] use evaporative cooling to prevent high temperatures from causing unsustainable [[metabolism|metabolic rates]].
[[Machine gun]]s used in fixed defensive positions sometimes use water cooling to extend barrel life through periods of rapid fire, but the weight of the water and pumping system significantly reduces the portability of water-cooled firearms. Water-cooled machine guns were extensively used by both sides during [[World War I]]
A [[hospital]] in [[Sweden]] relies on snow-cooling from [[Meltwater|melt-water]]
Some nuclear reactors use [[heavy water]] as
High-grade industrial water (produced by [[reverse osmosis]] or [[distillation]]) and potable water are sometimes used in industrial plants requiring high-purity cooling water. Production of these high
In 2018, researchers from the [[University of Colorado Boulder]] and [[University of Wyoming]] invented a radiative cooling [[metamaterial]] known as "RadiCold",
== See also ==
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* {{Cite book
|title=Limnology
|
|
|last2=Horne
|first2=Alexander J.
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|year=1979
}}
* {{Cite book |last=King
* {{Cite book |last=Reid
{{Refend}}
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