Editing Water (section)

====Heat exchange====
Water and steam are a common fluid used for [[heat exchanger|heat exchange]], due to its availability and high [[Heat capacity of water|heat capacity]], both for cooling and heating. Cool water may even be naturally available from a lake or the sea. It is especially effective to transport heat through [[vaporization]] and [[condensation]] of water because of its large [[latent heat of vaporization]]. A disadvantage is that metals commonly found in industries such as steel and copper are [[oxidation|oxidized]] faster by untreated water and steam. In almost all [[thermal power station]]s, water is used as the working fluid (used in a closed-loop between boiler, steam turbine, and condenser), and the coolant (used to exchange the waste heat to a water body or carry it away by [[evaporation]] in a [[cooling tower]]). In the United States, cooling power plants is the largest use of water.<ref name="Water Use in the United States">[http://nationalatlas.gov/articles/water/a_wateruse.html "Water Use in the United States"], ''National Atlas''. {{webarchive|url=https://web.archive.org/web/20090814045418/http://nationalatlas.gov/articles/water/a_wateruse.html |date=14 August 2009 }}</ref>

In the [[nuclear power]] industry, water can also be used as a [[neutron moderator]]. In most [[nuclear reactor]]s, water is both a coolant and a moderator. This provides something of a passive safety measure, as removing the water from the reactor also [[void coefficient|slows the nuclear reaction down]]. However other methods are favored for stopping a reaction and it is preferred to keep the nuclear core covered with water so as to ensure adequate cooling.