Editing Heat exchanger (section)

{{short description|Equipment used to transfer heat between fluids}}
[[Image:Tubular heat exchanger.png|thumb|Tubular heat exchanger]]
[[File:Shell and Tube Heat Exchanger of Chiller.jpg|thumb|Partial view into inlet plenum of shell and tube heat exchanger of a refrigerant based chiller for providing air-conditioning to a building]]
A '''heat exchanger''' is a system used to transfer heat between a source and a [[working fluid]]. Heat exchangers are used in both cooling and heating processes.<ref>{{Cite journal|url=https://dx.doi.org/10.1080/10407782.2017.1372670|doi=10.1080/10407782.2017.1372670|title=Heat transfer augmentation through convergence angles in a pipe|year=2017|last1=Al-Sammarraie|first1=Ahmed T.|last2=Vafai|first2=Kambiz|journal=Numerical Heat Transfer, Part A: Applications|volume=72|issue=3|pages=197–214|bibcode=2017NHTA...72..197A|s2cid=125509773|url-access=subscription}}</ref> The fluids may be separated by a solid wall to prevent mixing or they may be in direct contact.<ref>{{cite book|author1=Sadik Kakaç |author2=Hongtan Liu |title=Heat Exchangers: Selection, Rating and Thermal Design|edition=2nd|publisher=CRC Press|year=2002|isbn=978-0-8493-0902-1}}</ref> They are widely used in [[space heating]], [[refrigeration]], [[air conditioning]], [[power station]]s, [[chemical plant]]s, [[Petrochemical|petrochemical plants]], [[Oil refinery|petroleum refineries]], [[natural-gas processing]], and [[sewage treatment]]. The classic example of a heat exchanger is found in an [[internal combustion engine]] in which a circulating fluid known as [[engine coolant]] flows through [[radiator]] coils and [[air]] flows past the coils, which cools the coolant and heats the incoming [[air]]. Another example is the [[heat sink]], which is a passive heat exchanger that transfers the heat generated by an electronic or a mechanical device to a fluid medium, often air or a liquid coolant.<ref>{{Cite journal|url=https://dx.doi.org/10.1115/1.4041196|doi=10.1115/1.4041196|title=Constructal Design of Circular Multilayer Microchannel Heat Sinks|year=2019|last1=Farzaneh|first1=Mahsa|last2=Forouzandeh|first2=Azadeh|last3=Al-Sammarraie|first3=Ahmed T.|last4=Salimpour|first4=Mohammad Reza|journal=Journal of Thermal Science and Engineering Applications|volume=11|s2cid=126162513 |url-access=subscription}}</ref>