Block, SkipCaptcha, Upload, Automoderated users, Check users, delete, edit, Moderators, move, oversight, protect, ratelimit-exempt, rollback
19,940
edits
Changes
Jump to navigation
Jump to search
mLine 33:
Line 33: + + + + + − − ===Magnetic refrigeration=== − Magnetic refrigeration uses the Magnetocaloric Effect and the law of [[entropy]] to produce a cooling effect. It is a new technology which is has for some time been only useful in research and cryogenics. However, it is becoming a more common technology as it is quite efficient.<ref>http://www.eurekalert.org/features/doe/2001-11/dl-mrs062802.php</ref><br /> − Put simply, Magnetocaloric Materials heat up when exposed to magnetism. When the magnetic field is removed, they cool down again. When used for refrigeration, such a material is exposed to strong magnetism, so that it heat up, while heat sink removes as much heat as it can. Then the material is removed from the magnetic field, but is also isolated (usually by a vacuum). The material now has a high heat capacity, and is therefore cooler than the heat sink. it was just in contact with. This cold substance can now be used to cool the desired air or liquid, before the process is repeated.<ref>http://www.cooltech-applications.com/magnetic-refrigeration-principle.html</ref>
rearrange
Gas cycle refrigeration is used in some cases where high-pressure air is readily available, or chemical refrigerants (like ammonia) are considered too dangerous. One place this system is popular in aircraft, since both of these criteria are met.<ref>http://www.brighthubengineering.com/hvac/20589-methods-of-refrigeration-gas-cycle</ref>
Gas cycle refrigeration is used in some cases where high-pressure air is readily available, or chemical refrigerants (like ammonia) are considered too dangerous. One place this system is popular in aircraft, since both of these criteria are met.<ref>http://www.brighthubengineering.com/hvac/20589-methods-of-refrigeration-gas-cycle</ref>
===Magnetic refrigeration===
Magnetic refrigeration uses the Magnetocaloric Effect and the law of [[entropy]] to produce a cooling effect. It is a new technology which is has for some time been only useful in research and cryogenics. However, it is becoming a more common technology as it is quite efficient.<ref>http://www.eurekalert.org/features/doe/2001-11/dl-mrs062802.php</ref><br />
Put simply, Magnetocaloric Materials heat up when exposed to magnetism. When the magnetic field is removed, they cool down again. When used for refrigeration, such a material is exposed to strong magnetism, so that it heat up, while heat sink removes as much heat as it can. Then the material is removed from the magnetic field, but is also isolated (usually by a vacuum). The material now has a high heat capacity, and is therefore cooler than the heat sink. it was just in contact with. This cold substance can now be used to cool the desired air or liquid, before the process is repeated.<ref>http://www.cooltech-applications.com/magnetic-refrigeration-principle.html</ref>
==Other refrigeration methods==
===Thermoelectric refrigeration===
===Thermoelectric refrigeration===
Thermoelectric refrigeration uses the Peltier effect (discovered by Jean Peltier in 1834<ref>http://www.koolatron.com/test/images/thermoelectric.html</ref>) to transfer heat out of a space to be cooled. In such a system, two plates made of different metals are pressed together (usually with semiconductor beads between them) and electricity ([[Direct current|DC]]) is run through them. The negatively charged plate becomes cooler, while the positively charged one becomes warm. The negative plate is then used to cool an item or substance, while the positive side is cooled by a heat sink (which usually needs a fan).<ref>http://searchnetworking.techtarget.com/definition/thermoelectric-cooling</ref><ref>http://www.marlow.com/resources/general-faq/6-how-do-thermoelectric-coolers-tecs-work.html</ref><br />
Thermoelectric refrigeration uses the Peltier effect (discovered by Jean Peltier in 1834<ref>http://www.koolatron.com/test/images/thermoelectric.html</ref>) to transfer heat out of a space to be cooled. In such a system, two plates made of different metals are pressed together (usually with semiconductor beads between them) and electricity ([[Direct current|DC]]) is run through them. The negatively charged plate becomes cooler, while the positively charged one becomes warm. The negative plate is then used to cool an item or substance, while the positive side is cooled by a heat sink (which usually needs a fan).<ref>http://searchnetworking.techtarget.com/definition/thermoelectric-cooling</ref><ref>http://www.marlow.com/resources/general-faq/6-how-do-thermoelectric-coolers-tecs-work.html</ref><br />
Although not an incredibly effective method of refrigeration, this is can be a convenient, compact option which can use power directly from a battery.<ref>https://thermal.ferrotec.com/technology/thermoelectric-reference-guide/thermalref04</ref>
Although not an incredibly effective method of refrigeration, this is can be a convenient, compact option which can use power directly from a battery.<ref>https://thermal.ferrotec.com/technology/thermoelectric-reference-guide/thermalref04</ref>
===Vortex tube===
===Vortex tube===