Refrigeration

Refrigeration (from the Latin frigus, frost) is generally the cooling of a body by the transfer of a portion of its heat away from it. Applications include conservation, especially of food, and lowering the temperature of drinks to one that is more agreeable for consumption. Domestic refrigerators are common in kitchens, with separate sections or separate machines for cooling and freezing.

Thermodynamics of refrigerators

Most home and automotive refrigerators qualify as phase change heat pumps. They convert a refrigerant from gas to liquid and back again by compression in a refrigeration cycle. In principle, any endothermic process could be used provided it is balanced by an exothermic in another physical location so that it can operate in a cycle. For example, absorption of gaseous ammonia into water is used in most gas absorption refrigerators, and the Einstein refrigerator is a version of this which contains no moving parts — the cooling effect in this case coming from the heat absorbed by the ammonia when it evaporates from the water.

Related Topics:
Phase change heat pump - Refrigerant - Gas - Liquid - Refrigeration cycle - Endothermic - Exothermic - Ammonia - Water - Gas absorption refrigerator - Einstein refrigerator

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Other processes which have been used on a small scale include the Peltier effect for thermoelectric cooling.

Related Topics:
Peltier effect - Thermoelectric cooling

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