Refrigeration is a process in which work is done to remove heat from one location to another. It has many applications which includes household refrigerators, industrial freezers, cryogenics, air conditioning and heat pumps.
Following are the different refrigeration methods:
It consists of a refrigeration cycle in which heat is removed from a low temperature space or source and rejected to a high temperature sink with the help of external work. A refrigeration cycle describes the changes that take place in the refrigerant as it alternately absorbs and rejects heat as it circulates through a refrigerator. Cyclic refrigeration can be classified in to vapor cycle and gas cycle.
Non Cyclic Refrigeration:
In non cyclic refrigeration, ice or subliming dry ice is used as cooling agent and these agents are effective for maintaining products at low temperatures. Foodstuffs maintained at this temperature or slightly above have an increased storage life. Generally this method is used in small scale refrigeration such as in laboratories and workshops, or in portable coolers.
This method uses Peltier effect to create a heat flux between the junction of two different types of materials. This effect is commonly used in camping and portable coolers and for cooling electronic components and small instruments.
This is one of the methods of refrigeration which is based on the magneto caloric effect. The refrigerant is paramagnetic salt such as cerium magnesium nitrate. Because few materials exhibit the required properties at room temperature, applications of this method have so far been limited to cryogenics and research.
Air cycle machine used in aircraft, vortex tube used for spot cooling, steam jet cooling and thermoacoustic refrigeration are the other methods of refrigeration.