Refrigerator is a device a body can be maintained at a temperature less than outside temperature. It uses a special fluid generally referred as a 'refigerant' . There are wide varities of refrigerants an the market such as R-12,R-22(Freon-22).
R-12(chlorofluorocarbon) is the one which is used in our home fridges. Where as R-22 is used in Air Conditioners used in offices,malls and institutes. where as domestic refrigerators R-12 is used. Butdue to ozone layer depletion problems it has being replaced by R-290, R-134a, R-600.
The working principle of refrigerator is same as that of an air conditioners.These employ a closed cyclic process in which refrigerant is used. The refrigerant has a crucial property of being in vapour state at atmospheric temperature and pressure. Where as it turns into liquid state after compressing in
a compressor. Domestic refrigerators consists of evaporator, compressor, condenser and a expansion device for
refrigerant. Evaporater is the located in freezer, where refrigerant absorbs heat from items kept in refrigerator and
gets evaporated. Then, after turning into vapour it is compressed by compressor where it turns into liquid form.
While the liquid refrigerant is passed through condenser(the coils which are at the back side of the refrigerator) it gets cooled. After that it is sent to expansion device(capillary tube) where its pressure is decreased.In general freezer is the coldest portion of the cabinet. Then followed by chiller tray. While coming down, there are compartments with progressive higher temperatures. The bottom most portion compartment in the least cold one made for vegetables.
Applications:- They are widely used for
1). Domestic purpose
2). Fish storage
3). Cold storage
4). Diary industries
6). A/C busses, trains, cars, and airoplanes.
7). Telecom industry
8). Mostly in offices for better functioning of the computers