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Vapor Compressor Refrigeration system

Vapor compressor refrigeration system is the most widely used refrigeration system worldwide in both commercial as well as in domestic. It has mainly four major components 1) Compressor 2)Condenser 3) Expansion valve 4) Evaporator.

Working Principle: Each and every refrigerant have a certain temperature at certain pressure, where it can be converted in vapor or vice versa. Refrigerant in super heat state and low pressure suck by compressor and where it is compressed and as a result its temperature and pressure is increased by consuming high grade energy(electricity). The pressure of refrigerant after compressor is always higher than the saturated pressure of refrigerant at ambient temperature, so that it can converted into liquid in condenser. The energy consumed by the compressor to compress the refrigerant is divided in to two parts

1) The oil circulating in to compressor casing taking heat of compressor to maintain it below a specific temperature.
2) The remaining energy is added in to refrigeration cycle. This energy further divided in to two parts

              i) The sensible heat given by expansion valve
              ii) Remaining energy effective energy(from part 2), plus the cooling capacity is rejected to atmosphere by condenser.


In condenser, refrigerant gives its sensible as well as latent heat to atmosphere. This heat is equal to sum of cooling capacity of compressor and the effective energy added. The pressure drop in the condenser such that the pressure of refrigerant at outlet of condenser must be higher than the saturated pressure of refrigerant at ambient temperature so that it will not converted back into vapor again.

High pressure liquid from condenser enter in to expansion valve where its pressure is reduced to evaporator pressure. As result its temperature reduced. The sensible heat of refrigerant              (m*Cp*(T3-T4) is equal to latent heat of vaporization of refrigerant multiplied by quality of refrigerant enter at evaporator. Some companies used this heat to do super heating of refrigerant after during it flow in suction tube. This reuse and increase the energy the overall COP of system.

Low pressure and low temperature refrigerant with some vapor enter in to the evaporator where it exchange heat with the surrounding and take take heat from there by reducing temperature of surrounding and converted in low temperature vapor with some degree of super heating. The super heat refrigerant further heated in suction tube either by capillary sensible heat or by condenser outlet tube using annular heat exchanger.

This super heated vapor refrigerant enter into compressor where its pressure and temperature is increased and cycle continue.

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