Evaporator is the part of the refrigeration system where the refrigerant fluid undergoes a change of state, leaving the liquid phase to the gas phase. It is sometimes called a cooling coil, unit cooler, freeze coil, freezer, etc.
Although the evaporator is sometimes a very simple device, it really is the most important part of the system. Any refrigeration system is designed, installed and operated for the sole purpose of removing heat from any substance.
As this heat has to be absorbed by the evaporator, the efficiency of the system depends on the design and proper operation of the same.
The efficiency of the evaporator in a refrigeration system depends on three
Main requirements, which should be considered in the design and selection of the project:
1 - Have a sufficient surface to absorb the required heat load, without an excessive temperature difference between the refrigerant and the substance to be cooled.
2 - Sufficient space must be provided for the liquid refrigerant and also adequate space for the refrigerant vapor to separate from the liquid.
3 - Have sufficient space for the circulation of the refrigerant without excessive pressure drop between the inlet and the outlet.
