A vapor-compression chiller consists of four primary components of the vapor-compression refrigeration cycle. They include a compressor, evaporator, condenser and a metering device.
Vapor-compression chillers typically utilize HCFC or CFC refrigerants to achieve a refrigeration effect. Compressors are the driving force in a vapor-compression chiller and act as a pump for the refrigerant.
Compressed refrigerant gas is sent from the compressor to a condenser unit that rejects the heat energy from the refrigerant to cooling water or air outside of the system.
The transfer of heat allows the refrigerant gas to condense into a liquid which is then sent to a metering device.
The metering device restricts the flow of liquid refrigerant which causes a drop in pressure. The drop in pressure causes the warm refrigerant liquid to change phase from liquid to gas and in doing so absorbs heat from the water to be cooled due to
adiabatic flash evaporation.
The metering device is positioned so that the expanding refrigerant gas is contained within the evaporator, transferring the heat energy from the water to be cooled into the refrigerant gas. The warm refrigerant gas is then sent back to the compressor to start the cycle over again and the newly chilled water in the separate loop can now be used for cooling.