Refrigeration Cycle: Dynamic Displacement Compressors

A centrifugal compressor operates using the principles of dynamic displacement. Vapor is drawn into the center, or ‘eye’, of a rotating impeller. The vapor exits the impeller and passes through a diffuser, which reduces the vapor velocity. This process converts the kinetic energy of the vapor into pressure energy. The pressurized vapor is collected in a ‘volute’ where it is directed to the outlet of the compressor.

The compression ratio for centrifugal compressors is somewhat limited, but they can support high refrigerant flow rates, so these compressors are widely used for large, steady loads. Centrifugal compressors are often employed for chilling water and air-conditioning applications, but are rarely used in industrial refrigeration.