Centrifugal refrigeration compressor

　　The centrifugal refrigeration unit (or centrifugal chiller) for air conditioning is composed of a centrifugal refrigeration compressor, evaporator, condenser, main motor, air recovery device, lubrication system, control cabinet and starting cabinet. Some of these components are assembled in a decentralized manner, but most of them are “assembled” units in which the components are combined together. The units are divided into fully enclosed, semi-enclosed and open types.

　　Fully enclosed

　　It encloses all components in the same casing and is generally used for air conditioning in aircraft cabins. It has the characteristics of small cooling capacity, good air tightness, simple structure, low noise and vibration due to the cancellation of the speed increase device.

　　Semi-enclosed

　　The semi-enclosed unit adopts a double-exchange centrifugal refrigeration compressor with two-end support. Most of its refrigerants use R11 or R 22, which circulate in a closed system. The shape of each component and the connecting flange can still be identified from the appearance. The semi-enclosed unit has the advantages of compact structure, small space and area, low foundation requirements, convenient transportation and management, and large cooling capacity.

　　Open type

　　Open type units use reliable shaft end seals to make them open type units. The motor is water cooled, which can save 3% to 6% of electricity. It is easy to repair in case of failure. For refrigeration units used in chemical industry, open type units are generally used because they are multi-stage compressors, have high power and complex refrigeration systems.