6. Compressor flow control

Any change in the system's cooling capacity results from a change in the refrigerant flow rate of the compressor(s). There are a number of different procedures, summarized below:

• a change in the number of compressors in service ;

• modification of compressor rotation speed ;

• modification of the compressor displacement;

• the use of a power regulator.

Modifying the number of compressors commissioned according to instantaneous cooling requirements is a process widely used in the warehousing and food processing industries. It's an apparently simple method, based on the principle of all or less, or nothing. However, the control procedure for compressors and their auxiliaries is, depending on the equipment, more...