Method and apparatus for detecting and preventing fluid surge in a centrifugal compressor

摘要

A method and apparatus for controlling working fluid surge in a centrifugal compressor (10) include preventing surge by using a variable-speed prime-mover (14) to achieve a minimum desired surge margin. Surge prevention is also accomplished by continuously modulating a blowoff valve (52) to maintain an actual compressor pressure ratio at a predetermined target maximum value. Surge detection is accomplished by monitoring the time rate of change of the final stage discharge pressure.