What exactly is the phenomenon of surge in centrifugal compressors? During the operational run of a centrifugal compressor, intense vibrations occasionally occur; simultaneously, the flow rate and pressure of the gaseous medium undergo significant fluctuations. This is accompanied by a periodic roaring sound, and the oscillating airflow within the piping network generates intense noise.
Characteristics of Unit and Piping Network Operation During a Surge Event:
(1) The outlet pressure and inlet flow rate of the gaseous medium exhibit significant variations, and instances of reverse gas flow may occur.
(2) The piping network experiences periodic vibrations characterized by large amplitudes and low frequencies, accompanied by a rhythmic "roaring" sound.
(3) The compressor itself vibrates violently and emits intense, periodic airflow noise. Furthermore, the severe vibration of the compressor casing disrupts bearing lubrication conditions, potentially leading to bearing burnout; collisions may also occur between the rotor and the stator, resulting in component damage.
How to Implement Anti-Surge Control?
Surge poses a severe hazard, and a compressor must not be allowed to operate in a surging state for extended periods. When a surge event is imminent, immediate action must be taken utilizing one or a combination of the following three methods: partial gas venting, partial gas recirculation (recycle), or adjusting the compressor's operating speed. These measures aim to reduce the outlet pressure—or increase the inlet and outlet flow rates—thereby rapidly extracting the compressor from the surge condition and restoring stable operation.