CS20: Identification and Mitigation of H2 Recycle Gas Compressor Blade Pass Resonance

Abstract

A hydrogen compressor experienced intermittent vibration spikes during operation Review of the vibration plots revealed that the spikes appear at 11x running speed of the compressor The no of vanes of the impeller is 11 Further investigations revealed that the vibration spikes are coming up only in a specific speed band This correlation was consistent and it existed since commissioning of the machine The problem was deliberated with OEM and confirmed that this is vane pass resonance in the machine which is happening at this speed range due to the 19th eigenvalue of the rotor getting excited by the acoustic resonance in the impeller passage Campbell diagram & Safe diagram of the impeller were reviewed to see if this there was any interference between the vane pass excitation and impeller eigenvalue This case study presents the problem experienced, analysis performed and mitigation introduced to manage the risks