CW Pump Fluid Induced Vibration Troubleshooting Methodology

摘要

Fluid-machines experience a variety of forces during their operation result in different type of dynamic vibration behavior. Fluid induced instability phenomena are one such issue that typically manifests itself as a large amplitude sub-synchronous vibration of the pump shaft and pump structure due to whirl or vortex. When a pump is not operated at its Best Efficiency Point the part of mechanical energy is transferred to the fluid that develops Vortices. It occur in shear layers between the main flow and the re-circulating fluid .This rotating fluid (Vortex) having very low pressure in its centre and forms vapor bubbles at very high rate this vapor bubbles formation and collapse (cavitation) produce hammering effect that begins to participate in the system dynamics and can lead to fluid induced vibration and sound under certain machine state & operating regime favorable to the same. It should be avoided as it can lead to machine failures due to stress-cycle fatigue