Effect of Pressure Pulsations on the Vibration Isolating Properties of Fluid Filled Pipeline Compensators and Possibilities for Their Reduction by Pressure Pulsation Dampers of Various Designs

Abstract

Vibration isolating compensators of various designs are used to reduce vibrations in power‑plant piping. Their efficiency can be significantly reduced by pressure pulsations of the working fluid arising from various sources. Pressure pulsations can be mitigated by different types of pulsation dampers. Results are presented for pulsation reduction obtained by the combined use of a broadband damper based on spherical air cavities located outside the main pipe cross‑section and a Helmholtz resonator. Tuning the Helmholtz resonator to the frequency at which the spherical damper exhibits negative efficiency reduces the amplitude of the low‑frequency resonance by two orders of magnitude and widens the frequency range over which pulsations are efficiently attenuated. The design of a test rig is described for investigating the influence of the placement of high‑efficiency broadband pulsation dampers on vibration levels, pressure pulsations, and dynamic forces in a three‑dimensional pipeline system with a pump and working‑fluid flow, including placement of the dampers inside compensators.