Influence of eccentric impeller on pressure pulsation of large-scale vaned-voluted centrifugal pump

Abstract

Large-scale vaned-voluted centrifugal pump is a key component in water conveyance engineering. Hydraulic performance and pressure pulsation are important assessment indicators for operation efficiency and stability. During the common operation, the impeller eccentricity is easy to occur due to installation error, radial force and other reasons, which results the changes of hydraulic performance and pressure pulsation. In this study, the hydraulic performance and pressure pulsation in the vaneless region are analyzed by computational fluid dynamics method. The influence of eccentric impeller on the hydraulic performance in each components and the pressure pulsation is studied. Results show that the eccentric impeller causes the increasing of hydraulic dissipation especially in the volute. However, decreasing of the hydraulic dissipation happens in the draft tube. Impeller eccentricity significantly enhances the amplitude of rotation frequency, but has no obvious effect on the blade passing frequency and its harmonics. The peak-peak value of pressure pulsation of eccentric impeller increases rapidly with the eccentricity ratio. The results of this study provide scientific support for solving the stability problem caused by eccentric impeller in engineering cases.

Structural Analysis and Optimization of Ultra-High-Speed Centrifugal Pump Rotor System Considering Fluid–Structure Interaction

“…Three levels are set for each factor, which are listed in Table 5. For orthogonal design, range analysis [23] is adopted to seek the optimal parameter combination according to the results listed in Table 4.…”

“…This indicates that the highspeed multistage rotor system under these parameters has the smallest numerical value for the maximum average deformation. For orthogonal design, range analysis [23] is adopted to seek the optimal parameter combination according to the results listed in Table 4.…”

“…Recently, the study of fluid-structure interaction (FSI) of centrifugal pumps has become a new hot topic in research. The positional variation of the impeller has been found to impact the internal flow field of the pump, subsequently altering the pressure pulsation and pump performance [23,24]. Baun et al [25] investigated the impeller-to-volute position and tried to find the optimal position for different volutes.…”

Numerical Analysis on the Unsteady Radial Load on the Shaft of a Large-Scale Dredge Pump Unit

“…Dredge pumps are usually centrifugal pumps. There are two main causes of rotor vibration and shaft fatigue in centrifugal pump units: 1) the eccentric mass of a rotor due to poor machining quality or uneven wear leads to rotor imbalance during operations (Tan et al 2021;Lu et al 2022), and 2) the fluid excitation force exerted on the impeller has obvious unsteady characteristics due to rotor-stator interaction, especially in high-capacity pumps (Jia 2017;Yan 2017;Cui et al 2020;Zhu 2021). One component of the fluid excitation force, the hydraulic radial force, whose magnitude and direction usually vary with time, is a major cause of pump vibration.…”