Investigating the Performance Degradation of Centrifugal Pumps

Abstract

Centrifugal pumps are used in a variety of engineering applications such as power production, heating, cooling, and water distribution systems. Although centrifugal pumps are considered to be highly reliable hydraulic machines, they are susceptible to a wide range of damages due to several degradation mechanisms, operating away from the best efficiency point and improper installation. The most common forms of condition monitoring for rotating machines performance monitoring coupled with vibration analysis. The goal of this thesis is to document the performance degradation and vibration characteristics for an industrial scale centrifugal pump subjected to specific forms of damage, in particular impeller unbalance. In this work a 7.5 kW centrifugal pump rated for a flow rate of 17 L/s and 23 m of pressure head is tested in a state-of-the-art pump experimental setup, equipped with a wide range of sensors and control devices. Extensive performance and vibration measurements were collected to evaluate the effects of various levels of impeller unbalance using the time and frequency domain techniques coupled with principal component analysis. The results from this work can be used to evaluate and monitor the pump performance under prescribed degradation in order to enhance the preventative maintenance program.