Investigation of the Potential for Optimization of Hydraulic Axial Thrust Balancing Methods in a Centrifugal Pump

Authors

D. Lefor - Ruhr-Universität Bochum, Chair of Thermal Turbomachinery, Germany
J. Kowalski - Ruhr-Universität Bochum, Chair of Thermal Turbomachinery, Germany
T. Herbers - Klaus Union GmbH & Co KG, Germany
R. Mailach - Ruhr-Universität Bochum, Chair of Thermal Turbomachinery, Germany

Abstract

To reduce bearing loads in centrifugal pumps hydraulic axial thrust balancing methods are commonly used. Their disadvantage is the causing of significant flow losses, which result in a decline of the pump’s efficiency. Within this investigation the balancing methods casing ribs and J-Grooves are compared. The objective is to determine the potential for improvement of J-Grooves concerning the pump efficiency in contrast to previously examined casing ribs. The study is carried out on the basis of a CFD model of an industrial magnetic drive pump, which is validated by transient local static pressure measurements at different operating points. The geometry of the J-Grooves is parameterized. A stochastically based sensitivity analysis is performed, whereby the importance and correlations of the parameters are evaluated. An automatic optimization is subsequently carried out and leads to an efficiency improvement of up to 1.14 percentage points for a J-Groove design.