Design Optimization Of Balancing Hole In A Centrifugal Pump Impeller By Using Experimental Design Methods

Abstract

The aim of this study is to determine the optimal balancing hole to be drilled into the pump impeller in order to extend the bearing life by reducing the axial forces exposed on the bearings. In this study, as well as reduction of the axial forces, the changes in the pump efficiency are also considered. For this study, a single-stage centrifugal pump having a 1450 rpm speed, 350 m³/h flow rate and 51 m head is chosen. It is foreseen to optimize the design optimization of the balancing holes on the selected pump impeller is implemented by using the method of experimental design and Computational Fluid Dynamics (CFD). Ansys Fluent software is used for CFD analysis. In order to reach the optimum results, four parameters including the hole center angle, hole diameter, hole center diameter and number of balancing holes in the impeller are selected, and the optimization study is carried out by using Multi-Objective Taguchi Method. Low axial force and high pump efficiency are accepted as objectives. CFD results are evaluated according to the analysis of variance (ANOVA) and signal/noise (S/N) ratio. As a result, it is determined that the hole diameter is the most effective parameter on these objectives. The optimum design parameters are found to be 0°, 12 mm, 100 mm and 6 for the parameters given above, respectively.