Effect of Adjusting Balance Hole to Cavitation Area on Cavitation Performance of a Centrifugal Pump

Abstract

In this study, the cavitation flow field of a centrifugal pump with four different positions of balance holes was studied by experiment and simulation. The results show that: the critical cavitation number decreases first and then increases with the position, the critical cavitation numbers of positions 2, 3 and 4 are smaller than the original model, and the effect of improving cavitation performance is obvious. The input of the high-pressure liquid from the balance cavity increases the absolute pressure of the cavitation area, and changes the pressure gradient in the cavitation area, then the cavitation suppressed. The position of the balance hole has obvious influence on the axial force, positions 2 and 3 reduce the axial force and improve the stress condition of the centrifugal pump, while positions 1 and 4 increase the axial force. It can be concluded that the positions o 2, 3 and 4 can improve the cavitation performance, so the cavitation performance of the centrifugal pump can be significantly improved by setting balance holes along the 2, 3 and 4 lines, also the balance hole should be avoided at position 1.