Influence of cavitation on pressure pulsation through impeller of large pumps

Abstract

The article provides the main recommendations for studying the processes of cavitation development on the models of pumping units OPV-10-260 and V 20-13/45 with an impeller diameter Dr = 250 mm. The nature of the effect of cavitation depends on forms of pressure pulsation. The purpose of this work is to study abrasive-cavitation erosion of large pumps. The research objectives are to develop a methodology for calculating their operating modes, taking into account the minimum deterioration of working parts. Strongly developed cavitation leads to disruption of regular pulsations and an increase in the swing of the high-frequency component. Investigations of operating mode of pumps with deterioration of elements of flow section were carried out, and the characteristics of materials for the manufacture of hydromechanical equipment for resistance to cavitation deterioration were refined. According to experiments, the influence of pressure on the pressure fluctuation range begins to significantly affect if the pump pressure is less than 5 m. The nature of the effect of cavitation depends on the forms of pressure pulsation. The complexity of composition, high cost of high-alloy steels, and non-ferrous alloys make it irrational to use them in massive parts operating under cavitation-abrasive conditions. It is recommended to use the developed dependencies on machine water elevating systems to reduce deterioration by improving the quality of impeller materials.