Energy Performance Prediction Model for Mixed-Flow Pumps by Considering the Effect of Incoming Prerotation

Mixed-flow pump is one of the most broadly applied sorts of power equipment in the field of petrochemical and water conservancy. The effect of inlet prerotation on the energy characteristics and operational stability of a pump is a significant consideration. The aim of this study is to analyze the relationship between inlet prerotation and the total energy consumption of a mixed flow pump by developing a predictive model. The impact of prerotation on the pumping performance and energy conversion for a typical mixed-flow pump has been investigated by a combined approach of theoretical derivation, numerical simulation, and experimental verification. Validation of the numerical methods was achieved by comparing the results to the experimentally obtained data. A prediction model was developed for head and power, which incorporated inlet prerotation. The study utilized a mathematical model and numerical simulation to compute the head and power output of a mixed-flow pump for a wide range of inlet prerotation angles. The results of the two methods were highly consistent. Moreover, the effects of prerotation on the flow structure of the mixed-flow pump were analyzed. It was found that prerotation led to an increase in the incoming flow angle, resulting in unstable flow patterns causing secondary flows and low-pressure vortex in the impeller flow path. This induced a rise in energy consumption of the impeller. The prediction model and analysis of the internal flow structure provide a theoretical foundation for predicting the hydraulic performances of mixed-flow pumps under prerotation conditions and improving their stability of operation.