Sediment erosion in the impeller of a double-suction centrifugal pump - A case study of the Jingtai Yellow River Irrigation Project, China

摘要

Double-suction centrifugal pumps are widely used in irrigation projects along the Yellow River due to their high capacity and high reliability. Sediment erosion of the impeller and the corresponding pump performance degradation are key issues since the double-suction centrifugal pump operates in sediment-laden water. Experiments and numerical method were used to study the erosion wear of the impeller in a double-suction pump in the Jingtai Yellow River Irrigation Project(JYRIP). The effects of particle size, particle shape and particle concentration on the pump performance were investigated. Observations during operation combined with scanning electron microscope(SEM) were used to verify the erosion mechanisms at different positions of the impeller blade. Regarding the numerical method, the Eulerian-Lagrangian approach combined with the Mclaury model was employed to predict the sand particles erosion. Numerical results for the erosion distribution and locations of severe erosion wear were consistent with the experimental observations. There was a transition of erosion wear from impacting to cutting from the leading edge(LE) to the trailing edge(TE) of the blade surface. Erosion wear damage was found to be mainly distributed near the LE and the TE. Larger, angular particles and a higher particle concentration caused more severe erosion damage and increased the pump performance reduction rate. Moreover, the effect of particle shape on the performance was less than the effect of particle size and particle concentration. These results provide a reference for optimization of the design of anti-wear blades of the double- suction pump and can help predict the performance of the pump with sediment-laden water.