Adaptation fo an existing mixed flow pump hydraulic to extreme part load oepration conditions

摘要

In the presnet paper,the adaptation of existing mixed flow casing pumps to extreme part load conditions by cutting down the impeller in the meridional plane is described.the influence of different impeller shapes on the head curve characteristic and the development of the part load recirculation zone is investigated theoretically.The theoretical investigations are accompanied by model pump tests.Besides the hnead curve and efficiency characteristics,the noise and vibration levels were measured and assessed for the different impeller shapes.especially the vibrations hsow a distinct characteristic which allws a very precise deifntion of limiting flow rate.Comparing the theoretical and experimental results,good agreement cna be claimed.Especially the onset of the prt load recirculation is predicted very well.