Influence of diffuser vane number on energy loss of multistage centrifugal pump

As a key component of a multistage pump, the diffuser affects the efficiency of the multistage centrifugal pump. However, the loss mechanism inside the diffuser and links between the loss mechanism and vane numbers of diffuser were still not fully understood. In order to investigate the influence of the number of diffuser vane on the energy loss characteristics of multistage centrifugal pump, this paper analyzes the energy loss characteristics of pump with different number of diffuser vane by utilizing entropy production theory. The results show that under the design condition, when the number of diffuser vane increases to 11, the head is increased by 1.2m and the efficiency is increased by 3%. At the same time, with the increase of the number of diffuser vane, the backflow and eddy phenomena are gradually weakened, flow stream is more stable, the entropy production rate is significantly reduced, but the intensity of pressure pulsation in the diffuser is increased slightly. © 2021, Turbomachinery Society of Japan. All rights reserved.