Effect of the flow in blade root-leakage on hydraulic characteristic in axial flow pump system

Asian Working Group- IAHR's Symposium on Hydraulic Machinery and Systems

Xie, R.S.^1 ; Tang, F.P.^2 ; Yang, F.^2 ; Xiang, C.^1

School of Machinery and Automobile Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou

310018, China^1

School of Hydraulic, Energy and Power Engineering, Yangzhou University, Yangzhou

225100, China^2

关键词: Axial flow pump;    Conversion formulas;    Flow condition;    High-precision;    Hydraulic characteristic;    Theoretical derivations;    Vertical axial flow pump;    Work abilities;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/163/1/012123/pdf
DOI  :  10.1088/1755-1315/163/1/012123

来源: IOP

【 摘 要 】

The clearance locate on blade root is almost 10∼20 times than tip in adjustable axial flow pump, the flow in blade root clearance has obvious impact on the hydraulic characteristic in pump systems. In order to research the effect of blade root clearance on hydraulic characteristic in axial flow pump system, a vertical axial flow pump system is researched by numerical simulation and experiment. After considering the root clearance, the result has high precision under large and design flow condition. The simulation result shows with the effect of the blade root clearance, the velocity distribution from hub to shroud is trend bad, and the streamline near the blade root is changed greatly, under the same flow condition, the flow far away from the hub in the cascade is increasing, the work ability of blade is reducing, the head has a sharp fall. In this paper, only 0.5mm clearance exist, 2.9% blade surface area is loss, the head decrease 7.86%, shaft power decrease 6.35%, the efficiency from 76.04% down to 74.82%. The conversion formula between the pump station with and without gap clearance is gained by theoretical derivation.