Influence of volute cross-sectional area profile on hydraulic performance of double-suction centrifugal pump
ZHAO Wanyong1,CHEN Shuai1*,ZHAO Qiang1,LI Yanbin2
1. School of Energy and Power Engineering, Lanzhou University of Technology, Lanzhou, Gansu 730050, China; 2. Lanzhou Shichang Hydraulic Machinery Co. Ltd., Lanzhou, Gansu 730050, China
Abstract：Aiming at the problem of shaft breakage caused by the operation of S700-500-730 double-suction centrifugal pump in a pump station, the CFD numerical simulation method is used to analyze the influence of the volute cross-sectional area profile on the hydraulic performance and radial thrust. The original profile(Y-law)adopted in the pump is compared with the volute cross-sectional area li-near profile(L-law). The results show that the pumps with two kinds of volute cross-sectional area profiles share a similar hydraulic performance at the design point, the radial thrust in the pump with Y-law profile is increased by 24.77% compared with the pump with L-law profile. Under off-design conditions, however, compared with the pump with L-law profile, the hydraulic performance of the pump with Y-law profile is more superior, unfortunately, the radial thrust on the impeller is higher than the former.Under unsteady flow conditions, the pulsation amplitude and high frequency pulsation of radial thrust in the pump with Y-law profile are much more severe than the pump with L-law profile. The variation rule of volute cross-sectional area has a significant influence on the radial thrust ac-ting on the impeller. The results can provide a theoretical basis for solving the problem of shaft brea-kage caused by excessive radial thrust.
