Numerical study on transient stopping characteristics of the first stage impeller of a multistage pump

ZHANG Yuliang1,2, WANG Canfei3, ZHANG Chenliang2, TAO Junyu2, REN Saidong2

(1.Zhejiang Provincial Key Laboratory of Fluid Transmission Technology, Zhejiang SciTech University,
Hangzhou 310018, China; 2.College of Mechanical Engineering, Quzhou University, Quzhou 324000, China;
3.Zhejiang Institute of Mechanical & Electrical Engineering Co., Ltd., Hangzhou 310002, China)

Abstract: Aiming at the accident problems that may occur at the multistage centrifugal pump under the condition of sudden power lost, a prototype multistage centrifugal pump was employed as object to calculate the internal unsteady flow inside pump model during stopping period under the condition of shutoff and the given rotating speed decrease, wherein the sliding mesh technology, the user defined function (UDF) and SIMPLE algorithm were employed to compute the flow inside the first stage impeller of the multistage centrifugal pump. The evolution characteristics against time of the external performance and the internal flow fields were obtained through numerical calculation, wherein the variable characteristics of physics parameters at the inlet and outlet of the first stage impeller and at the outlet of the reverse guide vane were emphasized. The results indicate that the nondimensional instantaneous head is basically unchanged before stopping and at the earlier stage of stopping, and quickly falls at the later stage of stopping. In conclusion, this displays the pronounced transient behavior. The influence of the rotating effect on the physical parameters at the impeller outlet is most remarkable, the parameter variations at the impeller inlet is second, while that at the outlet of the negative guideblades is lightest.

Key words: multistage centrifugal pump; stopping; first stage impeller; numerical simulation