Study of unsteady pressure pulsation in multistage-pump as turbine impeller and guide vane

Abstract

Abstract: During the operation process of a multistage-pump as turbine, the pressure pulsation is one of the key factors affecting the stability of the unit. In order to investigate the regularity of pressure pulsation in this turbine, in this paper, the turbulence model of RNG k-ε is selected to carry out the unsteady numerical calculation. Both the time domain and frequency domain of pressure pulsation are analyzed by the data of pressure pulsation got from the monitoring points distributed in the various each-stages flow components. The results exhibited that the main frequency of pressure pulsation is mainly related to the rotation frequency of the impeller. Upon the optimal operation condition, the rotor-stator interaction between the impeller and the positive guide vanes is considered as the main reason for the pressure pulsation in the impeller. It is the combination effect of both the phenomenon of unstable flow in the impeller and the rotor-stator interaction between the impeller and the positive guide vanes on the increase of pressure pulsation at the monitoring points in the guide impeller under the other flow conditions. Additionally, the main frequency of the positive guide vanes at all levels is closely related to the blade frequency of the impeller, as well as the main frequency of the positive guide vanes is consistent with that of the impeller. The closer the flow passage along the positive guide vane is to the impeller, the greater the pressure pulsation is. Finally, the pressure pulsation in the anti-guide vanes presents a relatively disordered state, showing no obvious change rule.

Key words: multistage-pump as turbine, pressure pulsation, numerical simulation, static interference

CLC Number:

TH311

MIAO Sen-chun, TIAN Wang-long. Study of unsteady pressure pulsation in multistage-pump as turbine impeller and guide vane[J]. Journal of Lanzhou University of Technology, 2025, 51(1): 55-65.

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