Analysis and research on vibration characteristics of nuclear centrifugal pumps at low flow rates

Abstract

In order to investigate the vibration characteristics of nuclear centrifugal pumps at low flow rates, the simulation prototype of centrifugal pump was built by mean of ANSYA CFD software, and the mechanism of reverse flow and rotating stall at low flow rates was analyzed. The type HAZ50-250 centrifugal pump was selected as prototype and the vibration was tested via Enpac2500 analytical instrument, it was shown that vibration frequency was concentrated in the low frequency range from 0.23 times rotation frequency to 0.25 times rotation frequency. Because at low flow rates, the pumps blade frequency is very sensitive to hydraulic disturbance, the vibration frequency including rotation frequency and two times rotation frequency will be accompanied as well. With the vibration frequency characteristic which was researched, the root cause of nuclear centrifugal pumps hydraulic vibration was analyzed, the improvement and optimization suggestions was forwarded, relative conclusion and method which could be regarded as an important reference for vibration analysis and pumps design.

Keywords

• Centrifugal pumps in nuclear power station
• Low flow rates
• Reverse flow
• Rotating stall
• Vibration characteristics