입형 다단 원심펌프 진동 특성에 대한 실험적 연구

초록

Recently, vertical multistage centrifugal pumps are widely used to improve the pumping efficiency and reduce the installation space. The vibration characteristics of the vertical multistage pump is dependent on complex flow passage inside the pump with multistage impeller and diffuser and the dynamic response of the vertically installed pump and motor. However, studies on the vibration characteristics of vertical multistage pump have not been reported sufficiently compared to other types of pumps. In this study, the vibration characteristics of vertical multistage centrifugal pump was analyzed with experiments at various operating conditions. Using the 55kW test pump with the design flowrate of 150 m³/h and design head of 105 m, the functional and vibration data at various operating conditions was obtained using a control valve installed in the downstream of pump. From the frequency response analysis of measured vibration data, the random vibration due to the structural dynamic characteristics of vertically installed pump and the periodic vibration of shaft rotating frequency and blade passing frequency determined by the rotating speed of shaft and the number of impeller and diffuser blades was observed. The minimum vibration of pump was observed at the design operating conditions, and the magnitude of vibration increases with the increases of flowrate or head. Furthermore, the RMS value of vibration under the cavitation condition significantly increases compared to the periodic vibration component. It is expected that the experiment results can be used for the conditions monitoring and diagnostics of vertical multistage centrifugal pump.