关键词：
轴流泵装置;进水流道;试验;流态;压力脉动
摘 要：
进水流道出口流态是影响立式轴流泵装置运行稳定性的关键因素之一,基于立式轴流泵装置整体物理模型,采用在肘形进水流道出口段壁面布置丝状红线和压力脉动传感器,研究分析了不同转速时立式轴流泵装置肘形进水流道出口段的流态及压力脉动变化规律。结果表明,当流量小于0.7Qbep时肘形进水流道出口段内壁面的丝线偏移方向与叶轮旋转方向相同,各测点的脉动幅值均随转速的增加而增加;当流量大于0.7Qbep时肘形进水流道出口段内壁面的丝线偏移方向与泵轴方向相同,各测点的脉动幅值随转速的增加而减小。相同转速时,各测点的脉动幅值随流量的增大先减小后增大,在最优工况时脉动幅值最小。不同转速下,流道出口各测点的脉动主频均为4倍转频,最优工况时各测点的脉动次主频均为1倍转频。随转速增加,肘形进水流道出口段各测点主频幅值的增幅存在差异性,小流量工况时各测点的脉动主频幅值增幅小于最优工况和大流量工况。
译 名：
Experiment and Analysis on Outlet Flow Pattern and Pressure Fluctuation in Inlet Conduit of Vertical Axial-flow Pumping System
作 者：
YANG Fan;ZHAO Haoru;LIU Chao;HE Jiye;TANG Fangping;School of Hydraulic Energy and Power Engineering,Yangzhou University;Hydraulic Engineering Construction Bureau of Jiangsu Province;
关键词：
axial-flow pumping system;;inlet conduit;;test;;flow pattern;;pressure fluctuation
摘 要：
Pressure fluctuation in vertical axial-flow pumping system caused by outlet flow pattern of inlet conduit is the primary sources of operation instability. By means of pressure transduces and red threads installed in outlet section of inlet conduit,fluctuating pressure signals were obtained and recorded under various operating conditions. The signals in time and frequency domains of the signals were analyzed by using short-time Fourier transform method. The results showed that when the flow rate was less than0. 7 Qbep,the deviation direction of red threads of internal wall were the same as the impeller rotating direction in inlet conduit,while the flow rate was larger than 0. 7 Qbep,the deviation direction of red threads of internal wall was along the axial direction. With the increase of rotational speed,the pulsating amplitude of each measuring point was increased at Q < 0. 7 Qbep,while with the increase of rotational speed,the pulsating amplitude was gradually decreased. The pulsating amplitude was decreased firstly and then increased with the increase of flow rate at the same rotational speed,and the pulsating amplitude was the minimum under the optimum operating condition. The main frequency of each measuring points was four times of rotational frequency at different rotational speeds. The subdominant frequency of each measuring points was one time of rotational frequency in Qbep. Both flow rate and rotational speed had significant influence on the subdominant frequency of outlet section in inlet conduit under small and large flow rate conditions. With the increase of rotational speed,the increase amplitudes of measuring point pulsating amplitudes were different under different operating conditions. The pressure fluctuation amplitude was larger in the frequency range of 0 ~ 8 times of rotational frequency for inlet conduit outlet section at different rotational speed.
