叶轮与导叶匹配关系对立式离心泵水力特性影响的实验研究

大型含导叶立式离心泵广泛应用于高扬程远距离调水，旋转叶轮与静止导叶动静干涉引起的无叶区内高幅值压力脉动是影响其稳定运行的关键因素。为研究叶轮与导叶匹配关系对水泵水力特性的影响，对3台模型泵开展能量特性与压力脉动同台对比实验，分别监测了进水流道、无叶区和压水室的压力脉动信号，并进行时域和频域分析。结果表明：泵运行流量越靠近设计流量，压力脉动峰峰值越小，且设计流量下无叶区的压力脉动峰峰值分别是进水流道和压水室相应值的3.7和1.9倍；叶片型线改变导致出口安放角增大后，最优工况向大流量偏移，高效区拓宽，但无叶区内压力脉动幅值增大；导叶进口安放角减小后，最优工况向小流量偏移，高效区也得到拓宽，且无叶区内压力脉动幅值显著下降；改善叶轮出口和导叶进口的匹配关系可提高水泵能量特性，但压力脉动仅在导叶进口安放角减小时降低。本研究可为含导叶立式离心泵水力设计提供指导。

Experimental study on the influence of matching relationship between impeller and guide vane on the hydraulic characteristic of a vertical centrifugal pump

Large-scale vertical centrifugal pumps with guide vanes have been widely used in high-head and long-distance water supply. The high pressure fluctuation in vaneless region induced by the interference between the rotating impeller and the static guide vanes is a key factor that affecting the stable operation of the vertical centrifugal pumps. To study the influence of the matching relationship between the impeller and the guide vane on the hydraulic characteristic of a pump, the comparison experiments on the energy characteristics and pressure fluctuations of three model pumps were carried out. The pressure fluctuations in the inlet channel, the vaneless region and the volute casing were monitored, respectively, and time-domain and frequency-domain analyses were carried out. The results show that the peak-to-peak pressure fluctuation is reduced when the flow rate is close to the design flow rate. At design flow rate, the peak-to-peak pressure fluctuation in the vaneless region is 3.7 and 1.9 times of those in the inlet channel and volute casing, respectively. Due to the increase in the outlet angle of the impeller blade, the optimal working condition shifts to a larger flow rate, and the high efficiency zone is widened, but the pressure fluctuation amplitude in the vaneless region is increased. If the inlet angle of the guide vane is reduced, the optimal working condition shifts to a smaller flow rate, the high efficiency zone is also widened, and the pressure fluctuation amplitude in the vaneless region is significantly reduced. The energy characteristics can be improved by improving the matching relationship between the outlet angle of the impeller and the inlet angle of the guide vane, but the pressure fluctuation is only reduced when the inlet angle of the guide vane is reduced. This research can provide guidance for the hydraulic design of vertical centrifugal pumps with guide vanes.