侧壁式压水室离心泵的压力脉动特性

Pressure Pulsation of Centrifugal Pump with Tilt Volute

压力脉动是引起泵振动的主要因素之一,为有效地降低离心泵内压力脉动水平,提出具有特殊结构的侧壁式压水室。为研究其压力脉动特性,采用FLUENT软件对比转数130的侧壁式压水室离心泵进行数值计算,并将时域信号进行快速傅里叶变换为频域信号,结果如下:由于叶轮和隔舌的动静干涉作用,侧壁式压水室内压力脉动周期性明显,叶频在由压力脉动诱发的振动中占主导作用;由于隔舌位置及结构的变化,叶轮出口处液流与隔舌的直接冲击、干涉作用减弱,因此侧壁式压水室内隔舌附近监测点处的脉动幅值并未明显地高于其他点。与常规螺旋形压水室相比,侧壁式压水室可以大幅地降低泵内压力脉动水平,因此采用侧壁式压水室可以显著地降低由压力脉动诱发的振动,改善泵的振动性能。

Pressure pulsation is one of the main factors causing the vibration of the pump. A special tilt volute is proposed to decrease the vibration of the pump. A centrifugal pump with tilt volute at specific speed 130 is simulated based on FLUENT to obtain the pressure pulsation characteristics. Fast Fourier transform（FFT） is used to change time-domain pressure signals into frequency-domain pressure signals. The results show that： it is obvious that the pressure pulsation in the pump is periodic because of the interaction between impeller and volute tongue. Blade passing frequency is of a leading role in induced vibration by pressure pulsation. The amplitude of pressure pulsation at the monitoring point near the volute tongue does not higher than other points obviously. The pressure pulsation in the centrifugal pump with tilt volute is much lower than that in the normal spiral volute, so the vibration performance of the pump can be improved effectively.