轴伸贯流泵多工况下的压力脉动特性

Pressure pulsation characteristics of axial extension tubular pump under multiple working conditions

为了研究轴伸贯流泵在不同流量工况下的压力脉动特性,应用计算流体动力学软件对泵内流场进行数值计算,揭示不同流量工况下泵内压力脉动的变化规律,并利用真机进行压力脉动测试以验证数值计算方法的可靠性.结果表明:机组各监测面的压力脉动都具有一定的周期性,转轮处波峰和波谷与转轮叶片数相关,压力脉动主频为叶频;前导叶进口截面压力脉动主频为转频;在小流量工况下,流动较为紊乱,压力脉动抖动明显;转轮出口截面由于受动静干涉影响,流动紊乱,尤其在小流量工况下,压力脉动峰值最高为设计工况的12倍;在导叶进口以及导叶出口处监测点的压力脉动频域中出现了撞击和回流诱导的低频信号,低频段频谱复杂,出现明显的抖动.

In order to study the pressure pulsation characteristics of axial extension tubular pump under different flow conditions,the numerical method was used to calculate the flow field within the internal pump under different flow conditions,and the characteristics of pressure pulsation under different flow conditions were revealed.The reliability of the numerical calculation method was verified by the pressure pulsation test of the real machine.The results show that the pressure pulsation on each monitoring surface of the unit has a certain periodicity,and the peak and trough of the pressure pulsation at the runner are related to the number of the runner blades,and the main frequency of pressure pulsation is the blade frequency.The main frequency of pressure pulsation at the inlet section of the guide blade is the frequency of revolution.Under the condition of small flow,the flow is disordered and the pressure pulsation jitter was obvious.At the outlet section of the runner,due to the influence of rotor-stator interference,the flow is disordered,especially under the condition of small flow,the peak pressure pulsation reaches 12 times as high as the design condition.Low frequency signals induced by impact and backflow appears in the pressure pulsation frequency domain at the guide blade inlet and the monitoring point at the guide blade outlet.The low frequency frequency spectrum is complex and obvious jitter occurs.