双向轴流泵装置性能预测与内部流动分析

Performance Prediction and Internal Flow Analysis of the Reversible Axial-flow Pump Unit

对一采用S形叶片的双向轴流泵装置进行数值研究,在不同流量工况条件下分析泵的正、反向运转性能,对该泵的瞬时启动过程进行了监测并对泵内的非定常空化现象进行了分析。研究表明,正、反向运转时,泵的性能存在明显的差异,反向的扬程和效率均高于正向;在泵正向启动过程中,叶轮背面进口边产生空化区,反向运转时未发生明显的空化现象;两种运转模式下,叶轮进出口断面上压力脉动特征频率分布相似,但叶轮进口的压力脉动幅值较高。

A numerical study on a reversible axial flow pump unit with S-shaped blades was carried out.Under different flow rate conditions,the pump performance at forward and reverse operation modes was analyzed.The transient start-up process of the pump was monitored and the unsteady cavitation phenomenon in the pump was examined as well.The results show that obvious performance difference exists between the two modes and the pump head and efficiency at the reverse mode are higher than their counterparts.During the start-up process at forward mode,cavitation zone emerges at blade suction surfaces near the blade inlet,while no clear cavitation zone is witnessed at the reverse mode.Pressure fluctuation characteristics at impeller inlet and outlet cross sections for the two modes are similar,and regarding pressure fluctuation magnitude,impeller inlet is associated with high values relative to impeller outlet.