前置不同诱导轮高速离心泵旋转空化特性研究

Research on the Rotation Cavitation Performance of High-speed Rotation Centrifugal Pump with Different Pre-positioned Inducers

以高速诱导轮离心泵为研究对象,开展了无诱导轮、前置等螺距诱导轮、前置变螺距诱导轮及前置分流叶片诱导轮4种情况下离心泵全流道的空化数值模拟和汽蚀特性实验研究。通过外特性实验研究得到:在同一流量下,前置等螺距诱导轮离心泵的扬程最低,前置变螺距诱导轮离心泵的扬程次之,前置分流叶片诱导轮离心泵的扬程较两者稍高。通过汽蚀实验和数值模拟研究得到:在前置3种诱导轮的情况下,离心泵的汽蚀性能都得到了改善,其改善效果从低到高依次是:变螺距诱导轮、分流叶片诱导轮、等螺距诱导轮。通过对汽相体积分数分布情况的研究得到:诱导轮的吸力面除进口外缘容易发生汽蚀外,叶片出口靠近轮毂侧也较容易发生汽蚀;对比分析主叶轮和诱导轮的汽蚀情况,得到诱导轮汽蚀的严重性与离心叶轮的汽蚀严重性并非成正比的结论。

Flow cavitation simulation and cavitation characteristics experiment of a high-speed centrifugal pump are carried out.The pump is equipped respectively without a inducer,with a pre-positioned equal pitch inducer,a pre-positioned variable pitch inducer and a pre-positioned shunt type inducer.The research of the external characteristics experiment reveals that the head of the centrifugal pump with a pre-positioned shunt type inducer is highest,next is the pump with a pre-positioned variable pitch inducer,while the lowest is that with a pre-positioned equal pitch inducer.The research of the cavitation experiment and simulation shows that the cavitation performance of the centrifugal pump with a pre-positioned equal pitch inducer is best,next is the pump with a pre-positioned shunt type inducer,and the last is that with a pre-positioned variable pitch inducer.Cavitation occurs easily on the outside edge of the inducer blade at the suction surface as well as at the outlet near the hub.A comparison of the cavitation of the impeller and the inducer shows that the degree of the cavitation of the inducer is not directly proportional to that of the impeller.