蜗壳喉部面积对低比转速离心泵性能的影响研究

Study of Effects of Volute Throat Area to Performance of Low Specific Speed Centrifugal Pump

为研究蜗壳喉部面积对低比转速离心泵性能的影响,以比转速ns=20.8的一台单级单吸离心泵为研究对象,针对同一叶轮,设计3种不同喉部面积的蜗壳,使用PumpLinx软件分别在进口压力p1=0.1 MPa和p1=0.015 MPa进行泵内定常数值模拟计算,分析了喉部面积变化对泵外特性和抗汽蚀性能的影响。结果表明:在同一进口压力下,在一定范围内,随着喉部面积的增大,扬程和效率有所升高,叶轮进口气体体积分数逐渐下降;合理的喉部面积能够明显改善蜗壳第Ⅶ、Ⅷ断面的局部压降。研究结果可为低比转速离心泵的优化设计提供一定的参考。

In order to study the effect of volute throat area to the performance of low specific speed centrifugal pump,single-stage single-suction centrifugal pump with rotary speed ns=20.8 was taken as the object of study,for the same impeller,three volute shells with different throat areas were designed.By using software PumPLinx,the numerical simulations for inlet pressures of p1=0.1 MPa and p1=0.15 MPa were carried out,respectively.The effects of the change in throat area to the external characteristics and cavitation resistance of the pump were analyzed.It was shown that for the same inlet pressure,to the certain extent,with the increase of throat area,head of delivery and efficiency will enhanced,and the volume fraction of the gas at impeller inlet will reduced;with appropriate throat area,local pressure drop at the seventh and eighth sections in volute shell can be improved.The results from above analysis may be referenced in the optimum design of low specific speed centrifugal pump.