楔形槽对离心泵口环磨损的影响分析

采用欧拉-拉格朗日多相流模型,对双吸式离心泵内的含沙水流进行了模拟,分析了楔形槽对口环附近泥沙浓度的影响,分析结果表明:口环附近流速较低,对泥沙颗粒的携带能力较弱,导致泥沙浓度较高,口环快速磨损;采用楔形槽可以提高邻近区域水流相对速度的径向分量,有效阻止泥沙颗粒在进入缝隙,降低了口环附近区域的泥沙浓度,减少口环的磨损,起到动态密封的效果;楔形槽增加了叶轮出口压力,水泵扬程得以提高。

Influence of Wedge-groove on Sediment Erosion of Impeller Ring in a Centrifugal Pumps

The water flow and movement of sediment in a prototype double suction centrifugal pump is simulated by using an Euler-Lagrange multiphase flow model.Wedge-groove is used to protect the impeller ring from sediment erosion.Sediment concentration near the impeller ring with/without wedge-groove is analyzed.The results show that the velocity of water flow near the impeller ring is too low to move the sediment out of the spacing between the impeller and the casing.The high sediment concentration near the impeller ring is the major contributor to sediment erosion of the ring.The wedge-groove is effective in increasing the radial relative velocity component of water flow of adjacent zones,preventing sediment from entering the spacing between the impeller and the casing and reducing the sediment concentration near the impeller ring;with the application of the wedge-groove,the impeller ring is protected from sediment erosion and the pump head increases.