双吸式离心泵叶片头部形状对泥沙磨损的影响

为了提高离心泵的抗磨蚀能力,采用欧拉-拉格朗日多相流模型模拟了水泵内水沙两相流运动,并利用离散相冲击磨损模型,对4种不同叶片头部形状下的叶片泥沙磨损情况进行了分析.结果表明:叶片上发生严重磨损的区域主要分布在叶片的头部和尾部,其中吸力面的平均磨损强度高于压力面;叶片磨损强度受相对流速分布和冲击角的影响,改变叶片的头部形式可改变叶片的泥沙磨损强度;缩短叶片头部外缘一侧的长度,可以使叶片头部的相对流速分布更均匀,改善叶片头部和尾部的集中磨损,但会降低水泵扬程;缩短叶片头部外缘一侧的长度,同时增大内缘一侧的相对液流角,可以有效改善叶片表面的泥沙磨损,并使水泵扬程略有提高.

Effect of blade leading edge shape on sediment erosion of blade in double-suction centrifugal pumps

In order to improve the anti-abrasion characteristics of pumps, the water flow and movement of silt in a double-suction centrifugal pump was simulated using an Euler-Lagrange multiphase flow model. The erosion rate of blade was predicted with a particle erosion model and the influence of the four different blade leading edge shapes on the erosion rate was analyzed. The results show that the blade leading edge and the blade trailing edge are usually severely destroyed by sediment erosion, and the average erosion rate on the suction side is always greater than that on the pressure side. The relative velocity and the incidence angle are the two major factors that influence on the erosion rate of blade, and are able to be controlled by changing the blade leading edge shape. The relative velocity near the blade leading edge appears uniform after cutting the tip area of the blade leading edge, and the erosion rates at both the blade leading edge and the blade trailing edge are decreased while the pump head is also decreased. Sediment erosion of the blade is effectively controlled and the pump head is slightly increased while cutting the tip side of the blade trailing edge as well as increasing the incidence angle near the hub.