粒径对离心泵叶片摩擦和碰撞磨损强度的影响

The influence of particle diameter on friction loss intensity and collision wear loss intensity along blades of centrifugal pump

采用雷诺时均N-S方程、RNGk-ε模型和SIMPLE算法,以含沙水为介质,基于代数滑移混合物模型(algebraic slip mixture model,ASME)对一台单级双吸式离心泵内固液两相流动进行全三维不可压缩定常流动数值模拟,其中转子与定子之间耦合方式采用"冻结转子法"实现.通过对比清水及含沙水介质时泵外特性试验数据与数值模拟结果,验证了数值计算方法的可靠性.对固相颗粒直径分别为0.019、0.036、0.076mm时叶片工作面和背面摩擦磨损强度和碰撞磨损强度进行预测.结果表明:在同一粒径时,从叶片进口至出口碰撞磨损强度逐渐增大,且工作面大于背面,摩擦磨损强度呈现先增大后减小,又逐渐增大的趋势;随着粒径的增大,叶片表面碰撞磨损强度和摩擦磨损强度逐渐增大,摩擦磨损强度沿着整个叶片均大于碰撞磨损强度.

Taking silt-laden water as medium and based on algebraic slip mixture model,the full-three-dimensional in compressible stationary flow of solid-liquid two-phase medium in a sing lest age double-suction centrifugal pump was simulated numerically on the basis of Reynolds time-averaged equation with RNGk-εturbulence mode,where＂frozen rotor method＂was used for coupling rotor to stator and SIMPLE algorithm was used for computation.By means of comparison of the external characteristic data of pump with fresh water to that with silt-laden water,the reliability of the numerical computation method was verified.The friction loss intensity and collision wear loss intensity along both sides of pump blade were predicted when the solid-phase particle diameter was 0.019,0.036,and 0.076 mm,respectively.The results showed that with identical particle diameter,from blade inlet to outlet,the collision wear loss intensity on blade suction surfaces would gradually increase and on blade pressure surfaces it would be greater than that on suction surfaces.The friction loss intensity would increase at first,then decrease,and finally increase again gradually.In addition,the loss intensity of friction and collision wear on the pressure and suction surfaces of the blades would increase with the particle diameter and the fraction loss intensity would be greater than the collision wear loss intensity.