分流叶片包角对低比转速离心泵固液两相非定常特性的影响

Influence of Shunt Blade Wrapping Angle on Solid-liquid Two-phase Unsteady Characteristics of Low Specific Speed Centrifugal Pumps

为了研究分流叶片包角对低比转速离心泵固液两相流动的影响。采用mixture多相流模型及ANSYS CFX软件对5组不同分流叶片包角的低比转速离心泵模型进行固液两相流动的数值模拟。探讨不同分流叶片包角的低比速速离心泵效率、扬程、静压分布、固相体积分数、径向力等的影响因素。结果表明:在清水条件下分流叶片包角φ=70°时,效率到达最高,在固液两相条件下效率均随分流叶片包角增大而降低;固体颗粒主要分布在叶片背面后侧,随分流叶片包角的增大,分流叶片上的固体颗粒逐渐向叶轮进口处扩散,主叶片上固体颗粒分布基本不变;分流叶片包角过大或者过小都不利于减小离心泵的压力脉动和径向力,存在最优分流叶片包角φ=70°。

In order to study the influence of shunt blade wrapping angle on solid-liquid two-phase flow in low specific speed centrifugal pump. This paper uses the mixture multiphase flow model and ANSYS CFX software to simulate the solid-liquid two-phase flow of five lowspecific speed centrifugal pumps with different blade angles. The influencing factors of low specific speed centrifugal pump efficiency, head, static pressure distribution, solid phase volume fraction and radial force with different blade angles are discussed. The results show that the efficiency reaches the highest when the shunt blade envelope angle φ=70° under clean water conditions, and decreases with the increase in the shunt blade envelope angle under the solid-liquid two phase condition. The solid particles are mainly distributed on the back of the blade.With the increase in the shunt blade envelope angle, the solid particles on the shunt blade gradually spread to the inlet of the impeller, and the distribution of solid particles on the main blade is basically unchanged. Too large or too small cladding angle of the shunt blade is not conducive to reducing the pressure pulsation and radial force of the centrifugal pump, and there exists the optimal cladding angle of the shunt blade φ=70°.