混流泵作透平的数值计算与试验

为探究混流泵作透平内部的流动特性,选取1台比转速为220的混流泵进行外特性试验,采用全流场和结构化网格技术对透平内部流动状况进行数值模拟,得到不同流量工况下透平内部的流场分布和压力分布,并用速度三角形对透平内部流场变化进行分析。结果表明,透平进口到出口压力逐渐降低,随着流量增加,透平进出口压差逐渐增加,叶轮内部涡漩位置和大小发生变化,尾水管内液流圆周分速度方向发生变化;透平总水力损失随流量的增加而增加,其中叶轮水力损失占比最高,因此混流泵作透平的优化应集中在叶轮部分。

Numerical Simulation and Experiment on Mixed-flow Pump as Turbine

To study the flow condition of the mixed-flow pump as turbine, a mixed-flow pump with specific speed of 220 was designed. An experiment was carried out and numerical simulation of the designed hydraulic turbine was performed by all domains and structural mesh technique. The flow condition and pressure distribution under different flow rate were obtained and velocity triangle was used to analyze the change of the interior flow field. The results show that the pressure difference between the inlet and the outlet of the turbine is increasing with the addition of the flow rate. With the increase of flow rate, the position and size of the vortex and the peripheral component of velocity in draft tube were changed. The total hydraulic loss of turbine increases and the hydraulic loss in the impeller is the largest, so the optimization of the turbine should be concentrated on the impeller.