基于速度系数法和型线方程相结合的螺旋离心泵叶轮设计方法

Design method of screw-centrifugal pump impeller by means of speed coefficient method combined with profile equations

针对螺旋离心泵采用速度系数法和采用型线方程进行设计中所存在的问题,根据螺旋离心泵叶轮结构特点,结合速度系数法设计方法和型线方程的螺旋离心泵设计方法,绘制螺旋离心泵的轴面投影图,检查轴面流道过水断面变化情况,将所绘制的轴面投影图上的所需结构参数值代入型线方程.此方法既避免了采用速度系数法进行水力设计时作图的繁杂和叶轮进出口附近区域流线分点不易确定和难以划分轴截面的欠缺,又避免了型线方程由于没有检查轴面流道过水断面变化情况而可能出现的轴面速度不均匀的情况.通过实例给出了此方法的的具体应用,并绘制出三维型线和三维模型.

Aimed at the problem occurred in designing screw-centrifugal pumps with speed coefficient method profile equation and according to the structural characteristics of the screw-centrifugal pump impel- ler, the axial plane projection diagram was drawn by means of speed coefficient method combined with pro- file equation, the variation of cross-sections of axial plane flow passage was checked, and then the struc- tural parameters on axial plane projection diagram were substituted into the profile equations. This method would not only avoid the complexity of plotting in the process of hydraulic designing with speed coefficient and the difficulty with determining the stream line separation points about the inlet-outlet of the propeller and the difficulty with dividing the axial cross-sections but also avoid the unevenness of axial plane velocity caused possibly by the lack of section variation checking of axial plane flow passage. A concrete application of this method was given out with an actual example and the three-dimensional profile and model were plotted.