在规定流量下, 定叶片轴流泵实测扬程高于设计扬程时, 需要对轴流泵的叶轮进行处理。为此, 采用切割翼型 长度法和修薄叶片出口边工作面厚度法相结合的方式来降低扬程, 且保证泵的最高效率不下降。多次试验结果表 明, 采用切割翼型长度方法, 当泵的扬程从9. 53 m 下降到8. 23 m( 降低量超过10%) 时, 泵的最高效率开始下降, 从 72%下降到71. 8%; 在前几次切割翼型长度基础上( 原叶轮翼型切割15 mm) , 再修薄叶片出口边工作面厚度( 共修 薄4 mm, 并光滑过渡) 后, 泵的扬程下降到7. 23 m, 最高效率约为72. 2%, 因此既有效解决了定叶片轴流泵扬程偏 高的问题, 又保证了泵的最高效率基本不变。

Under the prescr ibed flow, the measurement head of ax ial flow pump w ith the fix ed blade is hig her than the desig n head, and t he im peller of the ax ial flow pum p needs to be tr eat ed. I n or der to achieve low er head and ensur e that the hig hest effi2 ciency o f pump does not decrease, the metho d combining the cutting the leng th of airfoils and fix ing t he thickness of thin blade outlet side face was applied. T he test r esults showed that the highest Pump efficiency decr eases fr om 72% to 71. 8% w ith the pump head decreasing from 9. 53 to 8. 23 m( the decr easing rate is hig her than 10%) w hen the metho d o f cutt ing the length o f airfo ils is used. On the basis o f pr evio us cutting differ ent leng ths( cut ting the or ig inal impeller airfo il by 15 mm) , the thickness of the thin blade outlet side face is thinned( thinning the t otal thickness by 4 mm and smo othing the tr ansit ion) , the pump head decreases to 7. 23 m w ith the highest efficiency of 72. 2%. Therefor e, the purpose of reducing the pump head and ensuring the highest efficiency of pump is achieved.