不同翼型前置导叶正预旋对离心泵性能影响

Influence of positive preswirl generated by different airfoils on performance of centrifugal pump

为了优化离心泵运行工况调节,运用叶轮机械设计和前置导叶预旋调节的基本理论,在整流片和Gottingen-364翼型的基础上,设计出两种不同翼型的前置导叶预旋调节装置,研究了不同翼型前置导叶正预旋对离心泵水力特性的影响.试验结果表明:对于单吸离心泵,适当的前置导叶正预旋调节角度选择能够达到离心泵增效节能的效果.与无导叶工况相比,等厚直叶片使离心泵效率最大提高2.05%,功率消耗最多节省6.35%;Gottingen弯叶片使离心泵效率最大提高2.34%,功率消耗最多节省6.53%;两者都减小了扬程,但影响程度较小.等厚直叶片在两个预旋角度下最高效率点都往小流量区偏移到172 m3/h处;对于Gottingen弯叶片,20°预旋时,最高效率点往小流量区偏移到172 m3/h,40°预旋时,最高效率点往小流量区偏移到190 m3/h,两个预旋角度高效区都得到了扩大.

Two sets of inlet guide vanes with different airfoil sections were designed for the preswirl regulation in a centrifugal pump by using the basic design theory of turbomachinery to optimize its operation conditions.Subsequently,effects of positive preswirl induced by the guide vanes with different airfoils on the hydrodynamic performance of the centrifugal pump were studied.The result showed that an approp-riately designed positive preswirl could increase the efficiency of the single-suction centrifugal pump.Compared with the performance without the inlet guide vanes,the efficiency of the centrifugal pump installed the inlet guide vanes with straight constant-thickness could be increased as high as 2.05% and the responding shaft-power consumption could be reduced as low as 6.35%.For the guide vanes with Gottingen-364 airfoils,the efficiency of the pump was increased by 2.34% and the reduction in shaft-power consumption was lowered by 6.53%.The inlet guide vanes with both straight constant-thickness blade and Gottingen airfoil showed little influence on the head.For the straight constant-thickness blade,the best efficiency point was moved to a low flow rate 172 m3/h at the 20° and 40° preswirl angles;for the Gottingen airfoil,the best efficiency point was changed to 172 m3/h as well;however,the best efficiency occurred at 190 m3/h at the 40° preswirl angle.Clearly,the high efficiency range has been extended at the 20° and 40° preswirl angles for the inlet guide vanes with Gottingen airfoil.