叶片开缝对单叶片泵径向力的影响

为了改善单叶片泵的运行特性,降低径向受力不均匀性,采用数值计算与试验相结合的方法分析了单叶片离心泵径向力的动态特性.研究了3个不同流量工况(0.6Q_d,1.0Q_d和1.4Q_d)下径向力的变化规律,结果表明,单叶片离心泵叶轮叶片工作面与背面所受压差是径向力产生的主要原因,并在小流量工况下径向力达到最值.通过对试验与数值模拟结果的分析对比,提出了平衡单叶片泵径向力的新方法-叶片开缝,并在叶片包角方向上选取3个不同位置(0°,90°和270°)布置宽度为1.0 mm的缝隙,分析了不同开缝位置对径向力及泵外特性的影响情况.结果表明:当在叶片尾缘开缝时,对泵的外特性影响较小,并可以较大降低单叶片离心泵叶片工作面和背面的压差,减小叶轮径向受力情况,提高单叶片泵的可靠性和使用寿命.

Effect of blade slotting on radial thrust of single vane centrifugal pump

In order to improve the operating characteristics of single vane centrifugal pumps and reduce the radial thrust, the dynamic characteristics of the thrust in a single vane centrifugal pump was analyzed by using a combination method of numerical simulation and experiment. The variation rules of radial thrust were clarified under three flow rate conditions, such as 0.6Q_d, 1.0Q_d and 1.4Q_d. The results show that the static pressure difference across the blade pressure and suction sides mainly attribute to the radial thrust, which achieves the maximum value at a low flow rate. A new method-blade slotting for relieving the radial thrust in the pump was proposed by analyzing and comparing both the experimental and numerical results. Then, one 1.0 mm wide slot was made across the blade at three different circumferential positions selected such as 0°, 90° and 270°, respectively. The influences of the slot position on the radial thrust and pump performance were analyzed. The results show that when the slot is located near blade trailing edge the pump performance is less affected but the pressure difference across the blade pressure and suction sides is reduced greatly, and the radial thrust on the impeller is declined. Consequently, the reliability of single vane centrifugal pump will be improved, and its service life will be extended.