离心泵轴向力计算方法研究与试验验证

Calculation method and experimental verification for axial thrust on centrifugal pump

在设计工况下平衡腔液体压力数学模型计算中,引入了泵腔液体压力损失修正系数,解决了有液体泄漏时泵腔进口与后密封环进口液体压力差的计算问题.以降速后的IS80-50-315型离心泵为例,采用改变叶轮平衡孔直径和后密封环间隙来改变比面积的方法,研究了设计工况下平衡腔液体压力数学模型和轴向力的特性.研究结果表明,设计工况下平衡腔液体压力数学模型特性曲线,可以解决轴向力计算中平衡腔区域叶轮后盖板液体压力差计算这一关键问题;平衡腔液体压力是由平衡孔和后密封环构成的2道"闸阀"协联调节的结果,从控制轴向力角度,可通过轴向力特性曲线寻求叶轮平衡孔直径与后密封环间隙的最佳比值.用2个测试实例验证了应用设计工况下平衡腔液体压力数学模型计算轴向力的可靠性.

The correction coefficient was cited,which is liquid pressure loss in the pump side chamber. The calculation of liquid pressure difference between the inlet of pump side chamber and rear wear-ring was resolved when there was liquid leaking in the side chamber. The IS80- 50- 315 type centrifugal pump whose speed had been reduced was taken as the research object. Specific area was changed by altering both the balance holes diameter and the rear wear-ring clearance. Then the characteristics of the mathematic model of liquid pressure in the balance chamber and axial thrust were researched under design conditions. The results show that the characteristic curves of the mathematic model for liquid pressure of the balance chamber can solve the key problem of the calculation of liquid pressure difference in the balance chamber under design conditions. The joint regulation by the two sluice valves,balance holes and rear wear-ring affects the axial thrust caused by liquid pressure difference inthe area of balance chamber. From the point of view of controlling axial thrust,the optimum matching relationship between the balance holes diameter and rear wear-ring clearance could be obtained according to the characteristic curve of axial thrust. The reliability of the mathematic model was verified by two test cases.