离心泵平衡腔压力特性及轴向力的试验研究

Experimental investigation on pressure characteristics of balance cavity and axial force in centrifugal pump

设计了针对平衡腔内液体压力的测试装置,采用改变叶轮后密封环直径和平衡孔直径的方法,对离心泵平衡腔液体压力进行了测试.结果表明:对不同直径平衡孔,平衡腔液体压力随后密封环直径增大而增大.为了解决相似平衡腔液体压力的计算问题,绘制出不同直径后密封环时平衡腔压力系数与比面积的无因次曲线,随着比面积的增大,压力系数先急剧减少然后趋于平缓.从控制轴向力提高容积效率角度,提出在不同直径叶轮后密封环时比面积存在最佳的设计范围,计算得出不同直径叶轮后密封环时选择合适的平衡孔能使水泵工作在零轴向力或较小的正负轴向力状态.

A testing device is designed to measure liquid pressure in balance cavity of centrifugal pump.The pressure was changed by changing the diameter of both the back sealing ring and balance holes.The result shows that liquid pressure in balance cavity will increase with the diameter of back sealing ring with different diameter of balance hole.In order to calculate liquid pressure in similar balance cavity,the dimensionless curves of specific area and pressure coeficient are drawn for the back sealing ring with different diameters.The pressure coefficient will decrease sharply at first and then tend to be flat with the specific area.In view of controlling axial force and improving volumetric efficiency,an optimum design dimension of specific area is presented for the back sealing ring with different diameters.Selection of appropriate balance holes for back sealing ring with different diameters can make the pump work under condition of zero axial force or smaller positive and negative axial force.