离心泵浮动叶轮轴向间隙的液体流动分析及轴向力计算  

Analysis of liquid flow and axial force calculation in axial clearance for floating impeller of centrifugal pump

作　　者：刘在伦[1,2] 许立中[1] 贾晓[1] 吴佼[1] 王东伟[1,2] 

机构地区：[1]兰州理工大学能源与动力工程学院,兰州730050 [2]兰州理工大学温州泵阀工程研究院,温州325105

出　　处：《农业工程学报》2013年第12期79-85,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家自然科学基金资助项目(51269010);浙江省自然科学基金资助项目(Y12E90005)

摘　　要：为了研究浮动叶轮轴向间隙变化对其液体泄漏量及压力、液体作用在不锈钢盘上轴向力的影响规律,将径向和轴向的间隙液体流动分别简化为平行平板间粘性层流运动和轴对称二维粘性层流运动,基于液体通过径向和轴向的间隙泄漏量相等,推导出了计算轴向间隙的液体泄漏量及压力、液体作用在不锈钢盘上轴向力的数学表达式。并通过设计实例计算,绘制出了轴向间隙的液体泄漏量和液体作用在不锈钢盘上轴向力与轴向间隙变化的关系曲线,从控制一定泄漏量并减少轴向力的角度出发,分析得出轴向间隙取0.4～0.8mm较为适宜。并在平衡腔内不安装不锈钢盘和石墨盘条件下,计算出了平衡腔内液体作用在叶轮上轴向力。通过比较分析,浮动叶轮有明显减少轴向力的效果。Axial thrust balancing device is an important component for centrifugal pump stable operations.In special,the impeller which arranged in the same direction for segmental type pump and high head submerged（oil） pump is able to bring prodigious axial force.If excessive axial force exist in pump,it will cause safe accident,and influence work,and result in enormous economic expense.The floating impeller which integrated balance holes and the balance disc together is a new technology of balancing axial force automatically in the centrifugal pump.This technology has been applied in individual pumps with a significant and feasible effect,but it is still in its infancy which mainly concentrated on the introduction of principle and structure.In order to investigate the relationship of the fluid leakage,fluid pressure and the axial force on the stainless steel disc under different axial displacement,the flow characteristics in the radial and axial clearance on the back cover plate of floating impeller were analyzed.Fluid flow in radial clearance was simplified as viscous laminar flow of parallel plate model,and the fluid flow in axial clearance was simplified as 2D axisymmetric viscous laminar flow.Due to the equality the fluid leakage in radial and axial clearance,the mathematical expression of the fluid leakage,the fluid pressure and the axial force on the stainless steel disc in the axial clearance were obtained.The curves of the fluid leakage and the axial force on the stainless steel disc with the axial clearance were drawn by the calculation of the design example.The curves showed that the fluid leakage increased and the axial force on the stainless steel disc decreased with the increase of axial clearance,and these curves were relatively flat when the axial clearance was above 0.8mm.From the perspective of reducing leakage,the smaller the axial clearance,the better.But a small axial clearance would cause the sharp variation of the lubrication and the cooling condition in axial clearance,and sintering phenomenon b

关 键 词：泵 轴向力 叶轮 轴向间隙 泄漏量 

分 类 号：TH311[机械工程—机械制造及自动化]