“干态”下的悬臂式多级离心泵响应性能研究

Response Performance of Cantilever Multistage Centrifugal Pump in Dry State

悬臂式多级离心泵被广泛应用于国民经济的各个领域,鉴于其独特的结构形式,其振动相关研究十分重要。采用数值模拟的方法,重点分析了“干态”下悬臂式多级离心泵的响应性能。研究表明,随着不平衡力矩增大,泵体的振动幅度越大,尤其是泵启动后2.6~3.0 s内径向位移的不稳定突变明显。基于SAMCEF谐响应分析,发现二阶振型为扭转耦合振动,首级叶轮在二阶临界转速时的响应幅值随不平衡质量相位变化影响较大。当首级叶轮不平衡质量相位为180°时,螺母与首级叶轮的一阶加速度以及位移幅值达到最小。因此,通过提高零件的加工精度减小零件的不平衡力矩以及错开各级叶轮不平衡质量的相位可以减小转子径向振动,从而提高悬臂式离心泵的运行稳定性。

Cantilever multistage centrifugal pumps are widely used in various fields of national economy,and their vibration-related studies are important in view of their unique structural forms.In this paper,the method of numerical simulation was used to analyze the response performance of cantilever multistage centrifugal pump under"dry state".It is found that the vibration amplitude of the pump body increases with the increase of the unbalance torque,especially,the instability mutation of the radial displacement is obvious within 2.6~3.0 s after the pump starts.Based on SAMCEF harmonic response analysis,it is found that the second-order vibration type is torsional coupling vibration,and the response amplitude of the first-stage impeller at the second-order critical speed is influenced by the phase change of unbalance mass.When the unbalance mass phase of the first stage impeller is 180°,the first order acceleration and displacement amplitude of the nut and the first stage impeller reach the minimum.Therefore,by improving the machining accuracy of the parts to reduce the unbalanced moment of the parts and staggering the phase of the unbalanced mass of the impellers at all stages,the radial vibration of the rotor can be reduced,thus improving the operation stability of the cantilever centrifugal pump.