Research On Dynamic Multidimensional Force Measurement Technology Of Centrifugal Pump Impeller

In the complex flow field,the impeller of centrifugal pump is affected by axial force,radial force and torque.These forces are one of the key factors to determine whether the pump device can operate safely and reliably.Under some working conditions,excessive impeller thrust and radial force will cause damage or leakage to thrust bearing,motor and mechanical seal of centrifugal pump.Therefore,it is necessary to study the dynamic multi-component force of centrifugal pump impeller.In this paper,the dynamic multi-component force measurement technology of impeller will be studied to realize the dynamic measurement of dynamic multi-component force of impeller and provide effective reference for the design of key components of pump device.Firstly,the causes of dynamic multi-component force in the impeller of a centrifugal pump are analyzed and the current status of research on dynamic multi-component force measurement in the impeller of a centrifugal pump is introduced.A force measurement device based on biaxial piezoelectric sensors is proposed for measuring the dynamic multi-component force of the impeller of a pump unit.The force measurement device is rigidly connected to the pump spindle and the force measurement device rotates synchronously with the impeller to realize the integrated measurement of the dynamic multi-component force of the impeller of a centrifugal pump.In this paper,a two-stage measurement method is used to compensate for the influence of inertial forces on the measurement results due to the presence of external forces such as inertial forces,centrifugal forces and frictional moments during the dynamic multi-component force measurement of centrifugal pump impellers.This method compensates for the dynamic multi-component forces in the impeller of a centrifugal pump without the need for additional sensors or dynamic compensation devices.To solve the interference of high-frequency signal in the measurement results,wavelet transform,EMD(Empirical Mode Decomposition)decomposition and Hilbert transform are used to process the measurement signal to remove the high-frequency noise signal.Finally,the dynamic multi-component force measurement experiment is carried out on the centrifugal pump impeller.The analysis of the experimental results shows that the inertia force and centrifugal force of the centrifugal pump impeller in the case of high speed rotation is very large,and will even exceed the force of the fluid on the centrifugal pump impeller.With a flow rate of 1030m~3/h,for example,the hydrodynamic load in the radial direction accounts for 42.22%of the measurement results,the hydrodynamic load in the axial direction accounts for 69.39%of the measurement results and the hydrodynamic load in the torque direction accounts for 93.27%of the measurement results.The dynamic compensation method used can effectively compensate for dynamic multi-dimensional forces.