Modeling And Dynamic Analysis Of RCP Based On Timoshenko Beam Finite Element Model

Nuclear power energy is currently one of the most important clean energy sources in the world,and the large canned motor nuclear main pump is the key core equipment of a pressurized water reactor nuclear power plant.The basic system of the nuclear main pump rotor consists of a bearing box,stator,rotor and pump casing.The rotor-bearing system is an important part and core component of the nuclear main pump structure,and its vibration response and dynamic characteristics affect the safety and stability of the entire equipment system.Therefore,studying the influence of the dynamic parameters of the rotor-bearing system on its vibration response is of great significance to improving the design performance of the nuclear main pump.In order to study the dynamic response of the nuclear main pump structure,this paper adopts the finite element modeling method of Timoshenko beam element.The rotor and stator of the nuclear main pump with a tilting-pad thrust bearing with a counterweight structure are used for dynamic numerical modeling.In the model,the stator and rotor are coupled through the guide bearing and the thrust bearing,and the influence of the gap circulation between the stator and the rotor is considered.Use the precise integration method(PIM)to calculate and predict the dynamic response of the shielded nuclear main pump,and provide technical support for the dynamic design and calculation of the nuclear main pump.Based on the dynamic model,time-domain calculation and analysis are performed to study the dynamic response of the nuclear main pump,and the overall displacement distribution,shear stress distribution,bending moment distribution and stress distribution of the nuclear main pump are obtained.The results show that the thrust bearing adopting the balance weightthrust pad structure can greatly improve the uniform load capacity of the thrust bearing and improve the error tolerance rate of the thrust bearing in the process of machining or installation.On the other hand,for the dynamic response of the overall nuclear main pump model,the change law of the nuclear main pump response at different speeds is obtained.Through the movement state of the flywheel at different speeds in the time domain,it can be seen that the radial displacement of the flywheel in the suspended state of the rotor is increased,which shows that the stiffness of the liquid film between the thrust bearing and the flywheel has a huge influence on the displacement of the rotor flywheel..Based on the results of the dynamic response of the nuclear main pump under different prestress,the reference basis for determining the value range of the prestress is given.Based on the results of the dynamic response of the nuclear main pump under different flywheel eccentricities,it is concluded that the small assembly eccentricity error will have a huge impact on the overall dynamic response of the nuclear main pump.