The Seismic Response And Critical Speed Analysis Of Reactor Coolant Pump

Reactor coolant pump (referred to as the main pump) is the only continuous power source of the nuclear islands. It needs 60-year long causative time withstanding the test of extreme working conditions. Therefore, to ensure its safety, in particular, to ensure the integrity of its structure and function during an earthquake or a period, it's necessary to have seismic analysis. In addition, in order to avoid the serious violent incidents because of rotor vibration, it's also necessary to have critical speed analysis on reactor coolant pump rotor.Seismic analysis is studied on reactor coolant pump in the 300MW nuclear power plant. In this paper, INVENTOR is used to build three-dimensional solid model of reactor coolant pump, and then ANSYS is used to build finite element of the simplified model. The pre-processing functions and the finite element unit features of ANSYS are flexible used to build three-dimensional solid finite element dynamic model which is closer to real model than the particle system model. ANSYS is used to have model analysis to get 13-order natural frequencies and corresponding vibration mode of nuclear main pump, on the base of modal analysis, ANSYS is used to have response analysis. The three orthogonal directions seismic spectra is input in different angle respectively to get displacement and stress response of the pump under SSE earthquake loads. The results show that the maximum response value is in the angle of 90°, therefore the pump in the nuclear plant should be avoided installing in the angle of 90°. In addition, the maximum deflection of the rotor response analysis shows that the relative offset of rotor is less than running clearance, so it will not cause accident or wear between the rotor and stationary components.ANSYS is also used to have static mechanical analysis on nuclear main pump under the temperature load, gravity, pipe load and internal pressure to get stress and displacement of nuclear pump. The maximum stress and displacement are added with the peak value of stress and displacement under seismic load by the method of absolute value. The stress and displacement under operating conditions, design conditions and limit incidents are assessed by ASME III NB sub-volume. The results meet the specifications, so that the nuclear main pump during an earthquake or a period can guarantee the integrity of the results and functionality.Critical speed of the rotor is studies as another part. In this paper, the a simple rotor system is established, considering the two cases of the fluid-solid coupling and non-fluid-solid coupling, ANSYSWORKBENCH is simulated the rotor critical speed both in wet and dry state. Compared with the experimental results, the error is within the allowable range, which shows that the simulation analysis method is accurate.In this paper, the seismic analysis method, which is used on three-dimensional solid model of main pump, and the analysis method of critical speed in wet state are both mastered. The result of seismic response analysis provides the basis for the evaluation integrity of structure and function of nuclear the main pump, and it also provides the reference the installation point and input data for the analysis of fatigue life of main pump. The research method of critical speed in wet state lays the foundation of analysis of critical speed on the rotor of sealing reactor coolant pump in the future.