Strength Analysis of Primary Pump Motor in Primary Reactor

Abstract

The primary pump motor, as the driving source of nuclear reactor cooling loop, is the main device to ensure the safe and stable operation of nuclear power plant. Due to the difference in rotary inertia between the rotor and the rotating shaft, radial displacement, pressure and friction torque caused by centrifugal force during high-speed operation are different. The minimum fit tolerance, fit pressure safety factor and torsion strength safety factor are calculated by the strength check theory. Then, the finite element analysis of rotor stress of a 4500kW main pump motor is carried out and stress concentration is determined for rotor root and axial ventilation hole. Finally, the finite element analysis of stress field is carried out for end ring, copper bar, guard ring and pressure ring. It is found that there is obvious stress concentration at the top hole of the guard ring and the air duct of the pressure ring, and the bending stress of the copper bar and end ring is relatively high. Combined with the results of finite element analysis, the rotor end is improved, which can effectively improve the reliability of the end, increase the ventilation area of the end and save material cost.