Test Method on Starting Drag Torque of the Thrust Bearing of the Reactor Main Pump in Nuclear Power Plant

In order to obtain the ultimate starting drag torque of the thrust bearing of the reactor main pump in nuclear power plant during its lifetime, and ensure that the auxiliary motor performing the accident residual heat removal function can start the main pump under extreme conditions, a test method of the starting drag torque (which refers to the drag torque at the moment of starting) of the thrust bearing was proposed and a test device was designed. The orthogonal test method was used to study the three influencing factors (roughness, specific pressure and lubricating oil temperature) that affect the starting drag torque of the thrust bearing. The single factor method was used to test the influence of different downtime (which refers to the static loading time) on the starting drag torque of the thrust bearing. The results show that the starting drag torque changes little when the three factors change within the specified control range, but the downtime has a great impact on the starting drag torque of the thrust bearing. The design of the auxiliary motor was carried out based on the ultimate starting drag torque determined by the test, and has been verified by repeated start-stop tests of the thrust bearing prototype and the main pump prototype. The research in this paper can provide accurate and reliable input for the design of the starting drag torque of the auxiliary motor.