Dynamic Analysis for the Rotor Drop Process and Its Application to a Horizontal Rotor-Active Magnetic Bearing System in Helium Gas

Abstract

The high-temperature gas-cooled reactor pebble-bed modular (HTR-PM) has been proposed by the Institute of Nuclear and New Energy Technology of Tsinghua University, in which the active magnetic bearings (AMBs) are equipped to support the high-speed rotor in the helium circulator system. In the case of AMB failures, emergencies, or overload conditions, the auxiliary bearing is applied as the backup protector to provide temporary mechanical support and displacement constraint for the dropping rotor. A detailed dynamic model is established to reveal the behavior of the dropping rotor. This model is able to describe the rotor displacement and inclination around each axis. The left and right rotor orbits are revealed. Dropping experiments are also carried out to reveal the actual behavior of the dropping rotor in helium. The predicted and experimental results will benefit further study, design, and application of the auxiliary bearing in HTR-PM helium circulator.