Preliminary Structural Design and Dynamical Analysis of Auxiliary Bearing for HTR-10GT

The electromagnetic bearing was chosen to support the rotor of power conversion unit (PCU) and helium blower fan in 10MW high temperature gas-cooled reactor (HTR-10GT), and the auxiliary bearing was applied in the HTR-10GT as the backup protector. HTR-10GT is the second phase of the 10MW high-temperature gas-cooled testreactor (HTR-10). HTR-10 is the first module high-temperature gas-cooled test reactor in the world. It was constructed by INET at Tsinghua University of China. A direct gas cycle to replace the current steam cycle of HTR-10 was studied in the HTR-10GT. However, one implication of magnetic bearings is the requirement to provide backup support to mitigate the effects of failures or overload conditions. The auxiliary bearing is used to support the rotor when the magnetic bearing fails to work. Especially when the rotor is rotating with high speed, the magnetic bearing suddenly doesn’t support the rotor for the power off. So it is very important for the auxiliary bearing to protect the rotor system. The PCU rotor’s length is about 7 m, its weight is about 1500 kg and the rotating speed is 15000 r/min. The rotor’s length of helium blower fan is about 1.5 m, its weight is about 240 kg and the rotating speed is about 5400 r/min. The design of the auxiliary bearing is one of the challenging problems in the whole system. It is very important for HTR-10GT to make success. In this paper, the research status ofthe auxiliary bearing was summarized. A sort of preliminary scheme of auxiliary bearing structure was proposed. The falling course was analyzed. The stress of the rotor and auxiliary bearing was computed by the finite element method. MSC.Marc was selected to analyze the vibration mode and the natural frequency of the rotor. The scheme of auxiliary bearing and the analytical results offer the important theoretical base for the protector design of the HTR-10GT.