转子跌落保护系统试验台架的设计和研究

Design and Study of Experiment Platform for Rotor Dropping Protection System of Helium Circulator

高温气冷堆核电站的主氦风机采用电磁轴承支承转子,其中的辅助轴承用于当电磁轴承失电后临时支承高速跌落的转子,保护电磁轴承和转子系统的安全。辅助轴承采用滑动轴承的形式,在跌落期间因摩擦系数高、发热量大,较易损坏。本文研究一种气动保护装置,采用动静压结合的气体轴承技术,在转子发生跌落时对辅助轴承进行一定保护。设计了专门的试验台架以验证保护系统的可靠性。为模拟转子跌落时对保护轴承的冲击,设计了一种采用与电磁轴承原理类似的电磁载荷模拟器。这种电磁载荷模拟器通过电流产生的电磁力可直接在模拟转子上加载轴向载荷,其设计最大载荷为110kN,定转子间隙为1mm。通过计算校核表明,该模拟器可满足试验要求。

The rotor of helium circulator in high temperature gas-cooled reactor is sup- ported by magnetic bearing. The auxiliary bearing of the magnetic bearing is used to support and protect the rotor when the magnetic bearing loses the power. In this helium circulator, the auxiliary bearing is the sliding bearing which is easy to be broken by the frictional heat when the rotor drops down at the full speed. In this paper, a pneumatic protection system of the auxiliary bearing was designed, and it could reduce the impact when the rotor dropped and protect the auxiliary bearing from more damage. An experiment platform was designed to validate the reliability of the protection system. For simulating the impact of the auxiliary bearing when the rotor dropped, a magnetic load simulator was designed, which can exert axial load to the motor directly by electromagnetic force through a similar technology to the magnetic bearing. The design axial load of the magnetic load simulator is 110 kN with a clearance of 1 mm. By analyzing and calculating the parameter of the magnetic load simulator, the result shows that the magnetic load simulator can meet the loading requirement of this test.