CHARACTERISTIC ANALYSIS OF ROTOR DYNAMICS ANDEXPERIMENTS OF ACTIVE MAGNETIC BEARING FOR HTR-10GT

摘要

A 10MW high-temperature gas-cooled reactor (HTR-10) was constructed by the Institute of Nuclear and NewEnergy Technology (INET) at Tsinghua University of China. The helium turbine and generator system of 10MWhigh temperature gas-cooled reactor (HTR-10GT) is the second phase for the HTR-10 project. It is to set up adirect helium cycle to replace the current steam cycle. The active magnetic bearing (AMB) instead of ordinarymechanical bearing was chosen to support the rotor in the HTR-10GT. This rotor is vertically mounted to hold theturbine machine, compressors and the power generator together. The rotor's length is 7 m, its weight is about 1500kg and the rotating speed is 15000 r/min. The structure of the rotor is so complicated that dynamic analysis of therotor becomes difficult. One of the challenging problems is to exceed natural frequencies with enough stability andsafety during reactor start up, power change and shutdown. The dynamic analysis of the rotor is the base for thedesign of control system. It is important for the rotor to exceed critical speeds. Some kinds of softwares andmethods, such as MSC.Marc, Ansys, and the Transfer Matrix Method, are compared to fully analyze rotordynamics characteristic in this paper. The modal analysis has been done for the HTR-10GT rotor. MSC.Marc wasfinally selected to analyze the vibration mode and the natural frequency of the rotor. The effects of AMB stiffnesson the critical speeds of the rotor were studied. The design characteristics of the AMB control system for theHTR-10GT were studied and the related experiment to exceed natural frequencies was introduced. Theexperimental results demonstrate the system functions and validate the control scheme, which will be used in theHTR-10GT project.