Modeling And Analysis Of Dynamic Characteristics Of Gas Turbine Shaft

With the increasing attention of efficient clean energy and environmental problems all over the world,in the thermal power dominated structure of China’s power energy,the power generation technology based on the gas turbine and its combined cycle has developed rapidly.High-power and high-efficiency gas-steam combined cycle power generation units have become the mainstream of research and development in the field of gas-fired power generation.Heavy-duty gas turbine has gradually become the core thermal power generation equipment of efficient power generation at home and abroad.Heavy-duty gas turbine shaft structure is special,its operation dynamic characteristic is essential for the safe and stable operation of the unit.Taking the F-class heavy-duty gas turbine generator unit put into more operation in our country as the object,the dynamic characteristics of the shafting are modeled and analyzed by finite element method.After a reasonable simplification of the shafting,respectively establishing the model in different finite element softwares and continuing the rotor dynamics calculation and analysis.The main research contents are as follows:(1)Structural characteristics of heavy-duty gas turbine rotor shafting were summarised and analysed,taking GE 9FA gas turbine rotor as a prototype,the calculation model of rotor shafting was established,the bending and torsional vibration natural frequencies and modes of the model were calculated.(2)The modal analysis of heavy-duty gas turbine rotor shafting was carried out by using finite element software,the natural frequencies and modes of the simplified and refined rotor models were calculated with different finite element softwares,and compared with the natural frequency of the actual gas turbine.(3)Taking the finite element model as the object,the response characteristics under unbalanced excitation were studied,the influence of unbalanced mass size and position on rotor dynamic characteristics was discussed.(4)The crack faults of gas turbine rotor impeller model was simulated,the modal analysis and harmonic analysis of impeller model vibration characteristics were carried out.