关键词: 燃气轮机转子, 启动工况, 有限元方法, 应力场, 寿命评估

Abstract:

Taking a specific heavy-duty gas turbine of F class as study object, based on the monitoring data of actual operation, curves denoting temperature changes over time of measuring points in the F class heavy-duty gas turbine unit were extracted at cold starting and hot starting conditions. In these two starting conditions, the heat transfer boundary conditions were calculated throughout, the finite element method was used to analyze the transient temperature field and stress field of the gas turbine rotor in different starting conditions. Based on the results, the low-cycle fatigue life loss was assessed. The calculation results show that maximum thermal elastic stress generally appears at the bottom fillet on the outlet side of the turbine's first stage disc and rounded area on the middle part of the compressor's third stage disc; airflow parameter change speed has enormous influences on the rotor's stress distribution and the life loss of cold starting is up to 0.02%, greater than the corresponding value of the hot starting. The conclusion provides an important reference for the optimization of wheel structure design and the unit operating procedures.

Key words:  gas turbine rotor, starting condition, finite element method, stress field, life assessment