中文摘要：

降低汽轮机转子在起停过程中的热应力对于控制转子因热疲劳产生的裂纹萌生和扩展具有重要意义。采用有限元法估算660MW高中压转子的瞬态温度场，采用弹塑性有限元法计算转子的瞬态应力应变场。研究起动过程中温升分配对转予最大热应力的影响。研究表明，同样的起动时间，采用不同的温升分配模式可以使最大热应力降低34％；选择合理的温升分配模式可以有效降低起动过程转子热应力，减小起动时间。克服以往研究多认为局部高温升率是导致转子最大热应力的主要因素的不足。该研究对制定合理的起动曲线有指导作用。

英文摘要：

Reducing thermal stress of rotor during steam turbine start-up and shutdown process is very important for preventing the initiation and propagation of crack in rotor due to thermal fatigue. The finite element method is employed to calculate the transient temperature field of the high-intermediate pressure rotor of a 660 MW steam turbine. An elastic-plastic finite element model is used to determine the transient stress and strain field. The effect of temperature rising distribution on the thermal stress of rotor during steam turbine start-up is investigated. Calculated results show that the maximum thermal stress of rotor is reduced by thirty four percent than before by using different temperature rising model in the same period of start-up. It can be concluded that the appropriate model of the temperature rising during start-up could effectively reduce the thermal stress of the rotor, also shorten the start-up period. The conclusion drawn can be referenced for determining the reasonable curve of start up for steam turbines.