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汽轮机转子热应力是由蒸汽温度的变化引起转子体中温差而形成的。对上述过程分别建立复频域动态数学模型，经综合后得到转子热应力对蒸汽温度变化率的相应模型。并以某一机组的实际启动过程为算例，与有限元模型作了仿真比较，结果表明模型具有较高的精度。为了大幅缩减计算量，应用“主导极点”概念对所得模型作了合理简化，为热应力的在线监控提供了一个易于实现的通用模型。该模型对放热系数及转子材料物性参数的变化具有自适应能力。
Turbine rotor thermal stress is caused by changes in steam temperature caused by the temperature difference in the rotor body. The dynamic mathematical model of complex frequency domain is established respectively for the above process, and the corresponding model of rotor thermal stress on the rate of change of steam temperature is obtained after synthesis. The actual start-up process of a certain unit is taken as an example, and compared with the finite element model. The results show that the model has higher accuracy. In order to reduce the computational complexity greatly, the model is simplified by applying the concept of “dominant pole”, which provides an easy-to-implement universal model for on-line thermal stress monitoring. The model is adaptive to changes in the exothermic coefficient and rotor material properties.