监测汽轮机转子热应力的二维离散模型

Two-Dimensional Separation Model for Monitoring Thermal Stress of Steam Tubine Rotor

提出一种计算大型汽轮机转子热应力的二维离散模型。首先利用ＧＡＬＥＲＫＩＮ有限元法计算高中压转子的瞬态温度场，再根据该温度场在线计算转子的效应力。这种二维离散模型也可以进一步被用来计算转子轴向热膨胀和监测机组胀差。该模型的热应力计算结果表明，机组冷、热态启动中，中压转子最危险部位在第一级叶轮根部，高压转子最危险部位在调节级叶轮根部，与有限元分析结果完全一致。可以相信，以二维离散模型为基础的汽轮机转子热应力及热膨胀在线监测系统将会投入使用。

A two-dimensional separation model of the thermal stress for large steam turbine rotor is prosed in this paper. The temperature fields of H. P. and M. P. rotor in transient codition are cacluated using GALERKIN finite element method in order to estimate the thermal stress and the axial thermal expansion. The expansion difference between rotor and cylinder may further be estimated by the models. The calculation of thermal stress shows that the mOSt dangerous section is at the root of the first disc of M. P. rotor,another dangerous section is at the root of velocity stage disc during hot-start and coldstart. This modal will be used as a basis for on-line monitoring thermal stress and thermal expansion of steam turtine rotor.