三峡水轮发电机全定子非线性热-流体耦合网络模型研究

为了计算水轮发电机水冷定子温度场，提出了基于有限元法计算参数的三峡水轮发电机全定子非线性热-流体耦合网络模型。网络模型中热阻参数均采用有限元法计算发电机三维局部温度模型得到，提高了参数计算准确性。模型计及铜的电阻率和水铜交界面对流换热系数随温度的变化而造成耦合网络方程的非线性。该模型可克服解算定子局部模型时某些边界条件无法确定的问题，同时实现了热网络和流体网络的耦合求解，计算值与实际运行数据基本符合，说明了该模型的正确性和有效性。为研究大型发电机全定子温度场提供了一种新方法。

Research on the Nonlinear Thermal-liquid Coupled Network Model of Whole Stator of Three-gorge Generator

To calculate thermal field of water-cooled stator of hydro-generator, this paper presents a model of non-linear thermal-liquid coupled network of Three-gorge hydro- generator's whole stator. The thermal-resistances parameters of the network model were gotten from calculating the part model of stator by 3D finite-element method, which can improve the accurateness of thermal-resistance calculation. Considering the varying of the resistance-rate of copper and the convection coefficients on the surface between water and copper with temperature, the equation of coupled network is nonlinear. This model overcomes the problem that some boundary condition can not be decided in calculating the part model of stator. Meantime, the coupled solution of thermal-network and liquid-network is implemented. The results of calculation are basically agreed with the real-running data and it is showed that the model is correct and valid. This method of building model proves a way to research the thermal-field of whole stator of large generators.