大型发电机定子主绝缘温度场数值研究

Numerical investigation of stator main insulation temperature field for large generator

为了研究大型汽轮发电机定子温度场以及主绝缘温降分布规律,以一台具有异结构股线的特殊大型汽轮发电机为例,根据发电机的通风性能和结构特点,建立了发电机定子径向通风沟内二维流体场模型。并采用有限体积元法对其进行了数值计算。同时建立了发电机定子三维温度场的数学模型和物理模型,基于获得的各个散热表面的散热系数,利用有限元法对其进行了数值研究。研究表明温度场的计算结果与实测结果相吻合,最高温度位于定子上层线棒靠近槽口的股线上,上下层线棒主绝缘温降的最高值以及平均值都存在差异,且上层线棒的主绝缘温降较大。本研究可为大型发电机股线结构优化提供参考。

To explore stator temperature field and distribution principle of major insulation temperature drops inside large turbo-generator.A large generator with different structure strands is taken as an ex-ample,according to ventilation performance and structure characteristic of generator,two dimensional flu-id field model inside stator radial duct was given and it was numerically calculated using finite volume method（FVM）.Meanwhile,the mathematical model and physical model of three dimensional stator tem-perature field were established for generator with different structure strands and it was numerically ana-lyzed by finite element method（FEM） baesd on getting the heat transfer coefficients of all heat transfer surfaces.Investigation results show that calculated results of temperature correspond with measures re-sults,the highest temperature is located on the strand of upper bar adjacence to stator notch,maximum and anerage value of major insulation temperature drops of upper and bottom bar are not same,and tem-perature drops of upper bar are bigger than that of bottom bar.Thus the theoretical foundation can be of-fered for large generator strands structure optimization.