Research On Modeling Method Of Stator Fluid And Temperature Field And Cooling Structure Of Hydro-generator

The stator fluid heat transfer problem of large generator is closely related to the stator winding transposition path,the channel steel,interaction among ventilation grooves,the wedge shape and the segmentation.With the temperature rise of the generator,it is urgent to consider these factors comprehensively and comprehensively analyze the impact of these factors on the temperature rise of the generator.In this paper,a 250 MW full air-cooled hydro-generator is taken as an example to analyze the three-dimensional modeling method of the stator fluid heat transfer problem and design stator cooling structure.Considering several key factors affecting the temperature field of the generator systematically,three stator fluid heat transfer models are proposed.The loss of each part of the stator is calculated by numerical method and analytical method.The finite volume method is used to numerically study the fluid field and temperature field of each model,and compared with the experimental data.The experimental results verify the accuracy and rationality of the proposed model.The research results show that the proposed analytical model can improve the calculation accuracy of stator temperature rise.According to the proposed model of the stator fluid heat transfer,the influence of the incident angle of the cooling air on the stator fluid field and temperature field is analyzed.The effects of stator core segment,ventilation grooves' axial length and number and the stator channel structure on stator fluid field are studied.By analyzing the fluid field and its influencing factors,three kinds of stator cooling structures are proposed.The stator fluid field and temperature field of the corresponding structure are calculated and compared with the original structure.The influence of stator cooling structure on temperature rise is revealed.The research results show that the reasonable adjustment of the number of stator ventilation grooves and core segments can effectively reduce the maximum temperature of the transposition windings in the slots.