Investigation Of Heat Transfer Performance Within Doubly-fed Hydro-generator

With the development of the water power generation, doubly-fedhydro-generator power system with its stability of power and good adaptabilitycauses more and more attention widely. In the doubly-fed hydro-generator, the unitcapacity is continuously increasing and the working condition is becoming more andmore complicated. During the process of energy conversion, the problem that theproduced losses have an effect on its temperature rise becomes more serious. So,aiming at the investigation of heat transfer performance within doubly-fedhydro-generator, it has a certain theoretical significance and engineering guidancevalue to make a further research.In his paper, the basic theory was based on the electric machinery, computationalfluid dynamics and heat transfer. After the actual generation capacity and ventilationcooling structure was introduced, the design sheets and engineering drawings thatprovided by motor factory were used as basic data. In order to calculate the staticflow-heat coupled field, two kinds of3D FVM (finite volume method) physicalmodel were respectively established firstly. The one was a simplified model withsingle cogging and ventilation duct, and the other was a whole model withmulti-structure components. The solving technique which is based on conjugate heattransfer problem was used. According to the losses data of different structuralcomponents in the generator which was working under different conditions, the heatsource density of the structural components was changed. The heat transferperformance of the generator, under two working condition of4.4MW test capacityand6.5MW design capacity, was calculated and analyzed in detail. The generatorwas tested in the Ren Min hydropower station when it was working with test capacity.The text data of temperature rise was recorded which came from the platinumresistances that buried in the predicting position of the maximum temperature risebefore. Compared with the numerical calculation results, the test temperature data proved that the utilization of models and methods in this paper were reasonable andaccurate.According to the investigation in this paper, the accuracy and application scopeof difference models have been concluded. The detailed temperature rise distributionof the generator under different working condition have been obtained accurately. Atlast, the purpose, to determine the position of the maximum temperature rise and tocheck temperature rise margin, has been achieved.