Calculation and Analysis on Stator Ventilation Structure of Different Optimum Proposal in Air-cooled Turbogenerator

With the increase of turbogenerator capacity,the heat transferability of cooling system is becoming more and more vital to the component reliability. By reasonablely optimizing the stator structure in a turbogenerator,utilization rate of coolant could be improved,and the maximum temperature of turbogenerator could be reduced. Based on the experimental data and plenty of related operations of a 200 MW air-cooled turbogenerator,two optimization designs about stator structure were proposed. One was to change the iron core thickness with the stableness of overall size,total losses of stator core and the number of stator ventilations,the other is to increase the number of ventilations and reduce their length with the stableness of the overall size and total losses of stator core. With CFD principle and 3-D finite volume method,the modeling equations of air turbulent flow in cooling ducts are solved,and the effect of the ventilations' structure changing on coolant utilization ratio and distribution of stator temperature were studied. The study shows that,by adopting the two optimal structures,coolant can take away more heat from generator and the maximum temperature of generator can be reduced up to 9.13 ℃ more than original structure.