Influence of Large Turbo-Generator Stator Ventilation Ducts Structural Changes on Stator Temperature

For the complex status of fluid flow in stator radial ventilation ducts of large turbo-generator, the temperature distribution of stator is dramatically affected by the flow status of cooling medium in stator ventilating ducts. In this paper, a new ventilating ducts structure in stator is investigated. According to fixing a wind deflector on the stator teeth adjacent to the ventilation ducts, the fluid flow status of cooling air is changed flowing in stator ventilation ducts. For this reason, the effect of heat transfer in stator is changed. Taking an air-cooled turbo-generator as an example, considering the characteristics of fluid flow and heat transfer in turbo-generator ventilation system, the three-dimensional fluid flow and heat transfer coupling model is established. Using finite volume method, three-dimensional fluid field and temperature field control equations are coupling solved. Based on this, the velocity distribution in ventilating ducts is obtained. Besides that, the velocity distribution is studied with the cooling air flows into radial ventilation ducts at different incident angles. The influences of wind deflector and incident angles on the fluid velocity and temperature distribution are analyzed. Based on that, some useful conclusions are obtained.