发电机通风系统流场及转子温度场分析

针对电机温度场与通风系统流场间的耦合问题,依据流体力学和热传导理论,建立了某电站700kW灯泡贯流式水轮发电机的通风系统流场及转子温度场的三维有限元模型.采用有限元分析方法,分析了通风系统的流场,获得了通风系统压降和流体流速的分布,进而得到各表面的散热系数,并结合电机各部分损耗热源的计算,分析了发电机的转子温度场分布.结果表明:在满足风机流量下的电机通风压降为464 Pa,与实际运行时的实测数据483 Pa基本吻合;转子温度在其设计的绝缘容许温度范围内,且有足够裕度.

Analysis of ventilation fluid field and rotor temperature field of a generator

Aiming at the coupled problem of temperature field and ventilation system fluid field of generator,the three dimensional finite element models of ventilation system fluid field and rotor pole temperature field of a 700 kW bulb turbine generator are presented according to the hydrodynamics and heat transfer theory.By using the finite element method,the fluid field of the generator ventilation system is calculated,and the distributions of pressure and velocity of the ventilation system are obtained.Further,the coefficients of heat transfer are also obtained from the velocity distribution.Combining with the losses of different parts,the rotor temperature field distributions are analyzed.The results show that,the ventilation pressure is 464 Pa when the flux of air flow is satisfied,and the calculated pressure is coincident with the test value 483 Pa.The rotor temperature is in the range of the permissible temperature of designed insulation and has enough tolerance.