CFD Numerical Simulation On Thermal And Flow Fields Of 13MW Non-salient Pole Synchronous Motor

In the development phase of motors,every program should be conducted carefully and orderly,especially in the cooling design work which relates to multi-disciplinary knowledge.Due to the maximum temperature permission of insulation material and the close relationship between temperature rise and development phase,the studies of the thermal and flow fields of the motors have very important significance.In this paper,a 13 MW non-salient pole synchronous motor was taken as an example and the coupled flow and temperature fields was calculated based on computational fluid dynamics(CFD)theory.First,a three dimensional physical model of flow field of 1/8 motor structure was established including stator and rotor,and then the governing equations were solved numerically.The characteristics of velocity,pressure and flow rate in motor were obtained through simulating.The geometric factors which could affect the air flow rate distribution were searched,and this would lay the foundation of simulating rotor temperature on the basis of flow field.Then three dimensional flow field of 1/4 motor was analyzed and the results were compared with that of 1/8 motor,which could determine the consistency of the two models.Second,according to the experience of the research,the physical model including half axial section of NO.6 slot and end section of NO.5 slot was established based on the physical model of integrative flow field,and the rotor temperature was calculated and analyzed.Then the temperature distribution laws under different conditions were simulated and the positions of peak temperature were obtained.Third,on the basis of three dimensional physical model mentioned above,the computational domain of rotor temperature was enlarged.The temperature rise under different conditions was calculated and the temperature distribution in motor was analyzed.Then the position of peak temperature and the influence of computational domain size on the peak temperature was obtained,and the results were compared with the aforementioned results.The results showed that the distribution laws agreed with each other and the errors were about 3% which met the requirements of engineering calculation.The main factors which affect temperature rise were determined.The peak temperature was located on the center pole line at rotor end segment.Finally,in order to reach the distribution laws of air flow rate in stator core radial ducts along the circumferential direction,the reasonable physical model was established and the flow field was calculated.The good results were obtained.The calculation results in this paper are of great help to analysis the comprehensive performance of motors and to optimize the design of motors.