地铁用电机传热特性数值模拟与实验研究

To investigate the over-temperature problem of motors, this study took a loaded metro motor as the research object, and established a three-dimensional physical model taking the asymmetry of the motor structure into account. The flow and heat transfer characteristics were computed through coupled simulation using ANSYS. When the flow and temperature fields were under rated condition, the internal flow and temperature fields distribution characteristics of the motor and the influences of rotating speed of motor and ambient temperature on the flow and heat transfer characteristics were investigated. In addition, the experiments used embedded thermal resistors to measure the temperature of the stator coils in the rated condition, which verified the reliability of the numerical model. The numerical results suggest that in the longitudinal section through the axis, the peak temperature emerges at the position about 25 mm from the middle plane at the non-driving end; and in the cross section, the peak temperature emerges in the area between the bottom and the component supporting the input wires. So a complete model is more rational than the symmetrical model. In addition, it is shown that with the increase of rotating speed, the highest temperature of the stator coils rises linearly, and that the peak temperature increases by 6.2% and the maximum temperature rise increases by 7.5% for each speed rise of 1 000 r/min. The highest temperature of the stator coils increases linearly with the ambient temperature, and the highest temperature rise of the stator coils also goes up slightly. The peak temperature increases by 10.1% and the maximum temperature rise increases by 2.3% when the ambient temperature is raised by 10 ℃.