Flow–thermal analysis of ventilation and cooling capacity of centrifugal fans with splitter blades in high-voltage asynchronous motors

High-voltage asynchronous motors (HVAMs) face the problem of excessive internal temperatures during operation, which not only compromises operational safety, but may also shorten their service life. Therefore, finding an optimally effective cooling system is crucial. The performance of a centrifugal fan within the inner airflow path of an HVAM plays a critical role in determining the overall ventilation and cooling capacity. Installing splitter blades is an effective method to improve the performance of centrifugal fans. This study investigates the specific effects of splitter blade design on the performance of centrifugal fans, the internal flow field, and the rise in temperature of the motor. The performance of an internal fan in a 630 kW, 10 kV HVAM is analyzed using a combination of flow–thermal analysis and experiment. First, the effects of splitter blades with varying lengths and peripheral positions on the external characteristic parameters of the fan are investigated. A nonlinear relationship between the length and peripheral position of the splitter blades and the external characteristic parameters is identified, and the optimal configuration is determined. Second, the influence of splitter blades with different lengths and peripheral positions on the flow field of the inner loop is analyzed. The mechanisms through which splitter blades enhance the passage vortices are clarified. Finally, a comparison of the temperature fields between the optimal splitter blade configuration and the original centrifugal fan design demonstrates the effectiveness of the splitter blades in improving the ventilation and cooling capacity. The results of this study provide an optimized solution for the heat dissipation and cooling systems of HVAMs and can serve as a reference for the design of cooling systems for similar motors.