Thermal-hydraulic performance optimization of the spiral cooling channel in surface type permanent magnet synchronous motor

As the operation temperature of surface type permanent magnet synchronous motor (STPMSM) is very high, it is crucial to design a reasonable and efficient motor cooling system. In this work, a grooved spiral round channel (GSRC) is designed based on the ordinary spiral round channel (OSRC) and applied to the cooling system of the STPMSM. The heat transfer coefficients and pressure losses of the OSRC and the GSRC under different conditions are compared and analyzed. It is found that compared with the OSRC, the pressure loss and heat transfer coefficient of the GSRC are reduced and increased, respectively. Furthermore, performance evaluation criterion (PEC) is used to evaluate the thermal-hydraulic performance of the two spiral cooling channels. The results demonstrate that the thermal-hydraulic performance of the GSRC is significantly superior to the OSRC. The thermal-hydraulic performance of the GSRC is better with the increase of the groove width. When the coolant, mass flow rate, spiral pitch and groove width are water, 10 g/s, 40 mm and 3 mm, respectively, the pressure loss and heat transfer coefficient of the GSRC are decreased and increased by 58.13% and 39.12%, respectively. The PEC reaches 1.27 compared to the OSRC. This work indicates that the GSRC is more appropriate for applying in the cooling system of the surface type permanent magnet synchronous motor.

Automated summary

The design of a reasonable and efficient motor cooling system is crucial for a high temperature surface type permanent magnet synchronous motor (STPMSM). This work compares and analyzes the heat transfer coefficients and pressure losses of the ordinary spiral round channel (OSRC) and the grooved spiral round channel (GSRC) under different conditions. The results show that the GSRC has reduced pressure loss and increased heat transfer coefficient compared to the OSRC. Furthermore, the thermal-hydraulic performance evaluation using the performance evaluation criterion (PEC) demonstrates that the GSRC is significantly superior to the OSRC.