Investigation of Air Flow in Low Voltage Asynchronous Electrical Machines with Various Fan Housings

This study invcsti gates the cooling system of a low voltage electrical machine with various fan housings numerically, according to the theory of computational fluid dynamics(CF D) and experimentally. This electrical machine with an external radial fan at rated speed of 1475 rpm and the international cooling IC4ll (according to the Std. IEC60034-6) is tested in laboratories of Jovain Electrical Machines Industries Company (JEMCO). By using simplified model the air flow field on the frame is calculated. Two types of fan housing designs are investigated. The simulations results show that by adding a conical plate at the end of the fan housing the average velocity among fins on the frame increased, so the cooling system performance enhanced. Not only numerical results demonstrated these conclusions, but also the both electrical machines, which designed, manufactured and tested entirely, proved the same conclusions. The main result is that the velocity on the frame and cooling efficiency of electrical machine with conical fan housing increase in compared with electrical machine with initial fan housing.

Keywords:

low voltage asynchronous electrical machines , fan housing. cooling system , air flow , CFD