Application of magnetic cooling in electric vehicles

Abstract

The features of an active magnetic regenerator refrigerator are determined for its application in mobile air-conditioning systems. The thermal requirements of an electric vehicle have first been obtained and result in a cooling demand of 3.03 kW at a temperature span of 29.3 K. A comprehensive parametric study has been conducted in order to find the active magnetic regenerator refrigerator design and working parameters that fulfill the vehicle needs with a minimum electric consumption and device mass. Specifically, a permanent-magnet parallel-plate active magnetic regenerator refrigerator made of Gd-like materials is considered. According to the possibilities of current prototypes, in the study the cycle frequencies have been limited to 10 Hz and the applied magnetic fields, to 1.4 T. The results show that an active magnetic regenerator refrigerator made of plates between 30 and 40 μm thick and channels between 20 and 40 μm high could meet the vehicle demand with a coefficient of performance between 2 and 4 and a total mass between 20 and 50 kg. Compared to vapor-compression devices for mobile air-conditioning systems (coefficient of performance = 2.5 and mass 12 to 15 kg), the active magnetic regenerator refrigerator works optimally with fluid flow rates at least three times larger. In order to integrate active magnetic regenerator refrigerators into mobile air-conditioning systems, the hydraulic loops should be consequently redesigned.