Application of magnetic cooling in electric vehicles

Abstract

The features of an active magnetic regenerator refrigerator (AMRR) are determined for its application in mobile air-conditioning (MAC) systems. The thermal requirements of an electric vehicle have been firstly 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 AMRR design and working parameters that fulfill the vehicle needs with a minimum electric consumption and device mass. Specifically, a permanent-magnet parallel-plate AMRR 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 AMRR made of plates between 30 and 40 µm thick and channels between 20 and 40 µm high could meet the vehicle demand with a COP between 2 and 4 and a total mass between 20 and 50 kg. Compared to vapor-compression devices for MAC systems (COP=2.5 and mass 12 to 15 kg), the AMRR works optimally with fluid flow rates at least 3 times larger. In order to integrate AMRRs into MAC systems, the hydraulic loops should be consequently redesigned.