DESIGN OF A MAGNETIC COOLING DEVICE USING GADOLINIUM ALLOY AND PERMANENT MAGNETS

Traditionally, heat pumps and refrigerators utilize the vapor compression cycle to achieve cooling. These vapor compression cycles use hydrochlorofluorocarbons (R134a) as the cycle's working fluid. This refrigerant contributes to global waiuiing and is expected to be phased out. Consequently, new refrigerants as well as new refrigeration methods need to be developed. The research detailed in this article attempts to implement the magnetocaloric effect of gadolinium alloy in a designed apparatus to lower the temperature of air. Gadolinium alloy has a noticeable magnetocaloric effect within a strong magnetic field (5 T). This research is aimed at producing a noticeable temperature change (2 - 3 degrees C) in a relatively smaller magnetic field (1 T) produced with permanent magnets. This work tests the feasibility of magnetic cooling by introducing the design of a magnetic cooling apparatus, using Gadolinium alloy (Gd5Si2Ge2). Small pebbles were used as opposed to a solid plate in order to have an increased surface area to enhance the convection heat transfer process. Penuanent magnets were used in the apparatus, to decrease the operating cost. The maximum temperature change encountered in the heat exchanger of the apparatus built was 2.3 degrees C in a 1 T magnetic field.