Performance Analysis of Magnetic Refrigeration Systems Using Nanofluids with Propylene Glycol Mixture as Base Fluid

This work presents the performance of a magnetic refrigerator with the use of nanofluids as heat transfer fluids, specifically focusing on a base mixture with a 30% mass concentration of propylene glycol. Five types of nanoparticles were studied: aluminum oxide, copper oxide, zinc oxide, silicon dioxide, and silicon carbide. The nanofluid’s thermophysical characteristics like density, specific heat capacity, thermal conductivity, and dynamic viscosity were determined through empirical correlations available in literature. The results sufficed to draw a conclusion that volumetric concentration and particle size are the main parameters that define the performance of the nanofluid in a magnetic refrigeration system. It was observed that increasing volumetric concentration and reducing particle size improves refrigerating power, even though it decreases the Coefficient of Performance, especially for a small temperature span. The type of nanoparticle material seems to play a minor role in the results, which would indicate that, in regard to system efficiency, the size of the particles and their volumetric concentration are more important than the material of the nanoparticles. In addition, the overall performance was not affected by temperaturesensitive thermophysical properties. Thus, improving the performance of the system could be achieved by choosing the appropriate size and volumetric concentration of particles rather than choosing the specific material. In conclusion, the size of the particles and the volumetric concentration are the most important variables that affect the performance of the nanofluid, while the material selection is considered a tertiary factor for the efficiency of the magnetic refrigeration system.