Investigating the Impact of Water-Glycol Mixture Ratios as Heat Transfer Fluid on the Performance of a Rotary Magnetic Refrigerator

Magnetic refrigeration offers an eco-friendly and sustainable alternative for cooling applications. The selection of an appropriate working fluid is critical for heat removal and regeneration efficiency in Active Magnetic Regenerators (AMRs). This study evaluates various working fluids, focusing on water mixed with an antifreeze agent, glycol, to extend the temperature range and prevent corrosion. The thermophysical properties of such mixtures differ from pure water, influencing the refrigerator's performance. A parametric investigation using a numerical model of a rotative magnetic refrigerator was conducted to analyze the effects of varying the water-glycol mixture ratios. The study systematically varied operational parameters, such as rotation frequency and mass flowrate, to determine optimal performance conditions. Results indicate that the performance, measured by the Coefficient of Performance (COP), cooling load, and efficiency, declines with increasing glycol content, particularly at lower temperature spans. Increased viscosity in the mixture necessitates higher pumping power and torque for optimal operation, affecting the optimal rotational frequency. This study underscores the importance of balancing the mixture composition to enhance temperature range while minimizing negative impacts on performance, advocating for mixtures with lower glycol content.