Numerical investigation on the influence of operating temperature range of active magnetic regenerator

Magnetic refrigeration based on the magnetocaloric effect (MCE) is of great potential for the new generation of refrigeration technology. In traditional notion, making Curie temperature coincide with the midpoint between cold source temperature T_c and hot source temperature T_h is helpful to realize the best performance of active magnetic regenerator (AMR) since the magnetocaloric effect is strongest under such temperature range. However, such conclusion is lack of quantitative analysis. In this work, a one-dimensional numerical model for packed-bed AMR with Gd as magnetocaloric material is presented and validated. The performance parameters including cooling power and COP are focused on for investigation of the influence of the working temperature range between T_c and T_h under a fixed temperature span of 4 K. The results indicate that it is necessary to ensure T_ave coincide with the Curie temperature for the highest cooling power. But for higher COP, the temperature ranges of T_c and T_h should be removed to a higher level, which means T_ave should be above the Curie temperature. Finally, when high cooling power and COP are desired at the same time, the center of the temperature range should be higher than Curie temperature, which corresponds to the condition of T_c=294K, T_h=298K in this work.