A practical model for analysis of active magnetic regenerative refrigerators for room temperature applications

In this paper, a practical model for predicting the performance and efficiency of active magnetic regenerative refrigerators (AMRRs) has been developed. With this model, the refrigeration capacity, the power consumption (including the power required to move regenerator cylinder and drive heat transfer fluid) and consequently the coefficient of performance (COP) of a real AMRR system can be predicted with different heat transfer fluids. A dimensionless parameter, utilization at maximum refrigeration capacity (UMRC), is used to numerically characterize the performance of an AMRR. The numerical results indicate that the UMRC increases with increasing number of transfer units (NTU) and eventually reaches its maximum. Increasing operating frequency increases the refrigeration capacity of the AMRR while causes a reduction in COP. The influences of the physical properties of transfer fluids on the AMRR performance are also studied. Liquid is more favorable than gas for being used as heat transfer fluid in AMRR systems.