Performance evaluation of an active magnetic regenerator for cooling applications - part II: Mathematical modeling and thermal losses

In this second part of a two-part paper, a mathematical model of active magnetic regenerators is applied to identify and quantify the main losses taking place in the AMR evaluated experimentally in Part I. Among those losses, the heat interaction with the external environment and the presence of dead (void) volumes between each end of the regenerator and the hot and cold heat exchangers were found to be the main factors that affect the AMR performance. Demagnetizing losses were considered as a function of the matrix geometry, temperature and applied magnetic field. In addition to predicting the time-dependent behavior of the fluid temperature exiting the regenerator during each blow and the cycle average cooling capacity, the model was able to quantify the impact of each loss mechanism on the thermal performance of the AMR.