Performance characteristics of an irreversible regenerative magnetic Brayton refrigeration cycle using Gd0.74Tb0.26 as the working substance

The cycle model of an irreversible regenerative magnetic Brayton refrigerator using Gd0.74Tb0.26 as the working substance is established. Based on the experimental characteristics of iso-field heat capacities of the material Gd0.74Tb0.26 at 0 T and 2 T, the corresponding iso-field entropies are calculated and the thermodynamic performance of an irreversible regenerative magnetic Brayton refrigeration cycle is investigated. The effects of the irreversibilities in the two adiabatic processes and non-perfect regenerative process of the magnetic Brayton refrigeration cycle on the cooling quantity, the heat quantity released to the hot reservoir, the net cooling quantity and the coefficient of performance are discussed in detail. Some significant results are obtained.

► We model magnetic Brayton cycles using Gd0.74Tb0.26 as the working substance.
► We examine the impact of irreversible processes on cycle performance.
► The net cooling quantity is linearly decreasing as the irreversibilities increase.
► The heat rejected to the hot reservoir is more sensitive to the irreversibilities.
► The coefficient of performance is highly dependent on the irreversible processes.