On the basis of experimental iso-field heat capacities of
Gd0.74Tb0.26, Gd and (Gd3.5Tb1.5)Si4, a numerical comparison of
the main thermodynamic performances of these materials
individually and as the compounds of a composite taken as the
working substances in a regenerative Ericsson refrigeration
cycle, are evaluated and analyzed. A new definition of nonperfect
regenerative heat quantity is provided in the case of the
composite material. The calculation results show a very small
non-perfect regenerative heat quantity yielding to the largest
value of the net cooling quantity and COP for the composite. The
composite COP is found close to the COPCarnot showing the
interest for magnetic composite materials used as the working
substance in a refrigeration cycle.Moreover, this article provides
an effective method to evaluate the thermodynamic performance
of composite materials inmagnetic refrigeration cycles.
Because Gd, Gd0.74Tb0.26 and (Gd3.5Tb1.5)Si4 have different T0,
a possible and interesting consideration would be to design
these materials in a cascade refrigeration cycle (not be mixed)
with the same temperature range (e.g., from280 K to 300 K), and
to compare the thermodynamic performances between the
cascaderefrigerationcycle usingGd,Gd0.74Tb0.26 and (Gd3.5Tb1.5)
Si4 as the working substances and the refrigeration cycle using
only the composite material as the working substance.