Experimental study of non-bonded packed bed active magnetic regenerators with stabilized La(Fe,Mn,Si)13Hy particles

The aim of this study is to develop more stable magnetocaloric regenerators, made from non-epoxy-bonded La(Fe,Mn,Si)13Hy particles to address the instability issues of conventional regenerators with a first-order phase transition. The stabilized magnetocaloric materials are obtained by increasing the α − Fe content at the expense of a small reduction of the adiabatic temperature change. However, the experimental results show that the nonbonded structure improves the regenerator efficiency and reduces pressure drop, potentially compensating for the reduction of the material’s magnetocaloric effect. Compared to epoxy-bonded regenerators, non-bonded regenerators exhibit a larger temperature span (10.2 K at no load) and specific cooling power (27% improvement at a span of 4 K). Due to the elimination of the epoxy, a lower friction factor and higher packing density are
obtained. The long-term mechanical and chemical stabilities are verified by comparing specific heat, effectiveness, and pressure drop before and after a test period of more than one year.