Design Issues and Future Perspectives for Magnetocaloric Energy Conversion - Magnetocaloric Energy Conversion: From Theory to Applications - page 354

However, Murakami and Nemoto [ 11 ] published their work on experiments and
considerations on the behaviour of thermomagnetic motors in 1972. Later, in the
1980s, Kirol [ 12 , 13 ] and Salomon [ 14 ] investigated magnetocaloric power gen-
erators with solid working materials.
The idea of magnetocaloric power generation was later rediscovered by the
research group from the University of Applied Sciences of Western Switzerland,
guided by Egolf. As a result, a comprehensive study was performed for the Swiss
Federal Of

ce of Energy in 2008 [ 15 ]. Later, a number of publications were pro-
duced by the same group (see Diebold et al. [ 16 ], Egolf et al. [ 17 ], Vuarnoz et al.
[ 18 20 ]).

In the period 2006

-

ck from Delft
University (starting at the University of Amsterdam) was very active in

2014, also the group under the guidance of Br ü

-

nding
magnetocaloric materials that are suitable for magnetocaloric power generation.
They published a report on these developments as a result of collaboration with the
company BASF (see examples in Br

ck [ 22 ]).
In 2014 the same group published an article on a small proof-of-the concept
device [ 23 ].
Valuable work was also performed by Takahashi et al. [ 24 , 25 ], who published
work on analyses of thermomagnetic engines in 2004 and 2006.
It is important to mention the work on thermomagnetic wheels, which represents
a special case of magnetic energy harvesting and which have been published by
Karle in 2000 [ 26 ], Palmy in 2007 [ 27 ], Palmy and Egolf [ 28 ] and Alves et al. [ 29 ].
Some additional and newer publications on magnetocaloric power generation
can be found in Cleveland and Liang [ 30 ], Alves et al. [ 31 ], Ferreira et al. [ 32 ], and
Trapanese et al. [ 33 ].

ü ck et al. [ 21 ], Br ü

8.7 Future Perspectives and Guidelines for Magnetocaloric
Energy Conversion

According to our experiences and knowledge we put here some guidelines for the
future developments of magnetocaloric energy conversion. We believe that in the
future, magnetocaloric energy conversion devices will consist of static magnetoc-
aloric material and moving, rotating or switching magnetic

elds. Why not rotation
of the magnetocaloric material? All the present experiences with such devices show
a large problem associated with the dynamic sealing of such systems. Therefore, a
number of researchers doing such con gurations experienced internal or even

external leakage of the working fl uid or very large friction due to the dynamic seal.

On the other hand, if an ef cient valve for such a system is designed, it will

certainly represent an expensive part of the device. It is therefore easier to develop a
system in which the magnetocaloric material stays at rest, and therefore no dynamic
seal is required, unless a rotating valve system is also applied in this case.