Environmental Engineering Reference
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Fig. 6.32 Design concept of a cascade magnetocaloric device with thermal diodes: black arrows
magnetization, grey arrows demagnetization
ve MC materials are applied, each embodied within
thermal diodes on the top and bottom. Each MC material shares one thermal diode
with the neighbouring MC material. Only two MC materials at the hot and cold
ends have one thermal diode facing the hot or cold heat exchanger, respectively.
The magnetic
As seen from Fig. 6.32 ,
eld is applied to MC materials in a particular way: every second MC
material is magnetized or demagnetized. In Fig. 6.32 the black arrows represent the
applied magnetic
eld, whereas the grey arrows represent the demagnetization
phase. Therefore, in the given example in Fig. 6.32 , the MCMs denoted by numbers
1, 3 and 5 are magnetized, while the MCMs denoted by numbers 2 and 4 are
demagnetized. After this phase, the magnetic
eld should switch in a manner that it
magnetizes the MCMs denoted by numbers 2 and 4, while the MCMs denoted by
numbers 1, 3 and 5 are demagnetized. The operation of such a cascade system is
thoroughly shown and explained in Fig. 6.34 .
The alternating of the magnetic
eld in the cascade system is of great impor-
tance. Only in this manner can heat be transported via thermal diodes between two
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