Design Issues and Future Perspectives for Magnetocaloric Energy Conversion - Magnetocaloric Energy Conversion: From Theory to Applications - page 330

Fig. 8.2 Example of rotary movement for the magnetocaloric device, based on the same principle
as the linear device in Fig. 8.1 , classi cation no: R20(3)1(5)(6)00101(12)

When the uni-directional pump is applied, then the system in Fig. 8.1 requires a
valve system, which switches the fl uid fl ow in order to provide the oscillatory fl ow

of the uid through the AMRs. In this particular case, the system in Fig. 8.1 has to

be transformed into the one presented in Fig. 8.3 . In the case of uni-directional
pump the valve system should be as close as possible with regard to the AMR and
the heat exchangers. This is due to the same reason of avoiding or minimizing the
dead volume.
Note also that the

fl

ow through the heat sink HHEX and the heat source
CHEX is in this case always in the same direction, so no passive regeneration
occurs in the heat exchangers. The system in Fig. 8.3 , however, is more complex.
The switching-valve system can be stationary or rotary. A smart design can also
lead to a single, but complex, valve system. By using the Roman numbers from I to
XI in Fig. 8.3 we denote the different processes that the

fl uid fl

fl uid experiences.

ows from I through the CHEX.
Therefore, it absorbs heat from the cooled environment or media and reaches state

Let us take, for example, Fig. 8.3 a. The fl uid fl