Alternative Caloric Energy Conversions - Magnetocaloric Energy Conversion: From Theory to Applications - page 402

device is described in more detail later in this chapter. Here, a general description of
the active electrocaloric heat regenerator (AER) is given. Moreover, the working
principle of a refrigeration or heat pumping device based on an AER is described.
An AER is a porous structure of electrocaloric material through which a

fl uid

can ow [ 46 ]. An example of an AER is presented in Fig. 10.5 . According to

Fig. 10.5 the basic element of the AER is a plate consisting of an electrocaloric
material, which is coated on both sides with an electrically conductive

fl

lm. The
plates are put on top of each other and the distance holders are inserted in between
to create a void for the

ow. Simultaneously, the distance holders serve as
conductors for the electric current. The AER is put in a housing between the heat
sink (the hot heat exchanger) and the heat source (the cold heat exchanger), as
presented in Fig. 10.6 . The housing is

fl uid fl

lled with a dielectric fl uid and a mechanical

system, e.g. a bi-directional pump, is used to move the uid through the AER. The

working of the device can be divided into four main steps. First, the electrocaloric
material is polarized and, due to the electrocaloric effect, the electrocaloric material
heats up. Next, the

fl

fl uid is pumped from the heat source to the heat sink. The fl uid

fl ows through the voids between the electrocaloric plates and the heat generated due

to the electrocaloric effect is transferred from the electrocaloric plates to the

fl uid.

At the same time, part of the uid is already entering the heat sink, where it can

transfer the heat. In the third step, the material is depolarized and therefore it cools
down. Now the fluid flows from the heat sink to the heat source, and in this way the
fl

fl

uid is cooled as part of the process. Simultaneously, a part of the fl uid is already

Fig. 10.5 Schematic presentation of an AER