The technology used by MagnoTherm Solutions is based on the magneto-caloric effect (MCE), which manifests itself in a temperature change of a magnetocaloric material (MCM) when a magnetic field is applied. The operation of a magnetic refrigeration cycle is based on the cyclic application of the MCE.
The figure shows the scheme of such a cooling cycle. In the initial state, the magnetic moments are randomly oriented (Î”T=0). When the material is adiabatically magnetized, the magnetic moments align with the external magnetic field lines. Because of the MCE, the temperature of the material increases (Î”T>0) by an increase of the materialâ€™s thermal entropy compensating for the materialâ€™s decreased magnetic entropy. By expelling the excess heat in the applied magnetic field, the material is cooled to its initial temperature (Î”T=0). The subsequent adiabatic demagnetization of the material is accompanied by a decrease of the temperature, again because of the MCE (Î”T<0). Thereby, the material is able to absorb heat from the cooling cabinet.
With cyclic application, a cooling process can be realized similar to the gas compression cycle.
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