A Preliminary Numerical Study of Magnetic Refrigeration.

Kurzfassung

The basic computational model is a thermodynamic cycle simulation starting with given temperature distribution in the magnetic substance (refrigerant). Temperature changes and magnetic forces are calculated for discrete material segments at a number of time intervals over a complete operation cycle. The computation of the change in magnetic entropy is based on the molecular field theory and the calculation of the flow and heat transfer irreversibilities is based on the heat transfer properties of packed beds. In the case of an active magnetic refrigerator the temperature distribution in the refrigerant is determined through numerical solution of the differential equations which describe the heat transfer between the refrigerant and the heat transfer fluid. The simulation illustrates the cool-down procedure and the time-dependent temperature profiles in the active magnetic refrigerator until a steady cyclic state is established.