Magnetocaloric monostable and bistable inductors for electrical energy and refrigeration

摘要

A magnetocaloric inductor circuit operates either as a monostable or bi-stable device. Mirror symmetrical permanent magnets each include first and second poles. A pole shoe is connected to the first pole of each magnet. A control core with control coil is connected between the pole shoes. The opposite poles of the first and second permanent magnets are either connected to each other by a shunt or a second set of pole shoes with their own control core. A monocrystalline metamagnetic disk is connected to an end of each pole shoe or shunt. Yoke cores are connected between the disks for each permanent magnet. An induction coil is engaged around each yoke core. A leakage flux compensation core is also connected between the ends of the yoke core for accommodating leakage flux. By controlling the current through the control coil, the field intensity at the metamagnetic disk can be altered. The metamagnetic disks have a characteristic threshold field intensity above which they become ferromagnetically conductive. Below this threshold, the disks are non-ferromagnetically conductive. Current can thus be controlled through the induction coils of the yoke cores by utilizing a smaller control current through the control cores. Each time the magnetic condition of the disks changes, heat is absorbed from the ambient. In this way the apparatus both operates to convert electrical and magnetic energy and to produce a cooling effect.