Design concepts for a continuously rotating active magnetic regenerator

Design considerations for a prototype magnetic refrigeration device with a continuously rotating AMR are presented. Building the active magnetic regenerator (AMR) from stacks of elongated plates of the perovskite oxide material La0.67Ca0.33−xSrxMn1.05O3, gives both a low pressure drop and allows grading of the Curie temperature along the plates. This may be accomplished by a novel technique where a compositionally-graded material is tape cast in one piece. The magnet assembly is based on a novel design strategy, to create alternating high- and low magnetic field regions within a magnet assembly. Focus is on maximising the magnetic field in the high field regions but also, importantly, minimising the flux in the low field regions. The design is iteratively optimised through 3D finite element magnetostatic modelling.