Carl B. Zimm

TL;DR: In this article, a reciprocating magnetic refrigerator that uses water as a heat transfer fluid has been demonstrated to achieve cooling powers exceeding 500 watts at coefficients of performance of 6 or more.

TL;DR: A rotating magnetic refrigeration apparatus has magnetic regenerator beds arranged in a ring (21) that is mounted for rotation about a central axis, such that each bed moves into and out of a magnetic field provided by a magnet.

Abstract: A magnetic refrigeration apparatus (10) has an annular container (11) including a plurality of magnetic regenerator compartments (13) containing magnetocaloric material (12), and a magnet (40) mounted for rotation around the annular container (11), whereby the motion of the magnet (40) produces a variation of magnetic field strength in the magnetic regenerator compartments, which in term leads to a variation in temperature of the magnetocaloric material (12) in the magnetic regenerator compartments (13). Heat transfer fluid (17) is propelled by a pump (60), and directed to and from the regenerator compartments and hot and cold heat exchangers by valves. Each valve includes an axial port and a plurality of radial ports.

TL;DR: In this article, an active magnetic regenerator with a regenerator bed of material exhibiting the magnetocaloric effect is described, where the excess heat transfer fluid is diverted back to the hot side of the bed.