Reciprocating active magnetic regenerator refrigeration apparatus

Abstract

An active magnetic regenerator refrigeration apparatus includes one or more reciprocating regenerator beds and a heat transfer fluid distribution valve that is activated as the bed is moved between a position in which it is in the magnetic field of a magnet to a position in which it is outside the magnetic field of the magnet. The distribution valve has a first valve member and a moving second valve member slidingly engaged to each other, each of which has ports by which heat transfer fluid may be provided to and received from the valve member. The bed is mounted to the moving second valve member so that heat transfer fluid is conveyed to and through the valve in a single direction into the regenerator bed. The material of the bed exhibits the magnetocaloric effect and the temperature of the bed rises when it enters the magnetic field of the magnet and decreases when it exits the magnetic field, providing a refrigeration cycle. The direction of fluid flow to, from and through the distribution valve remains the same in both positions of the bed or beds, with the distribution valve serving to switch the direction of the fluid flow through the bed in the unmagnetized and magnetized positions of the bed, so that there is essentially no dead volume of heat transfer fluid.