A system including: an active magnetic regenerative refrigerator apparatus that includes a high magnetic field section in which a hydrogen heat transfer fluid can flow from a cold side to a hot side through at least one magnetized bed of at least one magnetic refrigerant, and a low magnetic field or demagnetized section in which the hydrogen heat transfer fluid can flow from a hot side to a cold side through the demagnetized bed; a first conduit fluidly coupled between the cold side of the low magnetic field or demagnetized section and the cold side of the high magnetic field section; and a second conduit fluid coupled to the first conduit, an expander and at least one liquefied hydrogen storage module.

This invention relates to magnetocaloric materials comprising ternary alloys useful for magnetic refrigeration applications. The disclosed ternary alloys are Cerium, Neodymium, and/or Gadolinium based compositions that are fairly inexpensive, and in some cases exhibit only 2.sup.nd order magnetic phase transitions near their curie temperature, thus there are no thermal and structural hysteresis losses. This makes these compositions attractive candidates for use in magnetic refrigeration applications. The performance of the disclosed materials is similar or better to many of the known expensive rare-earth based magnetocaloric materials.

A magnetic refrigeration system includes a plurality of heat transporters, a magnetic field application unit, and a drive mechanism. Each heat transporter is switched between a heat generating and heat absorbing states in response to magnetic field application and cancellation of the magnetic field application. The heat transporters are arranged between low and high temperature side heat exchangers. The magnetic field application unit applies a magnetic field to the heat transporters so that a heat transporter to which a magnetic field is applied and a heat transporter to which a magnetic field is not applied are alternately arranged. The drive mechanism periodically moves at least the plurality of heat transporters so that a heat transporter to which the magnetic field is applied is periodically switched and so that a state of thermal contact is periodically switched. An end portion of at least one heat transporter is a heat transfer accelerator.

A magneto-caloric thermal diode assembly includes a magneto-caloric cylinder. A plurality of thermal stages is stacked along an axial direction between a cold side and a hot side. A hot side heat exchanger is positioned at the hot side of the plurality of thermal stages. The hot side heat exchanger includes a plurality of pins or plates for rejecting heat to ambient air about the hot side heat exchanger. A cold side heat exchanger is positioned at the cold side of the plurality of thermal stages. A heat transfer fluid is flowable through the cold side heat exchanger. The cold side heat exchanger is configured such that the heat transfer fluid rejects heat to the cold side of the plurality of thermal stages when the heat transfer fluid flows through the cold side heat exchanger.

A magnetic refrigeration apparatus includes one or more beds of magnetocaloric material arranged along a circumferential direction. The apparatus also includes a heat transfer fluid, one or more hot side heat exchangers (HHEX), one or more pumps or fluid displacement devices configured to move the heat transfer fluid, and a magnetic-field source. The magnetic-field source generates magnetic flux oriented substantially in a radial direction through the beds. The field source advantageously includes one or more pole pieces, one or more axial-end magnets, and one or more axial-end flux return pieces. Additionally, one or more circumferential flux returns, one or more gap flux return pieces, one or more side magnets, and one or more side flux return pieces can be added to increase system performance and reduce cost.

A magnetic field application device includes a magnetic field application unit provided with a magnetic working substance, a permanent magnet, a yoke and a coil. The magnetic field application unit applies a magnetic field to the magnetic working substance. The yoke forms at least two closed magnetic circuits, each being a closed circuit that magnetically connects both ends in a magnetization direction of the permanent magnet. The coil is capable of changing an intensity of the magnetic field applied to the magnetic working substance. The coil is provided in at least one of the closed magnetic circuits. The magnetic field application unit is disposed in at least one of the closed magnetic circuits. A magnetic flux of the permanent magnet is branched to flow through two or more of the closed magnetic circuits including the closed magnetic circuit provided with the magnetic field application unit when the coil is non-energized.

A magnetic refrigeration apparatus includes a main channel, a magnetic refrigerator, a fluid transfer mechanism connected to the main channel, and at least one control valve. A heating medium flows through the main channel. The magnetic refrigerator includes a magnetic working substance, a casing having a channel connected to the main channel, and a magnetic field modulator that applies a magnetic field variation to the magnetic working substance. The fluid transfer mechanism alternately performs a first operation of transferring the heating medium in the main channel in a first direction, and a second operation of transferring the heating medium in a second direction opposite to the first direction. The main channel includes at least one branch channel branching from a portion of the main channel between the magnetic refrigerator and the fluid transfer mechanism. The at least one control valve is connected to the at least one branch channel.

A heat pump, as provided herein, may include a hot side heat exchanger, a cold side heat exchanger, a pump, and a caloric heat pump. The caloric heat pump may include a regenerator housing, a plurality of stages, and a field generator. The regenerator housing may extend along an axial direction between a first end portion of the regenerator housing and a second end portion of the regenerator housing. The plurality of stages may be arranged sequentially along the axial direction from the first end portion to the second end portion. The plurality of stages may be arranged so that caloric temperature peaks of the plurality of stages increase along the axial direction according to a predetermined, non-linear curve. The field generator may be positioned adjacent to the plurality of stages to subject the plurality of stages to a variable field generated by the field generator.

A magneto-caloric thermal diode assembly includes a first magneto-caloric cylinder and a second magneto-caloric cylinder. The second magneto-caloric cylinder and a second plurality of thermal stages are nested concentrically within the first magneto-caloric cylinder and a first plurality of thermal stages. A plurality of magnets is distributed along a circumferential direction within a non-magnetic ring in each thermal stage of the first and second pluralities of thermal stages. Each thermal stage of the first and second pluralities of thermal stages has a first half and a second half. A polarity of the magnets of the plurality of magnets within the first half is oriented opposite a polarity of the magnets of the plurality of magnets within the second half along the radial direction in each thermal stage of the first and second pluralities of thermal stages.

A magnetic refrigeration module includes a housing, low and high temperature inflow paths, low and high temperature outflow paths, and first and second intermediate flow paths. The housing houses a magnetic working substance, and forms a flow path. The low and high temperature inflow paths carry heating medium into first and second ends of the flow path. First and second spaces are formed between the first and second ends and the low and high temperature inflow paths. The low and high temperature outflow paths receive the heating medium from the first and second ends of the flow path. The first and second intermediate flow paths communicate with the low and high temperature inflow paths and the first and second spaces. The first and second intermediate flow paths expand heating medium flow from the low and high temperature inflow paths to the first and second spaces.