A magneto-caloric thermal diode assembly includes a magneto-caloric regenerator with a plurality of magneto-caloric stages. Each of the plurality of magneto-caloric stages has a respective Curie temperature. Each of the plurality of magneto-caloric stages also has a stack of magneto-caloric material blocks and metal foil layers distributed sequentially along an axial direction in the order of magneto-caloric material block then metal foil layer.

In various aspects, methods of making perovskite manganese oxide particles are provided as well as perovskite manganese oxide particles made therefrom. The perovskite manganese oxide particles exhibit a strong magnetocaloric effect, making them well suited for applications in power generation and magnetic refrigeration, especially at or near room temperature. The methods can include forming an aqueous mixture of (i) a low-molecular-weight polymeric polyalcohol gel precursor, (ii) a stoichiometric amount of metal salts or hydrates thereof, wherein the metal salts or hydrates thereof comprise at least a Manganese (Mn), and (iii) a polybasic carboxylic acid; polymerizing the aqueous mixture to form a gel containing perovskite manganese oxide nanoparticles entrapped therein; and calcining the gel to remove at least a portion of organic material in the gel and form the perovskite manganese oxide particles. Method and systems are also provided for power generation and magnetic refrigeration using the perovskite manganese oxide particles.

A cryostat system is kept at a cryogenic operating temperature without providing or supplying cryogenic fluids by a cryocooler. The cryostat system includes a superconducting magnet arrangement and a heat sink apparatus to prolong the time before the superconducting magnet arrangement quenches/returns to the normally conducting state if active cooling fails. The heat sink apparatus includes magnetocaloric material and is thermally connected to the superconducting magnet arrangement and/or to parts of the cryostat system through which ambient heat can flow to the superconducting magnet arrangement. In this way, the cryostat system can be operated in a truly cryogen-free manner while maintaining a sufficiently long time to quench in the event of potential operational malfunctions.

A mechano-caloric heat pump includes a mechano-caloric stage, an elongated lever arm pivotable about a point, and a motor is operable to rotate a cam. The elongated lever arm is coupled to the mechano-caloric stage proximate a first end portion of the elongated lever arm and to the cam proximate a second end portion of the elongated lever arm such that the motor is operable to stress the mechano-caloric stage via pivoting of the elongated lever arm as the cam rotates.

A caloric regenerator system includes a flow body that defines a plurality of cold side channels, a plurality of hot side channels and a central passage. A port body is received within the central passage of the flow body such that the flow body is rotatable relative to the port body. The port body defines a hot side port and a cold side port. A width of the hot side port is less than a width of the cold side port. An annular caloric regenerator is in flow communication with the plurality of cold side channels and the plurality of hot side channels such that a heat transfer fluid is flowable into the annular caloric regenerator through the plurality of cold side channels and out of the annular caloric regenerator through the plurality of hot side channels.

A method for operating a caloric heat pump system includes changing a cycle frequency at which a field of a field generator is applied to caloric material in the caloric heat pump system. The method also includes adjusting a speed of a hot side fan in response to the cycle frequency change and adjusting a speed of a cold side fan in response to the cycle frequency change. A respective one of three separate control loops changes the cycle frequency, adjusts the speed of the hot side fan, and adjusts the speed of the cold side fan.

A method of realizing a ferroic response is provided. The method includes applying a positive or negative conjugate field, which is of a first polarity, to a ferroic material to obtain a substantially minimized entropy of the ferroic material (301) and applying a slightly negative or a slightly positive conjugate field, which is of a second polarity opposite the first polarity, to the ferroic material to obtain a substantially maximized entropy of the ferroic material (302).

Magnetic cooling device comprising a magnetocaloric element, the magnetocaloric element comprising a paramagnetic garnet ceramic.

The density of the paramagnetic garnet ceramic is preferably greater than or equal to 90%.

The garnet ceramic is preferably a gadolinium gallium garnet ceramic or an ytterbium gallium garnet ceramic.

A magneto-caloric thermal diode assembly includes a magneto-caloric cylinder with a plurality of magneto-caloric stages. Each of the plurality of magneto-caloric stages has a respective Curie temperature. The magneto-caloric cylinder also includes a plurality of insulation blocks and a plurality of pins. The plurality of magneto-caloric stages and the plurality of insulation blocks are distributed sequentially along an axial direction in the order of magneto-caloric stage then insulation block. One or more the plurality of pins extends along the axial direction between each magneto-caloric stage and a respective insulation block within the magneto-caloric cylinder.

The present invention describes the design and fabrication of Multi-Material-Blades used as active regenerative regenerators in active regenerative magneto-caloric or electro-caloric engines. The blades consist of a plurality of elements (2) that divide the blade body along its length. Each element (2) is made of a different magneto-caloric or electro-caloric material selected appropriately, and a plurality of dedicated channels (3) penetrates the blade body (1) and extends along the length of the blade. The dedicated channels (3) can be provided with fluid mixing structures, porous layers or hydrophobic coatings to reduce the HE loss in an active regenerative engine. The Multi-Material-Blades are obtainable by ink jet printing techniques to reduce costs. The Multi-Material-Blades can further have a curved shape to form an involute blade body (1). All measures can improve the performance of active regenerative magneto-caloric or electro-caloric engines, and lay the basis for commercial solutions.