A thermoelectric conversion unit includes a plurality of pipes 1 and a thermoelectric conversion element. A first fluid flows through the pipe 1. The thermoelectric conversion element 2 is wound around each of the pipes 1, and generates electric power due to a temperature difference between the first fluid and a second fluid flowing outside the pipe 1. Further, the thermoelectric conversion element 2 has a sheet shape.

A passive thermal oscillator combines a thermoelectric device and a passive analog electrical circuit to produce a time-oscillating temperature difference. The oscillator makes use of a temperature difference imposed across a thermoelectric device to produce a Seebeck voltage to periodically trigger electrical current to pass through a switch. The periodic electrical current causes periodic Peltier cooling producing a time-oscillating temperature difference across the thermoelectric device. There is no requirement for additional external energy input because the thermal energy generates a voltage that is used as the driving force. The operation is purely passive. So long as there is a temperature difference across the thermoelectric device, then the passive thermal oscillator oscillates. The passive thermal oscillator can integrate multiple energy conversion device technologies to operate cooperatively. The cooperation of multiple energy conversion technologies yields a much higher overall system efficiency than just the conversion of thermal energy into electrical energy.

A passive thermal oscillator combines a thermoelectric device and a passive analog electrical circuit to produce a time-oscillating temperature difference. The oscillator makes use of a temperature difference imposed across a thermoelectric device to produce a Seebeck voltage to periodically trigger electrical current to pass through a switch. The periodic electrical current causes periodic Peltier cooling producing a time-oscillating temperature difference across the thermoelectric device. There is no requirement for additional external energy input because the thermal energy generates a voltage that is used as the driving force. The operation is purely passive. So long as there is a temperature difference across the thermoelectric device, then the passive thermal oscillator oscillates. The passive thermal oscillator can integrate multiple energy conversion device technologies to operate cooperatively. The cooperation of multiple energy conversion technologies yields a much higher overall system efficiency than just the conversion of thermal energy into electrical energy.

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.

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 Currie temperature. The magneto-caloric cylinder has a length along an axial direction. The plurality of magneto-caloric stages is distributed along the length of the magneto-caloric cylinder. A plurality of thermal stages also has a length along the axial direction. The length of the plurality of thermal stages is less than the length of the magneto-caloric cylinder. The magneto-caloric cylinder is received within the plurality of thermal stages such that the magneto-caloric cylinder is movable along the axial direction relative to the plurality of thermal stages.

[Problem] To provide a heat exchange device with which efficient electric power generation can be performed while transfer of a heat amount is maintained. [Solution] A heat exchange device comprising a heat exchange section 1 and a magnetic body 2. The heat exchange section 1 includes a first heat transmission interface 3 in contact with a heat source, and a second heat transmission interface 4 in contact with a heat bath having a temperature different from that of the heat source. The magnetic body 2 is interposed between the first heat transmission interface 3 and the second heat transmission interface 4 of the heat exchange section 1, and includes a magnetization component in a direction intersecting a heat flux produced between the first heat transmission interface 3 and the second heat transmission interface 4.

Integrated arrangements of electrical machines and power electronics converters are described. One such arrangement comprises: an electrical machine comprising one or more windings; a power electronics converter arranged to supply current to or receive current from the one or more windings of the electrical machine; a magnetocaloric effect (MCE) material in thermal contact with the power electronics converter; and a heat sink for removing heat from the MCE material. The MCE material is arranged in proximity to the one or more windings of the electrical machine whereby, in use, stray magnetic flux from the windings of the electrical machine passes through the MCE material and activates the MCE material. The repeated application and removal of the stray flux during normal operation of the electrical machine creates cycles of magnetic refrigeration, which removes heat from the power electronics converter.

Integrated arrangements of electrical machines and power electronics converters are described. One such arrangement comprises: an electrical machine comprising one or more windings; a power electronics converter arranged to supply current to or receive current from the one or more windings of the electrical machine; a magnetocaloric effect (MCE) material in thermal contact with the power electronics converter; and a heat sink for removing heat from the MCE material. The MCE material is arranged in proximity to the one or more windings of the electrical machine whereby, in use, stray magnetic flux from the windings of the electrical machine passes through the MCE material and activates the MCE material. The repeated application and removal of the stray flux during normal operation of the electrical machine creates cycles of magnetic refrigeration, which removes heat from the power electronics converter.

A thermoelectric conversion element that has a power generation layer containing an iron-aluminum based magnetic alloy material containing equal to or more than 70 weight percent of iron and aluminum in total. The power generation layer generates an electromotive force, due to an anomalous Nernst effect that develops in the magnetic alloy material in response to a temperature gradient applied thereto, in a direction intersecting both the magnetization direction of the magnetic alloy material and the direction of the applied temperature gradient.

A thermoelectric conversion element that has a power generation layer containing an iron-aluminum based magnetic alloy material containing equal to or more than 70 weight percent of iron and aluminum in total. The power generation layer generates an electromotive force, due to an anomalous Nernst effect that develops in the magnetic alloy material in response to a temperature gradient applied thereto, in a direction intersecting both the magnetization direction of the magnetic alloy material and the direction of the applied temperature gradient.