Heat transfer devices and systems are provided for the rapid cooling of pulsed high-powered, high-flux devices using flash boiling. Such devices comprise at least two fluidly connected chambers and a heat exchanger in thermal communication with a heat source. A flash boiling event is actively triggered at a location close to the heat source by rapid depressurization of the chamber containing a multi-phase coolant. This boiling process allows for high heat transfer rates from the heat source into the chambers due to the latent heat of vaporization, which results in the rapid cooling of the heat source. A porous medium may also be positioned within a chamber of the device to enhance boiling nucleation and extended surface heat transfer. Methods of rapidly cooling pulsed heat sources are also provided using the devices and systems hereof.

Heat transfer devices and systems are provided for the rapid cooling of pulsed high-powered, high-flux devices using flash boiling. Such devices comprise at least two fluidly connected chambers and a heat exchanger in thermal communication with a heat source. A flash boiling event is actively triggered at a location close to the heat source by rapid depressurization of the chamber containing a multi-phase coolant. This boiling process allows for high heat transfer rates from the heat source into the chambers due to the latent heat of vaporization, which results in the rapid cooling of the heat source. A porous medium may also be positioned within a chamber of the device to enhance boiling nucleation and extended surface heat transfer. Methods of rapidly cooling pulsed heat sources are also provided using the devices and systems hereof.

A heat storage and transfer system that incorporates a primary heat storage chamber or body that is thermally insulated and which in use contains a heat storing liquid or solid; and a secondary chamber external to and adjacent the primary heat storage chamber or body through which a liquid, heat transfer fluid or steam to be heated is passed in use, the system having a heat transfer mechanism to selectively transfer thermal energy from the heat storing liquid or solid of the primary heating chamber or body to the liquid or steam to be heated in the secondary chamber. The heat transfer mechanism has a drive that moves the secondary chamber from a first position that is thermally separated from the primary chamber into a second position that is substantially inserted in a void or recess within the primary chamber or body.

Embodiments of the disclosure relate generally to thermal control and management in hardware devices. A thermal control system includes a thermal node, a thermal bridge, and a thermal controller. The thermal node is configured to receive heat generated in a device. The thermal controller is configured to in response to an environment temperature of the thermal controller being greater than a first threshold temperature, cause heat transfer from the thermal node to a first heat sink and prevent heat transfer from the thermal node to a second heat sink. The thermal controller is also configured to, in response to the environment temperature of the thermal controller being greater than a second threshold temperature, cause heat transfer from the thermal node to the second heat sink and prevent heat transfer from the thermal node to the first heat sink.

Embodiments of the disclosure relate generally to thermal control and management in hardware devices. A thermal control system includes a thermal node, a thermal bridge, and a thermal controller. The thermal node is configured to receive heat generated in a device. The thermal controller is configured to in response to an environment temperature of the thermal controller being greater than a first threshold temperature, cause heat transfer from the thermal node to a first heat sink and prevent heat transfer from the thermal node to a second heat sink. The thermal controller is also configured to, in response to the environment temperature of the thermal controller being greater than a second threshold temperature, cause heat transfer from the thermal node to the second heat sink and prevent heat transfer from the thermal node to the first heat sink.

A composite heat dissipation device includes an electromagnetic radiation dissipation pile including a polar dielectric material assembly including a plurality of polar dielectric material units. The polar dielectric material assembly is configured to interact with solar radiation. Surfaces of the polar dielectric material units each are configured to interact with the solar radiation to generate scattering of light. The polar dielectric material units each include an optical phonon configured to interact with thermal radiation to increase strength of the thermal radiation.

A heat pipe comprises a first pipe and at least a second pipe. The first pipe includes an evaporator, a heat insulator and a condenser communicating with each other to define a hollow chamber. The second pipe disposed in the hollow chamber includes an accommodating space and a first capillary structure disposed in one end of the accommodating space closer to the evaporator. At least one side of an outer pipe wall of the second pipe directly abuts an inner pipe wall of the first pipe. The first pipe further includes a second capillary structure disposed in the hollow chamber closer to the evaporator and extended to an outside of the second pipe and occupies at least 2/3 volume of the evaporator. A first part of the first capillary structure and the second capillary structure are connected to each other by winding so as to enhance transportation therebetween.

A heat pipe comprises a first pipe and at least a second pipe. The first pipe includes an evaporator, a heat insulator and a condenser communicating with each other to define a hollow chamber. The second pipe disposed in the hollow chamber includes an accommodating space and a first capillary structure disposed in one end of the accommodating space closer to the evaporator. At least one side of an outer pipe wall of the second pipe directly abuts an inner pipe wall of the first pipe. The first pipe further includes a second capillary structure disposed in the hollow chamber closer to the evaporator and extended to an outside of the second pipe and occupies at least 2/3 volume of the evaporator. A first part of the first capillary structure and the second capillary structure are connected to each other by winding so as to enhance transportation therebetween.

A heat exchanger includes: a low temperature side channel through which low temperature liquid helium flows; a high temperature side channel through which high temperature liquid helium flows; and a thermal conduction unit that conducts heat from the high temperature side channel to the low temperature side channel. The thermal conduction unit has a partition member that separates the high temperature side channel and the low temperature side channel from each other and a thermal resistance reduction unit that reduces the thermal resistance between the partition member and the liquid helium. The thermal resistance reduction unit has a porous body having nano-size pores and fine metal particles having higher thermal conductivity than that of the porous body.

An energy conversion apparatus may include an engine assembly, such as a monolithic engine assembly. The engine assembly may include a first monolithic body segment and a plurality of second monolithic body segments directly coupled or directly couplable to the first monolithic body segment. The first monolithic body segment may define a combustion chamber and a recirculation pathway in fluid communication with the combustion chamber. The recirculation pathway may be configured to recirculate combustion gas through the combustion chamber. The plurality of second monolithic body segments may respectively define at least a portion of a piston chamber and a plurality of working-fluid pathways fluidly communicating with the piston chamber.