An exothermal vaporizer is provided. The exothermal vaporizer has a body including an air and vapor mix port, a fluid inlet port in communication with a reservoir, an air inlet, and a wicking material. A mouthpiece is coupled to the body and a temperature indicating cap is removable from the body. A counter flow design exothermal vaporizer, a modular exothermal vaporizer, and a vaporizer which is adjustable to modulate and/or regulate the flow ratio of dilution air and produced vapor are also disclosed.

A heat transfer tube includes a twisted baffle arranged in an inner wall of the tube. The twisted baffle extends spirally along an axial direction of the heat transfer tube. The twisted baffle is provided with a non-through gap extending along an axial direction of the heat transfer tube from an end to the other end of the twisted baffle. A cracking furnace uses the heat transfer tube. The heat transfer tube and cracking furnace have good heat transfer effects and small pressure loss.

A two-phase immersion-cooling heat-dissipation structure having skived fins with high surface roughness includes an immersion-cooling substrate and a plurality of skived fins. The immersion-cooling substrate has a top surface and a bottom surface that are opposite to each other, the bottom surface is used for contacting a heat source immersed in a two-phase coolant, the top surface is connected with the plurality of skived fins, a center line average roughness Ra of a surface of the plurality of skived fins is greater than 10 ?m, and a ten point average roughness Rz of the surface of the plurality of skived fins is greater than 20 ?m, such that a ratio between a surface area of the plurality of skived fins in contact with the two-phase coolant and a volume of the plurality of skived fins is greater than 400.

A thermal retention apparatus includes a tank and a phase change thermal energy storage unit contained within the tank that, in turn, includes a phase change material and a heat exchanger assembly. The heat exchanger assembly includes a phase change material (PCM) charging circuit for charging the phase change material, and a PCM discharging circuit for discharging the phase change material. The heat exchanger assembly includes a plurality of heat exchanger modules immersed within the phase change material, and the PCM charging circuit includes a fluid flow arrangement of the heat exchanger modules that is in parallel. The PCM discharging circuit includes a fluid flow arrangement of the heat exchanger modules that is in series.

A thermal retention apparatus includes a tank and a phase change thermal energy storage unit contained within the tank that, in turn, includes a phase change material and a heat exchanger assembly. The heat exchanger assembly includes a phase change material (PCM) charging circuit for charging the phase change material, and a PCM discharging circuit for discharging the phase change material. The heat exchanger assembly includes a plurality of heat exchanger modules immersed within the phase change material, and the PCM charging circuit includes a fluid flow arrangement of the heat exchanger modules that is in parallel. The PCM discharging circuit includes a fluid flow arrangement of the heat exchanger modules that is in series.

A thermal retention apparatus includes a tank and a phase change thermal energy storage unit contained within the tank that, in turn, includes a phase change material and a heat exchanger assembly. The heat exchanger assembly includes a phase change material (PCM) charging circuit for charging the phase change material, and a PCM discharging circuit for discharging the phase change material. The heat exchanger assembly includes a plurality of heat exchanger modules immersed within the phase change material, and the PCM charging circuit includes a fluid flow arrangement of the heat exchanger modules that is in parallel. The PCM discharging circuit includes a fluid flow arrangement of the heat exchanger modules that is in series.

A cold plate includes a main body in contact with a heat source. The main body has: an inflow hole through which a refrigerant flows in; an outflow hole through which the refrigerant flows out; and an internal space communicating with the inflow hole and the outflow hole and through which the refrigerant flows, and includes: a first heat exchange layer in the internal space; and a second heat exchange layer in the internal space. The first heat exchange layer and the second heat exchange layer are laminated in a thickness direction of the first heat exchange layer and of the second heat exchange layer.

A heat exchanger includes a metal tube and a composite polymer fin in thermal contact with the metal tube. The fin is formed of a polymer and a thermally conductive filler such that the fin has a thermal conductivity greater than or equal to 0.5 Watts per meter Kelvin.

A heat exchanger includes front and back walls forming a flue gas space such that a fluid flowing through a channel formed in the front and back walls can exchange heat with flue gas in the flue gas space, in use. The front wall includes a lower portion extending along the back wall, and an upper portion extending upwardly from an upper end of the lower portion and outwardly away from the back wall to form a combustion space of a flammable gas between the upper portion and the back wall. A length of the upper portion along a longitudinal direction thereof is longer than a length of the lower portion along a longitudinal direction thereof.

A heat exchanger includes a body defining a flow channel, and a pin extending across the flow channel, the pin including an at least partially non-cylindrical shape. The pin can be a double helix pin including two spiral branches defining a double helix shape. The two branches can include a uniform winding radius. The two branches include a non-uniform winding radius. The non-uniform winding radius can include a base radius and a midpoint radius, wherein the midpoint radius is smaller than the base radius. The two branches can be joined together by one or more cross-members.