Certain embodiments of the invention relate to a spacer element for a heat exchanger of the brazed plate and fin type, intended to be fitted between a first plate and a second plate of the exchanger, said spacer element comprising at least a first assembly portion configured to be assembled with the first plate and comprising a first pair of opposite surfaces, one of the surfaces of the first pair being oriented toward the first plate and the other of the surfaces of the first pair being oriented toward the second plate when the spacer element is in the fitted state, several fins or corrugation legs extending from said first assembly portion so as to delimit, when the spacer element is in the fitted state, a plurality of channels for the flow of a first fluid, and at least one surface texturing in the form of a porous structure or of reliefs formed on the surface of the spacer element, at least one fin or corrugation leg exhibiting said surface texturing. According to the invention, the first assembly portion is free of surface texturing on the surface of the first pair which, in the fitted state, is oriented toward the first plate.

A heat exchanger having a heat transfer surface provided with hyperthermophilic bacteria. The hyperthermophilic bacteria can be from the genera Archaea. The hyperthermophilic bacteria can further be from the genus Sulfolobus, and the hyperthermophilic bacteria can further be from the species Sulfolobus solfataricus. The heat exchanger can be adapted to pool-boiling heat transfer.

Coatings for enhancing performance of materials surfaces, methods of producing the coating and coated substrates, and coated condensers are disclosed herein. More particularly, exemplary embodiments provide chemical coating materials useful for coating condenser components.

The present invention relates to a method of enhancing heat transfer of metallic surfaces by (1) fabricating hierarchical micro-nanostructured surfaces using etching processes, and (2) fabricating hydrophobic and hydrophilic regions, using a printing or a coating technique, followed by etching. The said method enhances the density of condensation sites over a metallic surface and additionally facilitates the departure of condensed droplets from the surface. Such a surface also enhances the sensible heat transfer characteristics, and improves the coefficient of performance (COP) of refrigeration systems for applications like atmospheric water generators, dehumidifiers, air conditioners, etc.

Engineered surfaces, such as surfaces having nano- and/or micro-scale features, may provide an enhanced flow boiling Critical Heat Flux (CHF) at ambient or higher pressures, which may enhance cooling. Enhancing flow boiling CHF may be desirable for nuclear reactors, where heat is generated by a heater such as a nuclear reactor core. Enhanced flow boiling CHF may provide larger safety margins and/or better economics of nuclear reactors, for example, because reactor power rating may be increased as cooling is enhanced.

Flow paths and boundary layer restart features are provided. For example, a flow path comprises a flow path wall defining an inner flow path surface and an asymmetric notch defined in the flow path wall. The asymmetric notch comprises a first surface and a second surface and is asymmetric about a first line extending through an intersection of the first and second surfaces. Further, a flow boundary layer restart feature comprises a first surface extending inward with respect to a flow path surface of a flow path and a second surface extending inward with respect to the flow path surface. The second surface is asymmetric with respect to the first surface such that the first and second surfaces define an asymmetric notch. Additionally, a flow path wall may comprise an asymmetric notch that includes a flow expansion angle and a flow contraction angle that are unequal.

A heat exchanger includes a heat transfer tube. The heat transfer tube includes a first tube portion, and second tube portions connected in parallel with each other with respect to the first tube portion. The first tube portion has a first inner circumferential surface, and first grooves recessed relative to the first inner circumferential surface and arranged side by side in a circumferential direction of the heat transfer tube. The second tube portions each have a second inner circumferential surface, and a plurality of second grooves recessed relative to the second inner circumferential surface and arranged side by side in the circumferential direction. The first grooves are less than the second grooves in one or more of a number of grooves, a depth of each groove, and a lead angle of each groove.

A cycling heat dissipation module suited for dissipating heat generated from a heat source is provided. The cycling heat dissipation module includes an evaporator, a condenser, and a micro/nano-structure. The evaporator is thermal contacted with the heat source to absorb heat generated therefrom. The condenser is connected to the evaporator to form a loop, and a working fluid is filled in the loop. The working fluid in liquid state is transformed to vapor state by absorbing heat in the evaporator, and the working fluid in vapor state is transformed to liquid state by dissipating heat in the condenser. The micro/nano-structure is disposed in the condenser to destroy a boundary layer of the working fluid while passing through the condenser.

Provided is a heat exchanger capable of ensuring both heat exchange performance and reliability against corrosion. The heat exchanger includes a plurality of fins each having a flat plate shape, openings provided in each of the plurality of fins, and cylindrical parts arranged on outer peripheries of the openings, each having an inner diameter larger than an outer diameter of each of the openings. The plurality of fins are stacked on one another with the cylindrical parts interposed between the plurality of fins. The openings and the cylindrical parts are configured to form a liquid passage pipe, and the openings protrude further inside than are the cylindrical parts.

A heat transfer tube including an inner surface including a plurality of grooves. The plurality of grooves includes at least primary grooves and secondary grooves, wherein the primary grooves extend axially along a length of the tube, and the secondary grooves intersect the primary grooves.