An outer finned tube includes a tube body, an outer wall of the tube body is provided with outer fins spirally arranged in an extension direction of the tube body; grid fins are arranged between two adjacent spiral parts of the outer fins correspondingly; two ends of each grid fin are connected to the two adjacent spiral parts of the corresponding outer fin respectively; a gap is kept between each grid fin and the outer wall of the tube body; and the plurality of grid fins are spaced in the extension direction of the tube body. An enhancing cavity is formed in an area defined by the outer wall of the tube body, inner walls of the grid fins and the outer fins in an encircling way, which can form a larger degree of superheat, provides a nucleation point for a boiling/condensation process and improves a heat exchange performance.

In one embodiment, a plate for an evaporative cooler is disclosed. The plate may comprise a wicking material with an exposed surface and a sealed surface opposite the exposed surface. An impermeable barrier may be coupled to the sealed surface. One or more masks may line a portion of the exposed surface, wherein the masks may comprise an impermeable material. In some embodiments, the mask may be a strip of impermeable material and may be coupled to a flat area of the top surface. In further embodiments, the one or more masks may align with a liquid wick path of the wicking material. In further embodiments, the one or more masks may line the edge of perforations that pass at least partially through the plate.

Fins are formed monolithically from the material of a tube body. The fins extend from the tube body outer surface, and include a fin base and a fin top. Wings extending from a fin side surface between the fin base and fin top can produce upper and lower channels between adjacent fins. Depressions can be formed in the fin top with platforms below the depressions. The tube can also include helical ridges on an inner surface of the tube. The tubes are used for heat transfer, and can be included in shell and tube heat exchangers.

A method for fabricating a super-hydrophobic surface having excellent surface strength and an evaporator having the super-hydrophobic surface fabricated by the method are provided. The method includes preparing a metal base material, anodizing the metal base material to form a ceramic layer having a complex structure of a microstructure and nano-fiber structures on a surface of the metal base material, and applying a hydrophobic polymer material on the complex structure to form a polymer layer having the same surface shape as the complex structure.

Omniphilic and superomniphilic surfaces for simultaneous vapor condensation and airborne liquid droplet collection are provided. Also provided are methods for using the surfaces to condense liquid vapor and/or capture airborne liquid droplets, such as water droplets found in mist and fog. The surfaces provide enhanced capture and transport efficiency based on preferential capillary condensation on high surface energy surfaces, thin film dynamics, and force convection.

Sub-micrometer to centimeter scale rough symmetric and asymmetric structures are incorporated onto objects (e.g. tubes and fms). Asymmetric and hierarchically structured slippery structures can be applied to a broad range of materials and shapes of surfaces for manufacturing heat exchangers, dew harvesting devices, desalination devices, de-humidifiers, distillation towers, evaporation coils, anti-cavitation coatings, etc.

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.

Capillary trap-vapor pumps, systems, methods of heat management, and the like, are disclosed.

Vapor flow-diverting devices that re-direct upwardly flowing vapor, for example, in a downward direction across condenser tubes disposed in the upper or top section of a vapor-liquid contacting apparatus, are described. These devices are particularly beneficial in tubular condensers within distillation columns and may be used in combination with other associated equipment (e.g., a deflector plate and divider plate) as well as in combination with the tube surface enhancements to improve the heat transfer coefficient.

A data center cooling system includes a modular heat sink and a working fluid. The modular heat sink includes an evaporator configured to thermally contact a heat-generating electronic device to receive heat from the data center heat-generating electronic device; a condenser coupled to the evaporator and configured to transfer the heat from the heat-generating electronic device into a cooling fluid; and a plurality of transport tubes that fluidly couple the evaporator and the condenser, at least one of the plurality of transport tubes including an open end positioned in the evaporator and a closed end positioned in the condenser. The working fluid vaporizes in the evaporator based on receipt of the heat from the heat-generating electronic device, and circulates, in vapor phase, from the evaporator to the condenser in the transport member, and circulates, in liquid phase, from the condenser to the evaporator.