A tube sheet assembly for a heat exchanger is disclosed. The tube sheet assembly includes a plastic sheet having multiple tube-retention holes defined therein and a metal plate having multiple holes defined therein, each hole being substantially coaxial with a corresponding tube-retention hole of the plastic sheet. The metal plate is connected to the plastic sheet. The metal plate can be fabricated of, for example, steel or other metals. The plastic sheet can be fabricated of, for example, nylon, ultra-high-molecular-weight polyethylene, or polytetrafluoroethylene. Tubes can be disposed in the tube-retention holes of the plastic sheet and the holes of the metal plate. In an example, the tube-retention holes of the plastic sheet have a smaller diameter than the holes of the metal plate and the tubes contact the plastic sheet without contacting the metal plate.

A fluid coil includes a tube bundle having a series of straight tubing runs and a series of return bends extending between and fluidically connecting ones of the straight tubing runs, an expansion header fluidically connected to at least some of the return bends and a polymeric material disposed in the expansion header. The polymeric material has an initial shape and is compressible to repeatedly expand and contract between a first volume in which water is present in the tube bundle and a second volume in which the water undergoes a phase change. Contraction of the polymeric material absorbs an increase in volume as the water undergoes the phase change to prevent stressing and rupture of the tube bundle and upon an opposite phase change, the polymeric material returns to its initial shape. The polymeric material can be a pressurizable bladder. A system and method to prevent the rupture of a tube bundle in a fluid coil are also disclosed.

Passive radiative cooling structures and apparatus manufactured with such cooling structures conserve energy needs. A flexible film transparent to visible light incorporates particles at a volume percentage larger than 25% so as to absorb and emit infrared radiation at wavelengths where Earth's atmosphere is transparent. Another film transparent to visible light is thin and flexible and configured to absorb and emit infrared radiation at wavelengths where Earth's atmosphere is transparent, wherein etchings or depositions are present on one or both surfaces. A high efficiency cooling structure has an emissive layer sandwiched between a waveguide layer and a thermal conductive layer. A solar cell panel is covered by a transparent passive radiative cooling film. A container housing an active cooling unit incorporates passive radiative cooling structures on one or more exterior surfaces.

A heat-transfer device and methods for forming the heat-transfer device are disclosed. The method includes forming a first green structure using digital light processing, the first green structure including a different porosity in at least two sections. The method also includes exposing the first green structure to heat to remove resin used during the digital light processing from the first green structure. The method further includes sintering the first green structure to form at least a portion of the heat-transfer device.

A heat and mass transfer component comprises a lubricant-impregnated surface including hydrophobic surface features, which comprise nanostructured surface protrusions having a hydrophobic species attached thereto. The hydrophobic surface features are impregnated with a fluorinated lubricant having a viscosity in a range from about 400 mPa.Math.s to about 6000 mPa.Math.s. A method of fabricating a lubricant-impregnated surface on a heat and mass transfer component comprises: cleaning a thermally conductive substrate to form a cleaned substrate; exposing the cleaned substrate to a hot water or hot alkaline solution to form a thermally conductive substrate having nanostructured surface protrusions; depositing a hydrophobic species on the nanostructured surface protrusions to form hydrophobic surface features; and coating the hydrophobic surface features with a fluorinated lubricant having a viscosity in a range from 400 mPa.Math.s to 6000 mPa.Math.s. The heat and mass transfer component may exhibit a substantial increase in heat transfer coefficient during hydrocarbon condensation.

A wettable media pad comprises an inlet side and an outlet side and a porous structure made from a non-woven material, comprising a plurality channels having a hexagonal cross-section defined by six walls, the channels running from the inlet side to the outlet side, wherein the wettable media pad is configured to direct fluid from a top surface of the media pad to a bottom surface of the media pad along at least one of the walls of the channels, wherein the wettable media pad is configured to exchange heat and mass between a fluid positioned on or in a wall of the channels and a gas flowing through the channels as the gas flows from the inlet side to the outlet side, and wherein the wettable media pad is produced with additive manufacturing. A method of making a wettable media pad is also described.

The present invention is directed to a manifold for directing cooling fluid and/or gas to a heat exchanger in a flow configuration designed to optimize heat transfer from the heat exchanger. The manifold can take many different forms such as a layered construction with distributed inlet paths, local outlet paths, a central collection changer and a path for fluid removal. The manifold can be formed from a metal, plastic, rubber, ceramic, or other heat resistant material known to or conceivable by one of skill in the art. The manifold can also be combined with any type of heat exchanger known to or conceivable by one of skill in the art to form a thermal management unit. To optimize overall properties such as low pressure drop, high heat transfer, and excellent temperature uniformity of the thermal management unit, the manifold can be graded, expanded and scaled as needed.

Passive radiative cooling structures and apparatus manufactured with such cooling structures conserve energy needs. A flexible film transparent to visible light incorporates particles at a volume percentage larger than 25% so as to absorb and emit infrared radiation at wavelengths where Earth's atmosphere is transparent. Another film transparent to visible light is thin and flexible and configured to absorb and emit infrared radiation at wavelengths where Earth's atmosphere is transparent, wherein etchings or depositions are present on one or both surfaces. A high efficiency cooling structure has an emissive layer sandwiched between a waveguide layer and a thermal conductive layer. A solar cell panel is covered by a transparent passive radiative cooling film. A container housing an active cooling unit incorporates passive radiative cooling structures on one or more exterior surfaces.

A plurality of spacer devices for incorporation into a bent-tube heat exchanger that includes a spine and one or more fingers that protrude from opposite sides of the spine. The fingers are configured to exert a force against the tubes and to provide and maintain a separation between the tubes in the folded region. A heat exchanger includes a plurality of the spacer devices, such that one spacer device is positioned on every two tubes. The tubes may also include a coating in the folded region in order to reduce corrosion and increase the life-time of the heat exchanger. The method of forming the heat exchanger includes placing one of the spacer devices on every other tube, such that the fingers lay on the tubes in the region to be folded and assist in the folding process.

A fluid coil includes a tube bundle having a series of straight tubing runs and a series of return bends extending between and fluidically connecting ones of the straight tubing runs, an expansion header fluidically connected to at least some of the return bends and a polymeric material disposed in the expansion header. The polymeric material has an initial shape and is compressible to repeatedly expand and contract between a first volume in which water is present in the tube bundle and a second volume in which the water undergoes a phase change. Contraction of the polymeric material absorbs an increase in volume as the water undergoes the phase change to prevent stressing and rupture of the tube bundle and upon an opposite phase change, the polymeric material returns to its initial shape. The polymeric material can be a pressurizable bladder. A system and method to prevent the rupture of a tube bundle in a fluid coil are also disclosed.