Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and heat exchangers are provided that include nubbed, collared, and/or flapped fins. In certain embodiments, the fins include openings or slots with protrusions for spacing multichannel tubes from the fins. During assembly, the protrusions may be deformed by the tubes. Braze alloy may be positioned in the gaps created by the protrusions to affix the multichannel tubes to the fins. In other embodiments, the fins include flaps or collars designed to interface with the multichannel tubes. In these embodiments, the tubes may be expanded into the fins.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and heat exchangers are provided which include dissimilar internal configurations. The heat exchangers include multiple sets of multichannel tubes in fluid communication with each other. One set of multichannel tubes contains flow channels of one shape and size while the another set of multichannel tubes contains flow channels of a different shape and/or size. The dissimilar flow channels within the multichannel tube sets allow each set of tubes to be configured to the properties of the refrigerant flowing within the tubes.

Abstract: A technique is provided for forming and coating heat exchangers. The heat exchanger may be of any suitable type, such as employing two or more manifolds, with tubes, such as multichannel tubes extending between the manifolds, with fins being provided around or between the tubes. The overall heat exchanger structure is made as a slab that is advanced through an oven, such as in a brazing zone. Heat applied in the brazing zone heats the entire slab to an elevated temperature, and immediately after the brazing zone the slab is hot formed to provide bends or other configurations or contours. A coating is then applied at the elevated temperature, and the heat exchanger may advance through a curing station at which cooling is controlled to promote curing of the coating. The overall process provides a streamlined integrated assembly and manufacturing procedure for formed and coated heat exchangers.

Abstract: A multichannel heat exchanger is provided that may be used in any suitable application, such as air conditioning, refrigeration, heat pump, and similar systems. The heat exchanger provides for enhanced thermal exchange density within reduced envelope dimensions. Multichannel tubes may be oriented such that their major width is generally in a vertical plane, but such that their edges are inclined with respect to the vertical. The resulting envelope dimensions are reduced. Moreover, liquid condensate that may collect on the heat exchangers (e.g., when used as evaporators) may be channeled toward lower edges of the multichannel tubes along which the condensate flows for evacuation and collection.

Abstract: Heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems and heat exchangers are provided which include dissimilar internal configurations. The heat exchangers include multiple sets of multichannel tubes in fluid communication with each other. One set of multichannel tubes contains flow channels of one shape and size while the another set of multichannel tubes contains flow channels of a different shape and/or size. The dissimilar flow channels within the multichannel tube sets allow each set of tubes to be configured to the properties of the refrigerant flowing within the tubes.

Abstract: A heat exchanger (10) including a heat exchanger conduit and fins arranged on the conduit tubes (12, 12') to further heat transfer between the external fluid flowing over the fins (22, 22') and the fluid flowing within the conduit. The fins (22, 22') include a row of apertures through which tubes (12, 12') of the heat exchanger conduit extend. The leading (4, 6) and trailing (48) edges of the fins (22, 22') are contoured to substantially conform to isotherms around the circulating fluid flowing within the tubes (12, 12'). To achieve this edge configuration while also allowing for a dense packing of fins and tubes in a multi-row heat exchanger, the leading and trailing edges are wave-shaped such that adjacent fins can interfit together.

Abstract: A heat exchanger having a plurality of tubes for circulating a refrigerant fluid and a plurality of fins in heat exchange contact with the plurality of tubes. Each of the fins includes a plurality of aligned collars defining at least one row of longitudinally spaced apertures, the plurality of tubes extending through the apertures and engaged by the collars. A pair of reinforcing ribs extend longitudinally of the fin, one of the pair on each side of the at least one row of apertures. A plurality of longitudinally spaced flat portions, lying in a common plane, and extend transversely between the ribs, one of the flat portions circumscribing each of the collars. A plurality of central corrugated portions transversely spaced from the ribs, extend longitudinally, one of the corrugated portions lying between each two of the flat portions. At least two sets of longitudinally extending louvers are located transversely between the central corrugated portion and the ribs and longitudinally between the flat portions.

Abstract: A heat exchanger including a heat exchanger conduit and fins arranged on the conduit tubes to further heat transfer between the external fluid flowing over the fins and the fluid flowing within the conduit. The fins include a row of apertures through which tubes of the heat exchanger conduit extend. The leading and trailing edges of the fins are contoured to substantially conform to isotherms around the circulating fluid flowing within the tubes. To achieve this edge configuration while also allowing for a dense packing of fins and tubes in a multi-row heat exchanger, the leading and trailing edges are wave shaped such that adjacent fins can interfit together. Suitable wave shapes include a sinusoidal wave as well as a trapezoidal wave. The isothermally contoured leading and trailing edges result in a fin configuration which efficiently utilizes the materials of its construction as well as results in minimal wastage during construction with a minimal impact on heat transfer.

Abstract: The present invention involves a flat fin heat exchanger configuration with a plurality of louvers and a rib raised above the plane of the fin connecting adjacent tube collars. The raised rib configuration enhances the heat transfer characteristics of the fin, and allows for the use of thinner materials to lower cost without diminishing performance. The exterior fin surface "scoops" and redirects air flow from the leading edge to the trailing edge of the fin. This "scooping" effect directs the air flow over and in between the interrupted surfaces, thus breaking up air boundary layer around the fin. The louvers of the fin are oriented relative to the air flow in such a manner that each louver in effect creates another leading edge contributing to a higher heat transfer coefficient. Also, the location of the raised rib also enhances the heat transfer between the fin and the circulated air.

Abstract: An improved fin configuration is provided for use in central air conditioning unit heat exchangers in which heat transfer takes place between a first fluid, typically a refrigerant, flowing inside a nested plurality of tubes and a second fluid, typically air, flowing between the tubes and through a plurality of heat conducting fins attached to and arrayed between the tubes. Lanced pairs of streamwise adjacent bridge-like formations, one out each side of a generally corrugated fin surface, provide numerous leading edges to generate a plurality of reforming velocity and heat transfer boundary layers which leads to an increase in flow turbulence for enhanced heat transfer between the fins and the second fluid. By strategic location of a pair of such formations between tubes, with the upstream one of the pair at a positive angle of attack to the flow, air flow is directed through the fin to mix with flow on the other side of the fin and hence the heat transfer rate is improved.