초록 ▼

The invention involves a flat fin heat exchanger configuration 10 with a plurality of louvers 26 that are raised above the plane of the fin 16 between adjacent tube holes 19, 20 that receive tubes 14. Various alternative patterns of louvers enhance the heat transfer characteristics of the fin, and a

The invention involves a flat fin heat exchanger configuration 10 with a plurality of louvers 26 that are raised above the plane of the fin 16 between adjacent tube holes 19, 20 that receive tubes 14. Various alternative patterns of louvers enhance the heat transfer characteristics of the fin, and allow for the use of thinner materials to lower cost without diminishing performance. The exterior fin surface redirects air flow from the leading edge to the trailing edge of the fin. This 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, thus contributing to a higher heat transfer coefficient.

대표청구항 ▼

What is claimed is: 1. A heat exchanger assembly for use as a residential/industrial heating, ventilation, air conditioning refrigeration system that lies in the path of oncoming air, the assembly comprising: a plurality of heat transfer tubes; a plurality of fins, at least some of which being in c

What is claimed is: 1. A heat exchanger assembly for use as a residential/industrial heating, ventilation, air conditioning refrigeration system that lies in the path of oncoming air, the assembly comprising: a plurality of heat transfer tubes; a plurality of fins, at least some of which being in contact with the plurality of heat transfer tubes; at least some of the plurality of fins having a predetermined array in which one or more fins has a predetermined pattern of louvers, the geometry of which is characterized by a dimensionless parameter F that is a function of louver pitch PL, louver angle α, and fin pitch PF, such that the tangent of the louver angle times the louver pitch divided by the fin pitch is between about 0.20 and 0.65, where 20≦PF≦30 fins per inch; and wherein the tubes have longitudinal axes at a tube center thereof and the predetermined pattern of louvers associated with a fin is defined in relation to the centers of adjacent tube holes in the fins that receive the tubes, such that the louvers have end portions that lie at a constant radial distance rL from the tube axis, the louvers being parallel to an edge of the fin. 2. The heat exchanger assembly of claim 1, where the fin pitch PF is between about 25 to 30 fins per inch. 3. The heat exchanger assembly of claim 1, where the louver angle α is between about 20 to 35 degrees. 4. The heat exchanger assembly of claim 1, wherein the radial distance rL from a given tube hole center to the end portions of louvers in at least one pattern of louvers is constant. 5. The heat exchanger assembly of claim 1, wherein the radial distance rL from a given tube hole center equals the radial distance from an adjacent tube hole center and the pattern of louvers includes louvers with ends that terminate at the distance rL from each tube hole center. 6. The heat exchanger of claim 5, wherein at least some of the louvers comprise bridge louvers that run continuously between radii rL emanating from adjacent tube hole centers. 7. The heat exchanger of claim 5, wherein at least some of the louvers comprise gap louvers that are interrupted by one or more gaps. 8. The heat exchanger of claim 7, wherein at least some of the gap louvers are oriented with a radial component. 9. The heat exchanger of claim 7, wherein at least some of the gap louvers lie between rL and RL such that at least two adjacent louvers have edges that diverge from each other as distance from a tube hole center increases. 10. The heat exchanger of claim 5, wherein the pattern of louvers is selected from a group consisting of gap louvers, bridge louvers and combinations thereof. 11. The heat exchanger of claim 5, wherein the pattern of louvers associated with a given fin includes one or more louvers that have a uniform height h. 12. The heat exchanger of claim 5, wherein the pattern of louvers associated with a given fin includes louvers with unequal heights. 13. The heat exchanger of claim 1, wherein a fin has a louver that lies in a first plane (A) and an adjacent fin has a louver that lies in a plane (B) and at least some of the louvers in the adjacent fin are configured such that projections of planes (A) and (B) are spaced apart so that resistance to the passage of air flowing through the assembly is reduced. 14. The heat exchanger of claim 13, wherein a substantial amount of air entering the assembly between two fins that are interposed in a path of air moving at a velocity of 200-500 ft/mm is contained between and emerges from the assembly from between the same two fins, thereby minimizing air-side pressure drop. 15. The heat exchanger of claim 13, wherein plane (A) associated with a louver is substantially flat. 16. The heat exchanger of claim 13, wherein plane (A) associated with a louver has a topography that includes at least some regions that are curved. 17. The heat exchanger of claim 13, wherein plane (A) associated with a louver has a topography that includes at least some regions that are curvilinear. 18. The heat exchanger of claim 1, wherein at least some of the louvers associated with a fin have unequal pitches PL. 19. The heat exchanger of claim 1, wherein at least some of the louvers associated with a fin have unequal louver angles α. 20. The heat exchanger of claim 1, wherein at least some of the louvers associated with a fin have a pitch PL that varies along the length of the louver.