Fin with elliptical collar base and airfoil and related finned tube heat exchanger

Abstract

A finned tube heat exchanger and a fin are disclosed. A fin includes a corrugated plate having a first side and a second side opposite the first side, the corrugated plate having a plurality of alternating peaks and valleys relative to the first side of the corrugated plate, one of a plurality of elliptical collar bases protruding from the first side of the corrugated plate, and a first airfoil and a second airfoil, the first airfoil and the second airfoil extend between a major axis and a minor axis of one of the plurality of elliptical collar bases and bend around the one of the plurality of elliptical collar bases. The first airfoil is disposed in a first quadrant of the one of the plurality of elliptical collar bases. The second airfoil is disposed in a second quadrant of the one of the plurality of elliptical collar bases, the second quadrant being adjacent to the first quadrant at the long axis.

Description

Technical Field

[0001] The present disclosure relates to fins for heat exchangers used in refrigerant circuits of heating, ventilation, air conditioning, and refrigeration ("HVACR") systems. More particularly, the present disclosure relates to fins having an elliptical collar base and an airfoil for reducing fluid stagnation caused by wake separation in a trailing region behind a heat transfer tube extending through the fin as the fluid traverses the heat transfer tube at the elliptical collar base. Background Art

[0002] Heating, ventilation, air conditioning, and refrigeration ("HVACR") systems are typically used to heat, cool, and / or ventilate enclosed spaces (e.g., the interior of a commercial or residential building, the interior of a refrigerated transport unit, etc.). An HVACR system may include a refrigerant circuit for providing cooled or heated air to the area. The refrigerant circuit utilizes a working fluid containing a refrigerant to directly or indirectly cool or heat a process fluid (e.g., air). A heat exchanger may be used to facilitate heat exchange between the working fluid and the process fluid. The heat exchanger may include a plurality of fins. The process fluid may flow between the fins to exchange thermal energy with the working fluid through the fins and heat transfer tubes. Summary of the Invention

[0003] The present disclosure relates to fins for heat exchangers used in refrigerant circuits of heating, ventilation, air conditioning, and refrigeration ("HVACR") systems. More particularly, the present disclosure relates to fins having an elliptical collar base and an airfoil for reducing fluid stagnation caused by wake separation in a trailing region behind a heat transfer tube extending through the fin as the fluid intersects the heat transfer tube at the elliptical collar base.

[0004] In one embodiment, a fin includes a corrugated sheet having a first side and a second side opposite the first side, the corrugated sheet having a plurality of folds, the plurality of folds being alternating peaks and valleys relative to the first side of the corrugated sheet, one of a plurality of elliptical collar bases protruding from the first side of the corrugated sheet, and first and second airfoils extending between a major axis and a minor axis of the one of the plurality of elliptical collar bases and curving about the one of the plurality of elliptical collar bases, the first airfoil being disposed in a first quadrant of the one of the plurality of elliptical collar bases and the second airfoil being disposed in a second quadrant of the one of the plurality of elliptical collar bases, the second quadrant being adjacent to the first quadrant at the major axis.

[0005] In an embodiment, said one of said plurality of oval collar bases is pressed into said second side and protrudes from said first side onto one of said peaks.

[0006] In one embodiment, one of the plurality of oval collar bases extends across three adjacent folds in the corrugated sheet and within five adjacent folds in the corrugated sheet.

[0007] In an embodiment, a transition side connects said one of said plurality of oval collar bases to said corrugated sheet.

[0008] In one embodiment, the transition side is wedged outwardly from the one of the plurality of oval collar bases to the first side of the corrugated sheet.

[0009] In one embodiment, said one of said plurality of oval collar bases is centered about one of said peaks.

[0010] In one embodiment, said one of said plurality of oval collar bases is flush with said one of said peaks.

[0011] In an embodiment, one of the airfoils extends through one of the valleys in the aft region of the one of the plurality of elliptical collar bases.

[0012] In an embodiment, the one of the airfoils has a trailing end extending toward the major axis of the one of the plurality of elliptical collar bases and a leading end extending toward the minor axis of the one of the plurality of elliptical collar bases.

[0013] In an embodiment, the leading end of the one of the airfoils is disposed further away from the one of the plurality of elliptical collar bases (eg, relative to an outer edge of the one of the plurality of elliptical collar bases) than a trailing end of the first airfoil.

[0014] In an embodiment, one of said airfoils extends within three adjacent folds of said corrugated sheet.

[0015] In an embodiment, one of the airfoils is pressed into a first side of the corrugated plate and protrudes from a second side of the corrugated plate.

[0016] In an embodiment, the fins comprise corrugated edges.

[0017] In one embodiment, a plurality of heat exchange tubes extend through a plurality of fins. One of the plurality of fins comprises a corrugated plate having a first side and a second side opposite the first side, the corrugated plate having a plurality of alternating peaks and valleys relative to the first side of the corrugated plate. One of the plurality of elliptical collar bases protrudes from the first side of the corrugated plate. A first airfoil and a second airfoil extend between a major axis and a minor axis of the one of the plurality of elliptical collar bases and curve around the one of the plurality of elliptical collar bases. The first airfoil is disposed in a first quadrant of the one of the plurality of elliptical collar bases, and the second airfoil is disposed in a second quadrant of the one of the plurality of elliptical collar bases. The second quadrant is adjacent to the first quadrant at the major axis.

[0018] In an embodiment, the one of the plurality of elliptical collar bases is pressed into the second side and protrudes from the first side onto one of the peaks, and one of the airfoils is pressed into the first side of the corrugated plate and protrudes from the second side of the corrugated plate.

[0019] In one embodiment, the one of the plurality of fins includes a fin collar connected to the one of the plurality of elliptical collar bases, and an outer surface of one of the heat exchange tubes contacts the fin collar.

[0020] In an embodiment, one of the airfoils extends through one of the valleys in the aft region of the one of the plurality of elliptical collar bases, and the leading end of the one of the airfoils is disposed further from the one of the plurality of elliptical collar bases than the aft end of the first airfoil.

[0021] In one embodiment, a transition side connects the one of the plurality of oval collar bases to the corrugated sheet, and the transition side is wedged outwardly from the one of the plurality of oval collar bases to the first side of the corrugated sheet.

[0022] In one embodiment, the one of the plurality of oval collar bases is centered about one of the peaks, and the one of the plurality of oval collar bases is flush with the one of the peaks.

[0023] In one embodiment, the one fin of the plurality of fins has a leading edge and a trailing edge, and a corrugated edge disposed on one or both of the leading edge and the trailing edge.

[0024] By including an elliptical collar base and airfoils on fins according to embodiments of the present application, the fluid-side heat transfer coefficient of the fin (e.g., air-side heat transfer coefficient, etc.) can be improved by more than 5% (e.g., compared to a comparable fin having the same tube diameter, face spacing, row spacing, etc.) while increasing the pressure drop across the fin by a small percentage, which is generally offset by the gain in heat transfer coefficient. It should be understood that the pressure drop can be the pressure drop of a fluid (e.g., air) as the fluid flows through a fin-tube heat exchanger and exchanges heat with the refrigerant within the tubes. It should be understood that in one embodiment, the fluid-side heat transfer coefficient can be the air-side heat transfer coefficient of the fins of the heat exchanger, and the heat exchanger can be a fin-tube heat exchanger.

[0025] The improvement in the fluid-side heat transfer coefficient (e.g., air-side heat transfer coefficient, etc.) of the fins according to the present disclosure can be attributed, at least in part, to reducing boundary layer thickness and increasing turbulence in the fluid flowing between the fins and / or heat transfer tubes of a fin-tube heat exchanger. In some embodiments, as the fluid flows through the heat transfer tubes, it separates at a location where wake separation occurs in the tail region behind the respective tubes relative to the flow direction of the fluid (e.g., air flowing through the heat transfer tubes and / or between the fins). In the wake separation region, the fluid stagnates and limits heat transfer capacity. The fins of the present disclosure reduce the stagnation zone in the tail region, thereby improving the heat transfer coefficient.

[0026] According to embodiments of the present disclosure, the shape and size of the corrugated edges and / or the elliptical collar base on the fins can improve the stiffness of the fins (e.g., by optimizing the elliptical collar base size, the angle between the collar base and the corrugated plate of the fin, etc.). For example, a fin having a face pitch (e.g., 22 mm) and a row pitch (e.g., 19.05 mm) for receiving a 7 mm heat transfer tube, and three rows of fin collars for receiving heat transfer tubes and a large elliptical collar bottom size can have a maximum deformation of or approximately 5.2 millimeters (mm) and a maximum stress of or approximately 28.5 megapascals (MPa) under condition A, and a maximum deformation of or approximately 254.7 mm and a maximum stress of or approximately 222.5 MPa under condition B. By including an elliptical collar base (which may have predetermined dimensions) having three rows of openings for receiving heat transfer tubes, the maximum deformation can be reduced to 4.9 mm or approximately 4.9 mm and the maximum stress can be reduced to 27.5 MPa or approximately 27.5 MPa under Condition A, and the maximum deformation can be reduced to 176.1 mm or approximately 176.1 mm and the maximum stress can be reduced to 139.2 MPa or approximately 139.2 MPa under Condition B. It should be understood that "Condition A" may be a stress test condition in which a fin having a length of or approximately 1200 mm is clamped at both ends, while "Condition B" may be a stress test condition in which the same fin is supported in the middle. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a schematic diagram of one embodiment of a refrigerant circuit in a heating, ventilation, air conditioning, and refrigeration (HVACR) system.

[0028] Figure 2 A schematic diagram of the interior of a fin-tube heat exchanger according to one embodiment is shown.

[0029] Figure 3 is a top view of a fin according to an embodiment.

[0030] Figure 4 yes Figure 3 FIG. 4 is a cross-sectional view of a fin in an embodiment of the present invention.

[0031] Figure 5 yes Figure 3 Detailed perspective view of an elliptical collar base and a pair of airfoils in an embodiment of the present invention.

[0032] Figure 6 is a detailed top view of one of the oval collar bases according to one embodiment.

[0033] Figure 7 is an enlarged side view of an airfoil according to an embodiment.

[0034] Figure 8A Computational fluid dynamics (CFD) of the fluid flow on the second side of the fin according to the comparative design is shown.

[0035] Figure 8B CFD of fluid flow on the second side of the fin is shown according to an embodiment.

[0036] Figure 8C Shown according to Figure 8A Comparison of CFD designs of the fluid flow on the first side of the fin.

[0037] Figure 8D CFD of fluid flow on a first side of a fin is shown according to an embodiment.

[0038] Figure 9A The positions of Plane 1 and Plane 2 on the fin for CFD calculations are shown.

[0039] Figure 9B Is used to show Figures 9C-9F Legend for the colors corresponding to the fluid flow velocities shown in CFD.

[0040] Figure 9C CFD of fluid flow on plane 1 of a fin according to a comparative design is shown.

[0041] Figure 9DShown is the CFD of the fluid flow on plane 1 of the fin according to one embodiment.

[0042] Figure 9E Shown Figure 9C Comparison of the fluid flow CFD on Plane 2 of the designed fins.

[0043] Figure 9F The CFD of the fluid flow on plane 2 of the fin is shown according to one embodiment.

[0044] Figure 10A The positions of planes 3 and 4 on the fin for CFD calculations are shown.

[0045] Figure 10B Is used to show Figures 10C-10F Color legend corresponding to the fluid flow velocities shown in .

[0046] Figure 10C Shown according to Figure 9C Comparison of CFD fluid flow on Plane 3 of the designed fins.

[0047] Figure 10D CFD of the fluid flow on plane 3 of the fin is shown according to one embodiment.

[0048] Figure 10E Shown Figure 9C Comparison of the fluid flow CFD on Plane 4 of the designed fins.

[0049] Figure 10F The CFD of the fluid flow on the plane 4 of the fin according to one embodiment is shown.

[0050] Like reference numerals represent like features. DETAILED DESCRIPTION

[0051] The present disclosure relates to fins for heat exchangers used in refrigerant circuits of heating, ventilation, air conditioning, and refrigeration ("HVACR") systems. More particularly, the present disclosure relates to fins having an elliptical collar base and an airfoil for reducing fluid stagnation caused by wake separation in a trailing region behind a heat transfer tube extending through the fin as the fluid intersects the heat transfer tube at the elliptical collar base.

[0052] Figure 11 is a schematic diagram of one embodiment of a refrigerant circuit 101 in a heating, ventilation, air conditioning, and refrigeration (HVACR) system 100. The HVACR system 100 may be an industrial, commercial, or residential HVACR system 100 configured to condition the interior of a building (e.g., an office space, a residence, etc.). In one embodiment, the HVACR system 100 may be a transportation climate control system for heating or cooling the interior of a transportation unit (e.g., a shipping container, a transport / trucking container, a refrigerated truck, etc.) and / or a passenger vehicle (e.g., a bus, an airplane, etc.).

[0053] In one embodiment, the refrigerant circuit 101 includes a compressor 110, a condenser 120, an expander 130, and an evaporator 140. In one embodiment, the refrigerant circuit 101 can be modified to include additional components. For example, in one embodiment, the refrigerant circuit 101 can include an economizer heat exchanger, one or more flow control devices, a receiver tank, a dryer, a suction liquid heat exchanger, etc. The components of the refrigerant circuit 101 are fluidly connected. For clarity, Figure 1 Dashed and dashed lines are provided to indicate fluid flow through components (eg, condenser 120, evaporator 140), and it should be understood that no specific route within each component is specified.

[0054] In one embodiment, the refrigerant circuit 101 utilizes known principles of gas compression and heat transfer. The refrigerant circuit can be configured to heat or cool a process fluid (e.g., water, air, chiller fluid, etc.). In one embodiment, the refrigerant circuit 101 can represent a chiller that cools a process fluid such as water. In one embodiment, the refrigerant circuit 101 can represent an air conditioner and / or heat pump that cools and / or heats a process fluid such as air, water, etc.

[0055] During operation of the refrigerant circuit 101, a working fluid (e.g., a refrigerant, a refrigerant mixture, etc.) flows from the evaporator 140 into the compressor 110 in a gaseous state at a relatively low pressure. The compressor 110 compresses the gaseous working fluid to a high-pressure state, which also heats the gas. After being compressed, the gaseous working fluid at a relatively high pressure and temperature flows from the compressor 110 to the condenser 120. In addition to the working fluid flowing through the condenser 120, a first process fluid PF1 (e.g., external air, external water, cooling / hot water, etc.) also flows separately through the condenser 120. As the first process fluid PF1 flows through the condenser 120, it absorbs heat from the working fluid, which cools the working fluid as it flows through the condenser. The working fluid condenses into a liquid and then flows into the expander 130. The expander 130 allows the working fluid to expand, converting it into a mixed vapor and liquid state. As described herein, an "expander" may also be referred to as an expansion device. In one embodiment, the expander may be an expansion device such as an expansion valve, an expansion plate, an expansion vessel, an orifice, or other such expansion mechanism. It should be understood that the expander can be any type of expander used in the art for expanding a working fluid to cause a decrease in pressure and temperature of the working fluid. For example, the expander can be configured to throttle the working fluid from a liquid phase having a high pressure and high temperature state to a two-phase phase (e.g., a mixture of liquid and vapor) having a low pressure and low temperature.

[0056] The relatively low-temperature two-phase working fluid then flows into evaporator 140. A second process fluid PF2 (e.g., air, coolant, water, etc.) also flows through evaporator 140. As second process fluid PF2 flows through evaporator 140, the working fluid absorbs heat from the second process fluid PF2, which cools the second process fluid PF2 as it flows through evaporator 140. As the working fluid absorbs heat, it evaporates into vapor. The working fluid then returns from evaporator 140 to compressor 110. This process continues when refrigerant circuit 101 is operating, for example, in cooling mode.

[0057] The refrigerant circuit 101 can be configured as a cooling system (e.g., an HVACR chiller, an air conditioning system, an HVACR heat pump, etc.) that can operate in a cooling mode, and / or the refrigerant circuit 101 can be configured as a heat pump system that can operate in a cooling mode or a heating mode. In one embodiment, the refrigerant circuit 101 is a chiller that cools a second process fluid PF2, which is a chiller liquid (e.g., air, water, glycol, and / or a water mixture, etc.). In one embodiment, the refrigerant circuit 101 is a heat pump that cools and heats the second process fluid PF2 (e.g., air, water, glycol, and / or a water mixture, etc.).

[0058] Figure 2 FIG. 2 shows a schematic diagram of the interior of a fin-tube heat exchanger 200 according to an embodiment. Figure 2 The view omits the housing of the heat exchanger 200 (and / or the frame of the heat exchanger) to show the fins and tubes in the heat exchanger 200. In one embodiment, the heat exchanger 200 can be the condenser 120 or the evaporator 140, such as Figure 1 As shown and described. Figure 2 As shown, the heat exchanger 200 includes a plurality of fins 210 stacked on top of each other and a plurality of heat transfer tubes (“tubes”) 220 extending through the fins 210 .

[0059] In one embodiment, the fin 210 includes a corrugated plate 205 having a wavy shape with alternating folds 250 and 260. For example, the corrugated plate 205 can have a zigzag shape. The corrugated plate 205 has a first side 201 and a second side 202 opposite the first side 201 of the corrugated plate 205. In one embodiment, the folds 250 and 260 can be peaks 250 and valleys 260 located on the plurality of fins 210, and the folds 250 and 260 are aligned in the direction D. In one embodiment, the folds 250 and 260 alternate between peaks and valleys in the direction of fluid flow of the first fluid 230. It will be understood that with respect to Figure 2 25 and 260 can be characterized as peaks 250 and valleys 260 in a view of and / or relative to the first side 201 of the corrugated sheet of fin 210. The first fluid 230 flows in a flow path between the fin 210 (e.g., including the fin collar base) and the outer surface of the tube 220. It will be appreciated that in some embodiments, the tube 220 can be attached to the interior of the fin collar 325 (e.g., Figure 4 As shown), the fin collar 325 is connected to the oval fin collar base. In some embodiments, the tube and the fin collar can be in contact by an interference fit.

[0060] In one embodiment, the wavy shape of fin 210 includes a downward fin plate from a crest 250 to a trough 260 and a next adjacent upward fin plate from the same trough 260 to the next adjacent crest 250. Fin 210 may include an optimized number of fin waves for each row of heat transfer tubes in a fin-tube heat exchanger. In one embodiment, the angle between the downward fin plate and the upward fin plate may be within a predetermined angle range.

[0061] At least one tube 220 extends through at least one fin 210 and is connected to the fin 210. In one embodiment, multiple tubes 220 extend through multiple fins 210. The tubes 220 may be interference fit into the fin collar base and / or openings in the fin collar (e.g., Figure 5The finned tube heat exchanger facilitates heat transfer between the first fluid 230 and the second fluid 240 through the tubes 220 and fins 210.

[0062] The first fluid 230 is arranged to flow through the spaces between the fins 210 (e.g., above or below the fins, where the tubes are arranged in close contact with the fins). The second fluid 240 is arranged to flow through the spaces within the tubes 220. The first fluid 230 can exchange heat energy with the second fluid 240 through the fins 210 and the tubes 220. The first fluid 230 can flow above, between, and below the fins 210.

[0063] In one embodiment, the first fluid 230 can be air, for example, return indoor air from a climate-controlled space to be conditioned (e.g., heated, cooled, etc.) in the fin-tube heat exchanger 200. In another embodiment, the first fluid 230 can be outside air, conditioned by the second fluid 240 flowing in the tubes 220. The second fluid 240 can be a refrigerant, a refrigerant mixture, etc. The tubes 220 are arranged parallel to each other and / or perpendicular to the fins 210. The fins 210 can be arranged parallel to each other.

[0064] It should be understood that Figure 2 As shown, the tubes 220 are arranged in a grid pattern (eg, in-line, staggered, etc.) when viewed along the flow direction D of the second fluid 240. In one embodiment, the tubes 220 are arranged in a staggered pattern, for example, Figure 3 shown.

[0065] Figure 3 is a top view of a fin 300 according to one embodiment. In one embodiment, Figure 3 Can be along Figure 2 The fin 300 includes one or more elliptical collar bases 310 disposed on a corrugated sheet having a plurality of folds 305. The folds 305 may be Figure 2 The folds 250 and 260 in question.

[0066] like Figure 3 As shown, the fin 300 includes a plurality of oval collar bases 310 for directing the flow pattern of the first fluid 230 flowing over and / or under the fin 300. The first fluid 230 is directed to surround the heat transfer tubes (e.g., Figure 2 In one embodiment, the first fluid 230 is directed to flow laterally through the tubes (e.g., the tubes 220) and extends through the space above and / or below the fins 300. Figure 2 220) to the tail area of the tube.

[0067] In one embodiment, the first fluid 230 flows in the space between two adjacent fins of the fin stack (e.g., Figure 2 fins 210 are stacked as shown).

[0068] Openings 320 are provided in a plurality or all of the oval collar bases 310. The openings 320 are arranged to receive a tube (e.g., Figure 2 The tube 220 shown in FIG. 2 may extend through the fin 300 at the oval collar base 310 (e.g., at a location within the fin collar base 310). The opening 320 may be a space defined by a fin collar 325 surrounding the opening 320. The fin collar 325 may be in contact with the outer surface of the tube (e.g., as shown in FIG. Figure 2 The fin collar 325 is configured to contact the surface 225 of the tube 220 (shown) to promote heat transfer through the tube and the fin 300. In one embodiment, the fin collar 325 can be a circular / annular structure, or a tubular portion of a flange, that extends from the opening 320 of the collar base 310 and is configured to receive a heat transfer tube (not shown). It should be understood that in some embodiments, the fin collar 325 can have a height that is related to the fin pitch or wave height of the fin 300 (e.g., the vertical distance between the peaks and troughs of the corrugated sheet of the fin 300). In one embodiment, the opening 320 has a circular shape and a center 350 such that the opening 320 is centered on the fold 305 of the fin 300. It should be understood that in one embodiment, the opening 320 is provided in each and every one of the oval-shaped collar bases 310.

[0069] In one embodiment, the fin collar 325 may be in contact with the outer surface of the tube (e.g., Figure 2 The surface 225 of the tube 220 is shown in contact with the tube and has an interference fit with the tube to promote heat transfer through the tube / fin collar and the fins 300. It should be understood that the fin collar 325 can have rounded walls.

[0070] One or more tail regions 315 are located in the flow path of the first fluid 230, between the elliptical collar base 310, the fin collar (e.g., Figure 4 as shown) and / or tube (as Figure 3 For example, the tail region 315A is in the flow path downstream of the oval collar base 310A (and / or the tube and fin collar associated with the oval collar base 310A) relative to the flow direction of the first fluid 230.

[0071] It will be appreciated that as the first fluid flows through the heat transfer tube, a separation point occurs in the region trailing / behind the heat transfer tube. Following the separation point, a vortex forms, resulting in wake separation and a stagnant zone behind the tube. It will be appreciated that, relative to the flow direction of fluid 230, the trailing region 315 is located in the flow path above and below the fin 300, trailing the location of the elliptical collar base 310, the elliptical collar (not shown), and / or the tube (not shown).

[0072] One or more leading regions 316 are located in the flow path of the first fluid 230 upstream of the tail region 315. For example, the leading region 316A is in the flow path upstream of the tail region 315A (including, in some embodiments, the tubes and / or fin collars therein) relative to the flow direction of the first fluid 230. In one embodiment, the tail region 315 and the leading region 316 are adjacent to each other. In one embodiment, the leading region 316 is an area upstream of the location on the fin 300 where the velocity vector or local flow direction of the tubes, fin collars, and / or first fluid 230 flows in the overall flow direction 230. It should be understood that the flow path of the first fluid 230 can flow over and / or between fins, fin collars, and / or around heat transfer tubes extending through the fin 300, as shown. Figure 8B and 8D Computational fluid dynamics.

[0073] A plurality of pairs of airfoils 340 are located on the corrugated plate. Figure 3 As shown, a pair of airfoils 340 from the plurality of airfoils is located around one of the oval collar bases 310A. In one embodiment, the pair of airfoils 340 are each located around at least some or all of the oval collar bases 310 on the fin 300. The pair of airfoils 340 are located on the fin 300 such that the airfoils 340 extend from the trailing region 315 of the same oval collar base 310, tube (not shown), and / or fin collar (not shown) to the leading region 316. It should be understood that the airfoils 340 are configured to direct the flow pattern of the first fluid 230 in the leading region 316 to the trailing region 315 around the oval collar base 310, the fin collar (not shown), and / or the tube (not shown) extending through the fin 300 at the oval collar base 310. In one embodiment, each airfoil of the pair of airfoils 340 extends from a trailing region 315 to a leading region 316 of the same elliptical collar base 310 , tube (not shown), and / or fin collar (not shown).

[0074] Fin 300 has one, two, or more edges at the ends of fin 300. For example, edge 301 is provided at the leading end of fin 300, while edge 302 is provided at the trailing end of fin 300. The leading end can be located at the end of fin 300 upstream (relative to the flow direction of first fluid 230) from oval collar base 310 and / or at the location where first fluid 230 enters the fins in a fin-tube heat exchanger. The trailing end can be the end of fin 300 downstream from oval collar base 310 and / or at the location where first fluid 230 exits the fins in a fin-tube heat exchanger. One or both of edges 301 and 302 can be corrugated edges having folds / corrugations extending across and / or perpendicular to the flow direction of first fluid 230. It will be appreciated that by having corrugated edges, the stiffness of the fin 300 may be increased compared to the same design of fin without the corrugated edges.In one embodiment, both edges of the fin may be corrugated edges.

[0075] Figure 4 is a cross-sectional view of a fin 300 according to an embodiment. For example, Figure 4 It can be Figure 3 390. Line 390 may be positioned through the center of the oval collar bases 310C and 310D, as shown in FIG. Figure 3 shown.

[0076] The fin 300 includes a corrugated plate 400. The elliptical collar base 310 and the airfoil 340 are disposed on the corrugated plate 400. The corrugated plate 400 includes a first side 410 and a second side 420 opposite the first side 410. In one embodiment, the first side 410 is an upper surface of the corrugated plate 400, and the second side 420 is a lower surface of the corrugated plate 400.

[0077] The corrugated plate 400 of the fin 300 has a wave height 430 and an angle 450 (e.g., a v-waffle angle). The wave height 430 can be the vertical distance between the peak crease 431 and the valley crease 432 of the corrugated plate 400. In one embodiment, the wave height 430 can be the vertical distance between the highest point on the first side 410 and the lowest point on the second side 420 of the corrugated plate 400, as shown in FIG. Figure 4 shown in the cross-sectional view.

[0078] In one embodiment, angle 450 may range from about 150 degrees to about 160 degrees. For example, angle 450 may be about 150 degrees, 156.3 degrees, 160 degrees, etc. It should be understood that the angle may be one of the fin design factors for optimizing fin performance. Wave height 430 may depend on the v-waffle angle, and the dimensions corresponding to the v-waffle angle may be, for example, about 1.2761 mm, about 1 mm, about 0.8398 mm, etc.

[0079] Figure 5 It shows that Figure 3 A detailed perspective view of an elliptical collar base 310 and a pair of airfoils 340 is shown. For example, Figure 5 It can be Figure 3 The oval collar base 310A and its airfoil 345 are shown.

[0080] like Figure 5 As shown, the oval collar base 310 extends from the corrugated plate 400 and protrudes from the first side 410. The oval collar base 310 has a top surface 510. The top surface 510 can be a flat surface. The corrugated plate 400 is connected to the top surface 510 of the oval collar base 310 by a transition side 520, which at least partially surrounds the top surface 510 of the oval collar base 310. The transition side 520 can be wedged outward from the oval collar base 310 to the corrugated plate 400. The transition side 520 can have a predetermined transition angle between the transition side 520 and the corrugated plate 400 (e.g., intersecting the downward and upward fin plates on the first side 410 of the corrugated plate 400).

[0081] The corrugated sheet 400 includes a first side 410, a second side (blocked), and a plurality of folds 501-504. The folds 501-504 are relative to Figure 5 The views are arranged as alternating peaks and valleys such that, relative to the first side 410 of the corrugated sheet, folds 501 and 503 may be peaks and folds 502 and 504 may be valleys on the corrugated sheet 400 .

[0082] In one embodiment, the top surface 510 of the oval collar base 310 includes an inner edge 512 and an outer edge 514. The inner edge 512 is circular and is configured to be arranged around a cylindrical heat transfer tube. For example, the inner edge 512 can be circular to provide a circular opening at the end of the fin collar 325, into which a heat transfer tube (not shown) can be inserted through the oval collar base and the opening of the fin collar and through the corrugated plate 400.

[0083] Outer edge 514 may have an elliptical shape having a major axis and a minor axis. In one embodiment, the minor axis of the elliptical shape of outer edge 514 lies on the same line as peak fold 503. The major axis of outer edge 514 may be perpendicular to the line of peak fold 503. In one embodiment, the dimensions of the minor and major axes of outer edge 514 may provide superior fin stiffness with respect to the maximum deformation and maximum stress that the fin can withstand before plastic deformation and / or rupture occurs. For example, a fin may be subject to stress concentration or localized material yielding due to its own weight, resulting in plastic deformation of the fin under certain conditions. It should be understood that the elliptical shape may have a continuously curved outer edge line.

[0084] In one embodiment, when the inner edge 512 and the outer edge 514 are collectively centered about the fold 503, the elliptical collar base 310 can be characterized as being centered above the fold 503 (centered about the fold 503, with its center on the fold 503). In one embodiment, the top surface 510 of the elliptical collar base 310 can be parallel to the overall extension direction D of the corrugated sheet 400. 延伸 (like Figure 4 In one embodiment, the top surface 510 of the oval collar base 310 is flush with the peak 503 .

[0085] In one embodiment, multiple or all of the oval collar bases 310 (e.g., Figure 3 ) protrudes from the first side 410 of the corrugated sheet 400 on and / or above the folds of the corrugated sheet 400. At least some or all of the elliptical collar bases 310 are centered on the peaks of the folds of the corrugated sheet 400 (e.g., fold 503), such that the peak fold 503 and the collar base 310 protrude from the same side of the corrugated sheet 400 and extend in the same direction. In one embodiment, the collar bases 310 are arranged to span three adjacent folds (e.g., 502, 503, 504) on the corrugated sheet 400, and / or within five adjacent folds. For example, the top surface 510 of the elliptical collar base 310 includes a centrally located opening for receiving a heat transfer tube. It should be understood that the elliptical collar base can define a transition angle between the leading side 520A and the downward corrugated fin plate portion on one side of the elliptical collar base 310 and a transition angle between the trailing side 520B and the upward corrugated fin plate portion on the other side (relative to the side of the elliptical collar base 310 on the corrugated plate 400).

[0086] The transition side 520 connects the top surface 510 of the elliptical collar base 310 to the first side 410 of the corrugated plate 400 and / or provides rigidity / rigidity, for example, with respect to the maximum deformation and maximum stress that the fin can withstand before plastic deformation or rupture. For example, the fin may be subject to stress concentration or localized material yielding due to its own weight, thereby causing the fin to plastically deform under certain conditions. The transition side 520 is wedged outward from the top surface 510 of the elliptical collar base 310 to the first side 410 of the corrugated plate 400. In one embodiment, the sidewall 520 includes a trailing side 520B and a leading side 520A. The trailing side 520B is located in the trailing side of the fluid flow and extends from the fold 503 (peak), across the fold 502 (valley), and toward the fold 501 (peak). Leading side 520A is on the leading side of the fluid flow and extends from fold 503 (peak), across fold 504 (valley), and toward the next adjacent fold (peak) on corrugated sheet 400 .

[0087] The pair of airfoils 340 are at least partially disposed in the aft region 315 of the respective elliptical collar base 310. In one embodiment, the pair of airfoils 340 are completely disposed in the aft region 315 of the respective elliptical collar base 310.

[0088] In one embodiment, the elliptical collar base 310 protrudes from the first side 410 at a peak crease (eg, crease 503), and the airfoil 340 protrudes from the second side (eg, Figure 4 The second side 420 (shown) protrudes through a valley crease (e.g., crease 502) such that the elliptical collar base 310 and the airfoil 340 protrude from opposite sides of the corrugated sheet 400. In one embodiment, the airfoil 340 is recessed into the first side 410 at the valley crease (e.g., crease 502).

[0089] Figure 6 is a detailed top view of one of the oval collar bases according to one embodiment. For example, Figure 6 It can be Figure 3 A detailed top view of one of the oval collar bases 310 is shown. The surface of the oval collar base 310 has an oval shape including a first end 311C, a second end 311D, a first side 311A, and a second side 311B. The oval shape has a major axis Y and a minor axis X passing through the center 350 of the oval shape. It should be understood that the major axis Y extends along the wider dimension of the oval shape between the first end 311C and the second end 311D, and the minor axis X extends along the narrower dimension of the oval shape between the first side 311A and the second side 311B.

[0090] It will be appreciated that the major axis Y and the minor axis X divide the area around the elliptical collar base 310 (and / or around a tube (not shown) disposed therein) into first through fourth quadrants 601-604. The tail region 315 of the elliptical collar base 310 may be disposed in the first and second quadrants 601, 602, downstream of a fluid flow through the fin collar base 310, the fin collar, and / or a tube (not shown) disposed therethrough.

[0091] The leading region 316 of the elliptical collar base 310 can be disposed in the third quadrant 603 and the fourth quadrant 604 upstream of fluid flow through the fin collar base 310, the fin collar, and / or a tube (not shown) disposed through the fin collar. In one embodiment, the first airfoil 340A of the pair of airfoils 340 is disposed in the first quadrant 601, and the second airfoil 340B of the pair of airfoils 340 is disposed in the second quadrant 602.

[0092] The airfoil 340 may have an eyebrow shape (e.g., an arc shape with a wedge-shaped end and a sharp end) surrounding the oval collar base 310. The eyebrow shape of the airfoil 340 may have a trailing end and a leading end. The trailing end of the airfoil 340 extends from the trailing region 315 of the oval collar base 310 to or toward the leading end of the airfoil 340 in the leading region 316. It should be understood that a heat transfer tube may be provided through the oval collar base 310 and the fin collar.

[0093] In one embodiment, the pair of airfoils 340 are positioned on the corrugated fin plate at locations spaced apart from the outer edge of the elliptical collar base. It should be understood that the elliptical collar base can be positioned across a first wave (i.e., a portion of the corrugated plate between a crest, a trough, and a crest, in sequence) and a second wave adjacent to the first wave. The first wave is upstream of the second wave. The pair of airfoils 340 are positioned within the corresponding elliptical collar base, fin collar, and / or second wave of the heat transfer tube positioned through the elliptical collar base.

[0094] The airfoils 340 may each have a trailing end 341 and a leading end 342. The trailing end 341 is disposed in the trailing region 315, and the airfoils 340 extend toward the leading region 316 such that the trailing end 341 is closer to the elliptical collar base 310 than the leading end 341. It should be understood that, according to one embodiment, the trailing end 341 of the airfoil may be disposed closer to the outer edge 514 of the collar base 310 than the leading end 342 of the airfoil. In the example shown, the airfoils 340 extend continuously between the leading end 342 and the trailing end 341. It should be understood that the airfoils 340 may be provided in two segments (e.g., a leading segment and a trailing segment separated at a valley crease), three segments, and / or more segments.

[0095] The oval collar base 310 is arranged in an orientation such that the oval collar base is narrower transversely / perpendicular to the airflow direction and wider in the airflow direction. In such an orientation, a larger gap can be provided between two adjacent oval collar bases 310, so that interference between the two leading ends of the airfoils 340 of adjacent oval collar bases 310 can be avoided. It will be appreciated that such an orientation can provide excellent heat transfer.

[0096] Figure 7 is an enlarged side view of an airfoil according to an embodiment. For example, Figure 7 It can be Figure 6 A side view of the airfoil 340B is shown. Figure 7 As shown in the illustrative example of FIG, the corrugated sheet 400 has a first side 410 and a second side 420. Figure 7 In the illustrative example of FIG, the airfoil 340B can have a uniform thickness T in a side view of the fin 300. The thickness T of the airfoil 340B can be defined as the distance between the first side 410 of the corrugated plate 400 and the lower surface 701 of the airfoil 340B in a local cross-section of the corrugated plate 400 (i.e., the upper and lower portions of the corrugated plate between two adjacent folds) in the orthogonal direction. In one embodiment, the thickness is from or about 0.4 mm to or about 0.6 mm.

[0097] Figures 8A-8D Computational fluid dynamics (CFD) simulations of a fin having an elliptical collar base with a pair of airfoils according to an embodiment and CFD of comparative designs are included. Figure 8A CFD of the fluid flow on the second side of the fin according to the comparative design. Figure 8B is a CFD of the fluid flow on the second side of the fin according to an embodiment. Figure 8C is based on Figure 8A Comparative design of the fluid flow on the first side of the fin obtained by CFD. Figure 8D is a CFD of the fluid flow on the first side of the fin according to one embodiment. For example, Figure 8A and 8C The fin shown may be a fin without the airfoil of the disclosed embodiments. Figure 8B It can be Figure 4 The fin 300 is shown viewed from a second side 420 of the fin 300 . Figure 8D It can be Figure 4 The fin 300 is shown viewed from a first side 410 of the fin 300. It should be understood that Figures 8A-8D The tubes extending through the fins are omitted.

[0098] Figure 8ACFD is shown in the flow path layer of the bottom of the fin as a comparative design. Region 810 is located in the flow path, where the white or light gray dashed lines show the presence of fluid flow. Region 820A represents a portion of the tail region of the elliptical collar base (relative to the direction of fluid flow) in which the fin collar and / or heat transfer tubes can be located. With little white or light gray dashed line covering region 820A, the features of the fin itself are clearly shown, indicating the stagnation of fluid flow in this region 820A due to wake separation in the tail region behind the heat transfer tubes (and / or fin collar and collar base). It should be understood that stagnant fluid can have a lower heat transfer rate compared to areas with fluid flow. Therefore, by allowing more fluid flow to enter the stagnant region, the fluid-side heat transfer coefficient of the fin (e.g., the air-side heat transfer coefficient) can be improved.

[0099] Figure 8B FIG2 shows CFD in layers of a flow path on a fin bottom with an elliptical collar base and a pair of airfoils, which reduces stagnation of fluid flow, according to an embodiment of the present disclosure. Figure 8B As shown, Figure 8A A smaller portion of region 820B on the fin is shown more clearly than region 820A in FIG. Region 820B has a larger portion of the features on the fin blocked by the white or light gray dashed lines, which indicates the presence of fluid flow. Therefore, a smaller portion of region 820B has fluid flow stagnation, thereby Figure 8A The fins have higher heat transfer than the

[0100] Figure 8C The CFD in the flow path layer of the top of the fin is shown as a comparative design. Region 810 is located in the flow path where the white or light grey dashed lines represent the fluid flow. Region 820A shows the tail region of the oval collar, the base of the fin collar, and / or the heat transfer tube (relative to the direction of fluid flow). The features of the fin are shown in Figure 820C due to the less white or light grey dashed lines covering a larger portion of the region. Figure 8C This is more clearly shown in , indicating greater stagnation of fluid flow in this region 820C.

[0101] Figure 8D FIG. 5 shows CFD in layers of a flow path on top of a fin having an elliptical collar and a pair of airfoils according to an embodiment of the present disclosure. Figure 8D As shown in Figure 8C In contrast, a smaller portion of region 820D on the fin is clearly shown within region 820D. Thus, a smaller portion of region 820D has stagnant fluid flow due to a reduction in stagnant fluid flow (eg, due to a reduction in the wake formed in the trailing region).

[0102] and Figure 8A and Figure 8C Compared with the CFD of the fin design, Figure 8B and 8D The CFD of FIG. 1 (for fins according to one or more embodiments) shows a higher fluid-side heat transfer coefficient when the fluid flows through the fin. The improvement in the fluid-side heat transfer coefficient can be attributed, at least in part, to a reduction in stagnant fluid flow caused by a reduction in wake separation of the heat transfer tubes trailing in the trailing region of the elliptical collar base.

[0103] Figure 9A Shows the positions of plane 1 and plane 2 on the fin for CFD calculations. Figure 9B Is used to show Figures 9C-9F The color legend for the fluid flow velocity shown in the CFD is Figure 9C CFD of fluid flow on plane 1 of the fin according to the comparative design is shown. Figure 9D CFD diagram showing fluid flow on plane 1 of a fin according to an embodiment, Figure 9E Shown Figure 9C Comparison of designed fins on plane 2 of fluid flow CFD, Figure 9F The CFD of the fluid flow on plane 2 of the fin is shown according to one embodiment.

[0104] Figure 10A Shows the positions of planes 3 and 4 on the fin for CFD calculations. Figure 10B Is used to show Figures 10C-10F The color legend corresponding to the fluid flow velocity shown in Figure 10C Shown according to Figure 9C Comparison of designed fins on plane 3 of fluid flow by CFD, Figure 10D CFD diagram showing the fluid flow on plane 3 of the fin according to one embodiment, Figure 10E Shown Figure 9C Comparison of designed fins on plane 4 of fluid flow CFD, Figure 10F The CFD of the fluid flow on the plane 4 of the fin according to one embodiment is shown.

[0105] It will be appreciated that, generally, a lower pressure drop across (across or across) the fins may be more preferred for using less energy to move the fluid through the fin-tube heat exchanger. Also, a higher fluid-side heat transfer coefficient is generally more preferred because the same heat transfer area on the fins can support a greater amount of heat transfer.

[0106] aspect:

[0107] Any of aspects 1-13 may be combined with any of aspects 14-20.

[0108] Aspect 1: A fin, comprising:

[0109] a corrugated sheet having a first side and a second side opposite the first side, the corrugated sheet having a plurality of folds comprising alternating peaks and valleys relative to the first side of the corrugated sheet;

[0110] one of a plurality of oval-shaped collar bases projecting from the first side of the corrugated sheet; and

[0111] a first airfoil and a second airfoil extending between a major axis and a minor axis of one of the plurality of elliptical collar bases and curving about the one of the plurality of elliptical collar bases, wherein

[0112] the first airfoil being disposed in a first quadrant of the one of the plurality of elliptical collar bases, and

[0113] The second airfoil is disposed in a second quadrant of the one of the plurality of elliptical collar bases, the second quadrant being adjacent to the first quadrant at the major axis.

[0114] Aspect 2. The fin of aspect 1, wherein the one of the plurality of elliptical collar bases is pressed into the second side and protrudes from the first side onto one of the peaks.

[0115] Aspect 3. The fin of aspect 1 or 2, wherein the one of the plurality of elliptical collar bases extends across three adjacent folds on the corrugated sheet and within five adjacent folds on the corrugated sheet.

[0116] Aspect 4: The fin according to any one of aspects 1 to 3, wherein:

[0117] A transition side connects the one of the plurality of oval collar bases to the corrugated sheet.

[0118] Aspect 5. The fin according to aspect 4, wherein

[0119] The transition side is wedged outwardly from the one of the plurality of oval collar bases to the first side of the corrugated sheet.

[0120] Aspect 6. The fin according to any one of aspects 1 to 5, wherein:

[0121] The one of the plurality of oval collar bases is centered on (centered about) one of the peaks.

[0122] Aspect 7: The fin according to any one of aspects 1 to 6, wherein:

[0123] The one of the plurality of oval collar bases is flush with the one of the peaks.

[0124] Aspect 8. The fin according to any one of aspects 1 to 7, wherein:

[0125] The first airfoil extends through one of the valleys in the aft region of the one of the plurality of elliptical collar bases.

[0126] Aspect 9. The fin according to any one of aspects 1 to 8, wherein:

[0127] The first airfoil includes

[0128] a tail end extending toward the major axis of the one of the plurality of oval collar bases, and

[0129] A leading end extends toward the minor axis of the one of the plurality of oval collar bases.

[0130] Aspect 10. The fin according to any one of aspects 1 to 9, wherein:

[0131] The leading end of the first airfoil is disposed further away from the one of the plurality of elliptical collar bases than the trailing end of the first airfoil.

[0132] Aspect 11. The fin according to any one of aspects 1 to 10, wherein:

[0133] The first airfoil extends within three adjacent folds of the corrugated sheet.

[0134] Aspect 12. The fin according to any one of aspects 1 to 11, wherein:

[0135] The first airfoil is pressed into the first side of the corrugated plate and protrudes from the second side of the corrugated plate.

[0136] Aspect 13. The fin according to any one of aspects 1 to 12, wherein the fin further comprises a corrugated edge.

[0137] Aspect 14. A fin-tube heat exchanger comprising:

[0138] a plurality of heat exchange tubes extending through a plurality of fins, wherein one of the plurality of fins comprises:

[0139] a corrugated sheet having a first side and a second side opposite the first side, the corrugated sheet having a plurality of folds comprising alternating peaks and valleys relative to the first side of the corrugated sheet;

[0140] one of a plurality of oval-shaped collar bases projecting from the first side of the corrugated sheet; and

[0141] a first airfoil and a second airfoil extending between a major axis and a minor axis of the one of the plurality of elliptical collar bases and curving about the one of the plurality of elliptical collar bases, wherein

[0142] the first airfoil being disposed in a first quadrant of the one of the plurality of elliptical collar bases, and

[0143] The second airfoil is disposed in a second quadrant of the one of the plurality of elliptical collar bases, the second quadrant being adjacent to the first quadrant at the major axis.

[0144] Aspect 15. The fin-tube heat exchanger according to aspect 14, wherein:

[0145] said one of said plurality of oval collar bases being pressed into said second side and projecting from said first side onto one of said peaks, and

[0146] The first airfoil is pressed into the first side of the corrugated plate and protrudes from the second side of the corrugated plate.

[0147] Aspect 16. The fin-tube heat exchanger according to aspect 14, wherein:

[0148] The one of the plurality of fins further includes a fin collar connected to the one of the plurality of oval collar bases, and

[0149] An outer surface of one of the heat exchange tubes is in contact with the fin collar.

[0150] Aspect 17. The fin-tube heat exchanger according to aspect 14, wherein:

[0151] the first airfoil extending through one of the valleys in the aft region of the one of the plurality of elliptical collar bases, and

[0152] The leading end of the first airfoil is disposed further away from the one of the plurality of elliptical collar bases than the trailing end of the first airfoil.

[0153] Aspect 18. The fin-tube heat exchanger according to aspect 14, wherein:

[0154] a transition side connecting said one of said plurality of oval collar bases to said corrugated sheet, and

[0155] The transition side is wedged outwardly from the one of the plurality of oval collar bases to the first side of the corrugated sheet.

[0156] Aspect 19. The fin-tube heat exchanger according to aspect 14, wherein:

[0157] The one of the plurality of oval collar bases is centered about one of the peaks.

[0158] The one of the plurality of oval collar bases is flush with the one of the peaks.

[0159] Aspect 20. The fin-tube heat exchanger according to aspect 14, wherein:

[0160] The one fin of the plurality of fins has a leading edge and a trailing edge, and a corrugated edge disposed on one or both of the leading edge and the trailing edge.

[0161] The terms used herein are intended to describe particular embodiments and are not intended to be limiting. Unless expressly stated otherwise, the terms "a," "an," and "the" also include plural forms. When used in this specification, the terms "include" and / or "comprise" specify the presence of the stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, and / or components.

[0162] With respect to the foregoing description, it should be understood that changes may be made in detail, particularly in the construction materials employed and the shapes, sizes, and arrangements of the components, without departing from the scope of the present disclosure. This specification and the described embodiments are intended to be exemplary only, with the true scope and spirit of the present disclosure being indicated by the appended claims.

Claims

1. Fin, characterized in that, The fin comprises: a corrugated sheet having a first side and a second side opposite the first side, the corrugated sheet having a plurality of folds comprising alternating peaks and valleys relative to the first side of the corrugated sheet; one of a plurality of oval-shaped collar bases projecting from said first side of said corrugated sheet; and a first airfoil and a second airfoil extending between a major axis and a minor axis of the one of the plurality of elliptical collar bases and curving about the one of the plurality of elliptical collar bases, wherein the first airfoil being disposed in a first quadrant of the one of the plurality of elliptical collar bases, and The second airfoil is disposed in a second quadrant of the one of the plurality of elliptical collar bases, the second quadrant being adjacent to the first quadrant at the major axis.

2. The fin according to claim 1, characterized in that The one of the plurality of oval collar bases is pressed into the second side and protrudes from the first side onto one of the peaks.

3. The fin according to claim 1, characterized in that The one of the plurality of oval collar bases extends across three adjacent folds in the corrugated sheet and within five adjacent folds in the corrugated sheet.

4. The fin according to claim 1, characterized in that A transition side connects the one of the plurality of oval collar bases to the corrugated sheet.

5. The fin according to claim 4, characterized in that The transition side is wedged outwardly from the one of the plurality of oval collar bases to the first side of the corrugated sheet.

6. The fin according to claim 1, characterized in that The one of the plurality of oval collar bases is centered about one of the peaks.

7. The fin according to claim 1, characterized in that The one of the plurality of oval collar bases is flush with the one of the peaks.

8. The fin according to claim 1, wherein: The first airfoil extends through one of the valleys in the aft region of the one of the plurality of elliptical collar bases.

9. The fin according to claim 1, characterized in that The first airfoil includes a tail end extending toward the major axis of the one of the plurality of oval collar bases, and A leading end extends toward the minor axis of the one of the plurality of oval collar bases.

10. The fin according to claim 1, characterized in that The leading end of the first airfoil is disposed further away from the one of the plurality of elliptical collar bases than the trailing end of the first airfoil.

11. The fin according to claim 1, characterized in that The first airfoil extends within three adjacent folds of the corrugated sheet.

12. The fin according to claim 1, characterized in that The first airfoil is pressed into the first side of the corrugated plate and protrudes from the second side of the corrugated plate.

13. The fin according to claim 1, characterized in that The fin further includes a corrugated edge.

14. A fin tube exchanger, characterized in that: include: a plurality of heat exchange tubes extending through a plurality of fins, wherein one of the plurality of fins comprises: a corrugated sheet having a first side and a second side opposite the first side, the corrugated sheet having a plurality of folds comprising alternating peaks and valleys relative to the first side of the corrugated sheet; one of a plurality of oval collar bases projecting from said first side of said corrugated sheet; and a first airfoil and a second airfoil extending between a major axis and a minor axis of the one of the plurality of elliptical collar bases and curving about the one of the plurality of elliptical collar bases, wherein The first airfoil is disposed in a first quadrant of the one of the plurality of elliptical collar bases, and the second airfoil is disposed in a second quadrant of the one of the plurality of elliptical collar bases, the second quadrant being adjacent to the first quadrant at the major axis.

15. The fin-tube heat exchanger according to claim 14, characterized in that said one of said plurality of oval collar bases being pressed into said second side and projecting from said first side onto one of said peaks, and The first airfoil is pressed into the first side of the corrugated plate and protrudes from the second side of the corrugated plate.

16. The fin-tube heat exchanger according to claim 14, characterized in that The one of the plurality of fins further includes a fin collar connected to the one of the plurality of oval collar bases, and An outer surface of one of the heat exchange tubes is in contact with the fin collar.

17. The fin-tube heat exchanger according to claim 14, characterized in that the first airfoil extending through one of the valleys in the aft region of the one of the plurality of elliptical collar bases, and The leading end of the first airfoil is disposed further away from the one of the plurality of elliptical collar bases than the trailing end of the first airfoil.

18. The fin-tube heat exchanger according to claim 14, wherein: A transition side connects the one of the plurality of oval collar bases to the corrugated sheet, and the transition side is wedged outwardly from the one of the plurality of oval collar bases to the first side of the corrugated sheet.

19. The fin-tube heat exchanger according to claim 14, characterized in that said one of said plurality of oval collar bases being centered about one of said peaks, and The one of the plurality of oval collar bases is flush with the one of the peaks.

20. The fin-tube heat exchanger according to claim 14, wherein: The one fin of the plurality of fins has a leading edge and a trailing edge, and A corrugated edge is provided on one or both of the leading edge and the trailing edge.

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