BENDABLE HEAT EXCHANGER
A heat exchanger for disposition within a duct having a curved surface is provided and includes a frame formed to define an inlet, an outlet and an interior by which the inlet and outlet are fluidly communicative, the frame including first and second surfaces having curvatures similar to that of the curved surface on either side of the interior and a heat exchanger fin disposed in the interior, the fin having corrugations and being formed to define slots transverse to the corrugations such that the fin is bendable along the curvatures of the first and second surfaces.
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This application is U.S. Non-Provisional of U.S. Provisional Application No. 61/865,765 filed Aug. 14, 2013, the disclosures of which are incorporated by reference herein in their entireties.
BACKGROUND OF THE INVENTIONThe subject matter disclosed herein relates to heat exchangers and, more particularly, to bendable heat exchangers including a slotted fin.
Turbine engines utilize heat exchangers to manage thermal loads for the engine and aircraft. Heat exchangers are typically rectangular in shape and are fitted as best they can be into an arc sector in a fan duct. The resultant square peg in the round hole configuration leaves the package with unused volume that cannot be utilized by the heat exchanger.
Plate fin air/air heat exchangers present particular issues as at least one or more of the layers cannot be curved because of the orientation of the fins in parallel with the bend curvature. Fins are made by corrugating a piece of flat sheet metal. And curvature is easily achieved by bending the fins along the corrugation axis. Bending is difficult if not impossible to achieve, however, along the fin backbone. Heating the material to achieve bending is possible but control of the bend is difficult to maintain at temperatures near the melting point of the material.
BRIEF DESCRIPTION OF THE INVENTIONAccording to one aspect of the invention, a heat exchanger for disposition within a duct having a curved surface is provided and includes a frame formed to define an inlet, an outlet and an interior by which the inlet and outlet are fluidly communicative, the frame including first and second surfaces having curvatures similar to that of the curved surface on either side of the interior and a heat exchanger fin disposed in the interior, the fin having corrugations and being formed to define slots transverse to the corrugations such that the fin is bendable along the curvatures of the first and second surfaces.
According to another aspect of the invention, a heat exchanger fin is provided and includes a sheet of fin material having a first axis defined along a planned fin backbone and a second axis defined transversely to the planned fin backbone. The sheet is formed to define slots along the second axis such that the slots are transverse to the first axis and the planned fin backbone and includes corrugations along the second axis and the slots.
According to yet another aspect of the invention, a method of assembling a heat exchanger is provided and includes forming fin material into a sheet having a first axis defined along a planned fin backbone and a second axis defined transversely to the planned fin backbone, machining slots in the sheet along the second axis such that the slots are transverse to the first axis and the planned fin backbone and corrugating the sheet along the second axis to form a corrugated sheet with corrugations provided along the slots.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.
The subject matter, which is regarded as the invention, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:
The detailed description explains embodiments of the invention, together with advantages and features, by way of example with reference to the drawings.
DETAILED DESCRIPTION OF THE INVENTIONA heat exchanger with a potential for fin curvature in either the X or Y direction is provided and may be employed to realize a curved heat exchanger using plate-fin manufacturing methods. As will be discussed below, a flat piece of sheet metal is machined to enable curvature along the fin backbone axis. Prior to corrugation, cuts are machined perpendicular to the planned fin backbone such that the fin backbone bisects the machined cut. Once the array of cuts are made, the sheet is corrugated using normal processes. The result is a fin that is segmented and capable of being curved into an arc that effectively stretches the fin backbone. Wider cuts can be made into the pre-formed sheet metal to enable curvature toward the fin backbone if desired. The ability to curve fins in both the X and Y axes at the same time enables more efficient utilization of arc sector volumes that exist in engine core and fan ducts today where packaging concerns are a major concern for engine designers.
With reference to
The heat exchanger 10 includes a frame 20 and the above-noted heat exchanger fin 30 (see
In order to save space within the duct 11, to increase an aerodynamic performance of the duct 11 and to permit the heat exchanger 10 to fit tightly within the duct 11 with little to no space between the curved, inward facing surface 110 and the heat exchanger 10, the first surface 24 and, in some cases, the second surface 25 may have a curvature CHEX that is similar to a curvature CD of the curved, inward facing surface 110 on either side of the interior 23. Thus, the heat exchanger 10 is configured to be inserted and disposed in the duct 11 with little to no space between the heat exchanger 10 and the curved, inward facing surface 110.
With reference to
The corrugations 32 are folds in the heat exchanger fin 32 that extend in the z-axis from the baseline z-axis plane. As fluid flow proceeds through the interior 23 of the heat exchanger 10, the corrugations 32 aerodynamically interact with the fluid flow to cause turbulation that increases a degree of heat transfer or heat removal from the fluid. Thus, each corrugation 32 includes a first seam 320, a first leg 321, a second seam 322, a second leg 323 and third seam 324. The first, second and third seams 320, 322 and 324 extend in a first or x-axis (see
The slots 33 are oriented transversely or, in some cases, perpendicularly with respect to the corrugations 32. The slots 33 extend along the y-axis and are respectively associated with a single corrugation 32. That is, as shown in
In a conventional heat exchanger fin that has corrugations but not slots, the corrugations prevent the heat exchanger fin from being bent in the x-axis (or an equivalent axis). In accordance with embodiments, however, and, as shown in
With reference back to
In accordance with further aspects, a method of assembling the heat exchanger 10 is provided. The method includes forming fin material into a sheet having the first or x-axis defined along the planned fin backbone 40 and the second or y-axis defined transversely to the planned fin backbone 40, machining the slots 33 in the sheet along the second axis such that the slots 33 are transverse to the first axis and the planned fin backbone and forming the corrugations 32. The forming of the corrugations 32 includes corrugating or folding the sheet along the second axis. The method may further include bending the sheet along the first axis such that the sheet can be easily fit into the heat exchanger 10 and the duct 11.
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
Claims
1. A heat exchanger for disposition within a duct having a curved surface, the heat exchanger comprising:
- a frame formed to define an inlet, an outlet and an interior by which the inlet and outlet are fluidly communicative, the frame including first and second surfaces having curvatures similar to that of the curved surface on either side of the interior; and
- a heat exchanger fin disposed in the interior, the fin having corrugations and being formed to define slots transverse to the corrugations such that the fin is bendable along the curvatures of the first and second surfaces.
2. The heat exchanger according to claim 1, wherein the slots and corrugations are perpendicular.
3. The heat exchanger according to claim 1, wherein the fin comprises a metal or metallic alloy.
4. A heat exchanger fin, comprising:
- a sheet of fin material having a first axis defined along a planned fin backbone and a second axis defined transversely to the planned fin backbone;
- the sheet being formed to define slots along the second axis such that the slots are transverse to the first axis and the planned fin backbone; and
- the sheet including corrugations along the second axis and the slots.
5. The heat exchanger fin according to claim 4, wherein the sheet is bendable along the first axis.
6. The heat exchanger fin according to claim 4, wherein the first and second axes are perpendicular.
7. The heat exchanger fin according to claim 4, wherein the slots and corrugations are perpendicular.
8. The heat exchanger fin according to claim 4, wherein the fin material comprises a metal or metallic alloy.
9. A method of assembling a heat exchanger, the method comprising:
- forming fin material into a sheet having a first axis defined along a planned fin backbone and a second axis defined transversely to the planned fin backbone;
- machining slots in the sheet along the second axis such that the slots are transverse to the first axis and the planned fin backbone; and
- corrugating the sheet along the second axis to form a corrugated sheet with corrugations provided along the slots.
10. The method according to claim 9, further comprising bending the sheet along the first axis.
11. The method according to claim 9, wherein the first and second axes are perpendicular.
12. The method according to claim 6, wherein the slots and corrugations are perpendicular.
13. The method according to claim 9, wherein the fin material comprises a metal or metallic alloy.
Type: Application
Filed: Mar 5, 2014
Publication Date: Feb 19, 2015
Applicant: HAMILTON SUNDSTRAND CORPORATION (Charlotte, NC)
Inventor: William E. Rhoden (Glastonbury, CT)
Application Number: 14/197,946
International Classification: F28F 1/12 (20060101); B21D 53/02 (20060101);