Patent Application
20170198983
The invention relates to a heat exchanger, particularly to a lanced offset fin for a heat exchanger having angled walls.
As is commonly known, heat exchangers are employed to transfer heat between a fluid flowing through the heat exchanger and air. Heat exchangers typically contain a heat exchange core having a plurality of tubes or plates interposed with a plurality of fins. Air flows through the fins of the heat exchange core. The fins facilitate heat transfer between the fluid of the heat exchanger and the air. In certain applications, the fins can additionally provide structural support to the heat exchange core.
Various types of fins are known in the art to improve the heat transfer efficiency of the fins. For example, certain types of fins include louvres on a planar portion of the fin to increase turbulence. Increased turbulence increases a heat transfer coefficient between the surface of the fin and the air flowing therethrough. An increase in the heat transfer coefficient increases the heat transfer efficiency of the fin. In another example, U.S. Pat. Appl. Pub. No. 2013/0199760 discloses split mini louvered fins to further improve heat transfer efficiency. However, louvered fins increase fin weight, density, and materials employed, which can be undesirable. Louvered fins and split mini louvered fins reduce the structural integrity of the heat exchange core which can be problematic, especially in scenarios where greater loads are applied to the heat exchange core. Additionally, the mini louvered fins typically do not extend an entire height of the planar portions of the fins due to design constraints which limits maximum efficiency of the fins. Furthermore, because the louvres protrude from the planar portions of the fins, a cross-sectional flow area between adjacent planar portions of the fins is compromised, which may inhibit air flow through the fins.
In another example, lanced offset fins are employed in some heat exchangers. Lanced offset fins may be employed in heat exchangers having limited package size constraints and/or to increase the structural integrity of the heater core. An example of heat exchangers that may be limited in package size and require the heat exchange core to have an increased structural rigidity are water-cooled charge air coolers (WCAC's). The heat exchangers with limited package sizes, such as the WCAC's, require a high heat transfer density per heat exchanger volume. In applications where a high heat transfer density per heat exchanger volume is required, it is continually desired to improve the heat transfer efficiency.
It would therefore be desirable to provide a fin for a heat exchanger that maximizes heat transfer efficiency and maintains the structural integrity of the heat exchanger while minimizing a weight of the heat exchanger, an amount of material utilized for the heat exchanger, and a cost of manufacturing the heat exchanger
In accordance and attuned with the present invention, a fin for a heat exchanger that maximizes heat transfer efficiency and maintains the structural integrity of the heat exchanger while minimizing a weight of the heat exchanger, an amount of material utilized for the heat exchanger, and a cost of manufacturing the heat exchanger has surprisingly been discovered.
According to an embodiment of the disclosure, a fin for a heat exchanger is disclosed. The fin includes a fin member. A first row formed in the member. The first row has a plurality of valley sections alternating with a plurality of crest sections. The plurality of walls are interposed between and join the plurality of valley sections of the first row and the plurality of crest sections of the first row. At least one of the plurality of walls of the first row is angled with respect to a lateral axis of the member. A second row is formed in the member. The second row has a plurality of valley sections alternating with a plurality of crest sections. A plurality of walls are interposed between and join the plurality of valley sections of the second row to the plurality of crest sections of the second row. The plurality of crest sections of the first row and the plurality of valley sections of the first row are offset from the plurality of crest sections of the second row and the plurality of valley sections of the second row.
According to another embodiment of the invention, a fin for a heat exchanger includes a member. The member includes a plurality of transverse rows. Each of the plurality of rows has a plurality of valley sections alternating with a plurality of crest sections. The plurality of valley sections and the plurality of crest sections of adjacent ones of the plurality of rows are offset from each other. A plurality of walls are interposed between and integrally joining the plurality of valley sections and the plurality of crest sections of each of the plurality of rows. One of the plurality of walls are angled with respect to a lateral axis extending in a direction of a width of the member.
According to yet another embodiment of the invention, a fin for a heat exchanger includes a member. The member includes a plurality of transverse rows. Each of the plurality of transverse rows has a plurality of valley sections alternating with a plurality of crest sections. The plurality of valley sections and the plurality of crest sections of adjacent ones of the plurality of transverse rows are laterally offset from each other. A plurality of walls are interposed between and integrally joining the plurality of valley sections and the plurality of crest sections of each of the plurality of rows. Each of the plurality of walls are angled with respect to a lateral axis extending along a width of the member.
The above, as well as other objects and advantages of the invention, will become readily apparent to those skilled in the art from reading the following detailed description of an embodiment of the invention when considered in the light of the accompanying drawing which:
The following detailed description and appended drawings describe and illustrate various embodiments of the invention. The description and drawings serve to enable one skilled in the art to make and use the invention, and are not intended to limit the scope of the invention in any manner.
As shown in
In each of the rows 20, walls 22 are interposed between and integrally connect the valley sections 18 and the crest sections 19. Each of the crest sections 19 and the walls 22 adjacent to each of the crest sections 19 cooperate with each other to form a substantially rectangular cross-sectional shape. Likewise, each of the valley sections 18 and the walls 22 adjacent to each of the valley sections 18 cooperate with each other to form a substantially rectangular cross-sectional shape. In the embodiment shown, substantially orthogonal corners 24 having a substantially sharp edge are formed by the walls 22, the valley sections 18, and the crest sections 19. However, the corners 24 joining the walls 22 to the valley sections 18 and the crest sections 19 may have a slight radius or curvature, as illustrated by dotted lines in
In the embodiment shown in
Each of the sets of the rows 26a, 26b has an alternately staggered configuration 50 wherein the valley sections 18 and the crest sections 19 of alternating ones of the rows 20 are aligned with each other but offset from the valley sections 18 and the crest sections 19 of adjacent ones of the rows 20. In the alternately staggered configuration 50, each of the sets of the rows 26a, 26b includes first alternating rows 20a interposed between and interfacing with second alternating rows 20b. The valley sections 18 and the crest sections 19 of the first alternating rows 20a are laterally offset from the valley sections 18 and the crest sections 19 of the second alternating rows 20b. The first alternating rows 20a can be laterally offset from the second alternating rows 20b by any distance as desired. In a non-limiting example, the first alternating rows 20a can be laterally offset from the second alternating rows 20b by a distance equal to about 25% of a fin pitch Pf of each of the rows 20. In another example, the first alternating rows 20a can be laterally offset from the second alternating rows 20b by a distance equal to about 50% of the fin pitch Pf of each of the rows 20. In other examples, the offset distance can be equal to any percentage of the fin pitch Pf such as 10%, 30%, 75% or other percentage, as desired. In certain embodiments, such as shown, the first alternating rows 20a adjoin the second alternating rows 20b so a portion of each of the crest sections 19 of each of the first alternating rows 20a is continuous with a portion of the crest section 19 of the second alternating rows 20b at an interface 28.
As shown, each of the walls 22 of each of the rows 20 is non-orthogonally angled with respect to a lateral axis L extending in a direction of the width w of the fin 10 and nonparallel to the direction of the flow of air through the fin 10. Also as shown, the lateral axis L extending across the fin 10 is substantially parallel with the leading edge 14 and the trailing edge 16 of the fin 10. However, it is understood that some of the walls 22 of the rows 22 may be orthogonal to the lateral axis L and the leading edge 14 and the trailing edge 16 may have other orientations as desired. Acute angles α are formed between each of the walls 22 and the lateral axis L. The acute angles α formed can be any angle as desired to maximize a turbulence of air flowing through the fin 10 and the cross-sectional flow area formed between the walls 22. For example, the acute angle α can be greater than 60 degrees. However, the acute angle α can be less than 60 degrees, if desired.
As best shown in
In the continuously staggered configuration 60, the valley sections 118 and the crest sections 119 of each of the rows 120, in a direction from the leading edge 114 to the trailing edge 116, are successively offset from the valley sections 118 and the crest sections 119 of an adjacent preceding one of the rows 120 at an offset distance in an offset direction indicated by the dotted arrow. In the exemplary embodiment illustrated, the fin 110 has eight rows 120, consecutively numbered from the leading edge 114 to the trailing edge 116 as 120a, 120b, 120c, 120d, 120e, 120f, 120g, 120h. However, more or fewer than eight rows 120 can be contemplated, such as 10, 50, 100, or any other number configured to facilitate heat transfer efficiency, for example. The offset distance between the valley sections 118 and the crest sections 119 of each of the rows 120b, 120c, 120d, 120e, 120f, 120g, 120h and the valley sections 118 and the crest sections 119 of preceding adjacent ones of the rows 120a, 120b, 120c, 120d, 120e, 120f, 120g, is equal to a percentage of the fin pitch Pf of each of the rows 120a, 120b, 120c, 120d, 120e, 120f, 120g such as 15%, 20%, 25%, 50% of the fin pitch Pf or other percentage as desired. Each of the valley sections 118 and the crest sections 119 of each of the rows 120b, 120c, 120d, 120e, 120f, 120g is offset from the valley sections 118 and the crest sections 119 of each of the preceding rows 120a, 120b, 120c, 120d, 120e, 120f in the same offset direction. As shown in
The sets of the rows 226a, 226b are arranged in a substantially reverse configuration, or mirror image of, each other with respect to the axis a in the direction of the width w of the fin 210 intermediate the sets of the rows 226a, 226b. In this arrangement, the ends of the walls 222 of the rows 220 where the sets of the rows 226a, 226b converge align at the axis a. Other configurations can be contemplated, if desired. For example, the sets of the rows 226a, 226b can be arranged in a non-substantially reverse configuration, wherein the ends of the walls 222 of the rows 220 where the sets of the rows 226a, 226b converge are offset from each other at the axis a. In the embodiment illustrated, the fin 210 includes two sets of the rows 226a, 226b each including four rows 220. However, more than two sets of the rows 226a, 226 can be contemplated. Likewise, more or fewer than four rows 220 can be contemplated such as one, two, ten, twenty, or any other number, as desired. It is understood, in embodiments where the rows 220 are divided into more than the two 226a, 226b, the slope value of each of the walls 222 of each of the sets of the rows 226a, 226b may be equal to but opposite the slope values of the walls 222 of adjacent ones of the sets of the rows 226a, 226b to form a continuous series of alternating sets of the rows 226a, 226b with alternating patterns. It is also understood where the rows 220 are not divided into sets of rows, the slope value of each of the walls 222 of each of the rows 220 is equal to but opposite the slope value of each of the walls 222 of adjacent ones of the rows 220.
The fins 10, 110, 210, 310 illustrated in
The fins 10, 110, 210, 310 can be formed by any process suitable for forming lanced offset fins, now known or later developed. For example, the fins 10, 110, 210, 310 can be formed by a roll forming process from elongated strips of sheet metal or by a punching process. Any material suitable for forming the fins 10, 110, 210, 310 and maximizing heat transfer efficiency can be employed.
To assemble, the fin 10, 110, 210, 310 is positioned in the heat exchange assembly of the heat exchanger. The valley sections 18, 118, 218, 318 and the crest sections 19, 119, 219, 319 are configured to abut the plates or tubes of the heat exchange assembly. In application, the air flows through the fin 10, 110, 210, 310 from the leading edge 14, 114, 214, 314 to the trailing edge 16, 116, 216. 316 thereof. The angled walls 22, 122, 222, 322 effectuate an increase turbulence of the air along the entire height of the fins 10, 110, 210, 310. Heat is transferred between the air flowing through the fin 10, 110, 210, 310 and the fluid flowing through the plates or tubes.
Advantageously, due to the substantially rectangular cross-sectional shape formed by the valley sections 18, 118, 218, 318, the crest sections 19, 119, 219, 319, and the walls 22, 122, 222, 322, the lanced-offset fin 10, 110, 210, 310 enhances the structural rigidity of the heat exchange assembly. Additionally, the fins 10, 110, 210, 310 are beneficial in applications utilizing a heat exchanger, such as a WCAC, with limited package size and maximum efficiency requirements wherein minimizing weight and material is a key factor. With angled walls 22, 122, 222, 322, a turbulence of the air flowing through the fin 10, 110, 210, 310 can be increased. Increases in the turbulence increase a heat transfer coefficient between the surface of the fins 10, 110, 210, 310 and the air flowing therethrough. An increase in the heat transfer coefficient increases the heat transfer efficiency of the fin 10, 110, 210, 310. Further advantages of the fins 10, 110, 210, 310 include an increased turbulence of the air across the entire height of the fin 10, 110, 210, 310. With the fins 10, 110, 210, 310 of the present disclosure, neither heat transfer efficiency, structural integrity, nor desired weight or cost of heat exchanger is compromised, which often results when utilizing fins of the prior art.
From the foregoing description, one ordinarily skilled in the art can easily ascertain the essential characteristics of this invention and, without departing from the spirit and scope thereof, can make various changes and modifications to the invention to adapt it to various usages and conditions.
