HEAT EXCHANGE PROMOTION MEMBER AND HEAT EXCHANGER
20220373270 · 2022-11-24
Assignee
- Atago Manufacturing Co., Ltd. (Kiryu-shi, Gunma, JP)
- The University Of Tokyo (Tokyo, JP)
- DENSO CORPORATION (Kariya-shi, Aichi, JP)
Inventors
- Noboru Otomo (Kiryu-shi, Gunma, JP)
- Ken Yamamoto (Kiryu-shi, Gunma, JP)
- Kenichi Morimoto (Bunkyo-ku, Tokyo, JP)
- Yuji Suzuki (Bunkyo-ku, Tokyo, JP)
Cpc classification
F28D1/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28F3/027
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28F1/32
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28D1/03
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28F3/046
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28F1/325
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
F28F2215/04
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
International classification
Abstract
Provided is a heat exchange promotion member and a heat exchanger that can improve heat transfer performance while holding down an increase in pressure drag of a fluid that exchanges heat with the heat exchange promotion member. A heat dissipation fin 14 of the present invention is a heat exchange promotion member that exchanges heat with a flowing fluid. The heat dissipation fin 14 includes a planar part 12 which is a surface substantially parallel to the fluid flowing direction and a raised part 13 that protrudes from the planar part 12 toward the fluid. The raised part 13 has a portion slanted relative to the direction in which the fluid flows, and there are a plurality of the raised parts 13 formed spaced apart from one another in the fluid flowing direction.
Claims
1-9. (canceled)
10. A heat exchanger comprising: a plurality of heat dissipation fins that are arranged at constant intervals and exchange heat with a fluid; and a heat transfer tube that is thermally coupled with the heat dissipation fins and allows a heat medium to flow thereinside, the heat medium transporting heat energy, wherein the heat dissipation fins each include a planar part which is a flat surface substantially parallel to a direction in which the fluid flows and a raised part that extends in a direction intersecting with the direction in which the heat medium flows and that protrudes from the planar part toward the fluid, the raised part has a portion slanted relative to the direction in which the fluid flows, and the heat dissipation fins each have a plurality of shapes formed at substantially constant intervals in the direction in which the fluid flows, each of the shapes being a combination of the planar part and the raised part.
11. The heat exchanger according to claim 10, wherein the raised part alternately has a first raised portion slanted to one direction along a flow of the fluid and a second raised portion slanted to a different direction along the flow of the fluid, and a portion where the first raised portion and the second raised portion are continuous with each other forms a substantially letter-V shape.
12. The heat exchanger according to claim 10, wherein an angle at which the raised part is slanted from a direction orthogonal to a flow of the fluid is from at least 30° to not greater than 80°.
13. The heat exchanger according to claim 10, wherein a width of the raised part is from at least 0.6 mm to not greater than 4.5 mm.
14. The heat exchanger according to claim 10, wherein the raised part protrudes from the planar part by a length of from at least 0.2 mm to not greater than 1.5 mm.
15. The heat exchanger according to claim 10, wherein a cross section of the raised part at a tip end portion side is a substantially semicircular shape.
16. The heat exchanger according to claim 10, wherein there are at least four to not greater than sixteen pieces of the raised parts in a direction orthogonal to a flow of the heat medium.
17. A heat exchanger comprising: a plurality of heat dissipation fins that are arranged at constant intervals and exchange heat with a fluid; and a heat transfer tube that is thermally coupled with the heat dissipation fins and allows a heat medium to flow thereinside, the heat medium transporting heat energy, wherein the heat dissipation fins each include a planar part which is a flat surface substantially parallel to a direction in which the fluid flows and a raised part that extends in a direction intersecting with the direction in which the heat medium flows and that protrudes from the planar part toward the fluid, the raised part has a portion slanted relative to the direction in which the fluid flows, there are a plurality of the raised parts formed spaced apart from one another in the direction in which the fluid flows, when the direction in which the fluid flows is a first direction and a direction orthogonal to the first direction is a second direction, the heat transfer tube has a first heat transfer tube group and a second heat transfer tube group that are arranged in the first direction the first heat transfer tube group has a plurality of the heat transfer tubes arranged in the second direction, the second heat transfer tube group has a plurality of the heat transfer tubes arranged in the second direction, a plurality of the raised parts are formed between the first heat transfer tube group and the second heat transfer tube group, a plurality of the raised parts are formed between the heat transfer tubes included in the first heat transfer tube group, and a plurality of the raised parts are formed between the heat transfer tubes included in the second heat transfer tube group.
18. The heat exchanger according to claim 17, wherein the heat transfer tubes included in the first heat transfer tube group and the heat transfer tubes included in the second heat transfer tube group are arranged in a zigzag manner.
Description
BRIEF DESCRIPTION OF DRAWINGS
[0036]
[0037]
[0038]
[0039]
[0040]
[0041]
[0042]
[0043]
[0044]
[0045]
[0046]
DESCRIPTION OF EMBODIMENTS
[0047] An embodiment of the present invention is described in detail below based on the drawings. Although the following description shows an example where a heat exchange promotion member according to the present embodiment is used in a fin-and-tube heat exchanger, the heat exchange promotion member of the present embodiment can also be used in heat exchangers of other modes. For example, the heat exchange promotion member of the present embodiment can be used in, e.g., a plate heat exchanger or a heat transfer surface of a heat exchanger having a rectangular flow channel, which is specifically a heat transfer surface of an EGR cooler. In the following description, the X direction is a direction parallel to the direction in which a fluid flows, the Y direction is the direction of the thickness of a heat dissipation fin 14, and the Z direction is a direction orthogonal to the X direction and the Y direction.
[0048] The configuration of a heat exchanger 10 is described with reference to
[0049] Referring to
[0050] Various kinds can be used as the fluid to exchange heat with the heat dissipation fins 14, including a liquid such as water or a gas such as air. Also, various kinds can be used as the heat medium that flows through the inside of the heat transfer tubes 15, including a gas such as air, a liquid such as water, or a refrigerant used in a refrigeration cycle such as a vapor compression refrigeration cycle.
[0051] Each heat dissipation fin 14 is, for example, a plate member made of, e.g., metal with an excellent heat transfer rate, such as copper or aluminum, and here has a substantially rectangular shape with its long sides extending vertically. A large number of heat dissipation fins 14 are arranged at substantially equal intervals in their thickness direction. The heat dissipation fin 14 is one mode of a heat exchange promotion member and has an extended heat transfer surface.
[0052] Raised parts 13 are formed at each heat dissipation fin 14. The raised parts 13 are wall-shaped portions formed by partially protruding the heat dissipation fin 14 and extend in the Z direction in a meandering form. In
[0053] The heat transfer tubes 15 are tubular members made of metal with a high heat transfer rate such as copper and aluminum and have a meandering shape. By penetrating through the heat dissipation fin 14, the heat transfer tubes 15 are thermally coupled with the heat dissipation fin 14 at the penetration portions. Also, the heat transfer tubes 15 are arranged in a zigzag manner relative to the X direction in which the fluid flows.
[0054] Now, examples are given as to the sizes of the members forming the heat exchanger 10. As shown in
[0055] The diameter DC of the heat transfer tube 15 is the same as the diameter of a hole portion 16 (see
[0056] With reference to
[0057] The heat dissipation fin 14 is a heat exchange promotion member that promotes heat exchange between the fluid and the heat medium described above. To promote heat exchange further, the heat dissipation fin 14 has the raised parts 13 formed thereat.
[0058] The raised parts 13 are portions formed by protruding part of the heat dissipation fin 14 in the +Y direction. As a whole, the raised part 13 forms a meandering wall parallel to the Z direction, which is a direction orthogonal to the X direction which is the flowing direction in which the fluid flows. Locally, the raised part 13 extends obliquely relative to the Z direction. Specifically, the raised part 13 alternately has a slanted portion where a +Z-side portion thereof is slanted toward the +X side and a slanted portion where a +Z-side portion thereof is slanted toward the −X side. The raised part 13 is formed continuously from the +Z-side end portion to the −Z-side end portion of the heat dissipation fin 14.
[0059] Unlike the background art, the heat dissipation fin 14 of the present embodiment does not have slits formed therein. Thus, even if a heat exchanger using the heat dissipation fins 14 is disposed in an easily contaminated environment, such as outdoors or inside a factory, attachment of dirt and the like to the heat dissipation fins 14 can be inhibited.
[0060] With reference to
[0061] Referring to
[0062] An angle θ at which the raised portion 131 is slanted from the Z direction is, for example, 55°. A favorable range of the angle θ is from at least 30° to not greater than 80°, and a more favorable range is from at least 40° to not greater than 70°, and a particularly favorable range is from at least 50° to not greater than 60°. When the raised portion 131 has the angle θ slanted from the X direction within the above ranges, heat transfer characteristics can be improved, and also, pressure loss can be reduced, as will be described later.
[0063] The length LZ of the raised portion 131 measured in the Z direction is, for example, 4 mm. A favorable range of LZ is from at least 1.5 mm to 6.4 mm, a more favorable range is from at least 2.5 mm to 5.5 mm, and an even more favorable range is from at least 3.0 mm to 5.0 mm. When LZ is a value within those ranges, heat transfer characteristics can be improved, and also, pressure loss can be reduced, as will be described later.
[0064] The angle θ at which the raised portion 132 is slanted from the Z direction and the length LZ of the raised portion 132 measured in the Z direction are the same as those of the raised portion 131.
[0065] Referring to
[0066] The width w of the raised portion 131 is, for example, 2.5 mm. A favorable range of w is from at least 0.6 mm to not greater than 4.5 mm, a more favorable range is from at least 1.0 mm to 4.0 mm, and an even more favorable range is from at least 2.0 mm to 3.0 mm. When w is a value within those ranges, heat transfer characteristics can be improved, and also, pressure loss can be reduced, as will be described later.
[0067] Further, the number N of waves in a span direction is calculated from N=Pt/LZ, and an example value of N is from at least 4 to not greater than 16.
[0068] With reference to
[0069] Referring to
[0070] Consequently, swirls 171 to 175 are formed at the upper surface of the heat dissipation fin 14. The swirls 171, 173, and 175 are formed on the upper surface of a planar part 12 of the heat dissipation fin 14. The planar part 12 is a surface substantially parallel to the flow of fluid. Meanwhile, the swirls 172 and 174 are formed above the raised parts 13. In the swirls 171 to 175, a fluid flows, swirling about a rotation axis parallel to the X-axis. The rotation direction of the swirls 171, 173, and 175 formed above the planar part 12 is opposite from the rotation direction of the swirls 172 and 174 formed above the raised parts 13. Specifically, from the viewpoint in
[0071] Also, as described with reference to
[0072] Further, as shown in
[0073] Further, as is apparent from
[0074] This phenomenon is described with reference to
[0075] Referring back to
[0076] With reference to
[0077] Referring to
[0078] In
[0079] With reference to a graph in
[0080] In
[0081] Further, the j-factor is measured under the condition that the Reynolds number is a particular value, and this graph shows the value for the plane fin measured under the above condition with a “white-filled circle,” the value for the wavy fin (with two wavy parts) with a “black-filled circle,” the value for the wavy fin (with four wavy parts) with a “black-filled square,” and the heat dissipation fin having the shape according to the present embodiment with a “black-filled triangle.”
[0082] As is clear from the graph, by using the heat dissipation fin 14 according to the present embodiment, the j-factor can be 107% larger than that of the plane fin, and therefore, heat exchange efficiency can be improved dramatically.
[0083] In a graph shown in
[0084] Judging from the above, by using the heat dissipation fin 14 of the present embodiment, an increase in the j-factor can be 107% and an increase in the f-factor can be only 78%, compared to those of the plane fin. Thus, an increase in pressure loss can be suppressed while improving heat transfer performance. Thus, by using the heat dissipation fin 14 thus configured in a heat exchanger, heat exchange can be performed efficiently with low operational energy. Further, a heat exchanger using the heat dissipation fin 14 according to the present embodiment can reduce frosting and allows easy defrosting.
[0085] With reference to
[0086] Referring to
[0087] While the heat exchanger 10 is in operation, a high-temperature fluid and a low-temperature fluid flow in each heat exchanger 10 in the Y-axis direction. In the heat exchanger 10, the raised parts 13 are formed at predetermined intervals in such a manner as to form a substantially letter-V shape with respect to the flow of the high-temperature fluid or the low-temperature fluid. With such a configuration, the high-temperature fluid and the low-temperature fluid can effectively exchange heat with the heat exchanger 10.
[0088] Referring to
[0089] Referring to
[0090] As shown in
[0091]
[0092] Referring to
[0093] Although not shown, an introduction port and a discharge port are also formed in the side surface of the casing 19 facing the +Y side, and a high-temperature fluid is introduced into the casing 19 through the introduction port, and the high-temperature fluid after exchanging heat with the heat dissipation fins 14 is discharged to the outside through the discharge port.
[0094] Although the embodiment of the present invention has thus been described above, the present invention is not limited to this and can be modified without departing from the gist of the present invention. Also, the above-described modes can be combined with each other.
[0095] The heat dissipation fin 14 described above is applicable not only to the heat exchanger 10, but also to, for example, a crossflow heat exchanger or a heat exchanger for automobiles, i.e., a condenser, an evaporator, a radiator, or the like.
REFERENCE SIGNS LIST
[0096] 10 heat exchanger [0097] 12 planar part [0098] 13 raised part [0099] 131 raised portion [0100] 132 raised portion [0101] 133 edge portion [0102] 134 edge portion [0103] 14 heat dissipation fin [0104] 15 heat transfer tube [0105] 16 hole portion [0106] 171 swirl [0107] 172 swirl [0108] 173 swirl [0109] 174 swirl [0110] 175 swirl [0111] 18 hole portion [0112] 19 casing [0113] 20 introduction port [0114] 21 discharge port [0115] 22 high-temperature-side flow channel [0116] 23 low-temperature-side flow channel