Symmetrical trapezoidal convex fin and finned tube heat exchanger adopting same

Abstract

The invention provides a symmetrical trapezoid protruding fin and a finned tube heat exchanger with the same, the symmetrical trapezoid protruding fin comprises a symmetrical trapezoid protruding fin body, and the symmetrical trapezoid protruding fin body comprises a substrate and a plurality of symmetrical trapezoid protruding structures distributed on the end face of the substrate in an array mode. The symmetrical trapezoid protruding structure comprises two trapezoid structures which are symmetrically distributed, the long sides and the short sides of the trapezoid structures are all perpendicular to the substrate, the long sides of the two trapezoid structures are connected on the plane to form a triangle, and the connecting positions of the long sides face the gas flowing direction. When fluid flows through the symmetrical trapezoid protrusions on the substrate, vortexes can be generated, so that disturbance of the fluid on the side of the symmetrical trapezoid protrusion type fin is increased, the heat exchange coefficient of a tube fin type heat exchanger adopting the fin is improved, the size of the tube fin type heat exchanger can be effectively reduced, and manufacturing and operating cost is saved.

Description

Technical Field

[0001] The invention relates to the technical field of heat exchange, in particular to a symmetrical trapezoidal raised fin and a tube-fin heat exchanger using the fin. Background Art

[0002] In the tube-fin type, the gas usually flows outside the tube. In order to improve the heat transfer efficiency, these devices are equipped with fins on the gas side to increase the heat transfer surface area and reduce the thermal resistance on the gas side. However, when using traditional straight fin tubes, as the gas moves along the flow direction, a thickening boundary layer gradually forms on the fin surface, resulting in a weakening of the synergy of the velocity and temperature gradient fields in the downstream area, thereby reducing the heat transfer efficiency of the fins.

[0003] In order to solve this problem and further improve the performance of tube-fin heat exchangers, researchers have developed a variety of fin designs to enhance heat transfer effects, among which adding turbulent structures to the fins is a proven effective improvement method.

[0004] In summary, developing a reasonable spoiler structure is crucial to improving the overall performance of the heat exchanger. The ideal spoiler structure design should be able to maximize the interference with the fluid flow and the development of the boundary layer, improve the synergistic effect of the velocity and temperature fields, and improve the heat transfer efficiency, while minimizing the obstruction to the fluid flow and ensuring a small increase in the heat exchanger resistance. Summary of the invention

[0005] In order to solve the problems of the prior art, the present invention provides a symmetrical trapezoidal raised fin and a tube-fin heat exchanger using the fin, which has a stronger disturbance on the gas and a smaller obstruction to the flow, so that the heat transfer performance of the tube-fin heat exchanger is improved while the flow resistance is increased less, which can effectively reduce the volume of the tube-fin heat exchanger and save manufacturing and operating costs.

[0006] The present invention provides a symmetrical trapezoidal raised fin, comprising a symmetrical trapezoidal raised fin body, wherein the symmetrical trapezoidal raised fin body comprises a substrate and a plurality of symmetrical trapezoidal raised structures distributed in an array on both end surfaces of the substrate, wherein the symmetrical trapezoidal raised structures comprise two symmetrically distributed trapezoidal structures, wherein the long sides and short sides of the trapezoidal structures are both perpendicular to the substrate, and the long sides of the two trapezoidal structures are connected to form a triangle on a plane, and the connection of the long sides faces the gas flow direction.

[0007] As a further improvement, the symmetrical trapezoidal raised fin body is made by stamping a high-ductility aluminum alloy.

[0008] As a further improvement, both sides of the symmetrical trapezoidal raised fin body are provided with a flowing medium, and the flowing medium is gas.

[0009] As a further improvement, the arrangement density of the trapezoidal protrusion structures on the substrate increases from small to large along the gas flow direction.

[0010] As a further improvement, the long side of the trapezoidal protrusion structure is three times the thickness of the substrate, the short side of the trapezoid is twice the thickness of the substrate, and the trapezoidal angle is 60°.

[0011] The present invention also provides a tube-fin heat exchanger, which adopts the above-mentioned symmetrical trapezoidal protruding fins, wherein a plurality of serpentine tubes pass through the substrate of the symmetrical trapezoidal protruding fins, and the serpentine tubes and the symmetrical trapezoidal protruding structures on the symmetrical trapezoidal protruding fins are staggered. When the gas flows through the symmetrical trapezoidal protruding fins, more eddies are generated, thereby making it easier to enhance the disturbance on the gas side of the tube-fin heat exchanger, thereby enhancing the heat exchange effect of the heat exchanger.

[0012] As a further improvement, a plurality of symmetrical trapezoidal raised fins are stacked to form a symmetrical trapezoidal raised fin group, and a plurality of serpentine tubes pass through the symmetrical trapezoidal raised fin group to form a tube-fin heat exchanger.

[0013] The beneficial effects of the present invention are: 1. With the innovative structural layout, the gas will generate eddies when it flows from the long side to the short side of the symmetrical trapezoidal protrusion. This eddy phenomenon will occur when the gas flows through each symmetrical trapezoidal protrusion fin, resulting in increased gas disturbance, thereby optimizing the synergistic effect of gas velocity and temperature gradient, and effectively improving heat exchange efficiency.

[0014] 2. Since the symmetrical trapezoidal protrusions are arranged alternately, they conform to the flow direction of the gas, and the arrangement density of the symmetrical trapezoidal protrusions on the substrate increases from low to high along the gas flow direction, so the increase in gas resistance has little effect. These designs improve the heat transfer performance of the tube-fin heat exchanger, help reduce the volume of the heat exchanger, and reduce its manufacturing and operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0016] Figure 1 It is a schematic diagram of the overall structure of the heat exchanger using the present invention.

[0017] Figure 2 4 is a top view of a symmetrical trapezoidal raised fin according to an embodiment of the present invention.

[0018] Figure 3 yes Figure 2 Partial top view of the lower right corner.

[0019] Figure 4 yes Figure 3 Schematic diagram of the structure of the symmetrical trapezoidal protrusion.

[0020] In the figure: 1 heat exchanger body; 10 serpentine tube; 20 fin; 21 substrate; 22 symmetrical trapezoidal protrusion; 22a long side of symmetrical trapezoidal protrusion; 22b short side of symmetrical trapezoidal protrusion. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] like Figure 1 , is a schematic diagram of a tube-fin heat exchanger 1 using the present invention, the heat exchanger comprises a plurality of serpentine tubes 10 and a plurality of fins 20 mounted in parallel on the serpentine tubes 10, the fins 20 are made of very thin aluminum alloy plates, and are designed to contact the outer edge of the serpentine tubes 10 to increase the heat transfer area with the fluid outside the tubes, thereby improving the heat transfer performance of the heat exchanger. The fins can be stacked in multiple groups to form a combined structure.

[0023] The embodiment of the present application is a symmetrical trapezoidal raised fin for a tube-fin heat exchanger. Figure 2 A symmetrical trapezoidal protrusion type fin 20 suitable for a tube-fin heat exchanger comprises a substrate 21 and a symmetrical trapezoidal protrusion 22 formed by stamping the substrate.

[0024] In addition to the arrangement density of the symmetrical trapezoidal protrusions 22 on the substrate 21 being from small to large along the gas flow direction, the long side 22a of the symmetrical trapezoidal protrusions is facing the gas flow direction. The unique design of the symmetrical trapezoidal protrusions 22 enhances the disturbance of the gas flow and strengthens the heat exchange effect on the gas side. The trapezoidal protrusions 22 are arranged in a density from small to large along the gas flow direction, which can enhance the heat exchange effect of the tube-fin heat exchanger while reducing the increase in gas side resistance.

[0025] The symmetrical trapezoidal protrusion 22 has a long side 22a that is three times the thickness of the substrate 21 , a short side 22b that is twice the thickness of the substrate 21 , a symmetrical trapezoidal angle of 60°, and both the long side 22a and the short side 22b of the symmetrical trapezoidal protrusion are perpendicular to the substrate 21 .

[0026] The working conditions of the tube-fin heat exchanger equipped with the above fin structure will be described below: The fluid in the tube flows along the serpentine tube 10, and heat exchange occurs when the gas outside the tube passes through the space on one side of the fin 20. At this time, the gas flowing into this space undergoes the first heat exchange when it flows through the first symmetrical trapezoidal protrusion 22, and generates eddies, which strengthen the disturbance of the gas near the first symmetrical trapezoidal protrusion 22, thereby enhancing the heat exchange effect of the tube-fin heat exchanger 1. The trapezoidal protrusions 22 are arranged in a form of increasing density along the gas flow direction, so that the resistance of the gas flowing through the tube-fin heat exchanger 1 is reduced, thereby obtaining a better heat exchange effect.

[0027] Each embodiment in this specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device embodiment, the above is only a preferred embodiment of the present invention. Since it is basically similar to the method embodiment, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiment. The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited to this. Any technician familiar with the technical field is within the technical scope disclosed by the present invention. For ordinary technicians in the technical field, changes or replacements that can be easily thought of should be covered within the protection scope of the present invention without departing from the principle of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A symmetrical trapezoidal raised fin, characterized in that: It includes a symmetrical trapezoidal raised fin body, which includes a substrate and a plurality of symmetrical trapezoidal raised structures distributed in an array on the end surface of the substrate. The symmetrical trapezoidal raised structures include two symmetrically distributed trapezoidal structures, the long sides and short sides of the trapezoidal structures are perpendicular to the substrate, the long sides of the two trapezoidal structures are connected to form a triangle on the plane, and the long sides are connected to face the gas flow direction.

2. The symmetrical trapezoidal raised fin according to claim 1, characterized in that: The symmetrical trapezoidal raised fin body is made by stamping a high-ductility aluminum alloy.

3. The symmetrical trapezoidal raised fin according to claim 1, characterized in that: Both sides of the symmetrical trapezoidal raised fin body are provided with a flowing medium, and the flowing medium is gas.

4. The symmetrical trapezoidal raised fin according to claim 3, characterized in that: The arrangement density of the trapezoidal protrusion structures on the substrate increases from small to large along the gas flow direction.

5. The symmetrical trapezoidal raised fin according to claim 1, characterized in that: The long side of the trapezoidal protrusion structure is three times the thickness of the substrate, the short side of the trapezoid is twice the thickness of the substrate, and the trapezoidal angle is 60°.

6. A tube-fin heat exchanger, characterized in that: The symmetrical trapezoidal raised fin described in any one of claims 1 to 5 is adopted, a plurality of serpentine tubes pass through the substrate of the symmetrical trapezoidal raised fin, and the serpentine tubes and the symmetrical trapezoidal raised structures on the symmetrical trapezoidal raised fin are distributed alternately.

7. The tube-fin heat exchanger according to claim 6, characterized in that: The symmetrical trapezoidal raised fins are stacked to form a symmetrical trapezoidal raised fin group, and a plurality of serpentine tubes pass through the symmetrical trapezoidal raised fin group to form a tube-fin heat exchanger.

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