阅读说明：本技术 翅片结构及换热器 (Fin structure and heat exchanger ) 是由 熊建国 张凯 刘华 李明佳 何雅玲 袁国炉 于 2021-07-27 设计创作，主要内容包括：本发明公开了一种翅片结构及换热器,其中,翅片结构包括：翅片基体,翅片基体上具有用于穿设换热管的管孔结构,翅片基体为波纹翅片；多个凸起部,凸起部设置在翅片基体上,多个凸起部环绕在管孔结构的外周。本发明的翅片结构及换热器能够有效地提升翅片换热效果,强化换热器换热性能。(The invention discloses a fin structure and a heat exchanger, wherein the fin structure comprises: the fin comprises a fin base body, wherein the fin base body is provided with a pipe hole structure for penetrating a heat exchange pipe, and is a corrugated fin; and the plurality of protruding parts are arranged on the fin base body and surround the periphery of the pipe hole structure. The fin structure and the heat exchanger can effectively improve the heat exchange effect of the fins and strengthen the heat exchange performance of the heat exchanger.)

1. A fin structure, comprising:

the heat exchanger comprises a fin base body (10), wherein a tube hole structure (20) for penetrating a heat exchange tube is formed in the fin base body (10), and the fin base body (10) is a corrugated fin;

a plurality of bosses provided on the fin base (10), the plurality of bosses surrounding an outer periphery of the tube hole structure (20).

2. The fin structure according to claim 1, wherein the fin base (10) includes a plurality of first corrugated surfaces (11) and a plurality of second corrugated surfaces (12), the first corrugated surfaces (11) being spaced apart from the second corrugated surfaces (12), the first corrugated surfaces (11) corresponding to a node length L1 being greater than the second corrugated surfaces (12) corresponding to a node length L2.

3. The fin structure according to claim 2, characterized in that two of the first corrugated surfaces (11) have two of the second corrugated surfaces (12) therebetween, the two second corrugated surfaces (12) being disposed adjacently.

4. The fin structure according to claim 2, wherein the ratio h1/S of the corrugation height h1 to the fin pitch S of the fin base (10) is 0.58 to 0.62, and L1/L2 is 1.5 to 1.7.

5. The fin structure according to claim 2, wherein the plurality of protrusions include:

a collar structure (31), wherein the collar structure (31) is convexly arranged on the first corrugated surface (11);

a side convex structure (32), wherein the side convex structure (32) is convexly arranged on the second corrugated surface (12).

6. The fin structure according to claim 5, wherein the collar structure (31) is an annular convex structure, the number of the collar structures (31) is multiple, and the plurality of the collar structures (31) are symmetrically distributed on the periphery of the tube hole structure (20).

7. The fin structure according to claim 5, wherein the side convex structures (32) are boss structures, the number of the side convex structures (32) is multiple, and the plurality of the side convex structures (32) are symmetrically distributed on the outer periphery of the tube hole structure (20).

8. Fin structure according to claim 5, characterized in that the ratio h3/S of the projection height h3 of the collar structure (31) to the fin spacing S is 0.35-0.4.

9. The fin structure according to claim 5, wherein the ratio h2/S of the protrusion height h2 of the side convex structure (32) to the fin pitch S is 0.35-0.4.

10. Fin structure according to claim 2, characterized in that on said fin base (10) there are further provided:

the pipe hole structure (20) is located in the annular groove (40), the annular groove (40) and the pipe hole structure (20) are arranged concentrically, the periphery of the annular groove (40) is connected with the first corrugated surface (11) and the second corrugated surface (12), and the protrusions are located outside the annular groove (40).

11. The fin structure according to claim 10,

two second corrugated surfaces (12) are arranged between the two first corrugated surfaces (11), the two second corrugated surfaces (12) are arranged adjacently, and the two second corrugated surfaces (12) are intersected to form a valley line;

the joint of the annular groove (40) and the first corrugated surface (11) forms two symmetrical arc-shaped surfaces, and the joint of the annular groove (40) and the two second corrugated surfaces (12) forms two symmetrical planes.

12. The fin structure according to claim 11,

the annular groove (40) is tangent to the valley line in the direction perpendicular to the incoming flow; the included angle theta between the generatrix of the arc-shaped surface and the central axis of the heat exchange tube is 45 degrees.

13. The fin structure according to claim 10, wherein the ratio D1/D of the maximum outer diameter D1 of the annular groove (40) to the heat exchange tube outer diameter D is 1.6-1.7.

14. A fin structure according to claim 3, wherein two of said first corrugated surfaces (11) are symmetrically arranged with respect to said tube hole structure (20), and two of said second corrugated surfaces (12) are symmetrically arranged with respect to said tube hole structure (20).

15. The fin structure according to claim 1, wherein the ratio D1/D of the inner diameter D1 of the tube hole structure (20) to the outer diameter D of the heat exchange tube is 1.025-1.035.

16. A heat exchanger, characterized by comprising a fin structure according to any one of claims 1 to 15.

Technical Field

The invention relates to the technical field of refrigeration equipment, in particular to a fin structure and a heat exchanger.

Background

In the prior art, the finned tube heat exchanger is widely applied to the industries of chemical engineering, ventilation, heat supply, air conditioning, refrigeration and the like due to the characteristics of simple manufacture, strong applicability and the like, and how to transfer heat to the maximum extent and utilize heat energy (intensified heat transfer) is always the key point of research in the industry.

The fin structure of the finned tube heat exchanger mainly comprises a straight fin, a corrugated fin, a corresponding slotted (windowing) structure and the like, the conventional straight fin and the conventional corrugated fin often have poor heat exchange on the leeward side of a heat exchange tube, and the corresponding slotted structure increases the contact area of the air side, and meanwhile, the irregularity of the structure generates disturbance to a flow field, so that the mixing among fluids is enhanced, the flow separation of a boundary layer is delayed, and the overall heat exchange performance is enhanced. But the structure of slotting usually can make the through-flow clearance of fin diminish, the flow resistance increase, and the jam that frosts easily under wet operating mode shortens fin life, has reduced effective heat transfer area simultaneously, influences the actual heat transfer effect of fin. Considering the combination of resistance, heat exchange performance and processability, corrugated fins are one form that is more suitable for industrial applications. However, as the heat dissipation requirements of the heat exchanger are further improved, the performance requirements of the high-efficiency heat exchanger are difficult to meet by the conventional corrugated fin.

Disclosure of Invention

The embodiment of the invention provides a fin structure and a heat exchanger, which are used for improving the heat exchange effect of fins and strengthening the heat exchange performance of the heat exchanger.

To achieve the above object, the present invention provides a fin structure comprising: the fin comprises a fin base body, wherein the fin base body is provided with a pipe hole structure for penetrating a heat exchange pipe, and is a corrugated fin; and the plurality of protruding parts are arranged on the fin base body and surround the periphery of the pipe hole structure.

Further, the fin base comprises a plurality of first corrugated surfaces and a plurality of second corrugated surfaces, the first corrugated surfaces and the second corrugated surfaces are arranged at intervals, and the corresponding node length L1 of the first corrugated surfaces is larger than the corresponding node length L2 of the second corrugated surfaces.

Further, two second corrugated surfaces are arranged between the two first corrugated surfaces and are adjacently arranged.

Furthermore, the ratio h1/S of the corrugation height h1 of the fin matrix to the fin spacing S is 0.58-0.62, and L1/L2 is 1.5-1.7.

Further, the plurality of protrusions includes: the ring pipe structure is arranged on the first corrugated surface in a protruding mode; and the side convex structure is convexly arranged on the second corrugated surface.

Furthermore, the ring pipe structure is an annular convex structure, the number of the ring pipe structures is multiple, and the plurality of ring pipe structures are symmetrically distributed on the periphery of the pipe hole structure.

Furthermore, the side convex structures are boss structures, the number of the side convex structures is multiple, and the plurality of side convex structures are symmetrically distributed on the periphery of the pipe hole structure.

Furthermore, the ratio h3/S of the height h3 of the protrusions of the ring pipe structure to the space S between the fins is 0.35-0.4.

Furthermore, the ratio h2/S of the projection height h2 of the side convex structure to the fin spacing S is 0.35-0.4.

Further, the fin base body is also provided with: the pipe hole structure is located in the annular groove, the annular groove and the pipe hole structure are arranged concentrically, the periphery of the annular groove is connected with the first corrugated surface and the second corrugated surface, and the protruding portions are located outside the annular groove.

Furthermore, two second corrugated surfaces are arranged between the two first corrugated surfaces and are adjacently arranged, and the two second corrugated surfaces are intersected to form a valley line; the joint of the annular groove and the first corrugated surface forms two symmetrical arc-shaped surfaces, and the joint of the annular groove and the two second corrugated surfaces forms two symmetrical planes.

Further, the annular groove is tangent to the valley line in the direction perpendicular to the incoming flow; the included angle theta between the generatrix of the arc-shaped surface and the central axis of the heat exchange tube is 45 degrees.

Further, the ratio D1/D of the maximum outer diameter D1 of the annular groove to the outer diameter D of the heat exchange tube is 1.6-1.7.

Further, the two first corrugated surfaces are symmetrically arranged relative to the pipe hole structure, and the two second corrugated surfaces are symmetrically arranged relative to the pipe hole structure.

Furthermore, the ratio D1/D of the inner diameter D1 of the pipe hole structure to the outer diameter D of the heat exchange pipe is 1.025-1.035.

According to another aspect of the present invention, there is provided a heat exchanger comprising the fin structure described above.

The corrugated fin is structurally improved, and the plurality of bosses are arranged on the periphery of the pipe hole structure, so that airflow disturbance near the pipe hole structure (the installed heat exchanger) can be enhanced under the action of the bosses, the flow speed of a local area is improved, the mixing of cold and hot fluids is enhanced, the effective heat exchange area of the fin is increased, and the heat exchange performance of the heat exchanger is enhanced. Compared with a windowing fin, the fin structure provided by the invention has the advantages that the surface of the fin is not easy to frost under a wet working condition, and the condition of flow channel blockage can be effectively reduced. Compared with the common corrugated fin, the fin structure can effectively increase the heat exchange area and further improve the heat exchange effect.

Drawings

FIG. 1 is a schematic plan view of a fin structure of an embodiment of the invention;

FIG. 2 is a schematic perspective view of a fin structure according to an embodiment of the present invention;

FIG. 3 is a cross-sectional view A-A of the fin structure of FIG. 1;

FIG. 4 is a B-B cross-sectional view of the fin structure of FIG. 1;

FIG. 5 is a graph comparing data of heat exchange quantity Q with inlet wind speed;

FIG. 6 is a data comparison graph of Nu with inlet wind speed;

FIG. 7 is a graph of data comparing thermal resistance R with inlet wind speed;

FIG. 8 is a schematic diagram showing the comparison of flow field characteristics in the flow channel at an inlet wind speed of 2 m/s;

FIG. 9 is a schematic diagram showing the comparison of flow field characteristics in the flow channel at an inlet wind speed of 4 m/s;

FIG. 10 is a comparison of flow field characteristics in a flow channel at an inlet wind speed of 6 m/s.

Detailed Description

The invention is described in further detail below with reference to the figures and the examples, but without limiting the invention.

Referring to fig. 1 to 4, according to an embodiment of the present invention, a fin structure is provided, the fin structure includes a fin base 10 and a plurality of protrusions, the fin base 10 has a tube hole structure 20 for passing through a heat exchange tube, and the fin base 10 is a corrugated fin; the projections are provided on the fin base 10, and a plurality of projections surround the outer periphery of the tube hole structure 20.

The corrugated fin is structurally improved, and the plurality of bosses are arranged on the periphery of the pipe hole structure, so that airflow disturbance near the pipe hole structure (the installed heat exchanger) can be enhanced under the action of the bosses, the flow speed of a local area is improved, the mixing of cold and hot fluids is enhanced, the effective heat exchange area of the fin is increased, and the heat exchange performance of the heat exchanger is enhanced. Compared with a windowing fin, the fin structure provided by the invention has the advantages that the surface of the fin is not easy to frost under a wet working condition, and the condition of flow channel blockage can be effectively reduced. Compared with the common corrugated fin, the fin structure can effectively increase the heat exchange area and further improve the heat exchange effect.

With reference to fig. 1 and 2, the fin base 10 includes a plurality of first corrugated surfaces 11 and a plurality of second corrugated surfaces 12, the first corrugated surfaces 11 are spaced apart from the second corrugated surfaces 12, and the first corrugated surfaces 11 have a greater corresponding node length L1 than the second corrugated surfaces 12 have a corresponding node length L2. That is, the fin base 10 has a sheet surface divided into a large corrugated surface and a small corrugated surface, the first corrugated surface being the large corrugated surface, the second corrugated surface being the small corrugated surface, and the corrugated surfaces being spread in an M-shape in the direction of air flow.

Two second corrugated surfaces 12 are arranged between the two first corrugated surfaces 11, and the two second corrugated surfaces 12 are adjacently arranged. Preferably, the two first corrugated surfaces 11 are symmetrically arranged with respect to the pipe hole structure 20, the two second corrugated surfaces 12 are symmetrically arranged with respect to the pipe hole structure 20, and the two second corrugated surfaces 12 intersect to form a valley line. In the fin base 10 of the present embodiment, the first corrugated surface and the second corrugated surface are arranged such that the surface of the integrated sheet is spread in an M-shape along the direction of the air flow.

Further preferably, the ratio h1/S of the corrugation height h1 to the fin spacing S of the fin base 10 is 0.58-0.62, and L1/L2 is 1.5-1.7. The relationship between the corrugation height and the fin spacing, and the relationship between the node length L1 corresponding to the first corrugation surface 11 and the node length L2 corresponding to the second corrugation surface 12 can improve the heat exchange capability of the fin.

Referring to fig. 2, the plurality of protrusions include a collar structure 31 and a side protrusion structure 32, the collar structure 31 is protrudingly disposed on the first corrugated surface 11; the side convex structure 32 is convexly arranged on the second corrugated surface 12. The circular pipe structure 31 and the side convex structure 32 are reinforced to fluid disturbance, and the two structures are arranged on different corrugated surfaces so as to delay the phenomenon of flow separation of a boundary layer and improve the heat exchange performance of the fins.

The ring pipe structure 31 is a circular convex structure, the number of the ring pipe structures 31 is multiple, and the plurality of ring pipe structures 31 are symmetrically distributed on the periphery of the pipe hole structure 20. In the present embodiment, the collar structure is a four-segment annular protrusion structure symmetrically arranged on the first corrugated surface 11.

The side convex structures 32 are boss structures, the number of the side convex structures 32 is multiple, and the plurality of side convex structures 32 are symmetrically distributed on the periphery of the pipe hole structure 20. The side convex structures 32 are four-section square-platform convex structures symmetrically arranged on the second corrugated surface 12, and the side convex structures 32 are in a rectangular square-platform shape. The arrangement of the side convex structure 32 and the circular pipe structure 31 strengthens the air flow disturbance near the heat exchange pipe, improves the flow velocity of a local area, enhances the mixing of cold and hot fluids, reduces the thickness of a boundary layer, obviously reduces the area of the tail trace behind the pipe, and increases the effective heat exchange area of the fin.

In order to take account of the balance between the airflow and the height of the collar structure 31, the ratio h3/S of the height h3 of the projections of the collar structure 31 to the distance S between the fins is 0.35-0.4.

In order to consider the balance relationship between the air flow and the height of the side convex structure 32, the ratio h2/S of the convex height h2 of the side convex structure 32 to the fin spacing S is 0.35-0.4.

Preferably, the fin base 10 is further provided with an annular groove 40, the tube hole structure 20 is located in the annular groove 40, the annular groove 40 is concentrically arranged with the tube hole structure 20, the outer periphery of the annular groove 40 is connected with the first corrugated surface 11 and the second corrugated surface 12, and the protrusions are located outside the annular groove 40. The structure setting of annular groove 40 is convenient for the peripheral stamping forming of side convex structure and ring canal structure, has promoted the technology practicality, and the processing degree of difficulty can be simplified to the structure of annular groove 40, has reduced the processing cost of fin structure, possesses very high industrial value.

Two second corrugated surfaces 12 are arranged between the two first corrugated surfaces 11, the two second corrugated surfaces 12 are arranged adjacently, and the two second corrugated surfaces 12 intersect to form a valley line. The joint of the annular groove 40 and the first corrugated surface 11 forms two symmetrical arc-shaped surfaces, and the joint of the annular groove 40 and the two second corrugated surfaces 12 forms two symmetrical planes. The annular groove 40 is tangential to the valley line in the direction perpendicular to the incoming flow; the included angle theta between the generatrix of the arc-shaped surface and the central axis of the heat exchange tube is 45 degrees.

The ratio D1/D of the maximum outer diameter D1 of the annular groove 40 to the outer diameter D of the heat exchange tube is 1.6-1.7. The ratio D1/D of the inner diameter D1 of the pipe hole structure 20 to the outer diameter D of the heat exchange pipe is 1.025-1.035.

The invention also provides an embodiment of the heat exchanger, and the heat exchanger comprises the fin structure of the embodiment.

In the embodiment, simulation verification is performed through ANSYS Fluent, the inlet air flow rates during simulation are respectively 2m/s, 3m/s, 4m/s, 5m/s and 6m/s, the inlet air temperature is 35 ℃, the pipe wall temperature is 50.62 ℃, and the change conditions of the heat exchange quantity Q, the Nu-Seal number and the thermal resistance R before and after the side convex structure and the ring pipe structure are set and the flow field characteristics in the flow channel are compared under the same flow condition, wherein the heat exchange quantity Q, the Nu-Seal number and the thermal resistance R are defined as follows:

Q＝mC_p(T_out-T_in)

m is mass flow, and the unit is kg/s; cp is the specific heat capacity at constant pressure, and the unit is j/(kg. K); t is_outIs the average temperature of the air flow channel outlet, and the unit is K; t is_inIs the average air flow inlet temperature in K.

h is convection currentThermal coefficient in units of w/(m)²K); de is the equivalent diameter of the air circulation surface, and the unit is m; λ is the thermal conductivity of air, with the unit w/(m · K).

S is the heat exchange surface area of the fin, and the unit is m²(ii) a Δ Tm is the log mean temperature difference in K.

ΔT_max＝T_wall-T_inΔT_min＝T_wall-T_out

T_wallIs the average temperature of the fin surface in K.

The heat exchange quantity Q, the Nu and the R can be calculated by extracting simulation data, and the larger the heat exchange quantity Q and the Nu are, or the smaller the R is, the better the heat exchange performance is.

The change of the heat exchange quantity Q along with the wind speed at the inlet is shown in figure 5, the lifting quantity of the heat exchange quantity can be increased along with the increase of the wind speed at the inlet, and the lifting quantity is increased to 4.37 percent at 6m/s compared with the original fins. In fig. 5, the new fin is the fin mechanism of the present invention, and the original fin is the fin structure of the prior art.

The change of the Nu along with the inlet wind speed is shown in FIG. 6, the Nu along with the inlet wind speed increases gradually, and at 2m/s, the Nu relative to the original fin increases the maximum, is 11.16%. In fig. 6, the new fin is the fin mechanism of the present invention, and the original fin is the fin structure of the prior art.

The variation of the thermal resistance R along with the inlet wind speed is shown in FIG. 7, the thermal resistance is gradually reduced along with the increase of the inlet wind speed, and the thermal resistance is reduced to 14.52% at 2m/s, which is the largest compared with the original fins. In fig. 7, the new fin is the fin mechanism of the present invention, and the original fin is the fin structure of the prior art.

The invention also provides the comparison of the flow field characteristics in the flow channel before and after the side convex structure and the ring pipe structure are arranged, and the inlet wind speeds are 2m/s, 4m/s and 6m/s, as shown in figures 8-10. Wherein, FIG. 8 shows the comparison of flow field characteristics in the flow channel at an inlet wind speed of 2 m/s; FIG. 9 shows a comparison of flow field characteristics in the flow channel at an inlet wind speed of 4 m/s; FIG. 10 shows a comparison of flow field characteristics in the flow channel at an inlet wind speed of 6 m/s.

The fin structure of the prior art is compared with the fin structure of the invention at different inlet wind speeds, the same flow field characteristic difference is shown, the arrangement of the side convex structure and the circular pipe structure strengthens the airflow disturbance near the heat exchange pipe, improves the flow speed of the local area, enhances the mixing of cold and hot fluids, reduces the thickness of a boundary layer, obviously reduces the wake area behind the pipe, increases the effective heat exchange area of the fin, and thus strengthens the heat exchange performance of the heat exchanger.

It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular is intended to include the plural unless the context clearly dictates otherwise, and it should be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of features, steps, operations, devices, components, and/or combinations thereof.

It should be noted that the terms "first," "second," and the like in the description and claims of this application and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the application described herein are capable of operation in sequences other than those illustrated or described herein.

Of course, the above is a preferred embodiment of the present invention. It should be noted that, for a person skilled in the art, several modifications and refinements can be made without departing from the basic principle of the invention, and these modifications and refinements are also considered to be within the protective scope of the invention.