CN215676622U

CN215676622U - Fin structure, heat exchanger and air conditioner

Info

Publication number: CN215676622U
Application number: CN202121719422.6U
Authority: CN
Inventors: 熊建国; 张凯; 李明佳; 张仕强; 何雅玲; 刘华
Original assignee: Gree Electric Appliances Inc of Zhuhai; Xian Jiaotong University
Current assignee: Gree Electric Appliances Inc of Zhuhai; Xian Jiaotong University
Priority date: 2021-07-27
Filing date: 2021-07-27
Publication date: 2022-01-28
Anticipated expiration: 2031-07-27

Abstract

The utility model discloses a fin structure, a heat exchanger and an air conditioner, wherein the fin structure comprises: a fin base body; surface, the first corrugated surface; the tube hole structure is arranged on the fin base and used to pass the heat exchange tube, and the tube hole structure is located at the position of the two second corrugated surfaces; the two first corrugated surfaces are relative to the center of the tube hole structure Symmetrically arranged, the two second corrugated surfaces are arranged symmetrically with respect to the center of the tube hole structure; ring tube structure, the ring tube structure is protruded and arranged on the first corrugated surface located downstream of the tube hole structure in the airflow direction, and the ring tube structure surrounds the tube hole The outer periphery of the structure; the side convex structure, the side convex structure is protrudingly arranged on the second corrugated surface located upstream in the airflow direction among the two second corrugated surfaces, and the side convex structure surrounds the outer periphery of the tube hole structure. The fin structure and the heat exchanger of the utility model can effectively improve the heat exchange effect of the fins.

Description

Fin structure, heat exchanger and air conditioner

Technical Field

The utility model relates to the technical field of refrigeration equipment, in particular to a fin structure, a heat exchanger and an air conditioner.

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.

SUMMERY OF THE UTILITY MODEL

The embodiment of the utility model provides a fin structure, a heat exchanger and an air conditioner, 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 comprises a first corrugated surface, two second corrugated surfaces and a first corrugated surface which are sequentially connected along the airflow flowing direction, and the length L1 of a corresponding node of the first corrugated surface is greater than the length L2 of a corresponding node of the second corrugated surface; the tube hole structures are arranged on the fin base body and used for penetrating the heat exchange tubes, and the tube hole structures are located at the positions of the two second corrugated surfaces; the two first corrugated surfaces are symmetrically arranged relative to the circle center of the pipe hole structure, and the two second corrugated surfaces are symmetrically arranged relative to the circle center of the pipe hole structure; the ring pipe structure is arranged on a first corrugated surface at the downstream of the airflow direction of the pipe hole structure in a protruding mode and surrounds the periphery of the pipe hole structure; and the side convex structure is convexly arranged on the second corrugated surface which is positioned on the upstream of the two second corrugated surfaces in the airflow direction and surrounds the periphery of the pipe hole structure.

Further, the two second corrugated surfaces are intersected to form a valley line, and the valley line penetrates through the circle center of the pipe hole structure.

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

Furthermore, two symmetrical arc-shaped surfaces are formed at the joint of the annular groove and the first corrugated surface, and two symmetrical planes are formed at the joint of the annular groove and the two second corrugated surfaces.

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 annular groove.

Further, the side convex structures are boss structures, the number of the side convex structures is multiple, and the side convex structures are symmetrically distributed on the periphery of the annular groove.

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.

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 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.

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.

Furthermore, the fin base body is of an M-shaped structure integrally, and the two second corrugated surfaces are of a V-shaped structure integrally.

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

According to another aspect of the present invention, there is provided an air conditioner including the heat exchanger described above.

The utility model is improved based on the corrugated fins, effectively avoids the reduction of through-flow gaps on the premise of ensuring the heat exchange performance, and is not easy to frost and block under the wet working condition. A side convex structure is additionally arranged on a second corrugated surface at the upstream relative to the airflow direction, the position of the side convex structure is far away from the heat exchange tube, the side convex structure is determined by optimizing a field cooperation principle, and the main strengthening principle is to slow down the separation of the corrugated surface and fluid and increase the disturbance of the heat exchange area and the main flow. The annular pipe structure is additionally arranged on the first corrugated surface at the downstream in the direction opposite to the airflow direction, the strengthening principle is mainly to slow down the separation of the wake vortex and the corrugated surface, namely different structures are arranged at different positions to improve the heat exchange effect, and the flow resistance loss is smaller.

The corrugated fin is structurally improved, and the effective heat exchange area of the corrugated fin is increased, so that the heat exchange performance of the heat exchanger is enhanced. Compared with a windowing fin, the fin structure provided by the utility model 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 utility model;

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 temperature distribution test simulation of a prior art fin structure at an inlet wind speed of 2 m/s;

FIG. 6 is a schematic view of the flow field characteristics of a prior art fin structure at an inlet wind speed of 2 m/s;

FIG. 7 is a temperature distribution test simulation of the fin structure of the present invention at an inlet wind speed of 2 m/s;

FIG. 8 is a schematic view of the flow field characteristics of the fin structure of the present invention at an inlet wind speed of 2 m/s.

Detailed Description

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

Referring to fig. 1 to 4, according to an embodiment of the present invention, there is provided a fin structure including a fin base 10, a tube hole structure 20, a collar structure 31, and a side protrusion structure 32. The fin base body 10 comprises a first corrugated surface 11, two second corrugated surfaces 12 and a first corrugated surface 11 which are sequentially connected along the airflow flowing direction, wherein the corresponding node length L1 of the first corrugated surface 11 is greater than the corresponding node length L2 of the second corrugated surface 12. The pipe hole structure 20 is arranged on the fin base body 10 and used for penetrating through the heat exchange pipe, and the pipe hole structure 20 is positioned on the two second corrugated surfaces 12; the two first corrugated surfaces 11 are symmetrically arranged with respect to the center of the pipe hole structure 20, and the two second corrugated surfaces 12 are symmetrically arranged with respect to the center of the pipe hole structure 20. The ring pipe structure 31 is arranged on the first corrugated surface 11 which is arranged at the downstream of the pipe hole structure 20 in the airflow direction in a protruding mode, and the ring pipe structure 31 surrounds the periphery of the pipe hole structure 20; the side convex structure 32 is convexly arranged on the second corrugated surface 12 which is positioned at the upstream of the air flow direction in the two second corrugated surfaces 12, and the side convex structure 32 surrounds the periphery of the pipe hole structure 20.

The two second corrugation surfaces 12 intersect to form a valley line which passes through the center of the pipe hole structure 20. The fin base 10 has a sheet surface divided into a large corrugated surface and a small corrugated surface, the first corrugated surface being a large corrugated surface, the second corrugated surface being a small corrugated surface, and the corrugated surfaces being M-shaped in the airflow direction. The fin base body 10 is of an M-shaped structure as a whole, and the two second corrugated surfaces 12 are of a V-shaped structure as a whole.

The fin base body 10 is further provided with an annular groove 40, the pipe hole structure 20 is located in the annular groove 40, the annular groove 40 and the pipe hole structure 20 are concentrically arranged, the periphery of the annular groove 40 is connected with the first corrugated surface 11 and the second corrugated surface 12, and the collar structure 31 and the side convex structure 32 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.

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 collar structure 31 is an annular convex structure, the number of the collar structures 31 is multiple, and the plurality of collar structures 31 are symmetrically distributed on the periphery of the annular groove 40. In the present embodiment, the collar structure is a two-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 the side convex structures 32 are symmetrically distributed on the periphery of the annular groove 40. The side convex structures 32 are two end 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 ratio h1/S of the corrugation height h1 of the fin substrate 10 to the fin spacing S 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.

The ratio h3/S of the protrusion height h3 of the ring tube structure 31 to the fin spacing S is 0.35-0.4. The ratio h2/S of the protrusion height h2 of the side protruding structure 32 to the fin spacing S is 0.35-0.4. 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 direction perpendicular to the incoming flow direction is a direction plane perpendicular to the blowing direction of the air flow.

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 utility model also provides an embodiment of the heat exchanger, and the heat exchanger comprises the fin structure of the embodiment.

The utility model also provides an embodiment of the air conditioner, which comprises the heat exchanger of the embodiment.

The simulation verification is carried out through ANSYS Fluent, the inlet air flow rate is 2m/s and 5m/s during simulation, the inlet air temperature is 35 ℃, the pipe wall temperature is 50.62 ℃, and the heat exchange performance of the fins is evaluated by using a j-f factor analysis method. j-f factor analysis was proposed by Kays and London in 1950, where f is a drag factor, indicating pressure drop performance; j is a heat transfer factor, representing the heat transfer performance; the area quality factor j/f ^1/3 is the evaluation index of the comprehensive performance of the heat exchange performance and the resistance, and the larger the factor is, the stronger the comprehensive performance is. The relevant definitions are as follows:

P_inthe average pressure at the inlet of the air flow channel; p_outIs the air flow channel outlet average pressure; ρ is the density of air; u. of_mThe average speed of the airflow in the flow channel; l is the distance between the inlet and the outlet of the flow passage.

Where μ is the dynamic viscosity of air. The heat exchange amount Q and the nussel number Nu are defined as follows:

Q＝mC_p(T_out-T_in)

m is mass flow; c_pIs a constant pressure specific heat capacity; t is_outIs the average temperature at the outlet of the air flow channel; t is_inIs the average temperature at the inlet of the air flow channel.

h is the convective heat transfer coefficient and has the unit of w/(m)²·K)；D_eEquivalent diameter for the air flow surface; λ is the thermal conductivity of air.

S is the heat exchange surface area of the fin; delta T_mIs the logarithmic mean temperature difference.

ΔT_max＝T_wall-T_inΔT_min＝T_wall-T_out

T_wallIs the average temperature of the fin surface.

The larger the heat exchange quantity Q and the Nu are, the better the heat exchange performance is. The heat exchange quantity Q, the Nu, the resistance factor f, the heat transfer factor j and the area quality factor j/f ^1/3 can be calculated by extracting simulation data, and the main results under the inlet wind speeds of 2m/s and 5m/s are as follows:

the first table and the second table show the same change conditions, and the heat exchange quantity Q, the Nu number Nu and the heat transfer factor j are increased after the side convex structure and the circular pipe structure are arranged, which shows that the heat exchange effect is improved after the improvement; the resistance factor f is increased along with the increase of the resistance factor f, the proportion of the resistance factor f is often higher than the change of the heat transfer factor j, which is the difficulty of the research of the heat transfer enhancement technology, and the increase amplitude of the flow resistance caused by the structure turbulent flow is reduced as much as possible while the heat transfer enhancement is carried out; considering the factor of the resistance factor f, the influence brought by the flow resistance can be comprehensively considered by using the area quality factor j/f ^1/3, and the table shows that the change value of the area quality factor j/f ^1/3 is lower than the change value of the heat transfer factor j, which indicates that the influence brought by the flow resistance is lower than the improvement of the heat transfer effect, namely the fin can improve the heat exchange performance under the condition of less influence on the flow resistance to a certain degree.

Referring to fig. 5 and 6, fig. 5 shows a simulation diagram of temperature distribution test of a fin structure in the prior art at an inlet wind speed of 2m/s, and fig. 6 shows a schematic diagram of flow field characteristics of the fin structure in the prior art at an inlet wind speed of 2 m/s. Referring to fig. 7 and 8, fig. 7 shows a simulation diagram of temperature distribution test of the fin structure of the utility model at an inlet wind speed of 2m/s, and fig. 8 shows a schematic diagram of flow field characteristics of the fin structure of the utility model at an inlet wind speed of 2 m/s. The comparison shows that: the arrangement of the side convex structure and the circular pipe structure strengthens the airflow disturbance near the heat exchange pipe, enhances the mixing of cold and hot fluids, improves the heat exchange effect of local areas, further increases the average temperature of outlet airflow, reduces the area of the tail trace behind the pipe by the airflow, increases the effective heat exchange area of fins, and further strengthens the heat exchange performance of the heat exchanger.

Actually measuring and comparing the heat exchange quantity difference between the fin heat exchanger in the prior art and the fin heat exchanger disclosed by the utility model at different wind speeds, and finding that the raised structure on the surface of the fin plays an obvious role in enhancing the heat exchange effect within the wind speed range of 1-2.25 m/s, so that the heat exchange quantity of the novel fin heat exchanger is obviously improved. See the following table for specific measured data:

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 utility model, and these modifications and refinements are also considered to be within the protective scope of the utility model.

Claims

1. a fin structure, is characterized in that, comprises:

A fin base (10), the fin base (10) comprises a first corrugated surface (11), two second corrugated surfaces (12), and a first corrugated surface (11) connected in sequence along the flow direction of the airflow, so The length L1 of the corresponding node of the first corrugated surface (11) is greater than the length L2 of the corresponding node of the second corrugated surface (12);

a tube hole structure (20), which is arranged on the fin base body (10) and used for passing heat exchange tubes, the tube hole structure (20) is located at the positions of the two second corrugated surfaces (12); two The first corrugated surfaces (11) are symmetrically arranged with respect to the center of the tube hole structure (20), and the two second corrugated surfaces (12) are symmetrically arranged with respect to the center of the tube hole structure (20). ;

A ring-pipe structure (31), the ring-pipe structure (31) is protrudingly disposed on the first corrugated surface (11) located downstream of the pipe hole structure (20) in the airflow direction, the ring-pipe structure (31) ) surrounds the outer periphery of the tube hole structure (20);

a side convex structure (32), the side convex structure (32) is protrudingly arranged on the second corrugated surface (12) located upstream in the airflow direction among the two second corrugated surfaces (12), the side convex structure (32) The convex structure (32) surrounds the outer periphery of the tube hole structure (20).

2 . The fin structure according to claim 1 , wherein two second corrugated surfaces ( 12 ) intersect to form a trough line, and the trough line passes through the center of the tube hole structure ( 20 ). 3 .

3. The fin structure according to claim 1 or 2, characterized in that, the fin base (10) is further provided with:

an annular groove (40), 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 annular groove (40) The outer circumference of the groove (40) is in contact with the first corrugated surface (11) and the second corrugated surface (12), and the annular pipe structure (31) and the lateral convex structure (32) are both located on the Outside the annular groove (40).

4. The fin structure according to claim 3, wherein,

Two symmetrical arc-shaped surfaces are formed where the annular groove (40) and the first corrugated surface (11) meet, and the annular groove (40) is connected to the two second corrugated surfaces ( 12) Two symmetrical planes are formed at the junction.

5 . The fin structure according to claim 3 , wherein the ring-pipe structure ( 31 ) is an annular convex structure, the number of the ring-pipe structures ( 31 ) is multiple, and a plurality of the rings The pipe structures (31) are symmetrically distributed on the outer circumference of the annular groove (40).

6 . The fin structure according to claim 3 , wherein the lateral convex structures ( 32 ) are boss structures, the number of the lateral convex structures ( 32 ) is plural, and a plurality of the lateral convex structures The symmetrical distribution of the structures (32) is on the periphery of the annular groove (40).

7. The fin structure according to claim 1, wherein the ratio h1/S of the corrugation height h1 of the fin base body (10) to the fin spacing S is 0.58-0.62, and L1/L2 is 1.5- 1.7.

8 . The fin structure according to claim 1 , wherein the ratio h3 /S of the raised height h3 of the annular tube structure (31) to the fin spacing S is 0.35-0.4. 9 .

9 . The fin structure according to claim 1 , wherein the ratio h2 /S of the convex height h2 of the lateral convex structure (32) to the fin spacing S is 0.35˜0.4. 10 .

10. The fin structure according to claim 4, wherein,

The annular groove (40) is tangent to the trough line in the vertical incoming flow direction; the included angle θ between the generatrix of the arc-shaped surface and the central axis of the heat exchange tube is 45°.

11. The fin structure according to claim 3, wherein 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.

12. 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.

13. The fin structure according to claim 2, wherein the fin base body (10) has an M-shaped structure as a whole, and the two second corrugated surfaces (12) have a V-shaped structure as a whole.

14. A heat exchanger, characterized by comprising the fin structure according to any one of claims 1-13.

15. An air conditioner, characterized by comprising the heat exchanger of claim 14.