Horizontal heat exchange tubes, heat exchangers and air conditioners

Abstract

The present invention discloses a horizontal heat exchange tube, a heat exchanger and an air conditioner. A plurality of first grooves are sequentially arranged along the axial direction on the inner wall of the horizontal heat exchange tube. Each first groove is arranged in a circle along the circumferential direction. The groove width of the first groove gradually decreases from the top to the bottom of the first groove. The first groove arranged on the inner wall of the horizontal heat exchange tube proposed by the present invention causes boundary layer disturbance to strengthen the convective heat exchange between the gaseous refrigerant and the inner wall of the horizontal heat exchange tube. At the same time, the groove width of the first groove gradually decreases from the top to the bottom, so that the liquid film thickness at the top of the horizontal heat exchange tube is smaller than the liquid film thickness at the bottom of the horizontal heat exchange tube, so that the condensation heat transfer coefficient at the top of the horizontal heat exchange tube is greatly increased.

Description

Technical Field

[0001] The invention relates to the technical field of air conditioning equipment, and in particular to a horizontal heat exchange tube, a heat exchanger and an air conditioner. Background Art

[0002] Heat exchange tubes are one of the components of heat exchangers, used for heat exchange between two media. Heat exchangers can use various heat exchange tubes according to the performance and purpose of the product, and the forms of heat exchange tubes are also various. Since the complex gas-liquid two-phase tube medium undergoes phase change during the heat exchange process, the ordinary tube diameter cannot meet its best heat exchange performance. Therefore, it is necessary to optimize the structure of the heat exchange tube to improve the heat exchange efficiency of the heat exchange tube. Summary of the invention

[0003] In order to solve the technical problem of low heat exchange efficiency of ordinary heat exchange tubes in the prior art, the present invention provides a horizontal heat exchange tube, a heat exchanger and an air conditioner.

[0004] The technical solution adopted by the present invention is:

[0005] The present invention proposes a horizontal heat exchange tube, a heat exchanger and an air conditioner. A plurality of first grooves are arranged on the inner wall of the horizontal heat exchange tube in sequence along the axial direction. Each of the first grooves is arranged in a circle along the circumferential direction. The groove width of the first groove gradually decreases from the top to the bottom of the first groove.

[0006] Furthermore, a plurality of second grooves are sequentially arranged on the inner wall of the horizontal heat exchange tube along the circumferential direction, each of the second grooves extends along the axial direction and has a constant groove width, and the second grooves intersect with the first grooves.

[0007] Furthermore, the depth of the first groove ranges from 0.6 mm to 1 mm.

[0008] Furthermore, the width of the first groove at the top is in the range of 1 mm to 2 mm.

[0009] Furthermore, the groove width at the bottom of the first groove ranges from 0.4 mm to 0.6 mm.

[0010] Furthermore, the width of the second groove is in the range of 0.1 mm to 0.3 mm.

[0011] Furthermore, the depth of the second groove ranges from 0.2 mm to 0.4 mm.

[0012] Furthermore, the distance between the centers of any two adjacent first grooves is in the range of 2 mm to 3 mm.

[0013] A heat exchanger comprises the horizontal heat exchange tubes described above.

[0014] An air conditioner comprising the heat exchanger described above.

[0015] Compared with the prior art, the first groove provided on the inner wall of the horizontal heat exchange tube proposed in the present invention causes boundary layer disturbance to strengthen the convective heat exchange between the gaseous refrigerant and the inner wall of the horizontal heat exchange tube. At the same time, the groove width of the first groove gradually decreases from the top to the bottom, so that the liquid film thickness at the top of the horizontal heat exchange tube is smaller than the liquid film thickness at the bottom of the horizontal heat exchange tube, so that the condensation heat transfer coefficient at the top of the horizontal heat exchange tube is greatly increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments or the description of the prior art 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 labor.

[0017] Figure 1 Schematic diagram of the axial cross-sectional structure of a horizontal heat exchange tube in an embodiment of the present invention;

[0018] Figure 2 It is a structural schematic diagram of another viewing angle of the axial section of the horizontal heat exchange tube in an embodiment of the present invention;

[0019] Figure 3 Schematic diagram of the radial cross-sectional structure of a horizontal heat exchange tube in an embodiment of the present invention;

[0020] 1. Horizontal heat exchange tube; 2. First groove; 3. Second groove; 4. Protruding teeth. DETAILED DESCRIPTION

[0021] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0022] Heat exchange tubes are one of the components of heat exchangers, used for heat exchange between two media. Heat exchangers can use various heat exchange tubes according to the performance and purpose of the product, and the forms of heat exchange tubes are also various. Since the complex gas-liquid two-phase tube medium undergoes phase change during the heat exchange process, the ordinary tube diameter cannot meet its best heat exchange performance. Therefore, it is necessary to optimize the structure of the heat exchange tube to improve the heat exchange efficiency of the heat exchange tube.

[0023] Therefore, in order to solve the technical problem of low heat exchange efficiency of heat exchange tubes in the prior art, the present invention proposes a horizontal heat exchange tube, on the inner wall of which a plurality of first grooves are sequentially arranged along the axial direction, each first groove is arranged in a circle along the circumferential direction, and the groove width of the first groove gradually decreases from the top of the first groove to the bottom of the first groove. Therefore, the groove width at the top of the first groove is the largest, and the groove width at the bottom of the first groove is the smallest, so when the gaseous refrigerant flows along the horizontal heat exchange tube, the liquid film thickness at the top and bottom of the horizontal heat exchange tube is uneven, and the uneven distribution of the condensed liquid film will reduce the average thermal resistance, greatly increase the heat flux density, and thus improve the heat exchange efficiency of the horizontal heat exchange tube.

[0024] In summary, the first groove with gradually changing groove width provided in the horizontal heat exchange tube proposed by the present invention enables the refrigerant to form liquid films of different thicknesses on the inner wall of the horizontal heat exchange tube, thereby improving the heat exchange efficiency of the horizontal heat exchange tube.

[0025] The structure and working principle of the horizontal heat exchange tube proposed by the present invention are explained below in conjunction with the drawings and embodiments.

[0026] like Figure 1-Figure 3 As shown, in this embodiment, the horizontal heat exchange tube 1 is columnar, and a plurality of first grooves 2 are evenly spaced in sequence on the inner wall of the horizontal heat exchange tube along the axial direction of the horizontal heat exchange tube, each first groove 2 is arranged in a circle along the circumference of the horizontal heat exchange tube, and the first groove 2 is arranged in a circle along the circumference of the horizontal heat exchange tube. The groove width of the first groove 2 changes gradually, the groove width at the top of the first groove 2 is the largest, and the groove width at the bottom of the first groove 2 is the smallest, and the groove width of the first groove gradually decreases from the top of the first groove 2 to the bottom of the first groove 2. When the gaseous refrigerant flows axially in the horizontal heat exchange tube, the boundary layer is disturbed by the first groove and destroyed, which strengthens the convection heat exchange between the gaseous refrigerant and the inner wall of the horizontal heat exchange tube, accelerates the condensation of the refrigerant into liquid on the inner wall of the horizontal heat exchange tube, and due to the effect of surface tension, most of the liquid refrigerant accumulates in the first groove.

[0027] Furthermore, let the width of the top of the first groove be r 1 , the width of the bottom of the first groove is r 2 , r 1 Greater than r 2 Due to the influence of the width of the first groove, crescent-shaped condensate with different radii will be formed in the first groove. According to the Young-Laplace equation, the pressures generated by the condensate in the first groove at the top of the horizontal heat exchange tube and the first groove at the bottom of the horizontal heat exchange tube are:

[0028]

[0029]

[0030] In the formula, γ LV is the surface tension coefficient, due to r 1 >r 2 Therefore, the pressure p generated by the condensate in the first groove at the top of the horizontal heat exchange tube is l1 Greater than the pressure p generated by the condensate in the first groove at the bottom of the horizontal heat exchange tube l2 , under the action of pressure difference or surface tension, the condensate at the top of the horizontal heat exchange tube flows continuously to the bottom of the horizontal heat exchange tube. Therefore, the liquid refrigerant forms layers in the horizontal heat exchange tube, and the thickness of the liquid film at the bottom of the horizontal heat exchange tube is greater than the thickness of the liquid film at the top of the horizontal heat exchange tube, which greatly increases the condensation heat transfer coefficient at the top of the horizontal heat exchange tube. (Similar to the "Gregoring" effect - the condensation heat transfer coefficient of the heat exchange tube with uneven liquid film thickness is greater than the condensation heat transfer coefficient of the heat exchange tube with uniform liquid film thickness).

[0031] In summary, the first groove provided on the inner wall of the horizontal heat exchange tube proposed by the present invention causes boundary layer disturbance to strengthen the convective heat exchange between the gaseous refrigerant and the inner wall of the horizontal heat exchange tube. At the same time, the groove width of the first groove gradually decreases from the top to the bottom, so that the liquid film thickness at the top of the horizontal heat exchange tube is smaller than the liquid film thickness at the bottom of the horizontal heat exchange tube, so that the condensation heat transfer coefficient at the top of the horizontal heat exchange tube is greatly increased.

[0032] Further, such as Figure 1-Figure 3 As shown, in order to increase the heat exchange area of ​​the horizontal heat exchange tube, a plurality of second grooves 3 are evenly spaced in sequence on the inner wall of the horizontal heat exchange tube 1 along the circumference of the horizontal heat exchange tube. Each second groove extends along the circumference of the horizontal heat exchange tube. The length of each second groove is equal to the length of the horizontal heat exchange tube, and each second groove is parallel to the axial direction of the horizontal heat exchange tube. The groove width of each second groove is fixed. The second groove intersects with the first groove, so a convex tooth 4 is formed between any two adjacent first grooves and any two adjacent second grooves. At the same time, the combination of the second groove and the first groove also intensifies the curvature change of the surface of the inner wall of the horizontal heat exchange tube, increases the unevenness of the liquid film thickness in all directions, thereby locally strengthening the "Gregoring" effect and improving the condensation heat transfer coefficient of the horizontal heat exchange tube.

[0033] Furthermore, the depth of the first groove ranges from 0.6 mm to 1 mm. Preferably, the depth of the first groove is 0.8 mm.

[0034] Further, the groove width at the top of the first groove is in the range of 1 mm to 2 mm. Preferably, the groove width at the top of the first groove is 1.5 mm.

[0035] Furthermore, the groove width at the bottom of the first groove ranges from 0.4 mm to 0.6 mm. Preferably, the groove width at the bottom of the first groove is 0.5 mm.

[0036] Furthermore, the width of the second groove is in the range of 0.1 mm to 0.3 mm. Preferably, the width of the second groove is 0.2 mm.

[0037] Further, the depth of the second groove ranges from 0.2 mm to 0.4 mm. Preferably, the depth of the second groove is 0.3 mm.

[0038] Further, the distance between the centers of any two adjacent first grooves is in the range of 2 mm to 3 mm. Preferably, the distance between the centers of any two adjacent first grooves is 2.5 mm.

[0039] In addition, the present invention also proposes a heat exchanger, in which the horizontal heat exchange tube mentioned above is arranged. Specifically, at least one horizontal heat exchange tube is arranged in the heat exchanger, and a plurality of first grooves are evenly spaced in sequence along the axial direction of the horizontal heat exchange tube on the inner wall of the horizontal heat exchange tube, each first groove is arranged in a circle along the circumference of the horizontal heat exchange tube, and the first groove is arranged in a circle along the circumference of the horizontal heat exchange tube. The groove width of the first groove changes gradually, the groove width at the top of the first groove is the largest, and the groove width at the bottom of the first groove is the smallest, and the groove width of the first groove gradually decreases from the top of the first groove to the bottom of the first groove. Preferably, the depth of the first groove is 0.8 mm, the groove width at the top of the first groove is 1.5 mm, the groove width at the bottom of the first groove is 0.5 mm, and the spacing between the centers of any two adjacent first grooves is 2.5 mm. Under this size design, the first groove can maximize the condensation heat transfer coefficient at the top of the horizontal heat exchange tube. In addition, a plurality of second grooves are evenly spaced in sequence on the inner wall of the horizontal heat exchange tube along the circumference of the horizontal heat exchange tube, each second groove extends along the circumference of the horizontal heat exchange tube, the length of each second groove is equal to the length of the horizontal heat exchange tube, and each second groove is parallel to the axial direction of the horizontal heat exchange tube, the groove width of each second groove is fixed, and the second groove intersects with the first groove, so a convex tooth is formed between any two adjacent first grooves and any two adjacent second grooves. Preferably, the width of the second groove is 0.2 mm, and the depth of the second groove is 0.3 mm. Under this size design, the second groove can not only increase the heat exchange area of ​​the horizontal heat exchange tube, but also further improve the condensation heat transfer coefficient of the horizontal heat exchange tube.

[0040] In addition, the present invention also proposes an air conditioner, in which a heat exchanger is provided, and the heat exchanger is provided with the horizontal heat exchange tube mentioned above, and a plurality of first grooves are evenly spaced in sequence along the axial direction of the horizontal heat exchange tube on the inner wall of the horizontal heat exchange tube, and each first groove is arranged in a circle along the circumference of the horizontal heat exchange tube, and the first groove is arranged in a circle along the circumference of the horizontal heat exchange tube. The groove width of the first groove changes gradually, the groove width at the top of the first groove is the largest, and the groove width at the bottom of the first groove is the smallest, and the groove width of the first groove gradually decreases from the top of the first groove to the bottom of the first groove. Preferably, the depth of the first groove is 0.8 mm, the groove width at the top of the first groove is 1.5 mm, the groove width at the bottom of the first groove is 0.5 mm, and the distance between the centers of any two adjacent first grooves is 2.5 mm. Under this size design, the first groove can maximize the condensation heat transfer coefficient at the top of the horizontal heat exchange tube. In addition, a plurality of second grooves are evenly spaced in sequence on the inner wall of the horizontal heat exchange tube along the circumference of the horizontal heat exchange tube, each second groove extends along the circumference of the horizontal heat exchange tube, the length of each second groove is equal to the length of the horizontal heat exchange tube, and each second groove is parallel to the axial direction of the horizontal heat exchange tube, the groove width of each second groove is fixed, and the second groove intersects with the first groove, so a convex tooth is formed between any two adjacent first grooves and any two adjacent second grooves. Preferably, the width of the second groove is 0.2 mm, and the depth of the second groove is 0.3 mm. Under this size design, the second groove can not only increase the heat exchange area of ​​the horizontal heat exchange tube, but also further improve the condensation heat transfer coefficient of the horizontal heat exchange tube.

[0041] It should be noted that the terms used above are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0042] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present application. At the same time, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant field may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the authorization specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so that once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0043] In the description of the present application, it should be understood that the directions or positional relationships indicated by directional words such as "front, back, up, down, left, right", "lateral, vertical, perpendicular, horizontal" and "top, bottom" are usually based on the directions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. Unless otherwise specified, these directional words do not indicate or imply that the device or element referred to must have a specific direction or be constructed and operated in a specific direction, and therefore cannot be understood as limiting the scope of protection of the present application; the directional words "inside and outside" refer to the inside and outside relative to the contours of each component itself.

[0044] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0045] In addition, it should be noted that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of this application.

[0046] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. Horizontal heat exchange tubes, It is characterized in that A plurality of first grooves are sequentially arranged at intervals along the axial direction on the inner wall of the horizontal heat exchange tube, each of the first grooves is arranged in a circle along the circumferential direction, and the groove width of the first groove gradually decreases from the top to the bottom of the first groove; so that when the gaseous refrigerant flows along the horizontal heat exchange tube, the liquid film thickness at the bottom of the horizontal heat exchange tube is greater than the liquid film thickness at the top of the horizontal heat exchange tube, thereby increasing the condensation heat transfer coefficient at the top of the horizontal heat exchange tube; The width of the first groove at the top is in the range of 1 mm-2 mm, and the width of the first groove at the bottom is in the range of 0.4 mm-0.6 mm.

2. The horizontal heat exchange tube according to claim 1, It is characterized in that A plurality of second grooves are arranged on the inner wall of the horizontal heat exchange tube in a circumferential direction in sequence and at intervals, each of the second grooves extends in the axial direction and has a constant groove width, and the second grooves intersect with the first grooves.

3. The horizontal heat exchange tube according to claim 1, It is characterized in that The depth of the first groove ranges from 0.6 mm to 1 mm.

4. The horizontal heat exchange tube according to claim 2, It is characterized in that The width of the second groove is in the range of 0.1 mm to 0.3 mm.

5. The horizontal heat exchange tube according to claim 2, It is characterized in that The depth of the second groove ranges from 0.2 mm to 0.4 mm.

6. The horizontal heat exchange tube according to claim 1, It is characterized in that The distance between the centers of any two adjacent first grooves is in the range of 2 mm to 3 mm.

7. Heat exchanger, It is characterized in that It comprises a horizontal heat exchange tube as described in any one of claims 1 to 6.

8. Air conditioning, It is characterized in that Comprising the heat exchanger as claimed in claim 7.

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