High-efficiency reverse fin evaporation tube

Abstract

The utility model relates to a kind of high-efficiency inverted fin evaporation pipe, it is related to the technical field of evaporation heat exchange pipe in air conditioner, refrigeration system, solve the problem of how to significantly improve the comprehensive heat exchange performance of evaporation pipe in limited space. Including pipe body and the outer fin integrally formed with the pipe body, which is extended along the radial direction of the pipe body and extended around the pipe body in spiral state on the outer surface of the pipe body by the material on the pipe body;The outer fin is inclined to one side direction, and the top of the outer fin is bent to form a fin top bending structure in the inclined direction;The gap between adjacent two outer fins constitutes outer fin channel;The bottom of the outer fin channel is provided with groove bottom groove along the spiral extension direction of the outer fin;The waist of the outer fin one side or both sides is provided with boss spaced apart along the spiral direction, and the boss separates the outer fin channel into interconnected upper channel and lower channel. The overall heat transfer performance of the evaporation pipe is improved in a leap.

Description

Technical Field

[0001] This utility model relates to the technical field of evaporative heat exchange tubes in air conditioning and refrigeration systems, and particularly to a high-efficiency inverted fin evaporator tube. Background Technology

[0002] The evaporator is the core heat exchange component in central air conditioning and refrigeration units, and its performance directly determines the energy efficiency ratio and operating efficiency of the entire unit. Traditional smooth evaporator tubes, due to their simple structure, have an inherent bottleneck in heat transfer efficiency, making it difficult to meet the requirements of modern refrigeration systems for high energy efficiency, compactness, and environmental friendliness.

[0003] To overcome the performance limitations of bare tubes, existing technologies commonly employ enhanced heat transfer tubes. The core principle of this approach is to alter the physical structure of the inner and outer surfaces of the tube to increase the heat transfer area, disrupt fluid flow, and thin the thermal boundary layer. In terms of external enhancement technology, a common practice is to install helical fins on the outer wall of the tube. These fins do indeed increase the heat transfer area and create disturbances by guiding the fluid. However, this conventional helical fin structure still has several limitations: First, conventional fins are usually vertical or near-vertical sheet structures, which have limited ability to disturb the fluid. Especially in the area at the top of the fin, a stable liquid film is easily formed, which leads to increased thermal resistance and affects the boiling heat transfer efficiency.

[0004] Secondly, the channel structure between the fins is too simple, resulting in an insufficient number of vaporization nuclei. During evaporation, vaporization nuclei are crucial for bubble generation; a limited number of nuclei directly restricts the intensity of nucleated boiling, thus hindering the improvement of overall heat transfer capacity.

[0005] Furthermore, while some existing complex finned structures improve performance to a certain extent, they often neglect the issue of uniform refrigerant distribution on the tube wall surface. This can easily lead to excessively thick liquid films in some areas, creating additional thermal resistance; while in other areas, refrigerant drying may occur, causing heat transfer deterioration. In addition, these structural improvements can sometimes significantly increase the weight and material cost of the tube, which is detrimental to economic efficiency.

[0006] Therefore, there is an urgent need in this field for a new type of evaporator tube structure that can significantly increase the vaporization core, efficiently disturb the fluid, and promote uniform distribution of the liquid film by comprehensively optimizing the internal and external structures of the tube without significantly increasing cost and weight, thereby achieving a leapfrog improvement in heat transfer efficiency. Utility Model Content

[0007] The purpose of this invention is to provide a high-efficiency inverted fin evaporator tube, which solves the problem of how to significantly improve the overall heat exchange performance of the evaporator tube within a limited space.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This utility model provides a high-efficiency inverted-fin evaporator tube, including a tube body and an outer fin integrally formed with the tube body, which is formed by extending material from the tube body along the radial direction of the tube body and spirally extending around the tube body on the outer surface of the tube body; the outer fin is inclined to one side, and the top of the outer fin is bent in the inclined direction to form a fin-top bending structure; the gap between two adjacent outer fins forms an outer fin channel; the bottom of the outer fin channel is provided with a groove at the bottom along the spiral extension direction of the outer fin; the waist of the outer fin is provided with protrusions distributed at intervals along the spiral direction on one or both sides, and the protrusions divide the outer fin channel into a connected upper channel and a lower channel.

[0009] Furthermore, the outer fin is provided with a secondary channel extending in a direction intersecting the outer fin, and the bottom of the secondary channel is located above the boss.

[0010] Furthermore, the secondary channel divides the wing top bending structure into several wing top protrusions, and wing top grooves are formed on the wing top protrusions along the extension direction of the secondary channel. The depth of the wing top grooves is less than or equal to the depth of the secondary channel.

[0011] Furthermore, the groove at the bottom of the groove is a groove structure that is spaced apart or continuously arranged along the bottom of the outer wing channel.

[0012] Furthermore, the cross-sectional shape of the groove bottom is an inverted trapezoid.

[0013] Furthermore, the thickness of the boss decreases from its root, where it connects to the outer fin, towards its outer end.

[0014] Furthermore, the inner surface of the tube is provided with internal thread ribs, and the gap between two adjacent internal thread ribs forms an internal thread groove.

[0015] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art: This utility model discloses a high-efficiency inverted-fin evaporator tube. Through the integrated molding design of the tube body and outer fins, it ensures structural strength while avoiding the contact thermal resistance of split structures, thus improving basic heat transfer efficiency. The inclined arrangement of the outer fins and the bent structure at the fin tips increase the external heat exchange area and guide the fluid to form a spiral disturbance, disrupting the fluid boundary layer and reducing thermal resistance accumulation. The grooved channels on the outer fins, combined with the recessed bottom design, effectively increase the number of refrigerant vaporization nuclei, promoting bubble generation and detachment, and enhancing the boiling heat transfer effect.

[0016] The boss structure on the waist of the outer fin divides the outer fin channel into a composite channel that is connected from top to bottom. This increases the heat exchange area and optimizes the refrigerant flow path, avoiding a decrease in heat exchange efficiency caused by local liquid accumulation.

[0017] Furthermore, the combined design of the secondary channel and the fin top groove further refines the refrigerant distribution, reduces the liquid film thickness, and enhances the heat transfer effect by increasing the surface roughness.

[0018] The internal threaded rib structure on the inner surface of the tube simultaneously optimizes the heat transfer performance from the inside of the tube. By disturbing the fluid inside the tube and increasing the heat exchange area inside the tube, the heat transfer efficiency inside and outside the tube is improved in a coordinated manner.

[0019] The overall structure achieves triple efficiency enhancement through multi-dimensional structural innovation within a limited space, namely "increasing heat exchange area, optimizing fluid state, and strengthening phase change process". This significantly improves the overall heat exchange performance of the evaporator tube while taking into account structural lightweighting and manufacturing cost control, making it suitable for various high-efficiency air conditioning and refrigeration systems. Attached Figure Description

[0020] The following sections will describe some specific embodiments of the present invention in a detailed manner by way of example and not limitation, with reference to the accompanying drawings. The same reference numerals in the drawings denote the same or similar parts or components. Those skilled in the art should understand that these drawings are not necessarily drawn to scale. In the drawings: Figure 1 This is a three-dimensional structural diagram (a) of a high-efficiency inverted fin evaporator provided by this utility model; Figure 2 This is a three-dimensional structural diagram (II) of a high-efficiency inverted fin evaporator provided by this utility model; Figure 3 This is a top view of a high-efficiency inverted-fin evaporator provided by this utility model; Figure 4 This is a front view of a high-efficiency inverted-fin evaporator provided by this utility model; Figure 5 This is a right view of a high-efficiency inverted-fin evaporator provided by this utility model.

[0021] The reference numerals in the attached figures are explained as follows: 1. Pipe body; 2. Outer fins; 20. Fin tip bending structure; 3. Outer wing channel; 30. Upper channel; 31. Lower channel; 4. Groove bottom; 5. Boss; 6. Secondary channel; 7. Wing top groove; 8. Internal thread rib; 81. Internal thread groove. Detailed Implementation

[0022] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0023] like Figure 1 and Figure 2 The diagram shows a three-dimensional structure of a high-efficiency inverted-fin evaporator tube, which includes a tube body 1, an outer fin 2 integrally formed with the tube body 1, and an inner threaded rib 8.

[0024] Specifically, see Figures 1 to 5 The outer fin 2 extends radially along the tube body 1 and spirals around the tube body on its outer surface. The outer fin 2 is formed by extruding material from the tube body 1. This one-piece molding eliminates the contact thermal resistance between the outer fin 2 and the tube body 1, thereby reducing heat transfer loss between them.

[0025] The outer fin 2 is tilted to one side, and the top of the outer fin 2 is further bent in the tilting direction to form a fin-top bent structure 20. This tilted and bent design not only increases the local heat exchange area at the top of the fin, but more importantly, it can effectively guide and disturb the refrigerant flowing outside the tube, disrupting its stable liquid film layer.

[0026] The gap between two adjacent outer fins 2 forms an outer fin channel 3, which together constitutes the outer fin channel 3 for refrigerant flow, heat absorption, and vaporization. To significantly enhance external boiling heat transfer, grooves 4 are provided at intervals or continuously at the bottom of the outer fin channel 3 along its spiral extension direction. These grooves, as stable vaporization nuclei, can continuously promote the generation, growth, and detachment of bubbles, thereby greatly enhancing the nucleation boiling process.

[0027] In this example, the cross-section of the groove 4 at the bottom of the tank is preferably an inverted trapezoid. This structure, with a large opening and a small bottom, provides a more stable environment for bubble nucleation. The presence of sharp corners or narrow areas at the bottom of the groove reduces the energy required for local liquid evaporation, making it easier to reach boiling conditions and thus continuously and stably generate bubbles (i.e., "bubble nuclei"). Once bubble nuclei are formed, the wide groove opening creates a smooth channel for the subsequent growth, merging, and eventual detachment of the bubbles from the wall, preventing bubbles from being trapped in the tank due to a narrow opening, thereby continuously and efficiently enhancing the boiling heat transfer process. It is understood that the cross-sectional shape of the groove 4 at the bottom of the tank can also adopt an arc shape, a rectangle, or a V-shape, etc., all of which should be covered within the scope of protection of this utility model.

[0028] To further enhance performance, protrusions 5 are provided on one or both sides of the waist of the outer fin 2, spaced apart along the spiral direction. These protrusions 5 divide the originally single outer fin channel 3 into interconnected upper channels 30 and lower channels 31 in the height direction, thus forming a double-layered composite channel structure. This design achieves the following three effects: First, it further increases the effective heat exchange surface area; second, it creates more edge areas as additional vaporization nuclei; and finally, it generates secondary disturbances to the flowing refrigerant, optimizing the flow field.

[0029] In addition, secondary channels 6 are machined on the outer fins 2, extending in a direction intersecting with the spiral outer fins. The bottom of the secondary channels 6 is located above the bosses 5. The secondary channels 6 span multiple outer fins 2, dividing the continuous fin tip bending structure 20 into a series of independent fin tip bosses. Each fin tip boss has a finer fin tip groove 7 along the direction of the secondary channels 6, the depth of which is no greater than the depth of the secondary channels 6. The structure of the side bosses 5 is optimized, with its thickness gradually decreasing from the root connected to the outer fins 2 towards the free end. This ensures structural strength while avoiding excessive resistance to the fluid, which is beneficial for the generated bubbles to slide and detach quickly along its inclined surface under the action of buoyancy, preventing bubbles from accumulating and covering the vaporization core, thereby maintaining a continuous and efficient boiling heat transfer process.

[0030] The synergistic effect of the secondary channel 6 and the fin-top groove 7 is twofold. First, it promotes liquid distribution by guiding the liquid refrigerant laterally from areas with thicker liquid films to thinner ones through capillary action, resulting in more uniform wetting of the entire heat exchange surface. Second, it reduces weight by removing excess material while maintaining structural strength, achieving lightweight design. Third, it increases the surface area by incorporating more complex microstructures, thereby enhancing the overall heat exchange area.

[0031] To optimize the overall performance of the tube, the inner surface of the tube was also simultaneously strengthened in this example. Internal thread ribs 8 are integrally formed on the inner surface of the tube body 1 using the same process, and the gaps between adjacent internal thread ribs 8 form internal thread grooves 81. When fluid (such as refrigerant or water) flows through the tube, the internal thread ribs 8 periodically disturb the fluid, disrupting the development of its thermal boundary layer and transforming it from laminar flow to a strongly turbulent state. This significantly enhances the convective heat transfer intensity within the tube and reduces the internal heat transfer resistance.

[0032] This invention constructs a highly efficient multi-scale heat transfer system through the synergistic design of the external "tilting-bending-grooving-layering" multi-dimensional composite structure and the internal threaded rib structure. The core of the external structure lies in maximizing boiling heat transfer by increasing vaporization nuclei, optimizing liquid film distribution, and increasing the heat transfer area; while the internal structure focuses on enhancing convective heat transfer. The combination of these two elements enables the evaporator tube to achieve a doubling of heat transfer performance per unit volume, effectively solving the technical bottleneck of insufficient heat transfer efficiency in traditional evaporator tubes within a limited space.

[0033] The above embodiments are only for illustrating the technical concept and features of this utility model. Their purpose is to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be used to limit the protection scope of this utility model. All equivalent changes or modifications made in accordance with the spirit and essence of this utility model should be included within the protection scope of this utility model.

Claims

1. A high-efficiency inverted-fin evaporator, characterized in that, The device includes a tube (1) and an outer fin (2) integrally formed with the tube (1) by extending the material on the tube (1) along the radial direction of the tube (1) and spirally extending around the tube (1) on the outer surface of the tube (1); the outer fin (2) is inclined to one side and the top of the outer fin (2) is bent in the inclined direction to form a fin top bending structure (20); the gap between two adjacent outer fins (2) forms an outer fin channel (3); the bottom of the outer fin channel (3) is provided with a groove (4) along the spiral extension direction of the outer fin (2); the waist of the outer fin (2) is provided with a boss (5) distributed at intervals along the spiral direction, and the boss (5) divides the outer fin channel (3) into a connected upper channel (30) and a lower channel (31).

2. The high-efficiency inverted-fin evaporator tube according to claim 1, characterized in that, The outer fin (2) is provided with a secondary channel (6) extending in a cross direction with the outer fin (2), and the bottom of the secondary channel (6) is located above the boss (5).

3. The high-efficiency inverted-fin evaporator tube according to claim 2, characterized in that, The secondary channel (6) divides the wing top bending structure (20) into several wing top protrusions. A wing top groove (7) is provided on the wing top protrusion along the extension direction of the secondary channel (6). The opening depth of the wing top groove (7) is less than or equal to the opening depth of the secondary channel (6).

4. The high-efficiency inverted-fin evaporator tube according to claim 1, characterized in that, The groove (4) at the bottom of the groove is a groove structure that is arranged at intervals or continuously along the bottom of the outer wing groove (3).

5. The high-efficiency inverted-fin evaporator tube according to claim 4, characterized in that, The cross-sectional shape of the groove (4) at the bottom of the groove is an inverted trapezoid.

6. The high-efficiency inverted-fin evaporator tube according to claim 1, characterized in that, The thickness of the boss (5) decreases from its root where it connects to the outer fin (2) toward its outer end.

7. The high-efficiency inverted-fin evaporator tube according to claim 1, characterized in that, The inner surface of the tube body (1) is provided with internal thread ribs (8), and the gap between two adjacent internal thread ribs (8) forms an internal thread groove (81).

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