Outer surface multi-structure reinforced evaporation tube

Abstract

The utility model relates to a kind of outer surface multi-structure reinforced evaporation pipe, involve evaporative heat exchange tube technical field in air conditioner, refrigeration system, solve how to pass through optimization pipe body surface structure design, break through the bottleneck of existing evaporation pipe heat transfer, significantly improve the overall heat exchange efficiency of evaporation pipe. Including pipe body and the outer fin integrally formed with the pipe body, which is extended in the radial direction of the pipe body and extended in spiral state around the pipe body on the outer surface of the pipe body by the material on the pipe body;The gap between adjacent two outer fins constitutes outer fin channel;The bottom of the outer fin channel is provided with groove, and the extension direction of the groove is consistent with the extension direction of the outer fin;The waist side or both sides of the outer fin is provided with boss spaced apart in spiral direction, and the boss separates the outer fin channel into interconnected upper channel and lower channel. The overall heat transfer performance of evaporation pipe is realized by leaps and bounds.

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 an evaporative tube with a multi-structure reinforced outer surface. Background Technology

[0002] In the operation of air conditioning and refrigeration systems, the evaporator, as the core component for heat exchange, directly determines the energy efficiency ratio of the entire unit, and has a crucial impact on the system's energy saving, operational stability, and cooling effect. The evaporator tube, as the core element inside the evaporator responsible for heat transfer, is a key carrier for optimizing the evaporation process and improving overall heat exchange efficiency; its performance directly affects the operational performance of the evaporator and even the entire refrigeration system.

[0003] Currently, traditional evaporator tubes mostly adopt a bare tube structure. Limited by their surface morphology, their heat exchange area is limited, and a thick thermal resistance layer easily forms during fluid flow outside the tube. Furthermore, insufficient fluid disturbance leads to a significant bottleneck in heat transfer efficiency, making it difficult to meet the current development demands for miniaturization and energy efficiency in air conditioning and refrigeration systems. To overcome this limitation, the industry has gradually developed evaporator tube technology that enhances heat transfer by altering the surface structure inside and outside the tube. Its core principles revolve around two main directions: first, increasing the effective heat exchange area by optimizing the tube surface structure, directly improving the contact basis for heat exchange; and second, disturbing the fluid flow outside the tube through special structural design, reducing fluid stagnation and thinning the thermal resistance layer, thereby reducing heat transfer resistance and increasing the heat transfer rate.

[0004] With the increasing global demand for green energy conservation and low-carbon emission reduction, the requirements for energy efficiency of air conditioning and refrigeration systems are becoming increasingly stringent. This also places higher demands on the performance of evaporator tubes: they not only need to further improve heat transfer efficiency to adapt to the miniaturized design of the system and reduce the space occupied by the equipment; they also need to control production costs while ensuring high performance to achieve the economical application of the technology; in addition, they need to be better adapted to environmentally friendly refrigerants to ensure that efficient heat transfer is maintained under the premise of environmental friendliness.

[0005] However, there is still room for optimization in the structural design of existing enhanced evaporator tubes. For example, some products only increase the heat exchange area through a single fin structure without fully considering the synergistic effect of fluid disturbance and thermal resistance layer thinning, or although multiple structures are combined, the matching between the structures is insufficient, resulting in the enhanced heat transfer effect not reaching the optimal level, making it difficult to fully meet the current system's comprehensive requirements for high efficiency, energy saving and environmental protection.

[0006] Therefore, developing a reinforced evaporator tube with a more reasonable structural design and superior heat transfer performance has become an important direction for promoting the energy efficiency of air conditioning and refrigeration systems and helping the industry achieve its energy conservation and carbon reduction goals. Utility Model Content

[0007] The purpose of this invention is to provide an evaporator tube with a multi-structure reinforced outer surface, which solves the problem of how to break through the heat transfer bottleneck of existing evaporator tubes by optimizing the surface structure design of the tube body, and significantly improve the overall heat exchange efficiency of the evaporator tube.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows: This utility model provides an evaporator tube with a multi-structure reinforced outer surface, including a tube body and outer fins integrally formed with the tube body, which are formed by extending material on 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 gap between two adjacent outer fins forms an outer fin channel; the bottom of the outer fin channel is provided with a groove bottom, and the extension direction of the groove bottom is consistent with the extension direction of the outer fins. The outer fin has symmetrical protrusions distributed at intervals along the spiral direction on one or both sides of its waist, and the protrusions divide the outer fin channel into an interconnected upper channel and a lower channel.

[0009] Furthermore, the outer fin is provided with a secondary channel extending along the axial direction of the tube body and at an angle to the axial direction, and the bottom of the secondary channel is located above the boss.

[0010] Furthermore, the top of the outer fin is provided with a three-level channel, the extension direction of the three-level channel intersects the extension direction of the outer fin and the secondary channel, and the depth of the three-level channel is less than or equal to the depth of the secondary channel.

[0011] Furthermore, the secondary channel and the tertiary channel are arranged intersectingly, dividing the top surface of the outer fin into multiple independent fin platforms.

[0012] Furthermore, the top of the outer fin is planar.

[0013] Furthermore, the cross-sectional shape of the groove bottom is an inverted trapezoid.

[0014] Furthermore, the thickness of the boss decreases from the root to the outer end.

[0015] 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.

[0016] Due to the application of the above technical solution, this utility model has the following advantages compared with the prior art: This invention relates to an evaporator tube with a multi-structure reinforced outer surface. By setting a boss on the waist of the outer fin, a single outer fin channel is divided into two interconnected composite channels, one above the other. This structure not only significantly increases the heat transfer surface area outside the tube, but also creates more flow dead zones and sharp corners within the channels, providing a large number of stable vaporization nuclei and greatly enhancing the nucleation boiling heat transfer efficiency.

[0017] By intersecting secondary and tertiary channels on the spiral outer fins, the continuous fin surface is divided into multiple independent fin platforms. This design effectively disturbs and redistributes the refrigerant liquid, breaking the continuous liquid film and avoiding thermal resistance caused by excessively thick local liquid films or localized drying that leads to deterioration in heat transfer, thus ensuring the stability and efficiency of the heat exchange process.

[0018] The thickness of the boss decreases from the root to the outer end, forming a streamlined structure similar to an "airfoil". This ensures the structural strength of the boss and facilitates the smooth detachment of bubbles along its slope after generation, preventing bubbles from covering the vaporization nucleus and inhibiting the generation of subsequent bubbles, thus maintaining continuous and efficient boiling heat transfer.

[0019] All external surface reinforcement structures (outer fins, bosses, and channels at all levels) are integrally formed with the tube body, fundamentally eliminating contact thermal resistance caused by mechanical assembly or welding, and ensuring efficient and direct heat transfer from the tube wall to the refrigerant.

[0020] While strengthening the outer surface of the tube with multiple structures, internal thread ribs are set on the inner surface of the tube. This can effectively enhance the turbulence of the fluid inside the tube, reduce the thermal boundary layer inside the tube, and achieve a simultaneous increase in the heat transfer coefficient inside and outside the tube, thereby achieving a doubling effect on the overall heat transfer performance of the tube. Attached Figure Description

[0021] 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 of an evaporator tube with a multi-structure reinforced outer surface provided by this utility model; Figure 2 This is a top view of an evaporator tube with a multi-structure reinforced outer surface provided by this utility model; Figure 3 This is a front view of an evaporator tube with a multi-structure reinforced outer surface provided by this utility model; Figure 4 This is a right view of an evaporator tube with a multi-structure reinforced outer surface provided by this utility model.

[0022] The reference numerals in the attached figures are explained as follows: 1. Pipe body; 2. Outer fins; 3. Outer wing channel; 30. Upper channel; 31. Lower channel; 4. Groove bottom; 5. Boss; 6. Secondary channel; 7. Three-stage channel; 8. Internal thread rib; 81. Internal thread groove. Detailed Implementation

[0023] 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.

[0024] like Figure 1 The diagram shows a three-dimensional structure of an evaporator tube with a multi-structure reinforcement on the outer surface, which includes a tube body 1, an outer fin 2 integrally formed with the tube body 1, and an inner threaded rib 8.

[0025] Specifically, see Figures 1 to 4 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.

[0026] The gap between two adjacent outer fins 2 forms the outer fin channel 3, which serves as the core area for refrigerant flow, evaporation, and heat exchange outside the tube.

[0027] To create more vaporization nuclei within the aforementioned outer fin channel 3, in this example, a continuous groove 4 is provided at the bottom of the outer fin channel 3 along its length (i.e., consistent with the spiral extension direction of the outer fin 2). The cross-sectional shape of this groove 4 is preferably an inverted trapezoid. This geometry creates a stable V-shaped apex region at the bottom of the channel; these apex points are ideal bubble nucleation points, significantly promoting the frequency and quantity of bubble generation during boiling heat transfer. Of course, it is not limited to the aforementioned inverted trapezoidal cross-sectional shape of the groove 4. Those skilled in the art will understand that any cross-sectional shape that satisfies the core function of "increasing vaporization nuclei and promoting bubble generation and detachment" falls within the protection scope of this utility model.

[0028] In this example, protrusions 5 are symmetrically machined on one or both sides of the waist portion of the outer fin 2, spaced apart along a spiral direction. These protrusions 5 protrude from the fin sidewall into the space of the outer fin channel 3, thereby dividing the single outer fin channel 3 into two interconnected and more complex composite channels, namely the upper channel 30 and the lower channel 31. This design produces multiple positive effects: firstly, it directly increases the additional heat exchange surface area; secondly, it disrupts the continuous flow of the fluid, enhancing turbulence; and finally, the edges and sides of the protrusions 5 that come into contact with the fluid also become new, highly efficient vaporization nuclei.

[0029] Preferably, the thickness of the boss 5 is designed to decrease from its root (where it connects to the fins) outwards (to the free end). This streamlined wedge-shaped or airfoil-shaped structure ensures that the boss has sufficient structural strength and facilitates the rapid sliding and detachment of the generated bubbles along its inclined surface under buoyancy, preventing bubbles from accumulating and covering the vaporization core, thereby maintaining a continuous and efficient boiling heat transfer process.

[0030] To maximize the utilization of the heat exchange area outside the tube and precisely control the refrigerant liquid film, a multi-stage channel is introduced in this example. First, a secondary channel 6 is formed on the outer fin 2. The extension direction of the secondary channel 6 is set at an angle to the axial direction of the tube body 1, and the bottom of the secondary channel 6 is located above the boss 5 to ensure that it can effectively interrupt the continuity of the fin laterally without damaging the structure of the boss 5. The size of the angle can be reasonably adjusted according to actual production needs.

[0031] In addition, a third-level channel 7 is formed on the top plane of the outer fin 2. The extension direction of the third-level channel 7 intersects the extension direction of the second-level channel 6, and its depth is less than or equal to the depth of the second-level channel 6. The intersection of the second-level channel 6 and the third-level channel 7 forms a microscopic "grid" system on the top of the outer fin 2, dividing the originally continuous top surface of the fin into numerous independent, island-shaped or platform-shaped fin platforms.

[0032] This design, through the aforementioned gridded channel system, significantly increases the overall heat exchange perimeter and surface area. The channels guide and redistribute the refrigerant liquid via capillary action, ensuring that each individual fin is uniformly wetted, effectively preventing localized increases in thermal resistance or drying due to uneven liquid film distribution. Furthermore, while maintaining structural strength, the removal of some material achieves lightweighting of the tube body, while simultaneously further intensifying the fluid turbulence.

[0033] In this example, the top of the outer fin 2 is preferably planar, which provides an ideal reference surface for machining the three-stage channel 7 and forming a stable fin platform, and also facilitates manufacturing and measurement.

[0034] 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.

[0035] In addition, it should be noted that in this embodiment, the depth and width of each channel can be reasonably arranged according to actual needs.

[0036] In actual operation, the refrigerant outside the tube flows and absorbs heat to evaporate within the composite flow channel formed by the outer fin channel 3 and the groove 4 and boss 5 at the bottom of the channel. The edges of the groove 4 and boss 5 provide dense and efficient vaporization nuclei, where bubbles are generated, grow, and detach rapidly and in large quantities. The multi-stage channel system (secondary channel 6 and tertiary channel 7) ensures that the refrigerant liquid can uniformly cover the entire complex fin surface through capillary action, avoiding localized failures. At the same time, the fluid inside the tube achieves efficient convective heat transfer under the disturbance of the internal threaded ribs 8. Ultimately, through the organic combination of multi-structure synergistic nucleation boiling outside the tube and forced turbulent heat transfer inside the tube, a leapfrog improvement in the overall heat transfer performance of the evaporator tube is achieved.

[0037] 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. An evaporator tube with a multi-structure reinforced outer surface, characterized in that, It 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 extending in a spiral state around the tube (1) on the outer surface of the tube (1); 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 bottom (4), and the extension direction of the groove bottom (4) is consistent with the extension direction of the outer fin (2); The outer fin (2) has symmetrical protrusions (5) arranged at intervals along the spiral direction on one or both sides of its waist, and the protrusions (5) divide the outer fin channel (3) into an upper channel (30) and a lower channel (31) that are connected.

2. The multi-structure reinforced evaporator tube with an outer surface according to claim 1, characterized in that, The outer fin (2) is provided with a secondary channel (6) extending along the axial direction of the tube body (1) and at an angle to the axial direction, and the bottom of the secondary channel (6) is located above the boss (5).

3. The multi-structure reinforced evaporator tube with an outer surface according to claim 2, characterized in that, The top of the outer fin (2) is provided with a three-level channel (7). The extension direction of the three-level channel (7) intersects with the extension direction of the outer fin (2) and the secondary channel (6). The depth of the three-level channel (7) is less than or equal to the depth of the secondary channel (6).

4. The multi-structure reinforced evaporator tube with an outer surface according to claim 3, characterized in that, The secondary channel (6) and the tertiary channel (7) are arranged to intersect, dividing the top surface of the outer fin (2) into multiple independent fin platforms.

5. The multi-structure reinforced evaporator tube with an outer surface according to claim 3, characterized in that, The top of the outer fin (2) is planar.

6. The multi-structure reinforced evaporator tube with an outer surface according to claim 1, characterized in that, The cross-sectional shape of the groove (4) at the bottom of the groove is an inverted trapezoid.

7. The multi-structure reinforced evaporator tube with an outer surface according to claim 1, characterized in that, The thickness of the boss (5) decreases from the root to the outer end.

8. The multi-structure reinforced evaporator tube with an outer surface 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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