Enhanced heat exchange structure adopting drainage grooves

Abstract

The invention relates to an enhanced heat exchange structure adopting drainage grooves, which comprises a heat exchange tube and fins with grooves, the fins are of a strip-shaped structure, the roots of the fins are fixedly connected with the heat exchange tube, the surfaces of the fins are provided with the drainage grooves, and the drainage grooves guide condensed water into discrete liquid flow instead of continuous liquid films. The roots of the fins are provided with L-shaped feet, and the fins are tightly wound on the outer sides of the heat exchange tubes through the L-shaped feet. After the fins are wound, the roots of the fins and the heat exchange tube are firmly welded together through brazing. Due to the existence of the hydrophobic grooves, after being condensed on the surfaces of the fins, water drops flow down in strands through the hydrophobic grooves instead of being accumulated on the surfaces of the fins. The liquid drops flowing down through the drainage grooves can be in sufficient contact with the rising dead steam flow subsequently, so that sufficient heat exchange is achieved. The heat exchange efficiency of the fins can be greatly improved through disappearance of the liquid film.

Description

Technical Field

[0001] The present invention belongs to the technical field of heat exchangers, and in particular relates to an enhanced heat exchange structure suitable for high-humidity environments. It can be widely used in scenarios involving high-humidity airflow heat exchange, such as coolers of steam ejectors, air-conditioning condensers, and industrial dehumidification equipment. Background Art

[0002] The second-stage cooler of a two-stage vacuum pump is a crucial component of the jet vacuum pump. Its primary function is to transfer heat from the exhaust steam and air to the cooling water within the cooling tubes, condensing the exhaust steam into water and discharging the cooled air into the powerhouse. This is typically achieved using a shell-and-tube heat exchanger, with fins and inserts employed to enhance heat transfer efficiency.

[0003] At present, commonly used fin heat exchange structures such as Figure 1 The structure shown. Figure 1 The diagram below shows the structure of a traditional finned heat exchange tube. As can be seen from the diagram, the structure primarily consists of heat exchange tubes and fins. The cooling medium flows inside the tubes, while the high-humidity air flows outside. Figure 2 A schematic diagram of the liquid film on the fin surface is shown in Figure 2. As the exhaust steam exchanges heat on the fin surface and undergoes a phase change to saturated water, the droplets, under tension, form a liquid film on the fin surface. The presence of the liquid film significantly reduces the effective heat transfer area and heat transfer coefficient on the fin surface.

[0004] Prior art, such as patent document (CN2869743Y), which discloses a spiral fin tube with grooves, aims to disrupt airflow to improve heat exchange efficiency. However, this design fails to address the issue of liquid film in high-humidity environments. Instead, the grooves can become areas for liquid accumulation, exacerbating liquid film buildup. Patent document (CN101581555A) focuses on optimizing the structure of the teardrop-shaped fins within the tube, aiming to increase heat exchange efficiency by increasing the heat exchange area within the tube. However, this design targets the fluid within the tube and is unrelated to the liquid film issue in the high-humidity airflow outside the tube. Consequently, it fails to address the reduced heat exchange efficiency caused by liquid film on the fin surface.

[0005] Therefore, it is necessary to design a fin structure with hydrophobic grooves to improve the heat exchange efficiency of the finned heat exchange tube. Summary of the Invention

[0006] In response to the problem in the prior art that the liquid film on the fin surface affects the heat exchange efficiency, the present invention provides an enhanced heat exchange structure using hydrophobic grooves, which eliminates the liquid film by active hydrophobicity and uses the groove structure to enhance the airflow disturbance, thereby achieving a double improvement in heat exchange efficiency.

[0007] To achieve the above purpose, the technical solution of the present invention is: an enhanced heat exchange structure using hydrophobic grooves, comprising a heat exchange tube and a grooved fin, the fin being a strip-shaped structure, the fin root being fixedly connected to the heat exchange tube, the fin surface being provided with hydrophobic grooves, the hydrophobic grooves guiding the condensed water into discrete liquid flows rather than continuous liquid films

[0008] Furthermore, the root of the fin is provided with an L-shaped foot, and the fin is tightly wrapped around the outside of the heat exchange tube through the L-shaped foot.

[0009] Furthermore, after the fins are wound, the roots of the fins are firmly welded to the heat exchange tubes by brazing.

[0010] Furthermore, the fins are formed by stamping, and the material is copper or aluminum alloy.

[0011] Furthermore, the length of the L-shaped leg is 1 / 5-1 / 4 of the width of the fin, and the thickness is the same as the thickness of the fin.

[0012] Furthermore, the cross-section of the hydrophobic groove is V-shaped, and its opening angle is 30°-60°.

[0013] Furthermore, the depth of the hydrophobic groove is 1 / 4-1 / 3 of the thickness of the fin.

[0014] Furthermore, the hydrophobic grooves extend from the inside to the periphery along the fin surface, and the hydrophobic grooves are evenly distributed along the circumference of the fin surface.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] 1. Eliminate the influence of liquid film: The hydrophobic groove guides the condensed water into discrete liquid flow rather than a continuous liquid film, so that the liquid droplets flowing through the hydrophobic groove can subsequently fully contact with the rising exhaust steam flow.

[0017] 2. Enhanced airflow disturbance: The groove structure creates secondary disturbance on high-humidity airflow, promoting turbulent mixing of airflow and fins, and further enhancing heat transfer.

[0018] 3. Structural stability: L-shaped feet and brazing fixation ensure close connection between fins and heat exchange tubes, avoiding increase in contact thermal resistance caused by looseness.

[0019] In summary, thanks to the presence of the hydrophobic grooves, water droplets condensing on the fin surface flow down through the grooves in streams, rather than accumulating on the fin surface. The droplets flowing down through the grooves are then able to fully contact the rising exhaust steam flow, achieving sufficient heat exchange. The disappearance of the liquid film significantly increases the heat transfer efficiency of the fins. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a schematic diagram of the structure of a traditional heat exchange tube with fins;

[0021] Figure 2 It is a schematic diagram of the liquid film on the surface of a conventional fin;

[0022] Figure 3 is a front view of a fin structure with hydrophobic grooves according to the present invention;

[0023] Figure 4 It is an oblique view of the fin structure with hydrophobic grooves of the present invention. DETAILED DESCRIPTION

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0025] like Figure 3 4 shows a fin structure with hydrophobic grooves according to the present invention, which comprises a grooved fin 2 and a heat exchange tube 1. The surface of the fin 2 is provided with a hydrophobic groove 3. The fin 2 with hydrophobic grooves has an overall strip-like structure, which can be processed by stamping. The base of the fin 2 is provided with an L-shaped foot 4. The fin is then tightly wrapped around the outside of the cooling tube using a dedicated machine. After wrapping, the base of the fin 2 is firmly welded to the heat exchange tube 1 using brazing.

[0026] Preferably, the cross-section of the hydrophobic groove 3 is V-shaped, and the opening angle thereof is 30°-60°.

[0027] Preferably, the depth of the hydrophobic groove 3 is 1 / 4-1 / 3 of the thickness of the fin 2

[0028] Preferably, the hydrophobic groove 3 extends from the inside to the periphery along the surface of the fin 2 .

[0029] Preferably, the hydrophobic grooves 3 are evenly distributed along the circumferential direction of the surface of the fin 2 .

[0030] Preferably, the length of the L-shaped leg 4 is 1 / 5-1 / 4 of the width of the fin 2 , and the thickness is the same as the thickness of the fin 2 .

[0031] This invention fundamentally addresses the problem of reduced heat transfer efficiency caused by liquid film on the fin surface in high-humidity environments by designing hydrophobic grooves on the fin surface. Combined with the secure fixing structure of the L-shaped legs, this ensures long-term operational stability. Compared to existing technologies, the core innovation of this invention lies in focusing the structural design on hydrophobicity rather than simply on airflow disturbance or enhanced heat transfer within the tubes. This significantly improves heat transfer performance in high-humidity environments and has broad application value.

Claims

1. An enhanced heat exchange structure using a hydrophobic groove, characterized in that: It includes a heat exchange tube and a grooved fin. The fin is a strip-shaped structure. The root of the fin is fixedly connected to the heat exchange tube. The surface of the fin is provided with a hydrophobic groove, which guides the condensed water into a discrete liquid flow rather than a continuous liquid film.

2. The enhanced heat exchange structure using hydrophobic grooves according to claim 1, characterized in that: The root of the fin is provided with an L-shaped foot, and the fin is tightly wound around the outside of the heat exchange tube through the L-shaped foot.

3. The enhanced heat exchange structure using hydrophobic grooves according to claim 2, characterized in that: After the fins are wound, the roots of the fins are firmly welded to the heat exchange tubes by brazing.

4. The enhanced heat exchange structure using hydrophobic grooves according to claim 2, characterized in that: The fins are made by stamping and are made of copper or aluminum alloy.

5. The enhanced heat exchange structure using hydrophobic grooves according to claim 2, characterized in that: The length of the L-shaped foot is 1 / 5-1 / 4 of the width of the fin, and the thickness is the same as the thickness of the fin.

6. The enhanced heat exchange structure using hydrophobic grooves according to claim 1, characterized in that: The cross-section of the hydrophobic groove is V-shaped, and its opening angle is 30°-60°.

7. The enhanced heat exchange structure using hydrophobic grooves according to claim 6, characterized in that: The depth of the hydrophobic groove is 1 / 4-1 / 3 of the thickness of the fin.

8. The enhanced heat exchange structure using hydrophobic grooves according to claim 1, characterized in that: The hydrophobic grooves extend from the inside to the periphery along the fin surface, and the hydrophobic grooves are evenly distributed along the circumference of the fin surface.

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