Heat exchange tube and heat exchanger

Abstract

The present invention discloses a heat exchange tube and a heat exchanger. The heat exchange tube includes a tube body and at least two spiral flow disturbing structures. A fluid flow channel is formed between two adjacent spiral flow disturbing structures. The spiral flow disturbing structure includes a plurality of disturbing teeth distributed in a spiral shape. For the heat exchange tube and the heat exchanger of the present invention, by setting a spacing between the disturbing teeth, on the premise of ensuring the heat transfer area inside the tube, part of the fluid can flow through the spacing for cross-flow to cause secondary flow disturbance, effectively enhancing the turbulence degree inside the tube body. Moreover, the spacing is used to form sharp parts on the disturbing teeth, and the sharp parts can pierce the boundary layer, effectively reducing the flow resistance and improving the heat exchange efficiency. The spacing faces the side surface of the disturbing teeth, so that the fluid flowing in the spacing can wash the disturbing teeth to generate flow disturbance again, causing the fluid flow to have flow disturbance, perturbation, and destruction of the boundary layer, which is particularly effective for fluids with low Reynolds number and high viscosity.

Description

Technical Field

[0001] The present invention relates to the technical field of heat exchange equipment, and more specifically, it relates to a heat exchange tube and a heat exchanger. Background Art

[0002] High-efficiency heat exchange tubes are widely used in various heat exchangers. Their heat exchange performance directly affects the energy efficiency, size, and cost of the heat exchange unit. Under the current requirements of "energy conservation and emission reduction" and "dual carbon", it is particularly important to improve the performance of heat exchange tubes. The heat exchange tube is a wall-type heat exchange element. Generally, one fluid flows inside the tube, and heat is exchanged with another fluid outside the tube through the tube wall. Therefore, to enhance heat exchange, internal teeth are usually added inside the tube to reduce the heat transfer resistance inside the tube. The conventional internal tooth structure is a continuous thread structure with a trapezoidal or triangular cross-section. Although they can increase the heat transfer area inside the tube and enhance the fluid disturbance inside the tube, their ability to destroy the boundary layer is limited, and they will increase the flow resistance inside the tube and the pressure loss. At the same time, for fluids with high viscosity and low Reynolds number (such as ethylene glycol, etc.), their ability to enhance heat exchange alone is limited. Eventually, the problem of low heat exchange efficiency of the heat exchange tube is caused. Summary of the Invention

[0003] The present invention discloses a heat exchange tube and a heat exchanger, which solve the problems in the prior art that the continuous thread structure causes too large flow resistance to the fluid, resulting in too large pressure loss, and the limited improvement of heat exchange efficiency.

[0004] The present invention discloses a heat exchange tube, which includes a tube body and at least two spiral flow disturbing structures. A fluid flow channel is formed between two adjacent spiral flow disturbing structures. The spiral flow disturbing structure includes a plurality of disturbing teeth distributed in a spiral shape. And on the same spiral flow disturbing structure, there is a spacing between two adjacent disturbing teeth, and the spacing communicates with two adjacent fluid flow channels.

[0005] In two adjacent spiral flow disturbing structures, the spacing in one spiral flow disturbing structure faces the side surface of the disturbing teeth in the other spiral flow disturbing structure.

[0006] An overflow groove is formed on the disturbing teeth, and the overflow groove communicates with two adjacent fluid flow channels.

[0007] The cross-section of the overflow groove is triangular, and the angle β of the apex angle of the triangle ranges from 5° to 90°; and / or, the depth h3 of the overflow groove ranges from 0.05 mm to 0.5 mm.

[0008] The width a of the spacing ranges from 0.2 mm to 4 mm.

[0009] The cross-section of the disturbing teeth is triangular, and along the spiral direction of the spiral flow disturbing structure, the height of the disturbing teeth gradually increases or gradually decreases.

[0010] The spiral flow disturbing structure includes a first spiral structure and a second spiral structure. The first spiral structure and the second spiral structure are arranged at intervals on the inner surface of the pipe body. A fluid flow channel is formed between adjacent first spiral structures and second spiral structures, and along the same spiral direction, the height of the flow disturbing teeth in the first spiral structure gradually increases, and the height of the flow disturbing teeth in the second spiral structure gradually decreases.

[0011] The numerical range of the height h1 of the flow disturbing teeth in the first spiral structure is from 0.25 mm to 0.9 mm; and / or, the numerical range of the height h2 of the flow disturbing teeth in the second spiral structure is from 0.15 mm to 0.8 mm.

[0012] The flow disturbing teeth have a bottom surface arranged on the inner surface of the pipe body and a side edge away from the bottom surface. The angle range of the angle θ between the side edge and the plane where the bottom surface is located is from 15° to 75°.

[0013] Another aspect of the present invention provides a heat exchanger including the above heat exchange pipe.

[0014] For the heat exchange pipe and the heat exchanger of the present invention, by setting a spacing between the flow disturbing teeth, on the premise of ensuring the heat transfer area inside the pipe, part of the fluid can flow through the spacing for secondary flow disturbance, effectively enhancing the turbulence degree inside the pipe body. Moreover, the spacing forms a sharp part on the flow disturbing teeth, and this sharp part can pierce the boundary layer, effectively reducing the flow resistance and improving the heat exchange efficiency. The spacing faces the side surface of the flow disturbing teeth, so that the fluid flowing in the spacing can wash the flow disturbing teeth to generate flow disturbance again, making the fluid flow undergo flow disturbance, perturbation, and destroy the boundary layer, which is particularly effective for fluids with low Reynolds number and high viscosity. Moreover, the spiral flow disturbing structures with different heights can further reduce the fluid flow resistance and reduce the pressure loss generated by the heat exchange pipe. Description of the Drawings

[0015] Figure 1 is a schematic structural diagram of the inner surface of the heat exchange pipe according to an embodiment of the present invention;

[0016] Figure 2 is a schematic diagram of the fluid flow inside the heat exchange pipe according to an embodiment of the present invention;

[0017] Figure 3 is another schematic structural diagram of the inner surface of the heat exchange pipe according to an embodiment of the present invention;

[0018] Figure 4 is a schematic structural diagram of the flow disturbing teeth according to an embodiment of the present invention;

[0019] Figure 5 is another schematic structural diagram of the flow disturbing teeth according to an embodiment of the present invention;

[0020] Legend: 1. Pipe body; 2. Spiral flow disturbing structure; 3. Fluid flow channel; 4. Flow disturbing teeth; 5. Spacing; 6. Flow-through groove; 7. First spiral structure; 8. Second spiral structure. Detailed implementation mode

[0021] The present invention will be further described below in conjunction with embodiments, but is not limited to the content in the specification.

[0022] As Figures 1 to 5 shown, the present invention provides a heat exchange tube, including a pipe body 1 and at least two spiral flow disturbing structures 2. A fluid flow channel 3 is formed between two adjacent spiral flow disturbing structures 2. The spiral flow disturbing structure 2 includes a plurality of flow disturbing teeth 4 distributed in a spiral shape. On the same spiral flow disturbing structure 2, there is a spacing 5 between two adjacent flow disturbing teeth 4, and the spacing 5 communicates with two adjacent fluid flow channels 3. After the fluid enters the pipe body 1, the fluid will flow along the fluid flow channel 3 under the guiding action of the spiral flow disturbing structure 2. At the same time, part of the fluid will generate cross-flow in the spacing 5, so as to flow between two adjacent fluid flow channels 3. By setting the spacing 5 between the flow disturbing teeth 4, on the premise of ensuring the heat transfer area inside the pipe, part of the fluid can pass through the spacing 5 to generate cross-flow and secondary flow disturbance, effectively enhancing the turbulence degree inside the pipe body 1. Moreover, the spacing 5 is used to form a sharp part on the flow disturbing teeth 4, and this sharp part can pierce the boundary layer, effectively reducing the flow resistance and improving the heat exchange efficiency.

[0023] In two adjacent spiral flow disturbing structures 2, the spacing 5 in one spiral flow disturbing structure 2 faces the side of the flow disturbing teeth 4 in the other spiral flow disturbing structure 2. So that the fluid flowing in the spacing 5 can wash the flow disturbing teeth 4 to generate flow disturbance again, making the fluid flow generate flow disturbance, perturbation and destroy the boundary layer, which is particularly effective for fluids with low Reynolds number and high viscosity. Combining the secondary flow disturbance generated by the spiral flow disturbing structure 2 and the spacing 5, the three-time flow disturbance of the fluid is realized, effectively improving the heat exchange efficiency of the heat exchange tube.

[0024] Among them, the angle range of the spiral angle α of the spiral flow disturbing structure 2 is from 0° to 80°. Preferably it is 45°. The number range of the spiral flow disturbing structures 2 is from 6 to 90, and is specifically determined according to the length and pipe diameter of the pipe body 1.

[0025] The numerical range of the width b of the fluid flow channel 3 is from 0.15 mm to 3 mm, that is, the spacing range between two adjacent spiral flow disturbing structures 2 is from 0.15 mm to 3 mm.

[0026] The spoiler teeth 4 are provided with flow-through grooves 6, and the flow-through grooves 6 communicate with two adjacent fluid flow channels 3. The flow-through grooves 6 can increase the number of edges on the spoiler teeth 4, thereby enhancing the effect of piercing the fluid boundary layer and further increasing the spoiler effect of the spoiler teeth 4 on the fluid. The fluid flowing out within the spacing 5 can flow through the spoiler teeth 4 via the flow-through grooves 6, further enhancing the spoiler and boundary layer disruption effects of the spoiler teeth 4 on the fluid.

[0027] The cross-section of the flow-through groove 6 is triangular, and the triangle is a stable structure, ensuring the structural stability of the spoiler teeth 4 during the fluid scouring process, thereby guaranteeing the spoiler effect within the heat exchange tube. The angle β of the apex of the triangle ranges from 5° to 90°.

[0028] The value range of the depth h3 of the flow-through groove 6 is from 0.05 mm to 0.5 mm. This avoids the flow-through groove 6 being too deep and affecting the structural strength of the spoiler teeth 4, and also avoids the flow-through groove 6 being too shallow and unable to achieve the spoiler effect on the fluid.

[0029] Among them, the number range of the flow-through grooves 6 is from 1 to 3, which is specifically determined according to the length of the spoiler teeth 4.

[0030] The value range of the width a of the spacing 5 is from 0.2 mm to 4 mm. If the spacing 5 is too large, the spiral spoiler structure 2 formed by the spoiler teeth 4 cannot reliably spoil the fluid. If the spacing 5 is too small, the fluid cannot flow through the spacing 5, and thus the spacing 5 cannot be utilized for spoiling the fluid.

[0031] The cross-section of the spoiler teeth 4 is triangular. Along the spiral direction of the spiral spoiler structure 2, the height of the spoiler teeth 4 gradually increases or gradually decreases. Through the change in height, the spoiler teeth 4 can spoil the fluid at different positions, comprehensively disrupt and crush the boundary layer, thereby increasing the spoiler effect of the spoiler teeth 4 and fully improving the heat transfer within the tube.

[0032] Preferably, the cross-section of the spoiler teeth 4 is an isosceles triangle, enabling good spoiler heat transfer effects when the fluid enters from any one end of the tube body 1.

[0033] The spiral flow disturbing structure 2 includes a first spiral structure 7 and a second spiral structure 8. The first spiral structure 7 and the second spiral structure 8 are arranged at intervals on the inner surface of the pipe body 1. A fluid flow channel 3 is formed between adjacent first spiral structure 7 and second spiral structure 8, and along the same spiral direction, the height of the flow disturbing teeth 4 in the first spiral structure 7 gradually increases, and the height of the flow disturbing teeth 4 in the second spiral structure 8 gradually decreases. That is, the arrangement direction of the flow disturbing teeth 4 in the first spiral structure 7 is opposite to the arrangement direction of the flow disturbing teeth 4 in the second spiral structure 8. When passing through the flow disturbing teeth 4 in the first spiral structure 7 and the flow disturbing teeth 4 in the second spiral structure 8, the fluid will fluctuate, surge and collide up and down with the change of height, forming a multi-dimensional and full-flow field flow, which can cause all-round disturbance to the flow path of the fluid in the entire pipe body 1, greatly improving the turbulence degree of the fluid, completely destroying and crushing the boundary layer of the fluid, and fully improving the heat transfer in the pipe.

[0034] Specifically, the numerical range of the height h1 of the flow disturbing teeth 4 in the first spiral structure 7 is from 0.25 mm to 0.9 mm.

[0035] Specifically, the numerical range of the height h2 of the flow disturbing teeth 4 in the second spiral structure 8 is from 0.15 mm to 0.8 mm.

[0036] The flow disturbing teeth 4 have a bottom surface arranged on the inner surface of the pipe body 1 and a side edge away from the bottom surface. The angle range of the angle θ between the side edge and the plane where the bottom surface is located is from 15° to 75°. By adjusting the angle θ, the height difference between the two ends of the flow disturbing teeth 4 is adjusted, so as to adjust the flow disturbing effect of the flow disturbing teeth 4 on the fluid. At the same time, the height of the two side surfaces forming the spacing 5 can be controlled, and then the shape of the spacing 5 can be controlled, increasing the flow disturbing effect of the spacing 5 on the fluid.

[0037] Another aspect of the present invention provides a heat exchanger, including the above-mentioned heat exchange pipe.

[0038] Obviously, the above-mentioned embodiments of the present invention are only examples for clearly explaining the present invention, and are not limitations on the embodiments of the present invention. For those of ordinary skill in the art, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the embodiments here. Any obvious changes or modifications derived from the technical solutions of the present invention still fall within the protection scope of the present invention.

Claims

1. A heat exchange tube, characterized in that: It includes a pipe body (1) and at least two spiral flow disturbing structures (2). A fluid flow channel (3) is formed between two adjacent spiral flow disturbing structures (2). The spiral flow disturbing structure (2) includes a plurality of flow disturbing teeth (4) distributed in a spiral shape. And on the same spiral flow disturbing structure (2), there is a spacing (5) between two adjacent flow disturbing teeth (4), and the spacing (5) communicates with two adjacent fluid flow channels (3). The spiral flow disturbing structure (2) includes a first spiral structure (7) and a second spiral structure (8). The first spiral structure (7) and the second spiral structure (8) are arranged at intervals on the inner surface of the pipe body (1). The fluid flow channel (3) is formed between the adjacent first spiral structure (7) and the second spiral structure (8). And along the same spiral direction, the height of the flow disturbing teeth (4) in the first spiral structure (7) gradually increases, and the height of the flow disturbing teeth (4) in the second spiral structure (8) gradually decreases.

2. The heat exchange tube according to claim 1, wherein: In two adjacent spiral flow disturbing structures (2), the spacing (5) in one spiral flow disturbing structure (2) faces the side surface of the flow disturbing teeth (4) in the other spiral flow disturbing structure (2).

3. The heat exchange tube according to claim 1, wherein: Flow-through grooves (6) are formed on the flow disturbing teeth (4), and the flow-through grooves (6) communicate with two adjacent fluid flow channels (3).

4. The heat exchange tube according to claim 3, wherein: The cross-section of the flow-through groove (6) is triangular, and the angle range of the apex angle β of the triangle is 5° to 90°; and / or, the numerical range of the depth h3 of the flow-through groove (6) is 0.05 mm to 0.5 mm.

5. The heat exchange tube according to claim 1, wherein: The numerical range of the width a of the spacing (5) is 0.2 mm to 4 mm.

6. The heat exchange tube according to claim 1, wherein: The cross-section of the flow disturbing teeth (4) is triangular.

7. The heat exchange tube according to claim 1, wherein: The numerical range of the height h1 of the flow disturbing teeth (4) in the first spiral structure (7) is 0.25 mm to 0.9 mm; and / or, the numerical range of the height h2 of the flow disturbing teeth (4) in the second spiral structure (8) is 0.15 mm to 0.8 mm.

8. The heat exchange tube according to claim 6, wherein: The flow disturbing teeth (4) have a bottom surface arranged on the inner surface of the pipe body (1) and a side edge away from the bottom surface, and the angle range of the angle θ between the side edge and the plane where the bottom surface is located is 15° to 75°.

9. A heat exchanger, characterized in that: It includes the heat exchange pipe according to any one of claims 1 to 8.

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