A reverse helical flow channel coaxial heat exchanger
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NORTHWEST ENGINEERING CORPORATION LIMITED
- Filing Date
- 2025-07-02
- Publication Date
- 2026-06-19
AI Technical Summary
The heat transfer efficiency of existing coaxial heat exchangers is poor, mainly due to the straight tube design, which results in an excessively thick thermal boundary layer, insufficient turbulent mixing, and limited heat transfer area.
The design employs a reverse spiral flow channel, forming a flow channel between the inner and outer tubes. Spiral ribs with opposite spiral directions are set on the inner and outer tube walls to increase the heat exchange area and form high-intensity turbulence, thereby disrupting the thermal boundary layer.
It improves heat transfer efficiency, reduces the rate of fouling deposition, and enhances the fluid heat exchange effect.
Smart Images
Figure CN224382194U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of coaxial heat exchanger technology, and more specifically, to a reverse spiral flow channel coaxial heat exchanger. Background Technology
[0002] Coaxial heat exchangers are one of the commonly used heat exchange devices, and are widely used in geothermal extraction, chemical industry, energy and other fields due to their compact structure and high heat transfer efficiency.
[0003] In related technologies, coaxial heat exchangers typically consist of heat exchange tubes composed of two concentric circular tubes, i.e., the heat exchange tubes adopt a straight tube design. However, the straight tube design is not conducive to fluid heat exchange, which will result in poor heat transfer efficiency of the entire coaxial heat exchanger. Utility Model Content
[0004] The problem this invention addresses is: how to improve the heat transfer efficiency of a coaxial heat exchanger.
[0005] To solve the above problems, this utility model provides a reverse spiral flow channel coaxial heat exchanger.
[0006] This utility model provides a reverse spiral flow channel coaxial heat exchanger, including a heat exchange tube. The heat exchange tube includes an inner tube and an outer tube sleeved outside the inner tube. A flow channel is formed between the inner tube and the outer tube. The outer wall of the inner tube is provided with a first spiral rib, which extends spirally along the axial direction of the inner tube. The inner wall of the outer tube is provided with a second spiral rib, which extends spirally along the axial direction of the outer tube. The spiral direction of the first spiral rib is opposite to that of the second spiral rib.
[0007] Optionally, the phase difference between the first spiral rib and the second spiral rib is 180°.
[0008] Optionally, the sum of the protrusion height of the first spiral rib relative to the outer wall of the inner tube and the protrusion height of the second spiral rib relative to the inner wall of the outer tube is less than the distance between the outer wall of the inner tube and the inner wall of the outer tube.
[0009] Optionally, the inner tube and the first spiral rib are an integral structure, and the outer tube and the second spiral rib are an integral structure.
[0010] Optionally, the end face of the first spiral rib away from the inner tube is a first top surface, and the edges of the first top surface at both ends along the width direction are provided with a first rounded chamfer; the end face of the second spiral rib away from the outer tube is a second top surface, and the edges of the second top surface at both ends along the width direction are provided with a second rounded chamfer.
[0011] Optionally, the inner tube includes an inner layer tube and a first nested tube, the first nested tube being nested outside the inner layer tube so that the first nested tube and the inner layer tube are detachably connected, and the first spiral rib is provided on the outer wall of the first nested tube.
[0012] Optionally, the outer tube includes an outer tube and a second nested tube, the second nested tube being nested inside the outer tube so that the second nested tube and the outer tube are detachably connected, and the second spiral rib is provided on the inner wall of the second nested tube.
[0013] Optionally, the first helical rib satisfies: ,in, Let be the lead of the first spiral rib. The diameter of the outer tube is [missing information]. The helix angle of the first helical rib; and / or, the second helical rib satisfies: ,in, The lead of the second helical rib is given. The diameter of the outer tube is [missing information]. The helix angle of the second helical rib.
[0014] Optionally, the first spiral rib satisfies: 0.05D≤h1≤0.1D, where h1 is the diameter of the outer tube and h1 is the protrusion height of the first spiral rib relative to the outer wall of the inner tube; and / or, the second spiral rib satisfies: 0.05D≤h2≤0.1D, where h1 is the diameter of the outer tube and h2 is the protrusion height of the second spiral rib relative to the inner wall of the outer tube; and / or, the inner tube and the outer tube satisfy: 0.14D≤δ≤0.16D, where δ is the diameter of the outer tube and δ is the distance between the outer wall of the inner tube and the inner wall of the outer tube.
[0015] Optionally, it further includes a first connector and a second connector, which are respectively connected to the two ends of the heat exchange tube. The first connector is provided with a first fluid inlet and a second fluid outlet, and the second connector is provided with a first fluid outlet and a second fluid inlet. The first fluid inlet, the flow channel, and the first fluid outlet are sequentially connected and used to supply the flow of the first fluid. The second fluid inlet, the inner cavity of the inner tube, and the second fluid outlet are sequentially connected and used to supply the flow of the second fluid.
[0016] The beneficial effects of this invention's reverse spiral flow channel coaxial heat exchanger are as follows: By creating a flow channel between the inner and outer tubes, the fluid can flow within the channel and exchange heat with the fluid inside the inner tube; by providing a first spiral rib on the outer wall of the inner tube and a second spiral rib on the inner wall of the outer tube, the inner surface area of the annular flow channel can be relatively increased without changing the dimensions of the inner and outer tubes, thereby effectively expanding the heat exchange area and improving heat transfer efficiency; furthermore, by extending the first spiral rib along the axial direction of the inner tube and the second spiral rib along the axial direction of the outer tube, with the spiral direction of the first spiral rib being the same as that of the inner tube, the heat exchange efficiency can be improved. The second spiral ribs have opposite spiral directions, so that the inner and outer tubes have opposite spirals. The opposite spirals can generate a relative velocity difference between the fluids near the inner and outer tube walls in opposite directions, thereby forming high-intensity turbulence and improving heat transfer efficiency. In addition, the relative velocity difference caused by the opposite spirals also helps to form a strong shear layer. The shear layer can disrupt the steady growth of the thermal boundary layer, thereby keeping its thickness at a lower level and improving heat transfer efficiency. Furthermore, the high-intensity turbulence formed by the opposite spirals can continuously sweep the tube wall along the spiral channels, carrying away fine particles and initially attached dirt, thereby reducing the dirt deposition rate. Attached Figure Description
[0017] Figure 1 This is a schematic diagram of the structure of the coaxial heat exchanger with reverse spiral flow channel according to an embodiment of this utility model;
[0018] Figure 2 This is a partial schematic diagram of the coaxial heat exchanger with a reverse spiral flow channel according to an embodiment of the present invention;
[0019] Figure 3 This is a cross-sectional view of one embodiment of the reverse spiral flow channel coaxial heat exchanger of this utility model;
[0020] Figure 4 This is a cross-sectional view of another embodiment of the reverse spiral flow channel coaxial heat exchanger of this utility model.
[0021] Explanation of reference numerals in the attached figures:
[0022] 1. Inner tube; 11. Inner layer tube; 12. First nested tube; 2. Outer tube; 21. Outer layer tube; 22. Second nested tube; 3. First spiral rib; 31. First top surface; 32. First rounded chamfer; 4. Second spiral rib; 41. Second top surface; 42. Second rounded chamfer; 5. Flow channel. Detailed Implementation
[0023] To make the above-mentioned objects, features, and advantages of this utility model more apparent and understandable, specific embodiments of this utility model will be described in detail below with reference to the accompanying drawings. Although some embodiments of this utility model are shown in the drawings, it should be understood that this utility model can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this utility model. It should be understood that the drawings and embodiments of this utility model are for illustrative purposes only and are not intended to limit the scope of protection of this utility model.
[0024] In the attached figures, the X-axis represents the front-to-back position, with the positive direction of the X-axis representing the front and the negative direction representing the rear. The Y-axis represents the left-to-right position, with the positive direction representing the left and the negative direction representing the right. The Z-axis represents the up-down position, with the positive direction representing the top and the negative direction representing the bottom. It should be noted that the aforementioned representations of the X, Y, and Z axes are for ease of description and simplification of the invention, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention.
[0025] The term "comprising" and its variations as used herein are open-ended, meaning "including but not limited to"; the term "based on" means "at least partially based on"; the term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one additional embodiment"; the term "some embodiments" means "at least some embodiments"; and the term "optionally" means "optional embodiments". Definitions of other terms will be given in the following description. It should be noted that the concepts of "first," "second," etc., mentioned in this utility model are only used to distinguish different devices, modules, or units, and are not used to limit the order of functions performed by these devices, modules, or units or their interdependencies.
[0026] It should be noted that the terms "one" and "multiple" used in this utility model are illustrative rather than restrictive. Those skilled in the art should understand that, unless otherwise expressly indicated in the context, they should be understood as "one or more".
[0027] In related technologies, coaxial heat exchangers typically consist of heat exchange tubes composed of two concentric circular tubes, one inner and one outer. However, this straight-tube design often leads to problems such as an excessively thick thermal boundary layer, insufficient turbulent mixing, and limited heat transfer area, resulting in poor heat transfer efficiency. Specifically, regarding the excessively thick thermal boundary layer, because both the inner and outer tubes are straight, the fluid flows in a laminar state in the annulus between them. This causes the thermal boundary layer to thicken continuously along the tube wall. According to Fourier's law, the heat transfer rate is proportional to the temperature gradient, and the thickening of the thermal boundary layer significantly reduces the temperature gradient, thus affecting heat transfer efficiency. Regarding insufficient turbulent mixing, because both the inner and outer tubes are straight, there is a lack of active disturbance mechanisms in the annulus between them, resulting in insufficient turbulent mixing and affecting heat transfer efficiency. Regarding the limited heat transfer area, because both the inner and outer tubes are straight, the heat transfer area is limited by the size of the straight tubes. With the straight tube size remaining constant, it is usually difficult to increase the effective heat transfer area, resulting in limited heat transfer efficiency.
[0028] In order to solve the technical problems existing in the related technologies, this utility model provides a reverse spiral flow channel coaxial heat exchanger, which will be described in detail below with reference to specific embodiments.
[0029] like Figure 1 and Figure 2 As shown in the figure, an embodiment of the present invention provides a coaxial heat exchanger with a reverse spiral flow channel, including a heat exchange tube. The heat exchange tube includes an inner tube 1 and an outer tube 2 sleeved outside the inner tube 1. A flow channel 5 is formed between the inner tube 1 and the outer tube 2. The outer wall of the inner tube 1 is provided with a first spiral rib 3, which extends spirally along the axial direction of the inner tube 1. The inner wall of the outer tube 2 is provided with a second spiral rib 4, which extends spirally along the axial direction of the outer tube 2. The spiral direction of the first spiral rib 3 is opposite to the spiral direction of the second spiral rib 4.
[0030] Specifically, an annular flow channel 5 is formed between the inner tube 1 and the outer tube 2. The first spiral rib 3 protrudes from the outer wall of the inner tube 1 radially toward the flow channel 5, and the second spiral rib 4 protrudes from the inner wall of the outer tube 2 radially toward the flow channel 5.
[0031] In this embodiment, a flow channel 5 is formed between the inner tube 1 and the outer tube 2 to facilitate fluid flow within the flow channel 5 and heat exchange with the fluid in the inner tube 1. Furthermore, by providing a first helical rib 3 on the outer wall of the inner tube 1 and a second helical rib 4 on the inner wall of the outer tube 2, the inner surface area of the annular flow channel 5 can be relatively increased without changing the dimensions of the inner and outer tubes, thereby effectively expanding the heat exchange area and improving heat transfer efficiency. Additionally, by extending the first helical rib 3 along the axial direction of the inner tube 1 and the second helical rib 4 along the axial direction of the outer tube 2, with the helical direction of the first helical rib 3 being the same as that of the inner tube 1, the flow channel 5 is relatively increased. The spiral directions of the two spiral ribs 4 are opposite, so that the inner and outer tubes have opposite spirals. The opposite spirals can generate a relative velocity difference between the fluids near the inner and outer tube walls in opposite directions, thereby forming high-intensity turbulence and improving heat transfer efficiency. In addition, the relative velocity difference brought about by the opposite spirals also helps to form a strong shear layer. The shear layer can disrupt the smooth growth of the thermal boundary layer, thereby keeping its thickness at a lower level and improving heat transfer efficiency. Furthermore, the high-intensity turbulence formed by the opposite spirals can continuously sweep the tube wall along the spiral channels, carrying away fine particles and initially attached dirt, thereby reducing the dirt deposition rate.
[0032] Optionally, the reverse spiral flow channel coaxial heat exchanger may further include a first connector and a second connector, which are respectively connected to the two ends of the heat exchange tube. The first connector is provided with a first fluid inlet and a second fluid outlet, and the second connector is provided with a first fluid outlet and a second fluid inlet. The first fluid inlet, the flow channel 5, and the first fluid outlet are sequentially connected and used to supply the first fluid flow. The second fluid inlet, the inner cavity of the inner tube 1, and the second fluid outlet are sequentially connected and used to supply the second fluid flow.
[0033] The first fluid and the second fluid can be a hot fluid and a cold fluid, respectively. When the two fluids flow in the coaxial heat exchanger, they can exchange heat with each other. Specifically, the first connector can be connected to the inner tube 1 and the outer tube 2 respectively, and the second connector can be connected to the inner tube 1 and the outer tube 2 respectively, so that the positions of the inner tube 1 and the outer tube 2 are relatively fixed, ensuring that the inner and outer tubes are coaxial.
[0034] In this optional embodiment, the first fluid inlet, the flow channel 5, and the first fluid outlet are connected in sequence, so that the first fluid can flow into the flow channel 5 through the first fluid inlet and then be discharged through the first fluid outlet. The second fluid inlet, the inner cavity of the inner tube 1, and the second fluid outlet are connected in sequence, so that the second fluid can flow into the inner tube 1 through the second fluid inlet and then be discharged through the second fluid outlet. The first fluid and the second fluid can exchange heat with each other during their respective flow processes, thereby achieving coaxial heat exchange.
[0035] Optionally, such as Figure 1 and Figure 2As shown, the first spiral rib 3 has a right-hand spiral direction, and the second spiral rib 4 has a left-hand spiral direction.
[0036] In this optional embodiment, by setting the helical direction of the first helical rib 3 to right-handed (i.e., the first helical rib 3 is a right-handed helical rib) and setting the helical direction of the second helical rib 4 to left-handed (i.e., the second helical rib 4 is a left-handed helical rib), the helical directions of the two are opposite, thereby effectively enhancing turbulence, destroying the thermal boundary layer, and improving heat transfer efficiency.
[0037] Optionally, the phase difference between the first helical rib 3 and the second helical rib 4 is 180°.
[0038] It should be noted that the phase difference of 180° between the first spiral rib 3 and the second spiral rib 4 means that the phase difference between the first spiral rib 3 and the second spiral rib 4 is 180° in any cross-section of the coaxial heat exchanger. For example, in a cross-section of the coaxial heat exchanger, if the first spiral rib 3 is at a valley, then the second spiral rib 4 is at a corresponding peak.
[0039] In this optional embodiment, by setting the phase difference between the first helical rib 3 and the second helical rib 4 to 180°, a more significant relative velocity difference can be generated between the fluids near the inner and outer pipe walls in opposite directions, thereby further improving the intensity of turbulence.
[0040] Optionally, such as Figure 3 As shown, the sum of the protrusion height of the first spiral rib 3 relative to the outer wall of the inner tube 1 and the protrusion height of the second spiral rib 4 relative to the inner wall of the outer tube 2 is less than the distance between the outer wall of the inner tube 1 and the inner wall of the outer tube 2.
[0041] In this optional embodiment, by setting the sum of the protrusion height of the first helical rib 3 and the protrusion height of the second helical rib 4 to be less than the distance between the outer wall of the inner tube 1 and the inner wall of the outer tube 2, a gap can be achieved between the first helical rib 3 and the second helical rib 4 to facilitate fluid flow.
[0042] Further, the first spiral rib 3 satisfies: 0.05D≤h1≤0.1D, where h is the diameter of the outer tube 2 and h1 is the protrusion height of the first spiral rib 3 relative to the outer wall of the inner tube 1; and / or, the second spiral rib 4 satisfies: 0.05D≤h2≤0.1D, where h is the diameter of the outer tube 2 and h2 is the protrusion height of the second spiral rib 4 relative to the inner wall of the outer tube 2; and / or, the inner tube 1 and the outer tube 2 satisfy: 0.14D≤δ≤0.16D, where h is the diameter of the outer tube 2 and δ is the distance between the outer wall of the inner tube 1 and the inner wall of the outer tube 2.
[0043] Specifically, in some embodiments, h1 can be equal to 0.06D, h2 can be equal to 0.08D, and δ can be equal to 0.15D. This satisfies the above-mentioned size range and ensures that the sum of the protrusion height of the first spiral rib 3 and the protrusion height of the second spiral rib 4 is less than the distance between the outer wall of the inner tube 1 and the inner wall of the outer tube 2.
[0044] In this embodiment, by setting the protrusion height of the first spiral rib 3 and the second spiral rib 4 to between 0.05D and 0.1D, the heat exchange area can be effectively expanded without excessively increasing material costs. In addition, when the distance between the outer wall of the inner tube 1 and the inner wall of the outer tube 2 is too narrow, the resistance increases dramatically, and when it is too wide, the turbulence intensity is insufficient. However, this solution achieves a balance between flow rate and pressure drop by ensuring that the inner tube 1 and the outer tube 2 satisfy 0.14D≤δ≤0.16D, which is more conducive to promoting heat exchange.
[0045] Optionally, such as Figure 2 As shown, the inner tube 1 and the first spiral rib 3 are an integral structure, and the outer tube 2 and the second spiral rib 4 are an integral structure.
[0046] Specifically, the inner tube 1 and the first spiral rib 3 can be made of the same material so that they can be manufactured as a single piece. In addition, the outer tube 2 and the second spiral rib 4 can also be made of the same material so that they can be manufactured as a single piece.
[0047] In this optional embodiment, by setting the inner tube 1 and the first spiral rib 3 as an integral structure, the integrity of the inner tube 1 and the first spiral rib 3 can be improved. By setting the outer tube 2 and the second spiral rib 4 as an integral structure, the integrity of the outer tube 2 and the second spiral rib 4 can be improved, thereby avoiding assembly gaps and welding stress concentration, and reducing the risk of fatigue damage.
[0048] Optionally, such as Figure 2 and Figure 3 As shown, the end face of the first spiral rib 3 away from the inner tube 1 is the first top surface 31, and the edges of the first top surface 31 at both ends along the width direction are provided with a first rounded chamfer 32; the end face of the second spiral rib 4 away from the outer tube 2 is the second top surface 41, and the edges of the second top surface 41 at both ends along the width direction are provided with a second rounded chamfer 42.
[0049] Specifically, the cross-section of the first spiral rib 3 can be trapezoidal. Further, when the cross-section of the first spiral rib 3 is trapezoidal, the width of the top edge of the trapezoid can be 2.5h1, and the radius of the first rounded chamfer 32 can be 0.2h1. Additionally, the cross-section of the second spiral rib 4 can also be trapezoidal. Further, when the cross-section of the second spiral rib 4 is trapezoidal, the width of the top edge of the trapezoid can be 2.5h2, and the radius of the second rounded chamfer 42 can be 0.2h2.
[0050] In this optional embodiment, by providing a first rounded chamfer 32 at both ends of the first top surface 31 of the first helical rib 3 along the width direction and a second rounded chamfer 42 at both ends of the second top surface 41 of the second helical rib 4 along the width direction, local flow resistance can be reduced, thereby improving fluid pressure drop.
[0051] Alternatively, in other embodiments, such as Figure 4 As shown, the inner tube 1 includes an inner tube 11 and a first nested tube 12. The first nested tube 12 is nested outside the inner tube 11 so that the first nested tube 12 and the inner tube 11 can be detachably connected. The first spiral rib 3 is provided on the outer wall of the first nested tube 12.
[0052] In this optional embodiment, the inner tube 1 is configured as an inner layer tube 11 and a first nested tube 12, with the first nested tube 12 nested outside the inner layer tube 11, so that the first nested tube 12 and the inner layer tube 11 are detachably connected. At the same time, the first spiral rib 3 is provided on the outer wall of the first nested tube 12. In this way, when the first spiral rib 3 needs to be replaced after long-term use, the first nested tube 12 can be removed from the inner layer tube 11, and the first spiral rib 3 can be removed together without disassembling and replacing the entire inner tube 1, making maintenance more convenient.
[0053] Optionally, such as Figure 4 As shown, the outer tube 2 includes an outer tube 21 and a second nested tube 22. The second nested tube 22 is nested inside the outer tube 21 so that the second nested tube 22 and the outer tube 21 are detachably connected. The second spiral rib 4 is provided on the inner wall of the second nested tube 22.
[0054] In this optional embodiment, the outer tube 2 is configured as an outer tube 21 and a second nested tube 22, with the second nested tube 22 nested inside the outer tube 21, so that the second nested tube 22 and the outer tube 21 are detachably connected. At the same time, the second spiral rib 4 is provided on the inner wall of the second nested tube 22. In this way, when the second spiral rib 4 needs to be replaced after long-term use, the second nested tube 22 can be removed from the outer tube 21, and the second spiral rib 4 can be removed together without disassembling and replacing the entire outer tube 2, making maintenance more convenient.
[0055] Optionally, the first helical rib 3 satisfies: ,in, The lead of the first spiral rib 3 is given. The diameter of the outer tube 2 is [missing information]. The helix angle of the first helical rib 3; and / or, the second helical rib 4 satisfies: ,in, The lead of the second helical rib 4 is... The diameter of the outer tube 2 is [missing information]. The helix angle of the second helical rib 4.
[0056] Specifically, for the first helical rib 3 and the second helical rib 4, / and / It can be between 2 and 5, for example / It is 2.5. / The value is 3.
[0057] In this optional embodiment, by making the first helical rib 3 satisfy... And make the second spiral rib 4 satisfy This allows for an optimal balance between turbulence intensity and pressure drop, avoiding insufficient turbulence excitation or excessive pressure drop.
[0058] Although the present invention has been disclosed above, its protection scope is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the protection scope of the present invention.
Claims
1. A coaxial heat exchanger with a reverse spiral flow channel, characterized in that, The device includes a heat exchange tube, which includes an inner tube (1) and an outer tube (2) sleeved on the outside of the inner tube (1). A flow channel (5) is formed between the inner tube (1) and the outer tube (2). The outer wall of the inner tube (1) is provided with a first spiral rib (3), which extends spirally along the axial direction of the inner tube (1). The inner wall of the outer tube (2) is provided with a second spiral rib (4), which extends spirally along the axial direction of the outer tube (2). The spiral direction of the first spiral rib (3) is opposite to that of the second spiral rib (4).
2. The coaxial heat exchanger with a reverse spiral flow channel according to claim 1, characterized in that, The phase difference between the first spiral rib (3) and the second spiral rib (4) is 180°.
3. The coaxial heat exchanger with a reverse spiral flow channel according to claim 1, characterized in that, The sum of the protrusion height of the first spiral rib (3) relative to the outer wall of the inner tube (1) and the protrusion height of the second spiral rib (4) relative to the inner wall of the outer tube (2) is less than the distance between the outer wall of the inner tube (1) and the inner wall of the outer tube (2).
4. The coaxial heat exchanger with a reverse spiral flow channel according to claim 1, characterized in that, The inner tube (1) and the first spiral rib (3) are an integral structure, and the outer tube (2) and the second spiral rib (4) are an integral structure.
5. The coaxial heat exchanger with a reverse spiral flow channel according to claim 1, characterized in that, The end face of the first spiral rib (3) away from the inner tube (1) is the first top surface (31), and the first top surface (31) has a first rounded chamfer (32) at both ends along the width direction; the end face of the second spiral rib (4) away from the outer tube (2) is the second top surface (41), and the second top surface (41) has a second rounded chamfer (42) at both ends along the width direction.
6. The coaxial heat exchanger with a reverse spiral flow channel according to claim 1, characterized in that, The inner tube (1) includes an inner tube (11) and a first nested tube (12). The first nested tube (12) is nested outside the inner tube (11) so that the first nested tube (12) and the inner tube (11) can be detachably connected. The first spiral rib (3) is provided on the outer wall of the first nested tube (12).
7. The coaxial heat exchanger with a reverse spiral flow channel according to claim 1, characterized in that, The outer tube (2) includes an outer tube (21) and a second nested tube (22). The second nested tube (22) is nested inside the outer tube (21) so that the second nested tube (22) and the outer tube (21) can be detachably connected. The second spiral rib (4) is provided on the inner wall of the second nested tube (22).
8. The coaxial heat exchanger with a reverse spiral flow channel according to claim 1, characterized in that, The first helical rib (3) satisfies: ,in, Let be the lead of the first spiral rib (3). The diameter of the outer tube (2) is The helix angle of the first helical rib (3); and / or, the second helical rib (4) satisfies: ,in, The lead of the second helical rib (4) is given. The diameter of the outer tube (2) is The helix angle of the second helical rib (4) is given.
9. The coaxial heat exchanger with a reverse spiral flow channel according to claim 1, characterized in that, The first helical rib (3) satisfies: 0.05D≤h1≤0.1D, where, Let h1 be the diameter of the outer tube (2), and h1 be the protrusion height of the first helical rib (3) relative to the outer wall of the inner tube (1); and / or, the second helical rib (4) satisfies: 0.05D≤h2≤0.1D, where, h2 is the diameter of the outer tube (2), and h2 is the protrusion height of the second helical rib (4) relative to the inner wall of the outer tube (2); and / or, the inner tube (1) and the outer tube (2) satisfy: 0.14D≤δ≤0.16D, where, δ is the diameter of the outer tube (2), and δ is the distance between the outer wall of the inner tube (1) and the inner wall of the outer tube (2).
10. The coaxial heat exchanger with a reverse spiral flow channel according to claim 1, characterized in that, It also includes a first connector and a second connector, which are respectively connected to the two ends of the heat exchange tube. The first connector is provided with a first fluid inlet and a second fluid outlet, and the second connector is provided with a first fluid outlet and a second fluid inlet. The first fluid inlet, the flow channel (5), and the first fluid outlet are connected in sequence and used to supply the first fluid flow. The second fluid inlet, the inner cavity of the inner tube (1), and the second fluid outlet are connected in sequence and used to supply the second fluid flow.