Distributed high-efficiency heat exchange tube for middle-deep layer geothermal heating
By setting up a turbulence-inducing unit between the inner and outer tubes to form a spiral guiding structure, the problem of low heat exchange tube efficiency is solved, and a highly efficient and uniform heat transfer effect is achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XIAN SHENHENG ENERGY SAVING TECH CO LTD
- Filing Date
- 2026-03-11
- Publication Date
- 2026-05-01
AI Technical Summary
The heat exchange efficiency of existing distributed medium-deep geothermal heating heat exchange pipes is poor and cannot meet higher usage requirements.
Multiple sets of turbulence-inducing units, including guide fins and flow-guiding fins, are set between the inner and outer pipes to form a spiral guiding structure. Through the design of the spiral angle of the guide fins and the turbulence-inducing holes, the fluid is guided to form a three-dimensional spiral vortex, which enhances the contact between the fluid and the pipe wall and the flow stability, and prolongs the heat exchange time.
It significantly improves heat exchange efficiency, reduces boundary layer thickness by 30%-40%, increases flow velocity, ensures uniform contact between fluid and pipe wall, improves overall heat transfer coefficient, reduces flow resistance, and achieves efficient and uniform heat transfer.
Smart Images
Figure CN121953518A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of heat exchanger tube technology, and in particular to a high-efficiency heat exchanger tube for distributed medium-deep geothermal heating. Background Technology
[0002] High-efficiency heat exchange pipes for distributed medium-deep geothermal heating refer to high-efficiency heat exchange devices used in distributed geothermal heating systems to capture geothermal energy from medium-deep underground layers (usually hundreds to thousands of meters deep) and transfer it to the heating circulating water. They are mostly tubular in shape.
[0003] Heat exchange tubes are mostly composed of inner and outer tubes, with the outer tube sleeved on the outside of the inner tube. When fluid media of different temperatures flow through the inner tube and between the inner and outer tubes, heat exchange can occur. In the existing technology, the medium flowing through the pipe is relatively stable, and the inner walls of the inner and outer tubes are relatively smooth, which results in poor heat exchange efficiency of the pipe and cannot meet more application requirements. Summary of the Invention
[0004] In view of the problems existing in the current high-efficiency heat exchange tubes for distributed medium-deep geothermal heating, the present invention proposes a high-efficiency heat exchange tube for distributed medium-deep geothermal heating to solve these problems.
[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a high-efficiency heat exchange pipe for distributed medium-deep geothermal heating, comprising an outer heating pipe, an inner heating pipe, and a turbulence unit, characterized in that: the inner heating pipe is inserted into the outer heating pipe, a heating interlayer exists between the outer heating pipe and the inner heating pipe, and the turbulence unit is disposed within the heating interlayer; The turbulence unit includes multiple sets of guide fins that are equally divided around the heating inner pipe as the axis. Each set of guide fins has a corresponding guide fin at its lower end. The guide fins are fixedly connected to the outer wall of the heating inner pipe, and each set of guide fins has equally divided turbulence holes.
[0006] As a preferred embodiment of the high-efficiency heat exchange tube for distributed medium-deep geothermal heating described in this invention, the turbulence unit comprises multiple sets, which are spaced apart along the axial direction of the heating inner tube, and the spiral directions of the guide fins on adjacent sets of turbulence units are opposite.
[0007] As a preferred embodiment of the high-efficiency heat exchange tube for distributed medium-deep geothermal heating described in this invention, the guide fins are vertical flow-guiding fin structures, which are radially and uniformly distributed along the outer wall of the heating inner tube, thereby enhancing heat exchange efficiency by increasing the fluid contact area.
[0008] As a preferred embodiment of the high-efficiency heat exchanger tube for distributed medium-deep geothermal heating described in this invention, wherein: there are flow gaps between each pair of the guide fins, and the cross-section of the conveying channel formed by the combination of multiple sets of flow gaps is smaller than the flow cross-section of the heating jacket.
[0009] As a preferred embodiment of the high-efficiency heat exchange tube for distributed medium-deep geothermal heating described in this invention, wherein: the distribution angle of the turbulence hole on the guide fin is the same as the spiral angle of the guide fin, and the turbulence hole connects the heating interlayer on both sides of the guide fin.
[0010] As a preferred embodiment of the high-efficiency heat exchange tube for distributed medium-deep geothermal heating described in this invention, the inner heating tube is provided with a spiral turbulence wire with a spiral structure, and the spiral turbulence wire is provided with multiple spiral grooves, and the end of the previous spiral groove is connected to the beginning of the next spiral groove.
[0011] As a preferred embodiment of the high-efficiency heat exchange tube for distributed medium-deep geothermal heating described in this invention, the turbulence hole is a turbulence channel that penetrates the guide fins, and the turbulence hole connects the flow channels on both sides of the guide fins to form a local vortex, which further disrupts the boundary layer and improves the heat transfer coefficient.
[0012] As a preferred embodiment of the high-efficiency heat exchanger tube for distributed medium-deep geothermal heating described in this invention, the guide fins are spiral guide plates with a 1 / 4 circular arc transition, and smooth arc-shaped guide surfaces are formed on the upper and lower sides.
[0013] As a preferred embodiment of the high-efficiency heat exchange tube for distributed medium-deep geothermal heating described in this invention, the bending angle of the guide fins matches the fluid flow direction, which can guide the medium to form a spiral flow pattern, and the bending direction and bending angle of the guide fins on multiple sets of turbulence guiding components are the same.
[0014] As a preferred embodiment of the high-efficiency heat exchange tube for distributed medium-deep geothermal heating described in this invention, the inner heating tube is located at the axial position of the outer heating tube, and the internal spaces of the outer heating tube and the inner heating tube are independent and not connected to each other.
[0015] The beneficial effects of this invention are as follows: By setting multiple sets of turbulence-inducing units between the outer and inner pipes, precise guidance and control of the fluid can be achieved. The turbulence-inducing unit is composed of multiple sets of turbulence-inducing guiding components that are evenly distributed in a ring along the axial direction of the inner pipe to form a spiral guiding structure. This guides the fluid in the pipe side to the same direction at a specific spiral angle, so that the fluid forms a three-dimensional spiral vortex under the action of the turbulence-inducing guiding components. This creates a gradient velocity field distribution on different cross sections of the pipe. Through the synergistic effect of three mechanisms—strengthening the laminar flow bottom layer disturbance, increasing the radial mixing intensity of the fluid, and extending the heat exchange path—the heat exchange efficiency of the geothermal heating system can be significantly improved. Meanwhile, the unidirectional swirling flow guidance of the fluid medium can be achieved through the coordinated design of the helical angle of the guide fins, so that the heat exchange fluid forms an orderly three-dimensional helical flow field in the tube. This directional flow guidance structure avoids the eddy interference and chaotic flow direction in the traditional turbulent state. Meanwhile, the turbulence guiding component on the turbulence unit adopts a 1 / 4 circular arc transition design with a spiral angle to form a smooth arc-shaped guiding fin. This arc-shaped guiding surface guides the fluid medium to the outer wall of the inner tube through a specific inlet angle of attack, so that the fluid maintains a wall-attached flow state while flowing axially. This composite flow mode can reduce the fluid boundary layer thickness by 30%-40%, thereby enhancing the convective heat transfer between the wall and the fluid. Meanwhile, multiple sets of turbulence-inducing units are evenly distributed along the inner pipe axis, so that the fluid can be guided and turbulent every time it flows, thereby improving the heat exchange efficiency. At the same time, the turbulence-inducing units can reduce the fluid flow channel opening in the cross section, thereby increasing the fluid velocity and enhancing the turbulence effect on the fluid in the pipe, further improving the heat exchange efficiency. Meanwhile, the spiral flow can prolong the time the fluid flows in the pipe, thereby extending the time for heat transfer between the pipe and the fluid, allowing the fluid's heat to be transferred out more fully and powerfully, achieving the goal of efficient heat exchange. Attached Figure Description
[0016] Figure 1 This is a schematic diagram of the overall structure of the high-efficiency heat exchanger tube for distributed medium-deep geothermal heating according to the present invention. Figure 2 For the present invention Figure 1 Enlarged schematic diagram of the structure at point A in the middle; Figure 3 This is a schematic diagram of the internal structure of the high-efficiency heat exchanger tube for distributed medium-deep geothermal heating according to the present invention. Figure 4 This is a schematic diagram of the internal structure of the heating inner pipe of the high-efficiency heat exchange tube for distributed medium-deep geothermal heating according to the present invention. Figure 5 This is a schematic diagram of the structure of the high-efficiency heat exchange tube turbulence unit for distributed medium-deep geothermal heating of the present invention; Figure 6 This is a schematic diagram showing the direction of the swirling flow generated by the high-efficiency heat exchange tube turbulence unit for distributed medium-deep geothermal heating according to the present invention. Reference numerals in the attached drawings: 1. Heating outer pipe; 11. Heating jacket; 2. Heating inner pipe; 21. Spiral turbulence wire; 211. Spiral groove; 3. Turbulence guide assembly; 31. Guide fin; 32. Guide fin; 33. Turbulence hole. Detailed Implementation
[0017] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
[0018] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.
[0019] Reference Figures 1 to 6 This invention provides an embodiment of a high-efficiency heat exchange pipe for distributed medium-deep geothermal heating, comprising an outer heating pipe 1, an inner heating pipe 2, and multiple sets of flow-turbulence units. The inner heating pipe 2 is inserted into the outer heating pipe 1, and a heating interlayer 11 exists between the outer heating pipe 1 and the inner heating pipe 2. The flow-turbulence units are disposed within the heating interlayer 11. Precise fluid guidance and control are achieved by setting multiple sets of flow-turbulence units between the outer heating pipe 1 and the inner heating pipe 2. Reference Figure 5 The turbulence unit includes multiple sets of equally spaced guide fins 31 surrounding the heating inner pipe 2. Each set of guide fins 31 has a corresponding guide fin 32 at its lower end. The guide fins 31 and 32 are fixedly connected to the outer wall of the heating inner pipe 2. Each set of guide fins 32 has equally spaced turbulence holes 33. The guide fins 31 serve as the basic support structure to position the spatial angle of the guide fins 32. The guide fins 32 extend the residence time of the medium through spiral guidance and also guide the direction of fluid flow. The turbulence holes 33 enhance the turbulence intensity through jet disturbance, thus jointly improving the heat exchange efficiency.
[0020] Furthermore, in combination Figure 5 The turbulence unit forms a spiral guiding structure by means of multiple sets of guide fins 31 evenly distributed in a ring along the axial direction of the inner heating pipe 2. This guides the fluid in the pipe side in the same direction at a spiral angle of 30°-45°, so that the fluid forms a three-dimensional spiral vortex under the action of the guide fins 31. This creates a gradient velocity field distribution on different cross sections of the pipe. Through the synergistic effect of three mechanisms—enhancing the laminar flow bottom layer disturbance, increasing the radial mixing intensity of the fluid, and extending the heat exchange path—the heat exchange efficiency of the geothermal heating system can be significantly improved.
[0021] Combination Figure 3There are multiple sets of turbulence units, which are spaced apart along the axial direction of the inner heating pipe 2. The spiral directions of the guide fins 32 on adjacent sets of turbulence units are opposite. The opposite directions of the guide fins 32 make the adjacent sets of turbulence units form a "forward-reverse-forward" swirling alternating pattern. This alternating structure makes the fluid form a spiral flow field with a periodic rotation direction change in the heating jacket 11. The shear force generated by the direction switching destroys the boundary layer that has been formed, while avoiding the fluid segregation phenomenon caused by unilateral swirling. This makes the contact between the medium and the inner wall of the outer heating pipe 1 and the outer wall of the inner heating pipe 2 more uniform, which can improve the overall heat transfer coefficient and at the same time avoid causing large flow resistance.
[0022] Reference Figure 5 The guide fins 31 are vertical flow-guiding fin structures, which are radially and uniformly distributed along the outer wall of the heating inner pipe 2. By increasing the fluid contact area, the heat exchange efficiency is enhanced. The guide fins 31 are made of thin metal sheets with high thermal conductivity, and are radially and uniformly distributed along the outer wall of the heating inner pipe 2. Six sets are set at 60° intervals around the circumference. The top of the guide fins 31 is parallel to the axis of the heating inner pipe 2, and the bottom is fixed to the guide fins 32.
[0023] Reference Figure 2 , Figure 5 and Figure 6 There are flow gaps between each pair of guide fins 31. The cross-section of the conveying channel formed by the combination of multiple sets of flow gaps is smaller than the flow cross-section of the heating jacket 11. The smaller flow cross-section of the heating jacket 11 will cause the fluid to undergo a contraction transport phenomenon during transport. This contraction design increases the flow velocity of the fluid when passing through the gaps. At the same time, the periodic change of the flow area forms a "contraction-expansion" flow characteristic, generating local turbulence at the gap outlet. This structure enhances convective heat transfer by increasing the flow velocity and promotes forced convection between the fluid and the surface of the guide fins 31 by utilizing the pressure change in the contraction section. Simulation calculations show that the boundary layer thickness can be reduced by 30%-40%. Combined with the swirling effect of the spiral guide plate of the guide fins 32, the heat transfer uniformity of the entire flow field is improved.
[0024] Combination Figure 6 During the use of the turbulence guiding component 3, the guide fins 31 and 32 enhance heat exchange efficiency through a triple mechanism of increasing the contact area with the fluid, increasing the fluid velocity, and guiding the formation of a spiral turbulence. Specifically: first, the convective heat transfer is enhanced by increasing the contact area with the fluid through the outer surfaces of the guide fins 31 and 32; second, the fluid velocity is increased by utilizing the narrow flow channels between the turbulence guiding components 3; and third, the spiral structure of the turbulence hole 33 forms micro-vortices in the boundary layer, disrupting the thickness of the laminar sublayer, which can increase the local heat transfer coefficient and further improve the heat transfer efficiency.
[0025] Combination Figure 5The turbulence hole 33 is a turbulence channel that penetrates the guide fin 32. The turbulence hole 33 connects the flow channels on both sides of the guide fin 32 to form a local vortex, which further disrupts the boundary layer and improves the heat transfer coefficient. The distribution angle of the turbulence hole 33 on the guide fin 32 is 30°-45° and the spiral angle of the guide fin 32 is 30°-45°. The axis of the channel is designed to be inclined at 5°-8° with the normal of the surface of the guide fin 32, so as to ensure that the fluid penetrates the guide fin 32 vertically during the spiral flow. The turbulence hole 33 connects the flow channels of the heating jacket 11 on both sides of the guide fin 32 through the through hole structure, forming a "mainstream-tributary-mainstream" flow cycle, thereby further disrupting the boundary layer and improving the heat transfer coefficient.
[0026] Combination Figure 4 The heating inner pipe 2 is equipped with a spiral turbulence wire 21 with a spiral structure. The spiral turbulence wire 21 has multiple spiral grooves 211, and the end of the previous spiral groove 211 is connected to the beginning of the next spiral groove 211. The fluid medium flows along the axial direction of the heating inner pipe 2. Some of the fluid medium first flows into the first spiral groove 211, and then flows from the end of the first spiral groove 211 into the next spiral groove 211, until the heat exchange fluid medium flows out from the last spiral groove 211. Because the direction of the fluid medium flowing along the spiral groove 211 is different from the direction of the flow from one spiral groove 211 into the next spiral groove 211, the spiral turbulence wire 21 continuously changes the flow direction of the heat exchange fluid medium, thereby reducing the flow velocity of the heat exchange fluid medium, increasing the heat exchange time, and thus improving the heat exchange capacity.
[0027] Reference Figure 5 and Figure 6 The guide fin 32 is a spiral guide plate with a 1 / 4 arc transition. Its upper and lower sides form smooth arc-shaped guide surfaces. The guide fin 32 can guide the fluid to form a spiral vortex through its own structure. The spiral vortex can prolong the fluid's flow time in the pipe, thereby prolonging the heat transfer time between the pipe and the fluid. This allows the fluid's heat to be transferred outward more fully and powerfully, achieving the purpose of efficient heat exchange.
[0028] Combination Figure 6 The bending angle of the guide fin 32 matches the direction of fluid flow, which can guide the medium to form a spiral flow. At the same time, the bending direction and bending angle of the guide fin 32 on multiple sets of turbulence guiding components 3 are the same. The guide fin 32 adopts a spiral bending angle design of 30°-45°, and its bending direction is matched with the direction of fluid inlet pressure at an angle of 15°-20°. The smooth turning of the fluid is achieved through the arc-shaped flow guiding surface, which can guide the medium to form a spiral flow. This flow can prolong the residence time of the fluid in the heating jacket 11. At the same time, the same method of the guide fin 32 on multiple sets of turbulence guiding components 3 makes the spiral flow generated by adjacent turbulence units form a continuous superposition effect.
[0029] Reference Figure 2 Meanwhile, the heating outer pipe 1 and the heating inner pipe 2 have independent internal spaces and are not connected to each other. This means that both can transport fluid media independently, and if one is damaged, the other can continue to be used.
[0030] In summary, the core of this distributed medium-deep geothermal heating high-efficiency heat exchange pipe lies in its optimized turbulence unit design, which significantly improves heat exchange efficiency. The equipment consists of an outer heating pipe 1, an inner pipe 2, and a heating jacket 11. The turbulence unit is located within the heating jacket 11 and includes guide fins 31 and guide fins 32. The guide fins 31 are radially distributed on the outer wall of the inner pipe, serving as support and forming a spiral guiding structure, guiding the fluid to form a spiral angle of 30°-45°, generating a three-dimensional spiral flow, enhancing laminar sublayer disturbance and radial mixing. The contraction transport channel formed between the guide fins 31 increases the flow velocity, and the "contraction-expansion" characteristic generates local turbulence, enhancing convective heat transfer and reducing boundary layer thickness. The guide fins 32 are connected to the lower end of the guide fins 31, extending the medium residence time through spiral guidance and enhancing heat conduction. Its structure forms a smooth arc-shaped guide surface, guiding the fluid to form a stable spiral flow pattern. The turbulence hole 33 is set on the guide fin 32, which enhances the turbulence intensity, destroys the boundary layer, and improves the local heat transfer coefficient through jet disturbance and the "mainstream-tributary-mainstream" circulation connecting the two flow channels. In particular, multiple sets of turbulence units are arranged at intervals along the axial direction, and the spiral direction of the guide fin 32 of adjacent units is opposite, forming a "forward-reverse-forward" swirling alternation mode. This structure destroys the boundary layer through shear force, avoids fluid segregation, makes the medium and the tube wall more uniformly contacted, improves the overall heat transfer coefficient and reduces the flow resistance. In general, this heat exchange tube enhances the heat exchange process in multiple dimensions by increasing the contact area, increasing the flow velocity, forming multi-level spiral / turbulence and advanced swirling alternation design, so as to achieve efficient and uniform heat transfer.
[0031] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.
Claims
1. A high-efficiency heat exchanger pipe for distributed medium-deep geothermal heating, comprising an outer heating pipe (1), an inner heating pipe (2), and a turbulence-inducing unit, characterized in that: The inner heating pipe (2) is inserted into the outer heating pipe (1), and there is a heating interlayer (11) between the outer heating pipe (1) and the inner heating pipe (2). The turbulence unit is set in the heating interlayer (11). The turbulence unit includes multiple sets of guide fins (31) that are equally divided around the heating inner tube (2) as the axis. Each set of guide fins (31) has a corresponding guide fin (32) at its lower end. The guide fins (31) and guide fins (32) are fixedly connected to the outer wall of the heating inner tube (2), and turbulence holes (33) are equally divided on each set of guide fins (32).
2. The high-efficiency heat exchanger tube for distributed medium-deep geothermal heating according to claim 1, characterized in that: The turbulence unit consists of multiple sets, which are spaced apart along the axial direction of the heating inner pipe (2), and the spiral directions of the guide fins (32) on adjacent sets of turbulence units are opposite.
3. The high-efficiency heat exchanger tube for distributed medium-deep geothermal heating according to claim 1 or 2, characterized in that: The guide fins (31) are vertical flow guide fin structures, which are radially and uniformly distributed along the outer wall of the heating inner pipe (2), thereby enhancing the heat exchange efficiency by increasing the fluid contact area.
4. The high-efficiency heat exchanger tube for distributed medium-deep geothermal heating according to claim 1, characterized in that: There are flow gaps between each pair of the guide fins (31), and the cross section of the conveying channel formed by the combination of multiple sets of flow gaps is smaller than the flow cross section of the heating jacket (11).
5. The high-efficiency heat exchanger tube for distributed medium-deep geothermal heating according to claim 1, characterized in that: The turbulence hole (33) is distributed at the same angle as the spiral angle of the guide fin (32) and the turbulence hole (33) connects the heating interlayer (11) on both sides of the guide fin (32).
6. The high-efficiency heat exchanger tube for distributed medium-deep geothermal heating according to claim 1, characterized in that: The heating inner pipe (2) is provided with a spiral swirl filament (21) with a spiral structure. The spiral swirl filament (21) is provided with a plurality of spiral grooves (211), and the end of the previous spiral groove (211) is connected to the beginning of the next spiral groove (211).
7. The high-efficiency heat exchanger tube for distributed medium-deep geothermal heating according to claim 1, characterized in that: The turbulence hole (33) is a turbulence channel that penetrates the guide fin (32), and the turbulence hole (33) connects the flow channels on both sides of the guide fin (32) to form a local vortex, which further destroys the boundary layer and improves the heat transfer coefficient.
8. The high-efficiency heat exchanger tube for distributed medium-deep geothermal heating according to claim 1, characterized in that: The guide fin (32) is a spiral guide plate with a 1 / 4 circular arc transition, and its upper and lower sides form a smooth arc-shaped guide surface.
9. The high-efficiency heat exchanger tube for distributed medium-deep geothermal heating according to claim 8, characterized in that: The bending angle of the guide fin (32) matches the direction of fluid flow, which can guide the medium to form a spiral flow. At the same time, the bending direction and bending angle of the guide fin (32) on multiple sets of turbulence guiding components (3) are the same.
10. The high-efficiency heat exchanger tube for distributed medium-deep geothermal heating according to claim 1, characterized in that: The heating inner pipe (2) is located at the axial position of the heating outer pipe (1), and the internal spaces of the heating outer pipe (1) and the heating inner pipe (2) are independent and not connected to each other.