Efficient reinforced medium-deep layer geothermal heat exchange tube

Abstract

The invention relates to the technical field of heat exchange, in particular to an efficient reinforced medium-deep layer geothermal heat exchange pipe which comprises a heat exchange pipe opening, a water inlet pipe set and a water outlet pipe set, and the water inlet pipe set and the water outlet pipe set are fixedly installed below the heat exchange pipe opening and each formed by butt joint of an upper pipe body and a lower pipe body. The internal circular truncated cone partition barrel is used for periodically disturbing fluid and destroying a thermal boundary layer to strengthen convective heat exchange, the contact area with rock soil is increased through the external memory metal rod driving type heat dissipation fins, the heat exchange efficiency is multiplied through double channels, the heat dissipation fins can be unfolded according to the stratum temperature and retracted at the low-temperature section, the lowering resistance is reduced, and the heat dissipation efficiency is improved. According to the heat exchange pipe system, heat exchange is fully expanded and maximized in a high-temperature section, so that temperature sensing, heat exchange enhancement and mechanical connection are combined through the memory metal rod and the linkage mechanism, and the whole heat exchange pipe system achieves a self-adaptive and self-enhancement working state that the heat is higher and the connection is tighter under the high-temperature working condition of the geothermal well.

Description

Technical Field

[0001] This invention relates to the field of heat exchange technology, and in particular to a highly efficient enhanced medium-deep geothermal heat exchanger tube. Background Technology

[0002] Medium-deep geothermal heat exchange refers to the process of extracting heat energy from high-temperature rock layers or geothermal reservoirs thousands of meters underground through a specialized heat exchange system and transporting it to the surface for utilization. This process usually does not directly extract underground hot water, but instead injects low-temperature fluid into a closed downhole heat exchange pipe loop, using the deep high-temperature rock mass to heat the fluid. The heated fluid is then returned to the surface for power generation, heating, or industrial heating. Therefore, heat exchange pipes are needed to absorb heat from the rock mass during the geothermal heat exchange process in order to achieve subsequent clean, stable, and sustainable geothermal energy development.

[0003] Currently, the heat exchange tubes used in medium-deep geothermal heat exchange still have the following problems: To increase the heat exchange area, the heat exchange tubes currently used mostly adopt fixed external fins, which are mainly welded or cast on the outer wall of the heat exchange tube. However, fixed fins increase the outer diameter of the tube string. When lowering it into narrow wells thousands of meters deep, the frictional resistance increases dramatically, so there is a risk of tube jamming or scratching, or even failure to reach the target depth. In addition, the fin size is fixed and cannot be adaptively adjusted according to the temperature field at different depths of the formation. At the same time, the heat exchange tubes are mostly connected by traditional threaded or flanged connections, relying on the initial pre-tightening force to ensure the seal. However, the working conditions of geothermal wells are subject to periodic start-up and shutdown and temperature changes, which will cause the tubes to repeatedly expand and contract thermally. Under long-term action, the pre-tightening force of the threads or bolts will decay, resulting in loosening of the tube connection or failure of the seal, causing medium leakage. Once a connection leakage occurs in a deep well, the pipeline repair cost is extremely high, and it may even require the scrapping of the entire well. Summary of the Invention

[0004] In view of the problems in the above or existing technologies, such as the increased frictional resistance caused by the fixed external fins and the easy failure of pipeline sealing at the pipe connection, the present invention is proposed.

[0005] To solve the above-mentioned technical problems, the present invention provides a high-efficiency enhanced medium-deep geothermal heat exchange pipe, which is achieved by the following specific technical means: A high-efficiency enhanced medium-deep geothermal heat exchange pipe includes a heat exchange pipe inlet and an inlet pipe assembly and an outlet pipe assembly fixedly installed below it. The inlet pipe assembly and the outlet pipe assembly are both composed of two pipe bodies connected together. Several fixing rings are fixedly installed on the outer ring wall of the pipe body. Several heat dissipation fins are hinged in a circumferential array on the outer ring wall of the fixing rings. A memory metal rod is provided between the heat dissipation fins and the fixing rings. The memory metal rod expands or retracts the heat dissipation fins according to the temperature. Several frustum-shaped baffles are fixedly installed in a linear array inside the tube to generate periodic vortexes and detach the incoming liquid. A connecting sleeve is threaded between the upper and lower tubes. Several hook plates that mate with the frustum-shaped partition cylinder inside the upper tube are fixedly installed in a circumferential array on the inner ring wall of the connecting sleeve. A compression bolt corresponding to each hook plate is installed through the connecting sleeve to fit the hook plate into the frustum-shaped partition cylinder. A connecting component corresponding to each hook plate and fixedly connected to the corresponding heat dissipation fin is slidably installed inside the connecting sleeve. When the heat dissipation fin is unfolded, the compression bolt is pulled down by the connecting component to make the upper and lower tubes fit tightly with the connecting sleeve.

[0006] Preferably, spiral ribs are fixedly installed on the outer ring wall of both the inlet pipe assembly and the outlet pipe assembly, and the frustum-shaped partition cylinders inside the pipe bodies of both the inlet pipe assembly and the outlet pipe assembly are arranged radially upward with a small opening.

[0007] Preferably, the heat dissipation fin has an arc-shaped horizontal cross-section and a tapered lower end, and both the heat dissipation fin and the outer side of the fixing ring are provided with a heat-resistant coating.

[0008] Preferably, the heat dissipation fins and the fixing ring are provided with mounting components. The mounting components include a first fixing block fixedly mounted on the heat dissipation fins, a second fixing block fixedly mounted on the fixing ring corresponding to the heat dissipation fins, a memory metal rod fixedly mounted through the corresponding first and second fixing blocks, and a clamping bolt for clamping the memory metal rod threadedly connected to the fixing ring.

[0009] Preferably, the inclined surface of the frustum partition cylinder is provided with a plurality of arc-shaped water passage holes for the flow of liquid in a circumferential array.

[0010] Preferably, the upper end of the connecting sleeve is provided with an upper threaded interface that mates with the upper tube thread, and the lower end of the connecting sleeve is provided with a lower threaded interface that mates with the lower tube thread.

[0011] Preferably, the hook plate is composed of an upper hook-shaped strip and a lower bonding plate, the bonding plate being made of flexible metal, and the hook-shaped strip having the same curvature as the upper end of the frustum partition cylinder.

[0012] Preferably, the extrusion bolt is threaded through the outer ring wall of the connecting sleeve, and the outer ring wall of the upper tube has threaded holes corresponding to the extrusion bolts. The extrusion bolts apply a lateral locking force to the upper tube and the connecting sleeve.

[0013] Preferably, the inner ring wall of the connecting sleeve has a groove located at the extrusion bolt, the connecting assembly includes a collar movably installed in the groove, the collar is sleeved on the extrusion bolt, a connecting cable is fixedly installed on the collar, the connecting sleeve has a sliding hole that mates with the connecting cable, and a tension cable symmetrically mounted on the lower end of the connecting cable.

[0014] Preferably, a fixing block is fixedly installed at the lower end of the stretch cable, and the fixing block is fixedly connected to the side wall of the corresponding heat dissipation fin on the lower tube body near the lower tube body.

[0015] Compared with existing technologies, the beneficial effects of this invention are as follows: It utilizes the internal frustum-shaped partition cylinder to periodically disturb the fluid, disrupting the thermal boundary layer and enhancing convective heat transfer. This, combined with external memory metal rods driving the heat dissipation fins, increases the contact area with the soil and rock. Through a dual-channel system, heat exchange efficiency is doubled. Furthermore, the heat dissipation fins can expand according to the formation temperature, partially retracting in the low-temperature section to reduce downward resistance, and fully expanding in the high-temperature section to maximize heat exchange. Simultaneously, the expansion of the heat dissipation fins is converted into a continuous downward pulling force on the compression bolts, thereby actively increasing the pre-tightening force between the connecting sleeve and the pipe body when the pipe is heated. Dynamic self-locking compensates for the pre-tightening force loss caused by thermal expansion and contraction, improving the sealing reliability of the pipeline under long-term operating conditions. Thus, temperature sensing, heat exchange enhancement, and mechanical connection are combined through memory metal rods and linkage mechanisms, enabling the entire heat exchange pipe system to achieve an adaptive and self-reinforcing working state where the hotter the temperature, the stronger the heat exchange and the tighter the connection, under the high-temperature conditions of geothermal wells. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of the present invention; Figure 2 This is a three-dimensional structural diagram of the inlet pipe assembly and outlet pipe assembly of the present invention; Figure 3 This is a three-dimensional structural diagram of the water inlet pipe assembly and heat dissipation fins of the present invention; Figure 4 This is a partial cross-sectional three-dimensional structural schematic diagram of the tube body of the present invention; Figure 5 This is a three-dimensional structural diagram of the connection between the fixing ring and the heat dissipation fins of the present invention; Figure 6 This is a partial cross-sectional three-dimensional structural diagram of the connecting sleeve and the tube body of the present invention; Figure 7 This is a partial exploded view of the connecting sleeve and the tube body of the present invention; Figure 8 This is a partial cross-sectional perspective view of the three-dimensional structure of the connecting sleeve of the present invention; Figure 9 This is a cross-sectional schematic diagram of the connecting sleeve and the tube body of the present invention; Figure 10 This is a schematic diagram of the internal liquid flow of the inlet pipe assembly and outlet pipe assembly of the present invention. In the diagram: 1. Heat exchanger inlet; 2. Inlet pipe assembly; 21. Pipe body; 211. Spiral fins; 3. Outlet pipe assembly; 4. Fixing ring; 41. Heat dissipation fins; 42. Memory metal rod; 43. Mounting assembly; 431. First fixing block; 432. Second fixing block; 433. Clamping bolt; 5. Frustum partition cylinder; 51. Arc-shaped water passage hole; 6. Connecting sleeve; 601. Upper threaded interface; 602. Lower threaded interface; 61. Hook plate; 62. Extrusion bolt; 621. Screw hole; 63. Connecting assembly; 631. Collar; 632. Connecting cable; 633. Stretching cable; 634. Fixing block. Detailed Implementation

[0017] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0018] Please see Figure 1 , Figure 2 , Figure 3 , Figure 5 and Figure 10 A high-efficiency enhanced medium-deep geothermal heat exchange pipe includes a heat exchange pipe port 1 and an inlet pipe group 2 and an outlet pipe group 3 fixedly installed below it. The inlet pipe group 2 and the outlet pipe group 3 are both composed of two pipe bodies 21 connected together. Several fixing rings 4 are fixedly installed on the outer ring wall of the pipe body 21. Several heat dissipation fins 41 are hinged in a circumferential array on the outer ring wall of the fixing rings 4. A memory metal rod 42 is provided between the heat dissipation fins 41 and the fixing rings 4. The memory metal rod 42 expands or retracts the heat dissipation fins 41 according to the temperature.

[0019] Please see Figure 4 Inside the tube body 21, several frustum-shaped partition cylinders 5 are fixedly installed in a linear array to generate periodic vortex shedding of the incoming liquid.

[0020] Please see Figure 3 , Figure 6 , Figure 7 , Figure 8 and Figure 9 A connecting sleeve 6 is threadedly connected between the upper and lower tubes 21. Several hook plates 61 that cooperate with the frustum partition cylinder 5 inside the upper tube 21 are fixedly installed in a circumferential array on the inner ring wall of the connecting sleeve 6. A compression bolt 62 corresponding to the hook plates 61 and used to fit the hook plates 61 to the frustum partition cylinder 5 is provided through the connecting sleeve 6. A connecting component 63 corresponding to the hook plates 61 and fixedly connected to the corresponding heat dissipation fins 41 is slidably installed inside the connecting sleeve 6. When the heat dissipation fins 41 are unfolded, the compression bolt 62 is pulled down by the connecting component 63, so that the upper and lower tubes 21 and the connecting sleeve 6 are tightly fitted.

[0021] Among them, the inlet pipe group 2 and the outlet pipe group 3 are used to inject low-temperature fluid into the ground and lead high-temperature fluid out of the ground, respectively. When the heat dissipation fins 41 are unfolded, the heat exchange area can be increased, and when they are retracted, the outer diameter of the pipe body 21 can be reduced. The shape memory metal rod 42 is an alloy material with shape memory effect, which can restore to the preset shape according to temperature changes and is used to drive the unfolding or retraction of the heat dissipation fins 41.

[0022] Specifically, the fixing ring 4 is fixed to the outer wall of the tube body 21 by welding, riveting or mechanical snapping to ensure its stability in the deep well environment. The memory metal rod 42 undergoes a phase change when it reaches a specific temperature, thereby generating deformation force to drive the heat dissipation fins 41 to unfold or retract. For example, when the temperature rises, the memory metal rod 42 is heated and contracts, thereby pulling the heat dissipation fins 41 to unfold outward. When the temperature drops, the memory metal rod 42 cools down and returns to its original shape, causing the heat dissipation fins 41 to retract.

[0023] The frustum-shaped partition cylinder 5 is either larger at the top and smaller at the bottom or smaller at the top and larger at the bottom. Its main purpose is to change the direction of fluid flow. When the fluid flows through it, it generates periodic vortex shedding, thereby enhancing the turbulence of the fluid and improving the heat exchange efficiency of the fluid inside the pipe.

[0024] The hook plate 61 is installed on the inner wall of the connecting sleeve 6 by welding or bolting. Its shape contacts the inclined surface of the frustum partition cylinder 5, and the upper side of the hook plate 61 is engaged with the upper end of the frustum partition cylinder 5. By tightening the compression bolt 62, radial pressure can be applied to the hook plate 61, so that it fits tightly against the frustum partition cylinder 5, thereby providing additional connection and sealing protection.

[0025] In practical operation, the medium-deep geothermal heat exchange tubes are efficiently strengthened by introducing temperature-adaptive shape memory metal rods 42. When the heat exchange tubes are lowered into the deep well, the heat dissipation fins 41 are in a retracted state, which effectively reduces the outer diameter of the tube string, significantly reduces the frictional resistance with the well wall, and avoids the risk of tube jamming and scratching of the tube body 21.

[0026] When the heat exchange tube reaches the target depth and starts working, as the formation temperature rises, the shape memory metal rod 42 drives the heat dissipation fins 41 to automatically unfold, increasing the heat exchange area and enhancing the heat exchange efficiency. At the same time, the frustum partition cylinder 5 inside the tube body 21 can effectively disturb the fluid, further improving the heat exchange performance inside the tube.

[0027] Furthermore, one end of the connecting component 63 is fixedly connected to the heat dissipation fin 41, and the other end is slidably connected to the compression bolt 62. When the heat dissipation fin 41 unfolds according to temperature changes, it will cause the connecting component 63 to move. The displacement of the connecting component 63 will then pull the compression bolt 62 downward. After the compression bolt 62 is pulled, it will increase the compression force on the hook plate 61, thereby making the connection between the upper and lower pipe bodies 21 and the connecting sleeve 6 more tightly fitted. This effectively compensates for the pre-tightening force attenuation that may be caused by thermal expansion and contraction, ensures the long-term stability and sealing of the connection, effectively copes with the thermal expansion and contraction caused by periodic temperature changes under geothermal well conditions, prevents connection loosening and sealing failure, and ensures the long-term stable operation of the geothermal heat exchange system and zero leakage of the medium.

[0028] Please see Figure 7 , Figure 9 and Figure 10 Spiral ribs 211 are fixedly installed on the outer ring wall of the pipe body 21 of both the inlet pipe group 2 and the outlet pipe group 3. The frustum partition cylinders 5 inside the pipe body 21 of both the inlet pipe group 2 and the outlet pipe group 3 are arranged radially upward with a small opening.

[0029] Please see Figure 7 and Figure 9 The upper end of the connecting sleeve 6 is provided with an upper threaded interface 601 that is threaded with the upper tube body 21, and the lower end of the connecting sleeve 6 is provided with a lower threaded interface 602 that is threaded with the lower tube body 21.

[0030] In actual operation, the spiral fins 211 further increase the contact area between the outer surface of the tube body 21 and the stratum rock, further enhancing the ability to absorb heat from the stratum. The frustum partition cylinder 5 changes the cross-sectional area of ​​the fluid channel, forces the fluid to accelerate and generates a local pressure gradient, thereby inducing periodic vortex shedding, enhancing fluid mixing and convective heat transfer, and significantly increasing the convective heat transfer coefficient between the fluid inside the tube and the tube wall.

[0031] The spiral fins 211 and the frustum-shaped partition cylinder 5 work together to enhance the overall heat exchange performance of the heat exchange tube from both internal and external perspectives. This allows the heat exchange tube to make fuller use of geothermal resources within the limited wellbore space, improves heat extraction efficiency, and effectively solves the problems of insufficient heat exchange efficiency and lack of optimized fluid flow.

[0032] The small opening of the frustum-shaped partition cylinder 5 inside the water outlet pipe assembly 3 is radially upward. In order to effectively increase the flow speed of the heated liquid when the liquid passes through the narrowed fluid channel, this accelerated flow not only promotes the rapid discharge of the fluid, but also reduces the contact time and contact area between the high-temperature liquid and the pipe body 21, thereby reducing the meaningless loss of heat during the transportation process and ensuring that the heat energy obtained from the deep geothermal layer can be transported to the ground utilization end more efficiently and completely.

[0033] The upper threaded interface 601 and the lower threaded interface 602 provide bidirectional and direct mechanical locking points between the upper and lower pipe bodies 21 and the connecting sleeve 6, which can enhance the stability and anti-loosening ability of the connection. Under the conditions of periodic start-up and shutdown and temperature change of deep geothermal heat exchange pipes, the pipe body 21 will repeatedly experience thermal expansion and contraction. The upper threaded interface 601 and the lower threaded interface 602 can effectively resist the axial and radial displacement generated therefrom, maintain the pre-tightening force of the connection, and thus avoid connection loosening and sealing failure caused by the decay of pre-tightening force.

[0034] Please see Figure 3 , Figure 4 and Figure 5 The heat dissipation fin 41 has an arc-shaped horizontal cross section and a tapered lower end. Both the heat dissipation fin 41 and the outer side of the fixing ring 4 are provided with a heat-resistant coating.

[0035] In actual operation, the arc-shaped horizontal cross-section of the heat dissipation fin 41 promotes the uniform transfer of heat between it and the formation. The conical lower end of the heat dissipation fin 41 reduces the frictional resistance between the heat exchange tube and the well wall when it is lowered into the deep well, avoiding the risk of the tube getting stuck or scratched. This ensures that the heat exchange tube can be smoothly lowered to the target depth. The heat-resistant coating enhances the oxidation and corrosion resistance of the heat dissipation fin 41, thereby ensuring the long-term stable operation of the adaptive deployment or retraction mechanism of the heat dissipation fin 41 driven by the shape memory metal rod 42.

[0036] Please see Figure 4 , Figure 5 and Figure 9 The heat dissipation fins 41 and the fixing ring 4 are provided with mounting components 43. The mounting components 43 include a first fixing block 431 fixedly mounted on the heat dissipation fins 41, and a second fixing block 432 corresponding to the heat dissipation fins 41 fixedly mounted on the fixing ring 4. The memory metal rod 42 is fixedly mounted through the corresponding first fixing block 431 and second fixing block 432. The fixing ring 4 is threaded with a clamping bolt 433 for clamping the memory metal rod 42.

[0037] In actual operation, the first fixed block 431 and the second fixed block 432 provide positioning and support for the connection between the memory metal rod 42 and the heat dissipation fin 41 and the fixing ring 4. The clamping bolt 433 further fixes the memory metal rod 42, thereby preventing the memory metal rod 42 from failing due to long-term fatigue or loosening, and ensuring that the heat dissipation fin 41 can always expand or retract according to temperature changes, maintaining the best heat exchange efficiency.

[0038] Please see Figure 4 and Figure 9 The inclined surface of the frustum partition cylinder 5 is provided with several arc-shaped water passage holes 51 for the flow of liquid in a circular array.

[0039] In actual operation, the arc-shaped water passage 51 allows some fluid to smoothly bypass the main body of the frustum-shaped partition cylinder 5, reducing the impact force of the fluid on the frustum-shaped partition cylinder 5 and alleviating the complete blockage effect of the frustum-shaped partition cylinder 5 on the fluid, thereby avoiding local resistance concentration or uneven flow velocity, thus optimizing the overall water flow of the heat exchange tube and reducing the energy consumption of the pump in the heat exchange tube port 1.

[0040] Please see Figure 6 , Figure 7 , Figure 8 and Figure 9 The hook plate 61 is composed of an upper hook-shaped strip and a lower bonding plate. The bonding plate is made of flexible metal, and the hook-shaped strip has the same curvature as the upper end of the frustum partition cylinder 5.

[0041] Please see Figure 7 The threaded bolt 62 penetrates the outer ring wall of the connecting sleeve 6. The outer ring wall of the upper tube 21 has threaded holes 621 that correspond one-to-one with the bolt 62. The bolt 62 applies a transverse locking force to the upper tube 21 and the connecting sleeve 6.

[0042] In specific operations, during installation, the connecting sleeve 6 is directly screwed onto the upper tube body 21. At this time, the internal flexible metal bonding plate can deform, thus bringing the hook plate 61 to fit against the inner wall of the frustum partition cylinder 5 of the upper tube body 21. When the connecting sleeve 6 is fully fitted with the upper tube body 21, the arc of the upper end of the hook-shaped strip plate fits against the upper end of the frustum partition cylinder 5.

[0043] The flexible metal bonding plate can absorb thermal stress through its own elastic deformation, ensuring that the hook plate 61 and the frustum partition cylinder 5 always remain tightly fitted, avoiding gaps caused by temperature changes, thereby effectively preventing loose connections and media leakage.

[0044] Then the compression bolt 62 can be screwed into the corresponding screw hole 621. At this time, the compression bolt 62 acts directly on the outer ring wall of the upper tube 21, thereby generating a transverse clamping force between the upper tube 21 and the connecting sleeve 6, maintaining the tight fit of the connection interface between the two.

[0045] When the clamping bolt 62 is fully inserted into the upper tube 21, the clamping bolt 62 contacts the hook-shaped strip at the upper end of the hook plate 61. By tightening the clamping bolt 62, radial pressure can be applied to the hook plate 61, making it fit tightly against the frustum partition cylinder 5, thereby providing additional connection and sealing protection.

[0046] Please see Figure 6 , Figure 7 , Figure 8 and Figure 9The inner ring wall of the connecting sleeve 6 has a groove located at the extrusion bolt 62. The connecting assembly 63 includes a collar 631 movably installed in the groove. The collar 631 is sleeved on the extrusion bolt 62. A connecting cable 632 is fixedly installed on the collar 631. The connecting sleeve 6 has a sliding hole that mates with the connecting cable 632. A tension cable 633 symmetrical about it is fixedly installed at the lower end of the connecting cable 632.

[0047] Please see Figure 6 , Figure 7 , Figure 8 and Figure 9 A fixing block 634 is fixedly installed at the lower end of the stretch cable 633. The fixing block 634 is fixedly connected to the side wall of the corresponding heat dissipation fin 41 on the lower tube 21 near the lower tube 21.

[0048] In practice, when installing the lower tube body 21, first install the lower tube body 21 at the lower end of the connecting sleeve 6, and then fix the fixing block 634 to the side wall of the corresponding heat dissipation fin 41 near the lower tube body 21. At this time, the installation of the upper and lower tube bodies 21 is completed.

[0049] During this process, the groove provides guidance and limiting space for the collar 631, ensuring that the collar 631 always stays on the predetermined trajectory during the sliding process. The collar 631 is fitted onto the clamping bolt 62, so that the tension generated when the heat dissipation fin 41 unfolds can be transmitted to the clamping bolt 62, thereby ensuring that the clamping bolt 62 can stably apply a lateral locking force to the upper tube 21 and the connecting sleeve 6, enhancing the tightness of the connection.

[0050] In addition, the connecting cable 632, which is fixedly installed on the collar 631, allows the cable to slide as necessary when the temperature changes cause displacement through the sliding hole on the connecting sleeve 6, avoiding additional stress caused by the cable being restricted. The symmetrical tension cable 633 can balance the distribution of tension and avoid structural deformation of the component caused by unilateral force. This solves the problems of weak connection, uneven force transmission or component displacement that may occur in the connecting component 63 under long-term thermal expansion and contraction conditions, and significantly improves the reliability and sealing of the tube body 21 connection.

[0051] The fixing block 634 enhances the connection strength and stability between the tension cable 633 and the heat dissipation fin 41, effectively avoiding connection failure or detachment during the tensioning process. The fixed connection between the fixing block 634 and the heat dissipation fin 41 allows the tension generated by the tension cable 633 to be efficiently and accurately transmitted to the heat dissipation fin 41. Then, the connecting component 63 reliably pulls down the compression bolt 62, thereby ensuring that when the heat dissipation fin 41 is unfolded, the upper and lower tube bodies 21 and the connecting sleeve 6 can always maintain a tight fit. This effectively compensates for the thermal expansion and contraction effect caused by periodic start-up and shutdown and temperature changes under geothermal well conditions, thereby maintaining the sealing of the pipeline connection, significantly reducing the risk of medium leakage, and improving the long-term operational reliability of the heat exchange tube.

[0052] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A high-efficiency enhanced medium-deep geothermal heat exchanger pipe, comprising a heat exchanger inlet (1) and an inlet pipe assembly (2) and an outlet pipe assembly (3) fixedly installed below it, wherein the inlet pipe assembly (2) and the outlet pipe assembly (3) are each composed of two pipe bodies (21) joined together, characterized in that: Several fixed rings (4) are fixedly installed on the outer ring wall of the tube body (21). Several heat dissipation fins (41) are hinged on the outer ring wall of the fixed rings (4) in a circular array. A memory metal rod (42) is provided between the heat dissipation fins (41) and the fixed rings (4). The memory metal rod (42) expands or retracts the heat dissipation fins (41) according to the temperature. Inside the tube body (21), several frustum-shaped partition cylinders (5) are fixedly installed in a linear array to generate periodic vortex shedding of the incoming liquid. A connecting sleeve (6) is threaded between the upper and lower tubes (21). Several hook plates (61) that cooperate with the inner frustum partition cylinder (5) of the upper tube (21) are fixedly installed on the inner ring wall of the connecting sleeve (6) in a circumferential array. A compression bolt (62) that corresponds to the hook plate (61) and is used to fit the hook plate (61) with the frustum partition cylinder (5) is provided through the connecting sleeve (6). A connecting component (63) that corresponds to the hook plate (61) and is fixedly connected to the corresponding heat dissipation fin (41) is slidably installed inside the connecting sleeve (6). When the heat dissipation fins (41) are unfolded, the connecting assembly (63) pulls down the compression bolts (62) to make the upper and lower tubes (21) fit tightly with the connecting sleeve (6).

2. The high-efficiency enhanced medium-deep geothermal heat exchanger tube as described in claim 1, characterized in that: Spiral ribs (211) are fixedly installed on the outer ring wall of the pipe body (21) of the inlet pipe group (2) and the outlet pipe group (3). The frustum partition cylinder (5) inside the pipe body (21) of the inlet pipe group (2) and the outlet pipe group (3) is set radially upward with a small opening.

3. The high-efficiency enhanced medium-deep geothermal heat exchanger tube as described in claim 1, characterized in that: The heat dissipation fin (41) has an arc-shaped horizontal cross section and a tapered lower end. Both the heat dissipation fin (41) and the outer side of the fixing ring (4) are provided with a heat-resistant coating.

4. The high-efficiency enhanced medium-deep geothermal heat exchanger tube as described in claim 3, characterized in that: The heat dissipation fins (41) and the fixing ring (4) are provided with mounting components (43). The mounting components (43) include a first fixing block (431) fixedly mounted on the heat dissipation fins (41), a second fixing block (432) corresponding to the heat dissipation fins (41) fixedly mounted on the fixing ring (4), and a memory metal rod (42) fixedly mounted through the corresponding first fixing block (431) and second fixing block (432). The fixing ring (4) is threaded with a clamping bolt (433) for clamping the memory metal rod (42).

5. The high-efficiency enhanced medium-deep geothermal heat exchanger tube as described in claim 2, characterized in that: The truncated cone partition cylinder (5) has several arc-shaped water passage holes (51) arranged in a circular array on its inclined surface for the flow of liquid.

6. The high-efficiency enhanced medium-deep geothermal heat exchanger tube as described in claim 1, characterized in that: The upper end of the connecting sleeve (6) is provided with an upper threaded interface (601) that is threaded with the upper tube body (21), and the lower end of the connecting sleeve (6) is provided with a lower threaded interface (602) that is threaded with the lower tube body (21).

7. The high-efficiency enhanced medium-deep geothermal heat exchanger tube as described in claim 2, characterized in that: The hook plate (61) is composed of an upper hook-shaped strip and a lower bonding plate. The bonding plate is made of flexible metal, and the hook-shaped strip has the same curvature as the upper end of the frustum partition cylinder (5).

8. The high-efficiency enhanced medium-deep geothermal heat exchanger tube as described in claim 7, characterized in that: The extrusion bolt (62) is threaded through the outer ring wall of the connecting sleeve (6). The outer ring wall of the upper tube (21) is provided with threaded holes (621) corresponding to the extrusion bolt (62). The extrusion bolt (62) applies a transverse locking force to the upper tube (21) and the connecting sleeve (6).

9. The high-efficiency enhanced medium-deep geothermal heat exchanger tube as described in claim 8, characterized in that: The inner ring wall of the connecting sleeve (6) is provided with a groove located at the extrusion bolt (62). The connecting assembly (63) includes a collar (631) movably installed in the groove. The collar (631) is sleeved on the extrusion bolt (62). A connecting cable (632) is fixedly installed on the collar (631). The connecting sleeve (6) is provided with a sliding hole that mates with the connecting cable (632). A tension cable (633) symmetrical about it is fixedly installed at the lower end of the connecting cable (632).

10. The high-efficiency enhanced medium-deep geothermal heat exchanger tube as described in claim 9, characterized in that: The lower end of the stretch cable (633) is fixedly installed with a fixing block (634), and the fixing block (634) is fixedly connected to the corresponding heat dissipation fin (41) on the lower tube (21) near the side wall of the lower tube (21).

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