Double-circulation type geothermal energy collecting device

Abstract

The invention relates to the technical field of energy utilization, and provides a double-circulation type geothermal energy collection device which comprises a heat collection pipeline and a heat exchange pipeline, the heat collection pipeline is a closed pipeline, a heat exchange medium circulates in the heat collection pipeline, and the heat collection pipeline is laid in an underground rock stratum or soil and used for collecting underground heat energy; the heat exchange pipeline and the heat collection pipeline are arranged in parallel and form heat conduction contact, and the heat exchange pipeline is provided with a water inlet communicated with a surface water source through a water conveying pipeline and a water outlet communicated with a surface water storage tank through a water conveying pipeline. According to the technical scheme, the heat collection pipeline and the heat exchange pipeline are arranged in parallel and form heat conduction contact, so that the contact area of the heat collection pipeline and the heat exchange pipeline is maximized, and sufficient action space is provided for heat transfer. A countercurrent flow heat exchange mode is formed through the design that the fluid circulation directions in the heat exchanger and the heat exchanger are opposite, and compared with direct flow heat exchange, the countercurrent flow heat exchange can keep a large temperature difference gradient in the whole contact length, so that the heat transfer efficiency is remarkably improved.

Description

Technical Field

[0001] Embodiments of the present invention relate to the technical field of energy utilization, and more specifically, to a dual-cycle geothermal energy collection device. Background Art

[0002] As a clean and renewable energy source, geothermal energy has the advantages of rich reserves, wide distribution, stability and reliability, and has broad application prospects in the fields of building heating, power generation, industrial heating, etc. In the process of utilizing geothermal energy, the geothermal energy collection device is one of the key devices, and its performance directly affects the utilization efficiency of geothermal energy. Currently, when existing geothermal energy collection devices collect geothermal energy, they usually adopt a single-cycle or simple dual-cycle structure. In these devices, the layout of the heat collection pipeline and the heat exchange pipeline is not reasonable enough, and the heat conduction contact between the two is not sufficient enough, which will also lead to low heat transfer efficiency, unable to fully collect the geothermal energy underground, resulting in waste of geothermal energy and increasing the cost of energy utilization. Summary of the Invention

[0003] To overcome the above defects, embodiments of the present invention provide a dual-cycle geothermal energy collection device, which solves the technical problem of low heat exchange efficiency in the prior art when collecting geothermal energy.

[0004] According to one aspect, at least one embodiment of the present invention provides a dual-cycle geothermal energy collection device, including: A heat collection pipeline, which is a closed pipeline with a heat exchange medium flowing inside, and the heat collection pipeline is laid in underground rock formations or soil for collecting geothermal energy underground; A heat exchange pipeline, which is arranged in parallel with the heat collection pipeline and forms a heat conduction contact. The heat exchange pipeline has a water inlet connected to a surface water source through a water delivery pipeline and a water outlet connected to a surface water storage tank through a water delivery pipeline; Wherein, the circulation directions of the fluids in the heat collection pipeline and the heat exchange pipeline are opposite.

[0005] For example, in a dual-cycle geothermal energy collection device provided by at least one embodiment of the present invention, the laying directions of the heat collection pipeline and the heat exchange pipeline extend vertically downward, the heat collection pipeline and the heat exchange pipeline are in a mutually sleeved structure, and the heat collection pipeline is coated on the outside of the heat exchange pipeline.

[0006] For example, in a double - cycle geothermal energy collection device provided by at least one embodiment of the present invention, the heat collection pipeline includes an outer pipe body and an inner pipe body located inside the outer pipe body. The upper ends of the outer pipe body and the inner pipe body are connected, and the lower ends of the outer pipe body and the inner pipe body are connected through a circulation pump arranged on the inner pipe body to form a closed loop. The heat collection pipeline is located inside the inner pipe body, a heat collection area is formed between the outer pipe body and the inner pipe body, and a heat dissipation area is formed between the inner pipe body and the heat exchange pipeline.

[0007] For example, in a double - cycle geothermal energy collection device provided by at least one embodiment of the present invention, the heat exchange pipeline includes a water inlet pipe and a water return pipe located inside the water inlet pipe. The water inlet pipe is arranged to cover the outside of the water return pipe. A first partition plate is provided at the lower end of the water inlet pipe to separate the heat collection pipeline from the heat exchange pipeline. The lower ends of the water inlet pipe and the water return pipe are connected. A heat exchange area is formed between the water inlet pipe and the water return pipe, a water return area is formed inside the water return pipe, the upper end of the water inlet pipe forms the water inlet, and the upper end of the water return pipe forms the water outlet.

[0008] For example, in a double - cycle geothermal energy collection device provided by at least one embodiment of the present invention, the lower end of the water return pipe extends to abut against the first partition plate and has a number of liquid - passing holes on its side wall. The liquid - passing holes are used to connect the heat exchange area and the water return area.

[0009] For example, in a double - cycle geothermal energy collection device provided by at least one embodiment of the present invention, gravel is filled in the heat collection area, and the gravel is used to enhance the heat exchange efficiency between the heat collection area and the underground rock formation.

[0010] For example, in a double - cycle geothermal energy collection device provided by at least one embodiment of the present invention, a second partition plate is provided on the inner wall of the bottom of the inner pipe body. The circulation pump is installed on the second partition plate. A liquid - passing cavity is formed between the second partition plate and the bottom surface of the inner pipe body. The liquid - passing cavity communicates with the heat collection area, and the circulation pump is used to pump the heat exchange medium in the liquid - passing cavity into the heat dissipation area.

[0011] For example, in a double - cycle geothermal energy collection device provided by at least one embodiment of the present invention, the pipe wall of the water return pipe is made of a heat - insulating material to reduce the heat loss of the hot water in the water return pipe.

[0012] For example, in a double - cycle geothermal energy collection device provided by at least one embodiment of the present invention, the water inlet pipe is of a segmented splicing type, and the connection of the water inlet pipe is connected by a flange.

[0013] For example, in a double - cycle geothermal energy collection device provided by at least one embodiment of the present invention, the outer tube body, the inner tube body, the water inlet pipe, and the water return pipe are all coaxially arranged.

[0014] The beneficial effects of the embodiments of the present invention are as follows: In the present invention, by arranging the heat collection pipeline and the heat exchange pipeline in parallel and forming a heat conduction contact, the contact area between the two is maximized, providing sufficient space for heat transfer. The design of the opposite fluid circulation directions in the two forms a counter - current heat exchange mode. Compared with the co - current heat exchange, the counter - current heat exchange can maintain a large temperature difference gradient throughout the contact length, thus significantly improving the heat transfer efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments of the present invention. Obviously, the drawings described below are only some exemplary embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on the content of the exemplary embodiments of the present invention and these drawings.

[0016] Figure 1 It is a schematic structural diagram of a double - cycle geothermal energy collection device in an embodiment of the present invention; Figure 2 is Figure 1 the sectional top view at A - A in In the figure: 1. Heat collection pipeline, 2. Heat exchange pipeline, 21. Water inlet, 22. Water outlet, 11. Outer tube body, 12. Inner tube body, 13. Circulation pump, 111. Heat collection area, 121. Heat dissipation area, 23. Water inlet pipe, 24. Water return pipe, 25. First partition plate, 231. Heat exchange area, 241. Water return area, 242. Liquid - passing hole, 14. Second partition plate, 141. Liquid - passing cavity. DETAILED DESCRIPTION OF THE EMBODIMENTS The following will further elaborate on the present invention in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only for explaining the present invention and not for limiting the present invention.

[0017] To make the drawings concise, only the parts related to the disclosure are schematically shown in each figure, and they do not represent the actual structure of the product. Additionally, to make the drawings concise and easy to understand, in some figures, components with the same structure or function are only schematically shown for one of them, or only one of them is labeled. In this document, "one" not only means "only this one", but also can mean "more than one" situation, and "several" includes "two" and "more than two".

[0018] In this text, it should be noted that unless otherwise clearly specified and defined, the terms "install", "connect", and "join" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0019] In the present invention, unless otherwise clearly specified and defined, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or simply means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or simply means that the horizontal height of the first feature is lower than that of the second feature.

[0020] In the description of this embodiment, the orientation or positional relationship terms such as "above", "below", "left", and "right" are based on the orientation or positional relationship shown in the drawings. It is only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0021] In addition, in the description of this application, the terms "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0022] As Figures 1 - 2 shown, it shows a double - cycle geothermal energy collection device in an embodiment of the present invention. Its core components include a heat collection pipeline 1 and a heat exchange pipeline 2. The heat collection pipeline 1 is a closed pipeline with a heat exchange medium flowing inside. The heat collection pipeline 1 is laid in parallel in underground rock formations or soil. The specific laying form can be horizontal layered laying or vertical drilling laying according to geological conditions. Its function is to absorb geothermal energy from the ground through the heat exchange medium. The heat exchange pipeline 2 is arranged in parallel with the heat collection pipeline 1 in space. The two form a heat conduction path through physical contact. The heat exchange pipeline 2 has a water inlet 21 and a water outlet 22. The water inlet 21 is connected to a surface water source through a water delivery pipeline, and the water outlet 22 is connected to a surface water storage tank through a water delivery pipeline, forming a surface water circulation loop.

[0023] In the design of the fluid circulation direction, the flow direction of the heat exchange medium in the heat collection pipeline 1 is opposite to the flow direction of the water flow in the heat exchange pipeline 2. If the heat collection pipeline 1 is laid in a vertically downward extending manner, the heat exchange medium in the heat collection pipeline 1 can flow in from the lower end and flow out from the upper end, while the water flow in the heat exchange pipeline 2 flows in from the upper end and flows out from the lower end, forming a reverse flow; if it is horizontally laid, the heat exchange medium in the heat collection pipeline 1 flows from left to right, and the water flow in the heat exchange pipeline 2 flows from right to left. By setting a circulation driving device (such as a water pump) on the water supply pipeline, it is ensured that the water flow in the heat exchange pipeline 2 circulates in the set direction, and at the same time, the heat exchange medium in the heat collection pipeline 1 realizes circulation flow relying on the natural temperature difference or the built-in driving device.

[0024] The heat collection pipeline 1 and the heat exchange pipeline 2 are arranged in parallel and form a heat conduction contact, maximizing their contact area and providing sufficient space for heat transfer. The design of the opposite fluid circulation directions in the two forms a countercurrent heat exchange mode. Compared with the concurrent heat exchange, the countercurrent heat exchange can maintain a larger temperature difference gradient along the entire contact length, thus significantly improving the heat transfer efficiency. Specifically, at the water inlet end of the heat exchange pipeline 2, the low-temperature water contacts the high-temperature heat exchange medium heated by the ground, quickly absorbing heat; at the water outlet end, the water with increased temperature contacts the low-temperature heat exchange medium that has just flowed into the ground from the surface, further releasing heat, realizing the full exchange of heat, truly achieving heat extraction without water extraction, and protecting the environment to the greatest extent in the use of geothermal energy.

[0025] This structural design effectively solves the problems of unreasonable layout and insufficient heat conduction contact between the heat collection pipeline 1 and the heat exchange pipeline 2 in the prior art. By optimizing the fluid flow direction and pipeline layout, the geothermal energy in the ground can be transferred to the surface water more efficiently. After the surface water source absorbs the heat transferred by the heat collection pipeline 1 through the heat exchange pipeline 2, it enters the surface water storage tank at a higher temperature, providing a high-quality heat source for subsequent applications such as heating and power generation, reducing the waste of geothermal energy and lowering the energy utilization cost. At the same time, the double-circulation structure is independent and interacts with each other. The heat collection pipeline 1 focuses on geothermal energy collection, and the heat exchange pipeline 2 focuses on heat output. The two work together to improve the stability and reliability of the entire device.

[0026] Such as Figures 1 - 2As shown in the figure, the heat collection pipeline 1 and the heat exchange pipeline 2 are laid in a vertically downward extending manner, and the two are coaxially sleeved structures, with the heat collection pipeline 1 covering the outside of the heat exchange pipeline 2. During construction, a vertical hole is first drilled underground, and the heat exchange pipeline 2 composed of a water inlet pipe 23 and a water return pipe 24 sleeved together is placed at the center of the hole. The water inlet pipe 23 can adopt a corrugated pipe shape, and the heat exchange area is increased through the corrugated structure to improve the heat exchange efficiency. The water inlet pipe 23 is covered on the outside of the water return pipe 24, and a first partition plate 25 is provided at the lower end of the water inlet pipe 23; then the heat collection pipeline 1 composed of an outer pipe body 11 and an inner pipe body 12 sleeved together is sleeved outside the heat exchange pipeline 2. The upper ends of the outer pipe body 11 and the inner pipe body 12 are connected through a connecting fitting, and the lower ends are connected through a circulation pump 13 provided on the inner pipe body 12 to form a closed loop, and the inner pipe body 12 is located inside the heat exchange pipeline 2. The circulation pump 13 can select various models such as a centrifugal pump and a screw pump to meet different flow rate and head requirements. The selection of various models of the circulation pump 13 can be optimized according to the actual operation requirements of the system to improve the operation efficiency and reliability of the system. A heat collection area 111 is formed between the outer pipe body 11 and the inner pipe body 12, and a heat dissipation area 121 is formed between the inner pipe body 12 and the heat exchange pipeline 2; a heat exchange area 231 is formed between the water inlet pipe 23 and the water return pipe 24, and a water return area 241 is formed inside the water return pipe 24. The upper end of the water inlet pipe 23 is a water inlet 21, which is connected to the water delivery pipeline of the surface water source, and the upper end of the water return pipe 24 is a water outlet 22, which is connected to the water delivery pipeline of the surface water storage tank. The water of the surface water source enters the water inlet pipe 23 from the water inlet 21 under the action of a water pump, flows downward to the lower end, enters the water return pipe 24 through the lower end connection structure, and flows upward to the water outlet 22 in the water return area 241; the heat exchange medium in the heat collection pipeline 1, under the drive of the circulation pump 13, absorbs geothermal energy in the heat collection area 111, is pumped into the heat dissipation area 121 by the circulation pump 13, transfers the heat to the heat exchange pipeline 2, and then flows back to the heat collection area 111 through the upper end connection to circulate.

[0027] The structural design of vertical coaxial sleeving enables the heat collection pipeline 1 and the heat exchange pipeline 2 to form an annular heat exchange area in the vertical direction, increasing the contact area and enhancing the heat transfer efficiency. The layered structure of the heat collection pipeline 1 clearly divides the heat collection area 111 and the heat dissipation area 121. The heat collection area 111 directly contacts the underground heat source to absorb heat, and the heat dissipation area 121 focuses on heat conduction, reducing ineffective heat loss. The water inlet pipe 23 and the water return pipe 24 of the heat exchange pipeline 2 are sleeved to form countercurrent heat exchange, which can achieve a higher heat transfer efficiency under the same conditions compared to concurrent flow, increasing the hot water output temperature. The corrugated water inlet pipe 23 further increases the heat exchange area, strengthens the heat exchange process, and improves the geothermal energy collection efficiency. The circulation pump 13 can be installed at the bottom of the well in the form of a submersible pump or on the ground, and the circulation of the heat exchange medium in the heat collection pipeline 1 is realized through pipeline connection. The selection of different installation positions of the circulation pump 13 can be optimized according to the actual engineering requirements and environmental conditions, improving the adaptability and reliability of the system. The first partition plate 25 ensures the fluid independence of the heat collection pipeline 1 and the heat exchange pipeline 2, avoiding mixing, and enhancing the operation stability and safety of the device. This overall structural design reasonably plans the fluid path and heat transfer path, enabling the geothermal energy collection, transfer, and water heating processes to proceed orderly and efficiently, improving the heat exchange performance and energy utilization efficiency of the entire device.

[0028] As Figures 1 - 2 shown, based on the coaxial arrangement of the water inlet pipe 23 and the water return pipe 24, the lower end of the water return pipe 24 extends to abut against the first partition plate 25 to ensure the sealing effect between the water return pipe 24 and the water inlet pipe 23. Among them, the water inlet pipe 23 can adopt various forms such as a tubular heat exchanger, a plate fin heat exchanger, or a finned heat exchanger to enhance the heat exchange effect. A number of liquid passing holes 242 are evenly distributed on the side wall of the lower end of the water return pipe 24. When the water flows downward in the water inlet pipe 23 to the lower end, it enters the water return area 241 through these liquid passing holes 242 and then flows upward to the water outlet 22. The size and quantity of the liquid passing holes 242 are designed according to the actual water flow rate and heat exchange requirements to ensure the smooth passage of water and maintain an appropriate water flow velocity.

[0029] The setting of the liquid passing holes 242 improves the water circulation path in the heat exchange pipeline 2 and realizes the connection between the heat exchange area 231 and the water return area 241. The evenly distributed liquid passing holes 242 make the water more evenly distributed when entering the water return area 241, avoiding local water flow blockage and uneven heat exchange, and improving the hot water temperature uniformity in the water return area 241. The reasonably designed liquid passing holes 242 ensure the water flow rate and velocity, enhance the heat exchange effect between the water and the pipe wall, further improve the heat exchange performance of the device, make the output hot water temperature more stable, and cooperate with the countercurrent heat exchange structure to optimize the overall heat exchange efficiency. The design of the water inlet pipe 23 in various forms can be selected according to different application scenarios and heat exchange requirements, improving the flexibility and heat exchange efficiency of the system.

[0030] Based on the structure of the heat collection pipeline 1, gravel is evenly filled inside the heat collection area 111, and the filling amount reaches a reasonable proportion of the volume of the heat collection area 111 to ensure that there are appropriate gaps between the gravels for the heat exchange medium to flow. During installation, first sleeve the inner pipe body 12 and the outer pipe body 11, fill the heat collection area 111 with gravel, and then complete the connection of the upper ends of the outer pipe body 11 and the inner pipe body 12 and the installation of the circulation pump 13, so that the gravel is in close contact with the underground rock formation and soil, and at the same time is in full contact with the heat exchange medium.

[0031] Gravel is filled in the heat collection area 111. By utilizing the large specific surface area and good thermal conductivity of the gravel, the heat exchange efficiency between the heat collection area 111 and the underground rock formation is enhanced, the geothermal energy is absorbed more effectively and quickly transferred to the heat exchange medium, and the heating speed of the heat exchange medium is accelerated. The gravel can also play a guiding role in the heat exchange medium, making it flow more evenly in the heat collection area 111, avoiding insufficient local heat exchange, and cooperating with the layered structure of the heat collection pipeline 1 to further improve the geothermal energy collection efficiency and the performance of the entire device.

[0032] As Figures 1 - 2 shown, the basic heat collection pipeline 1 includes a sleeved structure of the outer pipe body 11 and the inner pipe body 12. A second partition plate 14 is fixedly arranged on the inner wall of the bottom of the inner pipe body 12. The partition plate is parallel to the bottom surface of the inner pipe body 12 and has a spacing therebetween, and a liquid passing cavity 141 is formed therebetween. A plurality of flow channels are opened on the outer peripheral wall of the bottom of the inner pipe body 12, that is, on the outer peripheral wall of the liquid passing cavity 141, so that the liquid passing cavity 141 is communicated with the heat collection area 111 between the outer pipe body 11 and the inner pipe body 12. The circulation pump 13 is fixed on the second partition plate 14 by bolts or buckles. Its inlet end is communicated with the liquid passing cavity 141, and its outlet end passes through the second partition plate 14 and extends to the heat dissipation area 121 between the inner pipe body 12 and the heat exchange pipeline 2.

[0033] During the operation of the device, after the heat exchange medium in the heat collection area 111 absorbs the heat of the underground rock formation, it flows into the liquid passing cavity 141 through the flow channels. Driven by the circulation pump 13, the heat exchange medium is pumped from the liquid passing cavity 141 into the heat dissipation area 121, and the heat is transferred to the parallel heat exchange pipeline 2 through the wall of the inner pipe body 12. Subsequently, the heat exchange medium returns to the heat collection area 111 through the upper communication port between the outer pipe body 11 and the inner pipe body 12, forming a closed cycle.

[0034] The structural design of the second partition plate 14 and the liquid passage cavity 141 optimizes the flow path of the heat exchange medium in the heat collection area 111: The liquid passage cavity 141 serves as a buffer area between the heat collection area 111 and the circulation pump 13, which can stabilize the inflow rate of the heat exchange medium and avoid uneven load on the circulation pump 13 caused by fluid fluctuations in the heat collection area 111; The second partition plate 14 provides rigid support for the circulation pump 13, reducing the vibration amplitude during the operation of the pump body, reducing mechanical losses and extending the service life. The liquid passage cavity 141 is connected to the heat collection area 111 through a flow passage, ensuring that the heat exchange medium evenly flows into the pump body under the dual action of gravity and the driving force of the circulation pump 13, improving the stability of fluid circulation. This structure collaborates with the layered heat collection design to make the geothermal energy collection process more efficient and orderly, avoiding the problem of reduced heat exchange efficiency caused by unstable fluid flow and ensuring the continuous and stable operation of the double-cycle system.

[0035] As Figures 1 - 2 shown, a heat insulation layer (not limited by material, only describing the structural form) is attached to the outer wall of the return water pipe 24 of the heat exchange pipeline 2. The heat insulation layer continuously covers along the axial direction of the return water pipe 24, and a sealing structure is adopted at the joints of the return water pipe 24 with components such as the second partition plate 14 and the inner layer pipe body 12 to prevent heat loss from the connection gaps. The return water area 241 inside the return water pipe 24 is adjacent to the heat dissipation area 121, and the heat in the heat dissipation area 121 is transferred to the wall of the return water pipe 24 through the wall of the inner layer pipe body 12 to heat the water flow in the return water area 241.

[0036] The heat insulation structure of the return water pipe 24 forms a heat conduction cooperation with the heat dissipation area 121: The heat insulation layer reduces the heat loss of the hot water in the return water area 241 during the upward flow, enabling the hot water heated by the heat dissipation area 121 to be transported to the ground at a higher temperature, forming a complete heat utilization chain of "collection - transfer - insulation" with the circulation path of the heat exchange medium in the heat collection pipeline 1. The combination of the two not only ensures the effective transfer of geothermal energy to the water body but also reduces the energy loss during the transmission process through the heat insulation design, improving the comprehensive energy efficiency of the entire device.

[0037] As Figures 1 - 2 shown, the water inlet pipe 23 is composed of multiple segmented pipe bodies. Flange plates are provided at both ends of the segmented pipe bodies, and the flange plates of adjacent segmented pipe bodies are connected by bolts and sealing gaskets to form a sealed pipeline system. The flange connection method facilitates the installation and disassembly of the water inlet pipe 23 and ensures the sealing of the pipeline at the same time. The segmented splicing structure of the water inlet pipe 23 can adapt to different installation environments and construction requirements, improving the scalability and maintainability of the system.

[0038] The segmented and spliced structure of the water inlet pipe 23 is convenient for transportation and installation, and can adapt to underground environments with different depths. The flange connection method ensures the tightness of the pipeline, prevents water leakage, and improves the reliability and stability of the system. This structural design can effectively isolate groundwater, avoid direct contact between groundwater and the heat exchange medium, achieve the environmental protection goal of heat extraction without water extraction, and reduce the impact on underground water resources.

[0039] As Figures 1 - 2 shown, in the double-cycle geothermal energy collection device, the outer pipe body 11, the inner pipe body 12, the water inlet pipe 23, and the water return pipe 24 are all arranged coaxially. The outer pipe body 11 is the outermost structure of the heat collection pipeline 1, and its central axis coincides with the central axis of the inner pipe body 12. The inner pipe body 12 is located inside the outer pipe body 11, and a heat collection area 111 is formed between the two. The water inlet pipe 23 is arranged inside the inner pipe body 12, and its central axis coincides with the central axis of the inner pipe body 12. The water return pipe 24 is located inside the water inlet pipe 23, and also maintains the coincidence of the central axis.

[0040] This coaxially arranged structure is precisely installed through a positioning device to ensure a uniform spacing between each layer of pipelines. In the heat collection pipeline 1, the heat exchange medium flows in the heat collection area 111 between the inner pipe body 12 and the outer pipe body 11; in the heat exchange pipeline 2, cold water flows downward from the annular space between the water inlet pipe 23 and the water return pipe 24, absorbs heat, and then returns to the ground upward through the water return pipe 24. Each pipeline is hermetically connected to form a complete circulation system to ensure the stable flow of the fluid in its respective circulation path.

[0041] The coaxial arrangement of the outer pipe body 11, the inner pipe body 12, the water inlet pipe 23, and the water return pipe 24 makes the structure of the entire device more compact and reasonable, reducing the floor area and the installation space requirements. This arrangement method makes the heat collection area 111 and the heat exchange area 231 form a uniform annular space, ensuring that heat can be evenly transferred in the radial direction, avoiding local overheating or overcooling phenomena, and improving the heat exchange efficiency.

[0042] The coaxial structure simplifies the pipeline connection and the fluid flow path, reducing the resistance and energy consumption of the system. At the same time, due to the uniform spacing between each pipeline, it is convenient to install thermal insulation materials and carry out maintenance and repair. In practical applications, this structural design can adapt to drilling construction under different geological conditions, improving the adaptability and reliability of the device, and providing a strong guarantee for the efficient collection of geothermal energy. The device can effectively isolate groundwater through a closed circulation system and a sealing structure, avoid pollution of underground water resources, and achieve a green and environmentally friendly way of using geothermal energy.

[0043] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present invention, and they should all be covered within the scope of the claims of the present invention.

Claims

1. A double-cycle geothermal energy collection device, characterized in that, Comprising: A heat collection pipeline (1), the heat collection pipeline (1) being a closed pipeline with a heat exchange medium flowing inside, the heat collection pipeline (1) being laid in an underground rock formation or soil for collecting geothermal energy from the ground; A heat exchange pipeline (2), the heat exchange pipeline (2) being arranged in parallel with the heat collection pipeline (1) and forming a heat conduction contact, the heat exchange pipeline (2) having a water inlet (21) connected to a surface water source through a water delivery pipeline and a water outlet (22) connected to a surface water storage tank through a water delivery pipeline; Wherein, the circulation directions of the fluids in the heat collection pipeline (1) and the heat exchange pipeline (2) are opposite.

2. A double-cycle geothermal energy collection device according to claim 1, characterized in that, The laying directions of the heat collection pipeline (1) and the heat exchange pipeline (2) extend vertically downward, the heat collection pipeline (1) and the heat exchange pipeline (2) having a mutually sleeved structure, the heat collection pipeline (1) being coated and arranged outside the heat exchange pipeline (2).

3. A double-cycle geothermal energy collection device according to claim 2, characterized in that, The heat collection pipeline (1) includes an outer pipe body (11) and an inner pipe body (12) located inside the outer pipe body (11), the upper ends of the outer pipe body (11) and the inner pipe body (12) being connected, the lower ends of the outer pipe body (11) and the inner pipe body (12) being connected through a circulation pump (13) arranged on the inner pipe body (12) to form a closed loop, the heat collection pipeline (1) being located inside the inner pipe body (12), a heat collection area (111) being formed between the outer pipe body (11) and the inner pipe body (12), and a heat dissipation area (121) being formed between the inner pipe body (12) and the heat exchange pipeline (2).

4. A double-cycle geothermal energy collection device according to claim 3, characterized in that, The heat exchange pipeline (2) includes a water inlet pipe (23) and a water return pipe (24) located inside the water inlet pipe (23), the water inlet pipe (23) being coated and arranged outside the water return pipe (24), a first partition plate (25) being provided at the lower end of the water inlet pipe (23) to isolate the heat collection pipeline (1) from the heat exchange pipeline (2), the lower ends of the water inlet pipe (23) and the water return pipe (24) being connected, a heat exchange area (231) being formed between the water inlet pipe (23) and the water return pipe (24), a water return area (241) being formed inside the water return pipe (24), the upper end of the water inlet pipe (23) forming the water inlet (21), and the upper end of the water return pipe (24) forming the water outlet (22).

5. A double-cycle geothermal energy collection device according to claim 4, characterized in that, The lower end of the water return pipe (24) extends to abut against the first partition plate (25) and has a plurality of liquid passing holes (242) on its side wall, the liquid passing holes (242) being used to connect the heat exchange area (231) and the water return area (241).

6. The double-cycle geothermal energy collection device according to claim 3, characterized in that, Gravel is filled in the heat collection area (111), and the gravel is used to enhance the heat exchange efficiency between the heat collection area (111) and the underground rock formation.

7. A double-cycle geothermal energy collection device according to claim 3, characterized in that, The inner tube body (12) is provided with a second partition plate (14) on the inner wall of the bottom. The circulation pump (13) is installed on the second partition plate (14). A liquid passing cavity (141) is formed between the second partition plate (14) and the bottom surface of the inner tube body (12). The liquid passing cavity (141) communicates with the heat collection area (111). The circulation pump (13) is used to pump the heat exchange medium in the liquid passing cavity (141) into the heat dissipation area (121).

8. A double-cycle geothermal energy collection device according to claim 4, characterized in that, The pipe wall of the return water pipe (24) is made of heat insulation material to reduce the heat loss of the hot water in the return water pipe (24).

9. A double-cycle geothermal energy collection device according to claim 4, characterized in that, The water inlet pipe (23) is of a segmented splicing type, and the joints of the water inlet pipe (23) are connected by flanges.

10. A double-cycle geothermal energy collection device according to claim 1, characterized in that, The outer tube body (11), the inner tube body (12), the water inlet pipe (23) and the return water pipe (24) are all coaxially arranged.

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