Closed mine terrestrial heat efficient mining device and method

Abstract

The invention belongs to the technical field of efficient mining of closed mine terrestrial heat, and particularly relates to an efficient mining device and method for closed mine terrestrial heat, the efficient mining device comprises an inner pipe, an outer pipe is arranged outside the inner pipe, the outer wall of the outer pipe is fixedly connected with a high-temperature-resistant lining layer, and the outer wall of the high-temperature-resistant lining layer is fixedly connected with an efficient heat preservation layer; the outer wall of the efficient heat preservation layer is fixedly connected with a protective outer layer. The inner pipe adopts a spiral shape and covers the fins, the outer pipe constructs a multi-layer protection system, and the inner pipe and the outer pipe cooperate to lay a foundation for efficient heat exchange and energy transmission. The inner pipe is made of aluminum bronze, heat of geothermal fluid can be rapidly absorbed by means of the high heat conductivity coefficient of 35-50 W / (m.K) of the inner pipe, the fluid flowing path is ingeniously prolonged by means of the spiral structure design, the fluid turbulence degree is enhanced in cooperation with fins, the heat exchange area is remarkably increased, and the heat exchange efficiency is improved by 30% or above compared with a traditional straight pipe structure.

Description

Technical Field

[0001] The present invention relates to the technical field of high-efficiency geothermal mining in closed mines, and in particular to a high-efficiency geothermal mining device and method for closed mines. Background Art

[0002] With the continued growth of global energy demand and the urgent pursuit of clean energy, the development and utilization of geothermal resources in closed mines, a highly promising clean energy source, is attracting increasing attention. Driven by energy restructuring and coal capacity reduction policies, the number of closed or abandoned coal mines has increased significantly in recent years. These closed mines contain abundant hot water and spatial resources, providing unique opportunities for geothermal development and potentially reducing the risks and investment costs of geothermal resource development.

[0003] Existing heat exchangers suffer from structural design flaws, resulting in low heat exchange efficiency. For example, most traditional heat exchangers utilize a simple straight-tube structure, which limits the heat exchange area. This shortens the contact time between the geothermal fluid and the heated medium, making it difficult to fully transfer heat and effectively extract geothermal energy. Furthermore, the thermal insulation of these energy transmission pipes is poor, resulting in a significant amount of heat being lost to the surrounding environment during the process of transferring geothermal heat to surface utilization facilities.

[0004] Therefore, in order to solve the above problems, a device and method for efficiently mining geothermal energy in closed mines are proposed. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this project addresses the structural design flaws of existing heat exchangers, which result in low heat exchange efficiency. For example, most traditional heat exchangers utilize a simple straight-tube structure, which limits the heat exchange area and shortens the contact time between the geothermal fluid and the heated medium, making it difficult to fully transfer heat and effectively extract geothermal energy. Furthermore, the thermal insulation of these energy transmission pipes is poor, resulting in a significant amount of heat being lost to the surrounding environment during the process of transmitting geothermal heat to ground-based utilization facilities.

[0006] The technical solution adopted by the present invention to solve its technical problem is: it includes an inner tube, an outer tube is arranged outside the inner tube, and the outer wall of the outer tube is fixedly connected with a high-temperature resistant inner lining layer, the outer wall of the high-temperature resistant inner lining layer is fixedly connected with a high-efficiency thermal insulation layer, and the outer wall of the high-efficiency thermal insulation layer is fixedly connected with a protective outer layer.

[0007] Preferably, the material of the inner tube is set to be a high thermal conductivity alloy material, and the high thermal conductivity alloy material is specifically set to be aluminum bronze.

[0008] Preferably, the shape of the inner tube is set to be a spiral shape, and the spiral pitch of the inner tube is one hundred to two hundred millimeters.

[0009] Preferably, the diameter of the inner tube is 0.6 to 0.8 times the inner diameter of the outer tube, and a fin structure is provided on the outer wall of the inner tube.

[0010] Preferably, the outer tube and the high temperature resistant inner lining layer form a bonding structure, and the high temperature resistant inner lining layer is made of ceramic fiber material and has a thickness of five to ten millimeters.

[0011] Preferably, the high temperature resistant lining layer and the high efficiency thermal insulation layer form a bonding structure, and the high efficiency thermal insulation layer is made of aerogel material, and its thickness is ten to twenty millimeters.

[0012] Preferably, the high-efficiency thermal insulation layer and the protective outer layer form a bonding structure, and the protective outer layer is made of a high-strength composite material, and its surface is coated with an anti-corrosion coating.

[0013] Preferably, the inner wall of the outer tube is provided with a plurality of support rings, and the support rings are used to fix the position of the inner tube and maintain the gap between the inner tube and the outer tube.

[0014] Preferably, the device further comprises a thermal fluid channel arranged between the inner tube and the outer tube, and the thermal fluid channel is used to guide the geothermal fluid to flow between the inner tube and the outer tube.

[0015] Preferably, the method comprises the following steps:

[0016] S1: Geothermal Well and Device Installation: Install the closed mine geothermal high-efficiency mining device according to any one of claims 1 to 9 in the shaft of the closed mine, ensuring that the thermal fluid channel between the inner and outer pipes of the device is connected to the fluid circulation system of the geothermal well; install a sealing device at the wellhead to prevent leakage of geothermal fluid, while ensuring that the high-temperature resistant lining and high-efficiency insulation layer of the device can effectively reduce heat loss;

[0017] S2: Geothermal fluid circulation start: Start the geothermal fluid circulation system, pump the geothermal fluid from the bottom of the well, and make it flow in the thermal fluid channel between the inner and outer pipes; adjust the flow rate of the circulation system to ensure that the geothermal fluid can fully contact the high thermal conductivity alloy material of the inner pipe to achieve efficient heat exchange;

[0018] S3: Geothermal Energy Extraction and Monitoring: The fin structure and spiral shape of the inner tube enhance the heat exchange efficiency between the geothermal fluid and the inner tube, efficiently transferring geothermal energy to the inner tube. Temperature and pressure sensors are installed on the outer tube of the device to monitor the temperature and pressure of the geothermal fluid in real time to ensure the system operates in optimal conditions.

[0019] S4: Geothermal Energy Utilization and Reinjection: The geothermal fluid after heat exchange is extracted from the wellhead and used for geothermal power generation, heating, or other geothermal energy utilization scenarios. After cooling the used geothermal fluid, it is reinjected into the reservoir of the mine through the reinjection system to achieve sustainable utilization of geothermal resources.

[0020] S5: System optimization and maintenance: Based on monitoring data, regularly adjust the flow, temperature and pressure of geothermal fluid, optimize system operating parameters, and improve the efficiency of geothermal energy extraction; regularly check the integrity of the device's high-temperature resistant lining, high-efficiency insulation layer and protective outer layer, and promptly repair or replace damaged parts to ensure long-term stable operation of the device.

[0021] The present invention is beneficial in that:

[0022] The closed-mine geothermal energy extraction device features a unique double-tube structure. The inner tube is spirally shaped and covered with fins, while the outer tube incorporates a multi-layered protection system. The two work in tandem to ensure efficient heat exchange and energy transmission. The inner tube is made of aluminum bronze, and with its high thermal conductivity of 35-50 W / (m·K), it can quickly absorb heat from geothermal fluids. The spiral structure cleverly extends the fluid flow path, and the fins enhance fluid turbulence, significantly increasing the heat exchange area and improving heat exchange efficiency by over 30% compared to traditional straight tube structures. This design not only enhances heat transfer but also effectively reduces fluid flow resistance, ensuring that geothermal fluids can circulate smoothly within the device.

[0023] 2. The multi-layered protection system on the exterior of the outer tube is also highly ingenious. The 5-10 mm thick high-temperature resistant ceramic fiber lining can withstand temperatures exceeding 300°C, effectively resisting the thermal shock of geothermal fluids and preventing damage to the device's outer structure. The 10-20 mm thick aerogel high-efficiency insulation layer, with its thermal conductivity as low as 0.01 W / (m·K), significantly reduces heat loss during transmission, reducing heat loss by over 60% compared to traditional insulation materials. The protective outer layer, made of high-strength composite materials, is coated with an anti-corrosion coating to withstand physical and chemical effects such as rock extrusion and groundwater erosion within the mine, while also protecting the internal insulation layer from moisture, ensuring long-term stable operation of the device in the complex mine environment. A support ring on the inner wall of the outer tube precisely positions the inner tube, ensuring a uniform gap between the inner and outer tubes. This further optimizes the stability of the thermal fluid channel, prevents inner tube displacement or collision due to fluid pressure fluctuations, reduces flow resistance, and ensures stable and efficient flow of geothermal fluids.

[0024] 3. In terms of mining methods, the system has built a complete and intelligent operating process. During the installation phase of the device, the wellhead sealing device works closely with the multi-layer insulation structure to eliminate the risk of geothermal fluid leakage from the source; temperature and pressure sensors monitor system parameters in real time, and dynamically adjust operating parameters such as flow and temperature through an intelligent feedback mechanism to ensure that the system is always in an efficient and safe operating state. After the geothermal fluid circulation is started, the flow is precisely controlled to ensure full contact with the inner pipe to achieve efficient heat exchange. After use, the geothermal fluid is cooled and re-injected into the mine reservoir through the reinjection system to maintain the pressure balance of the underground heat storage, avoid geological disasters such as ground subsidence, and achieve sustainable development and utilization of geothermal resources. In addition, regular maintenance and optimization mechanisms run through the entire system operation process. Through in-depth analysis of monitoring data, system parameters are continuously adjusted, and damaged components are repaired or replaced in a timely manner to ensure long-term and stable operation of the device and reduce the cost of the entire life cycle. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention as a whole;

[0027] Figure 2 It is a schematic diagram of the overall three-dimensional structure of the present invention from a top view;

[0028] Figure 3 It is a schematic cross-sectional structural diagram of the present invention as a whole;

[0029] Figure 4 It is a schematic diagram of the opened structure of the present invention as a whole.

[0030] In the figure: 1. Inner pipe; 2. Outer pipe; 3. High-temperature resistant inner lining; 4. High-efficiency thermal insulation layer; 5. Protective outer layer. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] Example 1

[0033] See also Figures 1 to 4 As shown, a closed mine geothermal efficient mining device includes an inner tube 1, an outer tube 2 is provided on the outside of the inner tube 1, and the outer wall of the outer tube 2 is fixedly connected with a high-temperature resistant inner lining 3, the outer wall of the high-temperature resistant inner lining 3 is fixedly connected with a high-efficiency thermal insulation layer 4, and the outer wall of the high-efficiency thermal insulation layer 4 is fixedly connected with a protective outer layer 5; the material of the inner tube 1 is set to a high-thermal conductivity alloy material, and the high-thermal conductivity alloy material is specifically set to aluminum bronze; the shape of the inner tube 1 is set to a spiral shape, and the spiral pitch of the inner tube 1 is one hundred to two hundred millimeters; the diameter of the inner tube 1 is 0.6 to 0.8 times the inner diameter of the outer tube 2, and the outer wall of the inner tube 1 is provided with a fin structure; the outer tube 2 and the high-temperature resistant inner lining 3 constitute a bonding structure, and the high-temperature The inner lining layer 3 is made of ceramic fiber material and has a thickness of five to ten millimeters. The high-temperature resistant inner lining layer 3 and the high-efficiency thermal insulation layer 4 form a bonded structure. The high-efficiency thermal insulation layer 4 is made of aerogel material and has a thickness of ten to twenty millimeters. The high-efficiency thermal insulation layer 4 and the protective outer layer 5 form a bonded structure. The protective outer layer 5 is made of high-strength composite material and its surface is coated with an anti-corrosion coating. The inner wall of the outer tube 2 is provided with multiple support rings, which are used to fix the position of the inner tube 1 and maintain the gap between the inner tube 1 and the outer tube 2. The device also includes a thermal fluid channel provided between the inner tube 1 and the outer tube 2, and the thermal fluid channel is used to guide the geothermal fluid to flow between the inner tube 1 and the outer tube 2.

[0034] Installation of geothermal wells and devices: Install the closed mine geothermal high-efficiency mining device of any one of claims 1-9 in the wellbore of the closed mine, ensuring that the thermal fluid channel between the inner tube 1 and the outer tube 2 of the device is connected to the fluid circulation system of the geothermal well; Install a sealing device at the wellhead to prevent leakage of geothermal fluid, while ensuring that the high-temperature resistant lining 3 and the high-efficiency thermal insulation layer 4 of the device can effectively reduce heat loss; Start the geothermal fluid circulation: Start the geothermal fluid circulation system, extract the geothermal fluid from the bottom of the well, and make it flow in the thermal fluid channel between the inner tube 1 and the outer tube 2; Adjust the flow rate of the circulation system to ensure that the geothermal fluid can fully contact the high thermal conductivity alloy material of the inner tube 1 to achieve efficient heat exchange; Geothermal energy extraction and monitoring: Enhance the heat exchange efficiency between the geothermal fluid and the inner tube 1 through the fin structure and spiral shape design of the inner tube 1 , efficiently transfer geothermal energy to the inside of the inner tube 1; install temperature sensors and pressure sensors on the outer tube 2 of the device to monitor the temperature and pressure of the geothermal fluid in real time to ensure that the system operates in the best state; geothermal energy utilization and reinjection: the geothermal fluid after heat exchange is extracted from the wellhead for geothermal power generation, heating or other geothermal energy utilization scenarios; after cooling the used geothermal fluid, it is reinjected into the reservoir of the mine through the reinjection system to achieve sustainable utilization of geothermal resources; system optimization and maintenance: according to the monitoring data, regularly adjust the flow, temperature and pressure of the geothermal fluid, optimize the system operating parameters, and improve the extraction efficiency of geothermal energy; regularly check the integrity of the high-temperature resistant lining layer 3, high-efficiency thermal insulation layer 4 and protective outer layer 5 of the device, and repair or replace damaged parts in time to ensure the long-term stable operation of the device.

[0035] Working Principle: The device is based on a double-layer structure consisting of an inner tube 1 and an outer tube 2. Inner tube 1 is made of a high-thermal-conductivity aluminum-bronze alloy with a thermal conductivity of 35-50W / (m·K), capable of rapidly absorbing heat from geothermal fluids. Inner tube 1 is designed in a spiral shape with a spiral pitch of 100-200 mm. Combined with the fin structure on the outer wall, this not only increases the heat exchange area but also creates turbulent flow in the fluid, enhancing the convective heat transfer effect. A support ring on the inner wall of outer tube 2 ensures a uniform gap between inner tube 1 and outer tube 2, forming a stable thermal fluid channel, guiding the geothermal fluid to spiral upward between the inner and outer tubes, extending the heat exchange path and improving the efficiency of heat energy extraction.

[0036] The device's outer protective system utilizes a multi-layer composite structure. The high-temperature resistant inner lining (3) is made of ceramic fiber, 5-10 mm thick, capable of withstanding temperatures exceeding 300°C and protecting the external structure from thermal shock from geothermal fluids. The high-efficiency thermal insulation layer (4) utilizes aerogel material, 10-20 mm thick, with a thermal conductivity as low as 0.01 W / (m·K), significantly reducing heat loss during transmission. The protective outer layer (5) is made of a high-strength composite material and coated with an anti-corrosion coating to withstand the physical and chemical erosion of the complex mine environment and ensure the long-term stability of the device.

[0037] During geothermal mining, the device is first installed in the shaft of a closed mine through step S1, and the fluid circulation system of the geothermal well is connected, and the wellhead sealing device prevents leakage of geothermal fluid. After starting the circulation system S2, the geothermal fluid is pumped out from the bottom of the well and enters the hot fluid channel between the inner and outer pipes, and its full contact with the inner pipe is ensured by adjusting the flow rate. In the geothermal energy extraction stage S3, the spiral inner pipe and fin structure enhance the heat exchange efficiency, and the temperature and pressure sensors monitor the system parameters in real time to ensure that it operates in the best state. The geothermal fluid after heat exchange is extracted for power generation or heating S4. After use, the fluid is cooled and re-injected into the mine reservoir through the reinjection system to achieve resource recycling. During the operation of the system, the parameters are regularly optimized S5 according to the monitoring data, and the protective layer is checked and repaired to ensure the long-term and efficient operation of the device.

[0038] This integrated design enables the device to achieve efficient extraction and transmission of thermal energy in complex mine environments, and maintains the pressure balance of underground heat storage through the reinjection system, which not only improves energy utilization efficiency but also ensures ecological and environmental safety, providing an innovative solution for the large-scale development of geothermal resources in closed mines.

[0039] The basic principles, main features, and advantages of the present invention are shown and described above. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes fall within the scope of the invention as claimed.

Claims

1. A closed mine geothermal high-efficiency mining device, characterized by: The invention comprises an inner tube (1), an outer tube (2) is arranged outside the inner tube (1), and the outer wall of the outer tube (2) is fixedly connected to a high-temperature resistant inner lining layer (3), the outer wall of the high-temperature resistant inner lining layer (3) is fixedly connected to a high-efficiency thermal insulation layer (4), and the outer wall of the high-efficiency thermal insulation layer (4) is fixedly connected to a protective outer layer (5).

2. The closed mine geothermal efficient mining device according to claim 1, characterized in that: The material of the inner tube (1) is set to be a high thermal conductivity alloy material, and the high thermal conductivity alloy material is specifically set to be aluminum bronze.

3. The closed mine geothermal efficient mining device according to claim 1, characterized in that: The shape of the inner tube (1) is set to be a spiral shape, and the spiral pitch of the inner tube (1) is one hundred to two hundred millimeters.

4. The closed mine geothermal efficient mining device according to claim 1, characterized in that: The diameter of the inner tube (1) is 0.6 to 0.8 times the inner diameter of the outer tube (2), and the outer wall of the inner tube (1) is provided with a fin structure.

5. The closed mine geothermal efficient mining device according to claim 1 is characterized by: The outer tube (2) and the high-temperature resistant inner lining layer (3) form a bonding structure, and the high-temperature resistant inner lining layer (3) is made of ceramic fiber material and has a thickness of five to ten millimeters.

6. The closed mine geothermal efficient mining device according to claim 1, characterized in that: The high-temperature resistant lining layer (3) and the high-efficiency thermal insulation layer (4) form a bonding structure, and the high-efficiency thermal insulation layer (4) is made of aerogel material and has a thickness of ten to twenty millimeters.

7. The closed mine geothermal efficient mining device according to claim 1, characterized in that: The high-efficiency thermal insulation layer (4) and the protective outer layer (5) form a bonding structure, and the protective outer layer (5) is made of a high-strength composite material, and its surface is coated with an anti-corrosion coating.

8. The closed mine geothermal efficient mining device according to claim 1, characterized in that: The inner wall of the outer tube (2) is provided with a plurality of support rings, and the support rings are used to fix the position of the inner tube (1) and maintain the gap between the inner tube (1) and the outer tube (2).

9. The closed mine geothermal efficient mining device according to claim 1, characterized in that: The device further comprises a thermal fluid channel arranged between the inner pipe (1) and the outer pipe (2), and the thermal fluid channel is used to guide the geothermal fluid to flow between the inner pipe (1) and the outer pipe (2).

10. The closed mine geothermal efficient mining device and method according to claims 1-9, characterized in that The following steps are involved: S1: Installation of geothermal well and device: Install the closed mine geothermal high-efficiency mining device according to any one of claims 1 to 9 in the shaft of the closed mine, ensuring that the hot fluid channel between the inner tube (1) and the outer tube (2) of the device is connected to the fluid circulation system of the geothermal well; install a sealing device at the wellhead to prevent leakage of geothermal fluid, and at the same time ensure that the high-temperature resistant lining layer (3) and the high-efficiency thermal insulation layer (4) of the device can effectively reduce heat loss; S2: Geothermal fluid circulation start: Start the geothermal fluid circulation system, pump the geothermal fluid from the bottom of the well, and make it flow in the thermal fluid channel between the inner tube (1) and the outer tube (2); adjust the flow rate of the circulation system to ensure that the geothermal fluid can fully contact the high thermal conductivity alloy material of the inner tube (1) to achieve efficient heat exchange; S3: Geothermal energy extraction and monitoring: The fin structure and spiral shape design of the inner tube (1) enhance the heat exchange efficiency between the geothermal fluid and the inner tube (1), and efficiently transfer the geothermal energy to the inside of the inner tube (1); a temperature sensor and a pressure sensor are installed on the outer tube (2) of the device to monitor the temperature and pressure of the geothermal fluid in real time to ensure that the system operates in the best state; S4: Geothermal Energy Utilization and Reinjection: The geothermal fluid after heat exchange is extracted from the wellhead and used for geothermal power generation, heating, or other geothermal energy utilization scenarios. After cooling the used geothermal fluid, it is reinjected into the reservoir of the mine through the reinjection system to achieve sustainable utilization of geothermal resources. S5: System optimization and maintenance: Based on monitoring data, regularly adjust the flow rate, temperature and pressure of the geothermal fluid, optimize the system operating parameters, and improve the efficiency of geothermal energy extraction; regularly check the integrity of the device's high-temperature resistant lining layer (3), high-efficiency insulation layer (4) and protective outer layer (5), and promptly repair or replace damaged parts to ensure long-term stable operation of the device.

Images