Middle-deep layer geothermal hole inner pipe heat gathering backflow device

Abstract

The utility model belongs to the technical field of medium-deep layer geothermal hole heat removal, and discloses a medium-deep layer geothermal hole inner pipe heat gathering backflow device which comprises a petroleum outer sleeve, a heat insulation inner pipe, an outer sleeve heat gathering device, a heat gathering conical sealing device and an internal heat gathering backflow heat exchange device. And a chromium-copper alloy pipe hoop is arranged between the petroleum outer sleeve and the heat-gathering conical sealing device. According to the utility model, the polyethylene heat insulation inner pipe is made of a material with smaller thermal resistance, so that a thermal medium and a cold medium are effectively isolated, and the heat loss of the heated medium in the inner pipe is reduced. The inner pipe is provided with the inner pipe heat gathering backflow outlet, the hole sectional area of the heat gathering backflow outlet is larger than the cross sectional area of the inner pipe, the PE inner pipe is small in heat resistance, the heat loss is effectively reduced, the inner wall of the heat insulation pipe is smooth, the flowing medium resistance is very small, and therefore the output heated medium flow is increased, the flow speed is increased, heat output is balanced, and the heat extraction effect is good.

Description

Technical Field

[0001] The utility model belongs to the technical field of heat extraction from medium-deep geothermal holes, and in particular relates to an inner tube heat gathering and reflux device for medium-deep geothermal holes. Background Art

[0002] At present, medium-deep geothermal holes are a drilling hole heat extraction technology for exploiting thermal energy below the surface. In the process of medium-deep geothermal holes, the outer wall of the oil casing absorbs the temperature of the hot rock and then transfers it to the medium inside the oil casing. The medium inside the oil casing enters the bottom of the oil casing through the annular space between the outer pipe and the inner pipe. The heat of the hot rock layer at the bottom is transferred to the circulating medium in the pipe through the outer wall of the oil casing. The heated medium enters the inner pipe at the bottom of the oil casing through the inner pipe heat collection and reflux device and returns through the inner pipe.

[0003] Through the above analysis, the problems and defects of the prior art are as follows:

[0004] When the heated medium returns upward along the inner tube, since the temperature of the heated medium on the outer side of the upper end of the inner tube is lower, heat conduction occurs when the heated medium returns upward through the wall of the inner tube, resulting in a large heat loss of the medium inside the inner tube. When the medium returns, heat conduction occurs to the outside, resulting in poor heat exchange efficiency. Utility Model Content

[0005] In view of the problems existing in the prior art, the utility model provides a mid-deep geothermal bore inner tube heat collection and reflux device to solve the technical problems in the prior art such as easy heat loss when the heat exchange medium returns and insufficient thermal insulation effect due to high heat exchange intensity at the bottom of the inner tube.

[0006] The preferred technical solution among the many technical solutions provided by the utility model has the technical effects of effectively reducing the heat loss of the heat exchange medium and simultaneously improving the heat exchange intensity of the bottom end of the inner tube. In order to achieve the above purpose, the following technical solution is provided.

[0007] The utility model is implemented as follows: a medium-deep geothermal bore inner tube heat collection and reflow device comprises an outer casing of an oil outer tube, an insulating inner tube, an outer casing heat collection device, a heat collection conical sealing device and an internal heat collection and reflow heat exchange device, wherein a heat-conducting medium is arranged in the outer casing heat collection device, and a chromium-copper alloy pipe clamp is arranged between the outer casing of the oil outer tube and the heat collection conical sealing device.

[0008] Furthermore, an inner tube is installed inside the oil outer casing, and a heat-collecting conical sealing device is provided at the bottom of the oil outer casing for sealing the bottom of the outer casing. A metal gravity heating rod is provided at the bottom of the inner tube and fits with the inner surface of the heat-collecting conical sealing device of the outer casing.

[0009] Furthermore, the heat-insulating inner tube is made of heat-insulating material, and there is a heat-insulating protective layer on the inner casing to isolate the heat loss of the heat medium during circulation. The inner tube and outer tube annular space between the inner casing and the outer oil casing is used for the heat-receiving medium between the heat-insulating casing and the outer oil casing to flow in, and is output upward after passing through the inner tube heat-collecting reflux outlet. At the same time, when the heat exchange medium enters the inner tube heat-collecting reflux outlet on the metal gravity heating rod of the inner heat-insulating casing in the inner tube and outer tube annular space, it will contact and conduct with the inner surface of the outer casing heat-collecting conical sealing device, and the heat-receiving medium absorbs the heat transferred to the inner heat-insulating metal gravity heating rod from the outer casing heat-collecting conical sealing device and the outer oil casing.

[0010] Furthermore, the metal gravity heating rod is made of copper alloy and has a very ideal heat conduction effect; the insulating inner tube is a solid polyethylene PE tube, the inner wall of the tube is very smooth, the thermal resistance is large, the water resistance is small, and it has a good thermal insulation effect; the outer oil casing is made of J55 seamless steel pipe, which has the characteristics of high temperature resistance, high pressure resistance, no deformation, and high and stable thermal conductivity.

[0011] In combination with the above technical solutions and the technical problems solved, the advantages and positive effects of the technical solutions to be protected by the utility model are as follows:

[0012] First, the utility model uses a polyethylene heat-insulating inner tube made of a material with low thermal resistance to effectively isolate the hot medium from the cold medium, thereby reducing the heat loss of the inner tube heat medium. By installing a metal gravity heat extraction rod at the bottom of the inner tube and closely fitting it with the outer tube heat-collecting conical sealer, it is easier to absorb the flowing heat medium and enhance the heat exchange capacity. By setting an inner tube heat-collecting reflux outlet in the inner tube, the cross-sectional area of ​​the heat-collecting reflux outlet opening is larger than the cross-sectional area of ​​the inner tube, and the PE inner tube has low thermal resistance, which effectively reduces heat loss. The inner wall of the heat-insulating tube is extremely smooth, and the resistance to the flow of the medium is very small, thereby increasing the output flow of the heat-collecting medium, increasing the flow rate, balancing the heat output, and achieving a good heat extraction effect.

[0013] The utility model can effectively reduce the heat loss of the heating medium in the inner tube, has a strong heat exchange capacity, can output heat more evenly, and has a good heat extraction effect.

[0014] The utility model uses a polyethylene heat-insulating inner tube made of a material with low thermal resistance to effectively isolate the hot medium from the cold medium, thereby reducing the heat loss of the heated medium in the inner tube. By installing a metal gravity heat extraction rod at the bottom of the inner tube and closely fitting it with the outer tube heat-collecting conical sealer, it is easier to absorb the flowing heat medium and enhance the heat exchange capacity. By setting an inner tube heat-collecting reflux outlet in the inner tube, the cross-sectional area of ​​the opening of the heat-collecting reflux outlet is larger than the cross-sectional area of ​​the inner tube, and the PE inner tube has low thermal resistance, which effectively reduces heat loss. The inner wall of the heat-insulating tube is extremely smooth, and the resistance to the flow of the medium is very small, thereby increasing the output flow of the heated medium, increasing the flow rate, balancing the heat output, and achieving a good heat extraction effect.

[0015] Second, the technical solution of the utility model overcomes technical prejudice: the utility model provides a medium-deep geothermal hole heat-collecting conical sealer device, which is installed at the bottom of the oil casing, and solves the problems and risks existing in the existing geothermal technology; for example: when hot water from geothermal wells is used to extract heat, the underground pressurized water pressure will be destroyed, and the extraction of geothermal water will cause ground subsidence, thereby affecting the safety of linear engineering, and the discharge of tail water may pollute the geological environment. The present invention overcomes the difficulties of the above geothermal well water heating technology, and solves the risks of polluting the geological environment, and solves the desire of people to "extract heat without taking water". The final successful realization also fills the technical gap in the geothermal heating industry at a depth of 2000 meters to 3000 meters underground at home and abroad. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the overall structure of the outer sleeve heat collecting device and the heat collecting conical sealing device provided in the embodiment of the utility model.

[0017] Figure 2 It is a general structural diagram of the internal heat collection and reflux heat exchange device and the metal gravity heat extraction rod provided in the embodiment of the utility model;

[0018] Figure 3 This is a diagram of the inner tube and outer tube annular space structure provided by an embodiment of the utility model;

[0019] In the figure: 1. outer casing of oil casing; 2. heat-conducting medium; 3. heat-collecting device of outer casing; 4. chromium-copper alloy pipe clamp; 5. heat-collecting conical sealing device; 6. hot rock and soil layer; 7. internal heat-collecting reflux heat exchange device; 8. outer oil casing; 9. heat-collecting reflux outlet of inner pipe; 10. heat-insulating inner pipe; 11. annular space between inner pipe and outer pipe. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical solution and advantages of the utility model more clear, the utility model is further described in detail in combination with the embodiments below. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not used to limit the utility model.

[0021] like Figure 1-3 As shown, a medium-deep geothermal bore inner tube heat collection and reflow device comprises an outer casing 1, an insulating inner tube 10, an outer casing heat collection device 3, a heat collection conical sealing device 5 and an internal heat collection and reflow heat exchange device 7, wherein a heat conducting medium 2 is arranged inside the outer casing heat collection device 3, and a chromium-copper alloy pipe clamp 4 is arranged between the outer casing 1 and the heat collection conical sealing device 5.

[0022] An inner tube is installed inside the oil outer casing 1, and a heat-collecting conical sealing device 5 is provided at the bottom of the oil outer casing 1 for sealing the bottom of the outer casing. A metal gravity heat extraction rod 12 is provided at the bottom of the inner tube to fit the inner surface of the heat-collecting conical sealing device 5 of the outer casing.

[0023] The heat-insulating inner tube 10 is made of heat-insulating material, and there is a heat-insulating protective layer on the inner casing to isolate the heat loss of the heat medium during circulation. The inner-tube-outer-tube annular space 11 between the inner casing and the outer oil casing 8 is used for the heat-receiving medium between the heat-insulating casing 10 and the outer oil casing 1 to flow in, and is output upward after passing through the inner-tube heat-collecting reflux outlet 9. At the same time, when the heat exchange medium enters the inner-tube heat-collecting reflux outlet 9 on the inner heat-insulating casing metal gravity heating rod 12 in the inner-tube-outer-tube annular space, it will contact and conduct with the inner surface of the outer casing heat-collecting conical sealing device 5. The heat-receiving medium absorbs the heat transferred from the outer casing heat-collecting conical sealing device 5 and the outer oil casing 8 to the inner heat-insulating metal gravity heating rod 12.

[0024] The metal gravity heat extraction rod 12 is made of copper alloy and has an ideal heat conduction effect; the heat-insulating inner tube 10 is a solid polyethylene PE tube, the inner wall of which is very smooth, with large thermal resistance and small water resistance, and has a good thermal insulation effect; the outer oil casing 8 is made of J55 seamless steel pipe, which has the characteristics of high temperature resistance, high pressure resistance, no deformation, and high and stable thermal conductivity.

[0025] The utility model discloses a novel medium-deep geothermal bore inner tube heat exchange device, wherein the oil outer casing 1 is a heat-conducting metal pipe, the heat-insulating casing 10 is made of heat-insulating material, and the inner casing is provided with a heat-insulating protective layer for isolating the heat loss of the heat medium during circulation. The inner-tube outer-tube annular space 11 between the inner casing and the outer oil casing is used for the heat-receiving medium between the heat-insulating casing 10 and the oil outer casing 1 to flow in, and output upward after passing through the inner-tube heat-collecting reflux outlet 9. This can increase the flow stroke of the heated medium at the bottom of the outer tube, thereby making the returned heat-receiving medium exchange heat evenly. At the same time, when the heat-exchange medium enters the inner-tube heat-collecting reflux outlet 9 on the inner-insulating casing metal gravity heat-collecting rod 12 in the annular space, it will contact and conduct with the inner surface of the outer casing heat-collecting conical sealing device 5. The heat-receiving medium absorbs the heat transferred from the outer casing heat-collecting conical sealing device 5 and the outer oil casing 8 to the inner-insulating metal gravity heat-collecting rod 12, thereby increasing the heat-exchange contact surface at the bottom of the inner tube and enhancing the heat exchange capacity.

[0026] The working principle of the deep-seated geothermal bore inner tube heat collection and reflux device is as follows:

[0027] First, the outer casing 1 is the main structure of the whole device, which goes deep into the ground and directly contacts the geothermal resources. A heat-collecting conical sealing device 5 is installed at the bottom of the outer casing. This device not only seals to prevent the leakage of geothermal medium, but also its special conical design helps to gather and guide the geothermal medium.

[0028] Inside, an insulating inner pipe 10 is installed in the outer casing 1 of the oil field. The inner pipe is made of insulating material to reduce the heat loss of the heat medium during circulation. There is a thermal insulation protective layer on the inner pipe, which further enhances its thermal insulation effect. An inner-outer-pipe annular space 11 is formed between the insulating inner pipe 10 and the outer casing 1 of the oil field, and the space allows the heat medium to flow in.

[0029] When the heated medium flows in from the bottom of the oil outer casing 1, it will first contact the outer casing heat collecting cone sealing device 5, where the geothermal temperature is the highest. As the heated medium flows upward, it will also pass through the outer casing heat collecting device 3, which has a heat conducting medium 2 inside, which can further enhance the heat conduction effect.

[0030] The heated medium continues to flow upward and enters the inner and outer tube annular space 11. In this process, it contacts the metal gravity heat extraction rod 12 on the heat-insulating inner tube 10. This heat extraction rod is made of copper alloy and has excellent thermal conductivity, which can quickly absorb and transfer the heat of the heated medium.

[0031] At the same time, when the heated medium flows through the annular space 11 between the inner and outer tubes, it will also contact the inner surface of the outer tube heat-collecting conical sealing device 5 and conduct heat, further improving the utilization rate of thermal energy.

[0032] Finally, the heated medium is discharged upward after passing through the inner tube heat collection reflux outlet 9, completing the entire heat collection reflux process. In this process, when the heat exchange medium enters the inner tube heat collection reflux outlet 9, it will also contact the inner surface of the outer tube heat collection conical sealing device 5 to further absorb heat.

[0033] Through reasonable structural design and material selection, the device achieves efficient heat accumulation of geothermal media and effective transfer of thermal energy, thereby improving the extraction efficiency and utilization rate of geothermal energy.

[0034] The annular space between the inner tube and the outer tube of the utility model is used for the heat receiving medium to flow in between the heat insulating sleeve and the outer petroleum sleeve, and to be output upward after passing through the heat collecting reflux outlet of the inner tube, so that the flow stroke of the heated medium at the bottom of the outer tube can be increased, so that the heat exchange of the returned heat receiving medium can be uniform. At the same time, when the heat exchange medium enters the inner tube heat collecting reflux outlet on the metal gravity heating rod of the inner heat insulating sleeve in the annular space, it will contact and conduct with the inner surface of the heat collecting conical sealing device of the outer tube. The heat receiving medium absorbs the heat transferred from the heat collecting conical sealing device of the outer tube and the outer petroleum sleeve to the inner heat insulating metal gravity heating rod, thereby increasing the heat exchange contact surface at the bottom of the inner tube and enhancing the heat exchange capacity.

[0035] The embodiment of the utility model provides a medium-deep geothermal bore inner tube heat collection and reflux device, which belongs to the field of medium-deep geothermal bore heat extraction technology. This device is made of a polyethylene heat-insulating inner tube made of a material with low thermal resistance to effectively isolate the hot medium and the cold medium, thereby reducing the heat loss of the inner tube heated medium. By setting an inner tube heat collection and reflux outlet in the inner tube, the cross-sectional area of ​​the heat collection and reflux outlet opening is larger than the cross-sectional area of ​​the inner tube, and the PE inner tube has low thermal resistance, effectively reducing heat loss. The inner wall of the heat-insulating tube is extremely smooth, and the resistance to the flow of the medium is very small, thereby increasing the output flow of the heated medium, increasing the flow rate, balancing the heat output, and achieving a good heat extraction effect.

[0036] The following are two specific embodiments of the mid-deep geothermal bore inner tube heat collection and reflux device:

[0037] Embodiment 1

[0038] In a geothermal mining project, a heat-gathering reflux device in the inner tube of a medium-deep geothermal hole was used to mine geothermal energy. First, the length and diameter of the outer casing 1 of the oil field were determined according to geological exploration data and mining requirements, and the high-temperature and high-pressure resistant J55 seamless steel pipe was selected as the material. A heat-gathering conical sealing device 5 was installed at the bottom of the outer casing to ensure the gathering and sealing of the geothermal medium.

[0039] Next, a heat-insulating inner pipe 10 is installed inside the outer casing 1, using a polyethylene solid PE pipe as the material to ensure good heat insulation and a smooth inner wall. An inner-outer-pipe annular space 11 is formed between the inner pipe and the outer casing for the inflow and circulation of the heating medium.

[0040] In order to further improve the utilization rate of heat energy, metal gravity heat extraction rods 12 are installed on the heat-insulating inner tube 10. The copper alloy material is used to ensure excellent heat conduction performance. These heat extraction rods fit tightly on the inner tube and can quickly absorb and transfer the heat of the heating medium.

[0041] During operation, the geothermal medium enters from the bottom of the oil outer casing 1, passes through the heat collecting conical sealing device 5 and the outer casing heat collecting device 3, flows in the inner and outer pipe annular space 11, conducts heat with the metal gravity heat collecting rod 12, and finally outputs upward through the inner pipe heat collecting reflux outlet 9. In this way, efficient heat collection of the geothermal medium and effective transfer of heat energy are successfully achieved.

[0042] Embodiment 2

[0043] In another geothermal project, a customized design of the mid-deep geothermal borehole inner tube heat collection and reflux device was carried out according to specific geological conditions and mining requirements. First, the length and diameter of the oil outer casing 1 were determined according to the depth and temperature distribution of the geological heat reservoir, and the appropriate material was selected to ensure its high temperature and high pressure resistance.

[0044] In the design of the heat-insulating inner tube 10, more advanced heat-insulating materials and processing techniques are used to improve its heat-insulating effect and durability. At the same time, the layout and number of the metal gravity heat-taking rods 12 are optimized to ensure that they can more evenly absorb and transfer the heat of the heating medium.

[0045] In actual operation, firstly, the outer casing 1 of the oil field is installed into the predetermined geothermal hole, and the heat collecting cone sealing device 5 and the outer casing heat collecting device 3 are installed. Then, the heat insulating inner pipe 10 is inserted into the inner part of the outer casing 1 of the oil field, and the metal gravity heat extraction rod 12 is fixed.

[0046] When the local heat medium enters from the bottom, it first passes through the heat collecting cone sealing device 5 and the outer tube heat collecting device 3, and then enters the inner tube outer tube annular space 11. In this space, the heat medium and the metal gravity heat extraction rod 12 undergo sufficient heat conduction, and the heat is quickly absorbed and transferred to the inner tube. Finally, the heat medium is output upward through the inner tube heat collecting reflux outlet 9, completing the entire heat collecting reflux process.

[0047] Through these two embodiments, it can be seen that the medium-deep geothermal bore inner tube heat collection and reflux device is flexible and customizable in practical applications, and can be designed and optimized according to different geological conditions and mining requirements to achieve more efficient geothermal energy mining and utilization.

[0048] The embodiments of the present invention have achieved some positive effects during the development or use process, and indeed have great advantages over the prior art. The following content is described in conjunction with data, charts, etc. of the test process.

[0049] The typical operating performance analysis of the embodiment is shown in the figure:

[0050] 1. Actual test results of thermal measurement operation

[0051] Numeric Total outlet water temperature of heat extraction side (℃) 40.7℃ Total outflow and return water temperature on the heat extraction side (℃) 23.1℃ <![CDATA[Total flow rate on the heat extraction side (m 3 / h)]]> 33.9 Heat extraction capacity of single hole on the heat extraction side (KW) 696.8 Heat extraction hole per linear meter (W / M) 248.9

[0052] 2. User-side working condition measurement results

[0053] Numeric User side water temperature (℃) 41 User side return water temperature (℃) 35.7 <![CDATA[Circulation water volume on the user side (m 3 / h)]]> 13.9 Total heat on user side (kw) 814 Actual heating area (㎡) 15000 Heat supplied by users per unit area (w / ㎡) 54

[0054] 3. Actual test results of energy consumption and energy efficiency of working system

[0055]

[0056]

[0057] Through the measured results in the above three tables, we can see that this technology has the characteristics of high temperature on the heat source side, large heat extraction, and high system operating performance. It can reduce operating costs, reduce heating energy consumption, and further improve economic benefits. It has better application prospects for promoting building energy conservation and efficient and clean heating.

[0058] The above description is only a specific implementation method of the present invention, but the protection scope of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention shall be covered by the protection scope of the present invention.

Claims

1. A medium-deep geothermal bore inner tube heat collection and reflux device, characterized in that: The inner tube heat collection and reflow device of the mid-deep geothermal hole comprises an outer casing of an oil outer tube, an insulating inner tube, an outer casing heat collection device, a heat collection conical sealing device and an internal heat collection and reflow heat exchange device. A heat-conducting medium is arranged inside the outer casing heat collection device, and a chromium-copper alloy pipe clamp is arranged between the outer casing of the oil outer tube and the heat collection conical sealing device.

2. The medium-deep geothermal bore inner tube heat collection and reflux device according to claim 1, characterized in that: An inner tube is installed inside the oil outer casing, and a heat-collecting conical sealing device is arranged at the bottom of the oil outer casing for sealing the bottom of the outer casing. A metal gravity heating rod is arranged at the bottom of the inner tube and fits the inner surface of the heat-collecting conical sealing device of the outer casing.

3. The medium-deep geothermal bore inner tube heat collection and reflux device according to claim 1, characterized in that: The heat-insulating inner tube is made of heat-insulating materials, and there is a heat-insulating protective layer on the inner casing to isolate the heat loss of the heat medium during circulation. The inner-tube-outer-tube annular space between the inner casing and the outer oil casing is used for the heat-receiving medium between the heat-insulating casing and the outer oil casing to flow in, and is output upward after passing through the inner-tube heat-collecting reflux outlet. At the same time, when the heat exchange medium enters the inner-tube heat-collecting reflux outlet on the metal gravity heating rod of the inner heat-insulating casing in the inner-tube-outer-tube annular space, it will contact and conduct with the inner surface of the outer-tube heat-collecting conical sealing device, and the heat-receiving medium absorbs the heat transferred to the inner-insulating metal gravity heating rod from the outer-tube heat-collecting conical sealing device and the outer oil casing.

4. The medium-deep geothermal bore inner tube heat collection and reflux device according to claim 2, characterized in that: The metal gravity heating rod is made of copper alloy and has an ideal heat conduction effect; the thermal insulation inner tube is a solid polyethylene PE tube, the inner wall of the tube is very smooth, the thermal resistance is large, the water resistance is small, and it has a good thermal insulation effect; the outer oil casing is made of J55 seamless steel pipe, which has the characteristics of high temperature resistance, high pressure resistance, no deformation, and high and stable thermal conductivity.

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