A heat exchange device for the wellbore of geothermal resource extraction wells

Abstract

This utility model discloses a geothermal well wall heat exchange device, including a geothermal well, a heating exchange structure, an absorbing heat exchange structure, and a heat storage tank. Both the heating and absorbing heat exchange structures are located inside the geothermal well, with the absorbing heat exchange structure located inside the heating exchange structure. A heat-conducting layer is provided between the heating and absorbing heat exchange structures. The absorbing heat exchange structure is connected to the heat storage tank, which is located outside the geothermal well. This utility model employs heat exchange within the geothermal well. The heating and absorbing heat exchange spiral tubes are concentrically nested, significantly increasing the heat exchange area compared to traditional single-tube structures, resulting in more efficient heat transfer. The heat-conducting layer uses graphene, combined with uniformly distributed heat-conducting holes, reducing thermal resistance and increasing the heat transfer rate. The insulation layer uses high-density polyurethane foam, with a full-wrap design on the outside of the spiral tubes, greatly reducing heat loss.

Description

Technical Field

[0001] This utility model relates to the technical field of geothermal energy development and utilization devices, and in particular to a geothermal resource extraction well wall heat exchange device. Background Technology

[0002] Geothermal resources are a clean and renewable new energy source with abundant reserves and wide distribution. my country has large proven reserves of geothermal resources and huge development potential. At present, the utilization of geothermal resources has covered multiple fields such as heating, power generation, agricultural planting, medical care and health care.

[0003] Existing geothermal heat extraction well heat exchange devices have the following shortcomings: most of them use geothermal energy to be transported to the ground through a pump body device for heat exchange, and the heat loss during pumping is serious; in addition, most of them currently use ground-type heat exchange structures, which have limited heat exchange area, insufficient heat transfer between the heat flow medium and the heat exchange medium, and low heat exchange efficiency; and they lack targeted insulation design, resulting in serious heat loss to the well wall and surrounding environment and the ground during the heat flow process. Utility Model Content

[0004] The purpose of this utility model is to address the shortcomings of existing technologies by proposing a geothermal well wall heat exchange device.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A geothermal well wall heat exchange device includes a heat extraction well, a heat supply and heat exchange structure, a heat absorption and heat exchange structure, and a heat storage tank. The heat supply and heat exchange structure and the heat absorption and heat exchange structure are both located inside the heat extraction well. The heat absorption and heat exchange structure is located inside the heat supply and heat exchange structure. A heat-conducting layer is provided between the heat supply and heat exchange structure and the heat absorption and heat exchange structure. The heat absorption and heat exchange structure is connected to the heat storage tank, which is located outside the heat extraction well.

[0007] The heating and heat exchange structure includes a heat supply pipe, a heat return pipe, and a heating and heat exchange spiral pipe. An insulation layer is provided on the outside of the heating and heat exchange spiral pipe. The heat supply pipe passes through the insulation layer and is connected to the bottom of the heating and heat exchange spiral pipe. The top of the heating and heat exchange spiral pipe is connected to a circulation pump B through a pipe. The circulation pump B is located outside the heat extraction well and is connected to the heat return pipe inside the heat extraction well through a pipe.

[0008] The heat absorption and heat exchange structure includes a heat exchange medium supply pipe, a heat exchange medium downflow pipe, and a heat absorption and heat exchange spiral pipe. The heat absorption and heat exchange spiral pipe is disposed within the heat conduction layer, and the heat exchange medium downflow pipe is disposed within the spiral of the heat absorption and heat exchange spiral pipe. The heat exchange medium supply pipe is disposed outside the heat extraction well and is connected to the heat exchange medium downflow pipe inside the heat extraction well. The bottom of the heat exchange medium downflow pipe is connected to the bottom of the heat absorption and heat exchange spiral pipe. The top of the heat absorption and heat exchange spiral pipe is connected to a circulation pump A through a pipe. The circulation pump A is disposed outside the heat extraction well and is connected to a heat storage tank through a pipe.

[0009] The heat-conducting layer is provided with uniformly distributed heat-conducting holes, the diameter of which is 5-8 mm.

[0010] The thermally conductive layer is made of graphene, which has high thermal conductivity;

[0011] The insulation layer is made of polyurethane foam with a thickness of 8-12cm, providing good insulation performance;

[0012] The heating and heat exchange spiral tubes are made of TA2 titanium alloy, which has high thermal conductivity and is resistant to underground high temperatures and corrosion.

[0013] The heat exchange medium in the heat absorption and heat exchange structure is synthetic heat transfer oil, and its circulation path is: heat exchange medium supply pipe → heat exchange medium downflow pipe → heat absorption and heat exchange spiral pipe → circulation pump A → heat storage box → (after heat release by external equipment) return to the heat exchange medium supply pipe, forming a closed loop.

[0014] The heat transfer medium in the heat exchange structure is underground hot water in the heat extraction well. Its circulation path is: heat transfer enrichment zone at the bottom of the heat extraction well → heat transfer medium heating pipe → heat exchange spiral pipe → circulation pump B → heat transfer medium return pipe → heat transfer replenishment zone in the middle of the heat extraction well, forming a closed loop.

[0015] The beneficial effects of this utility model are as follows:

[0016] The heat exchange is conducted within the heat extraction well. The heating and heat absorption spiral tubes are designed in a concentric nested manner, which greatly increases the heat exchange area compared to the traditional single-tube structure and makes the heat transfer more complete. The heat-conducting layer uses graphene and is combined with uniformly distributed heat-conducting holes to reduce thermal resistance and increase the heat transfer rate. The insulation layer uses high-density polyurethane foam and is designed to fully wrap the outside of the spiral tube, which greatly reduces the heat loss rate. Attached Figure Description

[0017] Figure 1 This is a cross-sectional view of the longitudinal integral structure of this utility model;

[0018] Figure 2 This is a partial cross-sectional view of the heat absorption and heat exchange structure of this utility model;

[0019] Figure 3 This is a partial cross-sectional view of the heat supply and heat exchange structure of this utility model;

[0020] In the diagram: 1. Heat extraction well; 2. Heat supply pipe for heat flow medium; 3. Heat return pipe for heat flow medium; 4. Heat supply and heat exchange spiral pipe; 5. Insulation layer; 6. Heat conduction layer; 61. Heat conduction hole; 7. Heat absorption and heat exchange spiral pipe; 8. Heat exchange medium downflow pipe; 9. Heat exchange medium supply pipe; 10. Circulation pump A; 11. Heat storage tank; 12. Circulation pump B. Detailed Implementation

[0021] The technical solution of this utility model will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0022] Example 1

[0023] like Figure 1-3 As shown, this utility model provides a geothermal resource heat extraction well wall heat exchange device, the structure of which includes a heat extraction well 1, a heat supply heat exchange structure, a heat absorption heat exchange structure and a heat storage box 11. The heat supply heat exchange structure and the heat absorption heat exchange structure are both set inside the heat extraction well 1. The heat absorption heat exchange structure is set inside the heat supply heat exchange structure. A heat-conducting layer 6 is set between the heat supply heat exchange structure and the heat absorption heat exchange structure. The heat absorption heat exchange structure is connected to the heat storage box 11. The heat storage box 11 is set outside the heat extraction well 1.

[0024] The heating and heat exchange structure includes a heat supply pipe 2, a heat return pipe 3, and a heating and heat exchange spiral pipe 4. An insulation layer 5 is provided on the outside of the heating and heat exchange spiral pipe 4. The heat supply pipe 2 passes through the insulation layer 5 and is connected to the bottom of the heating and heat exchange spiral pipe 4. The top of the heating and heat exchange spiral pipe 4 is connected to a circulation pump B12 through a pipe. The circulation pump B12 is located outside the heat extraction well 1 and is connected to the heat return pipe 3 inside the heat extraction well 1 through a pipe.

[0025] The heat absorption and heat exchange structure includes a heat exchange medium supply pipe 9, a heat exchange medium downflow pipe 8, and a heat absorption and heat exchange spiral pipe 7. The heat absorption and heat exchange spiral pipe 7 is disposed inside the heat conduction layer 6. The heat exchange medium downflow pipe 8 is disposed inside the spiral of the heat absorption and heat exchange spiral pipe 7. The heat exchange medium supply pipe 9 is disposed outside the heat extraction well 1. The heat exchange medium supply pipe 9 is connected to the heat exchange medium downflow pipe 8 inside the heat extraction well 1. The bottom of the heat exchange medium downflow pipe 8 is connected to the bottom of the heat absorption and heat exchange spiral pipe 7. The top of the heat absorption and heat exchange spiral pipe 7 is connected to the circulation pump A10 through a pipe. The circulation pump A10 is disposed outside the heat extraction well 1. The circulation pump A10 is connected to the heat storage tank 11 through a pipe.

[0026] The heat-conducting layer 6 is provided with uniformly distributed heat-conducting holes 61.

[0027] The heat extraction well 1 has a depth of 1200m and a diameter of 800mm; the heat supply and heat exchange spiral pipe 4 has an outer diameter of 500mm, a pitch of 300mm, and a total length of 550m; the heat absorption and heat exchange spiral pipe 7 has an outer diameter of 300mm, a pitch of 200mm, and a total length of 500m; the heat-conducting layer 6 has a thickness of 10mm, on which heat-conducting holes 61 with a diameter of 6mm are evenly distributed, with a hole spacing of 50mm; the insulation layer 5 has a thickness of 10cm, and is made of high-density polyurethane foam with a density ≥40kg / m³. 3 Both the heating spiral tube 4 and the heat absorption spiral tube 7 are made of TA2 titanium alloy with a wall thickness of 5mm; the rated power of the circulating pump A10 is 5.5kW and the head is 30m; the rated power of the circulating pump B12 is 7.5kW and the head is 40m; the volume of the heat storage tank 11 is 50m³. 3 .

[0028] Specifically, the heat flow medium circulation (heat supply and heat exchange structure):

[0029] The underground hot water at the bottom of the heat extraction well 1 serves as the heat flow medium. Driven by the circulating pump B12, it flows into the bottom of the heat exchange spiral pipe 4 through the heat flow medium supply pipe 2. Because the heat exchange spiral pipe 4 adopts a spiral structure, the contact time between the heat flow medium and the heat conduction layer 6 when the heat flow medium flows upward along the pipe wall is extended to three times that of the traditional straight pipe structure. The heat is transferred to the heat absorption spiral pipe 7 on the inner side through the heat conduction layer 6 and the heat conduction hole 61. After releasing the heat, the heat flow medium flows out through the top of the heat exchange spiral pipe 4. After being pressurized by the circulating pump B12, it is transported to the middle of the heat extraction well 1 through the heat flow medium return pipe 3. After mixing with the underground supplementary heat flow, it participates in the circulation again, forming a closed loop.

[0030] Heat exchange medium circulation (heat absorption and heat exchange structure):

[0031] The low-temperature synthetic heat transfer oil in the heat storage tank 11 serves as the heat exchange medium. It enters the heat exchange medium downflow pipe 8 through the heat exchange medium supply pipe 9, flows downwards along the central axis of the heat absorption spiral pipe 7 to the bottom, and then enters the spiral channel of the heat absorption spiral pipe 7. Since the spiral direction of the heat absorption spiral pipe 7 is opposite to that of the heat supply spiral pipe 4, the heat exchange medium forms a counter-current heat exchange with the heat transfer layer 6 during its upward flow, fully absorbing heat. The heated heat exchange medium flows out from the top of the heat absorption spiral pipe 7, is pressurized by the circulating pump A10, and then sent to the heat storage tank 11 for storage. Finally, it is used for building heating or to drive power generation equipment through a heat exchanger connected to the heat storage tank 11. The released low-temperature heat transfer oil flows back to the heat exchange medium supply pipe 9, completing the circulation.

Claims

1. A heat exchange device for the wellbore of a geothermal resource extraction well, characterized in that: The system includes a heat extraction well, a heat supply and heat exchange structure, a heat absorption and heat exchange structure, and a heat storage tank. Both the heat supply and heat absorption structures are located within the heat extraction well, with the heat absorption structure located inside the heat supply structure. A heat-conducting layer is provided between the heat supply and heat absorption structures. The heat absorption structure is connected to the heat storage tank, which is located outside the heat extraction well. The heat supply and heat exchange structure includes a heat flow medium supply pipe, a heat flow medium return pipe, and a heat supply and heat exchange spiral pipe. An insulation layer is provided on the outside of the heat supply and heat exchange spiral pipe. The heat flow medium supply pipe passes through the insulation layer and connects to the bottom of the heat supply and heat exchange spiral pipe. The top of the heat supply and heat exchange spiral pipe is connected to a circulation pump B via a pipe. Circulation pump B... Located outside the heat extraction well, the circulating pump B is connected to the heat flow medium return pipe inside the heat extraction well via a pipeline. The heat absorption and heat exchange structure includes a heat exchange medium supply pipe, a heat exchange medium downflow pipe, and a heat absorption and heat exchange spiral pipe. The heat absorption and heat exchange spiral pipe is located inside the heat conduction layer, and the heat exchange medium downflow pipe is located inside the spiral of the heat absorption and heat exchange spiral pipe. The heat exchange medium supply pipe is located outside the heat extraction well and is connected to the heat exchange medium downflow pipe inside the heat extraction well. The bottom of the heat exchange medium downflow pipe is connected to the bottom of the heat absorption and heat exchange spiral pipe. The top of the heat absorption and heat exchange spiral pipe is connected to the circulating pump A via a pipeline. The circulating pump A is located outside the heat extraction well and is connected to the heat storage tank via a pipeline.

2. The geothermal resource heat extraction well wall heat exchanger apparatus of claim 1, wherein: The heat-conducting layer is provided with uniformly distributed heat-conducting holes, the diameter of which is 5-8 mm.

3. The geothermal resource heat extraction well wall heat exchanger apparatus of claim 2, wherein: The thermally conductive layer is made of graphene.

4. The geothermal resource heat extraction well wall heat exchanger apparatus of claim 1, wherein: The insulation layer is made of polyurethane foam with a thickness of 8-12cm.

5. The geothermal resource heat extraction well wall heat exchanger apparatus of claim 1, wherein: The heating and heat exchange spiral tubes are made of TA2 titanium alloy.

6. The geothermal resource heat extraction well wall heat exchanger apparatus of claim 1, wherein: The heat exchange medium in the heat absorption and heat exchange structure is synthetic heat transfer oil.

7. The geothermal resource heat extraction well wall heat exchanger apparatus of claim 1, wherein: The heat transfer medium in the heat exchange structure is underground hot water from the heat extraction well.

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