Underground heat removal system for deep V-shaped well

Abstract

The utility model relates to the field of geothermal resource utilization, and discloses a deep-layer V-shaped well underground heat removal system which comprises a heat pump main machine, the left side of the heat pump main machine is fixedly connected with two overground heat preservation pipelines, and the bottom ends of the overground heat preservation pipelines are fixedly connected with a well mouth connecting device. A second heat exchange sleeve is fixedly connected to the bottom ends of the two wellhead connecting devices, heat insulation assemblies used for assisting heat exchange are arranged at the left end and the right end of the top end of the second heat exchange sleeve, and an underground cement well cementation section is fixedly connected to the bottom end of the second heat exchange sleeve; and a circulating conveying water pump is arranged in the middle of one overground heat preservation pipeline. In the field of heat extraction and utilization of the deep geothermal well, a novel heat extraction mode is provided aiming at an existing utilization mode of deep geothermal, a connection mode of the V-shaped butt joint well is adopted, efficient transfer and utilization of heat energy are achieved, and construction difficulty is reduced.

Description

Technical Field

[0001] The utility model relates to the field of geothermal resource utilization, in particular to a deep V-shaped well underground heat extraction system. Background Art

[0002] With the increasing severity of the greenhouse effect and air pollution, traditional fossil energy resources such as coal, oil, and natural gas are no longer sufficient to meet the requirements of my country's environmentally friendly social development. The development and utilization of new clean alternative energy sources such as solar energy, wind energy, and geothermal energy are gaining increasing attention, and their proportion in the energy structure is expected to increase annually. Geothermal energy, a thermal energy resource, has advantages over solar and wind energy, such as being unaffected by day and night, weather conditions, high energy density, and stable operation. Therefore, it holds great promise for building heating in northern my country.

[0003] Currently, deep geothermal heat exchange wells primarily utilize coaxial heat exchange. Due to the cross-section of the pipes used in the middle coaxial heat exchange jacket, the circulating water flow rate is low, resulting in low heat extraction efficiency. The previously studied U-shaped casing underground horizontal wells are difficult to drill, pose high risks, and have a low cost-effectiveness, preventing widespread application. To address these issues, a deep V-shaped well underground heat extraction system was proposed. Utility Model Content

[0004] In order to make up for the above shortcomings, the utility model provides a deep V-shaped well underground heat extraction system, which aims to improve the problem in the existing technology that the coaxial heat exchange form is affected by the pipe cross-section, resulting in the circulating water flow being affected and the heat exchange efficiency being reduced.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A deep V-shaped underground heat extraction system, comprising a heat pump main unit, two above-ground insulated pipes fixedly connected to the left side of the heat pump main unit, the bottom ends of the above-ground insulated pipes fixedly connected to a wellhead connection device, the bottom ends of the two wellhead connection devices fixedly connected to a second heat exchange sleeve, the left and right ends of the top of the second heat exchange sleeve are provided with insulation components for assisting heat exchange, the bottom end of the second heat exchange sleeve is fixedly connected to an underground cement cementing section, and a circulating water pump is provided in the middle of one of the above-ground insulated pipes;

[0007] As a further description of the above technical solution:

[0008] The heat insulation assembly includes two geological reservoirs, the interior of the geological reservoir is fixedly connected to the outer ends of the second heat exchange sleeve, and the exterior of the geological reservoir is fixedly connected to the first surface sleeve;

[0009] As a further description of the above technical solution:

[0010] The top of the geological reservoir is fixedly connected to the bottom end of the wellhead connection device, and the bottom end of the first surface casing is fixedly connected to the bottom end of the wellhead connection device;

[0011] As a further description of the above technical solution:

[0012] The above-ground heat-insulating pipe is made of heat-insulating casing material to reduce heat loss;

[0013] As a further description of the above technical solution:

[0014] The second heat exchange sleeve is made of high thermal conductivity petroleum sleeve, and its surface contacts the formation to achieve sufficient heat exchange.

[0015] The utility model has the following beneficial effects:

[0016] 1. In the utility model, the heat is extracted from the heat pump main unit, enters the second heat exchange sleeve along the ground insulation pipe at the output end, and then flows into the ground insulation pipe at the input end through the second heat exchange sleeve. This realizes the heat extraction and utilization of deep geothermal wells. A new heat extraction method is proposed for the existing deep geothermal utilization method. The V-shaped docking well connection method is adopted to achieve efficient transmission and utilization of heat energy and reduce construction difficulty. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a planar schematic diagram of a deep V-shaped well underground heat extraction system proposed in the utility model.

[0018] Legend:

[0019] 1. Heat pump main unit; 2. Above-ground insulation pipe; 3. Wellhead connection device; 4. Second heat exchange casing; 5. Geological reservoir; 6. First surface casing; 7. Underground cementing section; 8. Circulating water pump. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described 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.

[0021] Reference Figure 1The present invention provides an embodiment of a deep V-shaped underground heat extraction system, comprising a heat pump unit 1, which is responsible for extracting heat from a low-temperature heat source and raising it to a higher temperature level to meet heating or cooling needs. Two above-ground insulated pipes 2 are fixedly connected to the left side of the heat pump unit 1. The above-ground insulated pipes 2 are made of an insulating sleeve material to reduce heat loss during heat extraction. The above-ground insulated pipes 2 are used to connect the heat pump unit 1 to the underground heat exchange system, ensuring that heat loss is minimized during the transmission process.

[0022] The bottom end of the above-ground insulation pipe 2 is fixedly connected with a wellhead connection device 3. The above-ground insulation pipe 2 has two pipes, one for outputting circulating water and one for inputting circulating water. The underground positions where the two above-ground insulation pipes 2 are connected are both connected with a wellhead connection device 3.

[0023] The bottom ends of the two wellhead connecting devices 3 are fixedly connected with a second heat exchange sleeve 4. The second heat exchange sleeve 4 is made of high thermal conductivity oil casing material, and its surface contacts the formation to achieve sufficient heat exchange. The second heat exchange sleeve 4 pipeline is a V-shaped pipeline, and the pipeline is divided according to the research on geological strata, and the pipeline is buried 3,500 meters underground.

[0024] The left and right ends of the top of the second heat exchange sleeve 4 are provided with insulation components for assisting heat exchange. The insulation components include two geological reservoirs 5. The inside of the geological reservoir 5 is fixedly connected to the two ends of the outside of the second heat exchange sleeve 4. The outside of the geological reservoir 5 is fixedly connected with a first surface casing 6. The top of the geological reservoir 5 is fixedly connected to the bottom end of the wellhead connection device 3, and the bottom end of the first surface casing 6 is fixedly connected to the bottom end of the wellhead connection device 3. The first surface casing 6 is insulated because the temperature of the geological reservoir 5 is low. The two casings are connected to the wellhead connection device 3, buried underground, and close to the ground.

[0025] The bottom end of the second heat exchange sleeve 4 is fixedly connected to an underground cementing section 7. The underground cementing section 7 is a section of a wellbore fixed with cement and used to support the underground heat exchange sleeve and other equipment. This prevents groundwater from seeping into the system while ensuring stable operation of the system. A circulating water pump 8 is provided in the middle of one of the above-ground insulated pipes 2. The circulating water pump 8 is installed in the middle of the above-ground insulated pipe 2 (at the input end) and is responsible for driving the water source to circulate in the system. By turning on the circulating water pump 8, the water source can be kept flowing, thereby achieving efficient heat exchange processing.

[0026] Working principle: When constructing the geothermal well, a small-angle natural inclination is adopted for construction, and the operating system is installed in a closed operation.

[0027] After installation is complete, the control end is turned on to control the heat pump main unit 1 to deliver circulating water to the connected (water outlet) ground insulation pipe 2, and then enter the second heat exchange sleeve 4 through the wellhead connection device 3, so that the outside of the second heat exchange sleeve 4 contacts the formation for heat exchange. After heat exchange, the water source will flow along the V-shaped channel of the second heat exchange sleeve 4 to the outlet at the other end of the second heat exchange sleeve 4, circulate through the wellhead connection device 3 fixed at the other end of the second heat exchange sleeve 4, and the circulating water pump 8 is turned on to drive the water source to continue flowing, circulate into the ground (input end) ground insulation pipe 2, and pass through the circulating water pump 8 into the heat pump main unit 1 for heat exchange treatment. This increases the circulating water flow rate and improves the heat exchange.

[0028] During the whole process, the first surface casing 6 is used for heat insulation because the temperature of the geological reservoir 5 is low.

[0029] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A deep V-shaped underground heat extraction system, comprising a heat pump main unit (1), characterized in that: The left side of the heat pump main unit (1) is fixedly connected to two above-ground insulation pipes (2), the bottom ends of the above-ground insulation pipes (2) are fixedly connected to a wellhead connection device (3), the bottom ends of the two wellhead connection devices (3) are fixedly connected to a second heat exchange sleeve (4), the left and right ends of the top of the second heat exchange sleeve (4) are provided with insulation components for assisting heat exchange, the bottom end of the second heat exchange sleeve (4) is fixedly connected to an underground cement cementing section (7), and a circulating water pump (8) is provided in the middle of one of the above-ground insulation pipes (2).

2. The deep V-shaped underground heat extraction system according to claim 1, characterized in that: The heat insulation assembly comprises two geological reservoirs (5), the interior of the geological reservoir (5) is fixedly connected to the two exterior ends of the second heat exchange sleeve (4), and the exterior of the geological reservoir (5) is fixedly connected to a first surface sleeve (6).

3. The deep V-shaped underground heat extraction system according to claim 2, characterized in that: The top of the geological reservoir (5) is fixedly connected to the bottom of the wellhead connection device (3), and the bottom of the first surface casing (6) is fixedly connected to the bottom of the wellhead connection device (3).

4. The deep V-shaped underground heat extraction system according to claim 1, characterized in that: The above-ground heat-insulating pipe (2) is made of heat-insulating casing material, which reduces heat loss during heat extraction.

5. The deep V-shaped underground heat extraction system according to claim 1, characterized in that: The second heat exchange sleeve (4) is made of a high-thermal-conductivity petroleum sleeve material, and its surface contacts the formation to achieve sufficient heat exchange.

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