U-shaped multi-well butt joint enhanced heat exchange structure

Abstract

The application discloses a U-shaped multi-well butt joint reinforced heat exchange structure, which comprises a straight well, a first heat preservation cylinder and a second heat preservation cylinder, the upper end of the first heat preservation cylinder is clamped and fixed with the second heat preservation cylinder, the first heat preservation cylinder and the second heat preservation cylinder are sleeved on the straight well, the lower end of the first heat preservation cylinder is fixed with a drill bit, the periphery of the straight well is provided with a plurality of butt joint wells, the lower end of each butt joint well is communicated with a horizontal well, each butt joint well is communicated with the straight well through the horizontal well, the inside of the first heat preservation cylinder is provided with an inner cylinder coaxial with the first heat preservation cylinder, the inner wall of the first heat preservation cylinder is slidably connected with a fixing assembly, heat preservation cotton is arranged between the first heat preservation cylinder and the inner cylinder and fixed on the fixing assembly, the fixing assembly comprises upper and lower fixing rings, medium is gathered in the straight well and flows out through different butt joint wells and horizontal wells, the heat exchange channel is ensured to be large in the whole process, the contact area with the stratum is increased, the system ground source side circulating water volume is increased, and the downhole heat exchange efficiency can be effectively improved.

Description

Technical Field

[0001] This invention relates to the field of geothermal downhole heat exchange technology, specifically a U-shaped multi-well docking enhanced heat exchange structure. Background Technology

[0002] Geothermal energy, as a non-carbon-based energy source, can effectively reduce coal consumption and carbon dioxide emissions through its development and utilization. Closed-loop medium-deep buried pipe heat exchange technology involves drilling holes from the ground surface using mechanical equipment and installing metal pipe heat exchangers inside. The fluid medium circulates in the pipes, extracting heat from the surrounding rock and soil, and then combining it with a heat pump unit to meet the heating needs of buildings.

[0003] Chinese Patent Publication No. CN2021100667439 discloses a downhole enhanced heat exchange system and method, relating to the field of energy utilization. The downhole enhanced heat exchange system includes: a first wellbore lowered into a geothermal reservoir and a second wellbore located above and connected to the first wellbore; a flow passage is provided on the side wall of the first wellbore; a fixed platform is located at the bottom of the second wellbore; a heat exchanger sleeve is located in the second wellbore, with drainage holes provided on its side wall; a pipe body is located in the first wellbore; a pump body is connected to the fixed platform, with its inlet connected to the pipe body and its outlet connected to the heat exchanger sleeve; and a heat pump system, which includes a spiral heat exchanger located in the heat exchanger sleeve, a working fluid downcomer, a working fluid riser, a compressor, a condenser, a throttle valve, and the working fluid charged into the heat pump system. This application enables "heat extraction without water extraction" from deep geothermal wells, achieving efficient heat exchange and sustainable utilization of geothermal energy.

[0004] Chinese Patent Publication No. CN2021110124301 discloses a closed-loop downhole heat exchange device for medium-deep geothermal energy, comprising a heat-extracting inner pipe, a heat exchange sleeve, and a support device. The support device is located on the surface of the geothermal well. The upper end of the heat-extracting inner pipe is connected to the support device, and the lower end of the heat-extracting inner pipe extends into the bottom of the geothermal well. The heat exchange sleeve is fitted over the lower part of the heat-extracting inner pipe, and a packer is provided between the heat exchange sleeve and the geothermal well. A water injection pipe is provided on the side of the support device, and a water outlet pipe connected to the heat-extracting inner pipe is provided on the top of the support device. A screen pipe and a counterweight pipe are connected to the lower end of the heat-extracting inner pipe. This invention utilizes a screen pipe connected to the lower end of the heat-extracting inner pipe to filter the water flowing into the inner pipe before it enters. The screen pipe also prevents impurities in the water flow from entering the inner pipe, thus avoiding wear on the inner wall of the inner pipe and affecting its service life.

[0005] The above two solutions will still encounter the following situations during use:

[0006] 1. When the medium inside the pipeline enters the ground for heat exchange, the medium after heat exchange will come into contact with the cold medium, and then heat exchange will occur again, causing the temperature of the hot medium after heat exchange to drop, which affects the efficiency of heat exchange.

[0007] 2. When the heat-exchanged medium is close to the ground, the pipe on the side closest to the ground is affected by the ground temperature and has a lower temperature. When the hot medium enters the pipe near the ground, heat exchange will occur again, causing the hot medium to lose heat and resulting in a loss of medium temperature. Some existing pipes add insulation cotton to the outer wall, but the required insulation height varies depending on the temperature and cannot be adjusted. At the same time, after being buried underground for a long time, the insulation cotton has poor insulation effect and cannot be replaced quickly.

[0008] 3. When a large amount of heat is required, new vertical wells need to be added. The system cannot increase the circulating water volume on the ground source side, which leads to an increase in the cost of heat extraction. Summary of the Invention

[0009] The purpose of this invention is to provide a U-shaped multi-well docking enhanced heat exchange structure, which solves the problems in the prior art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: a U-shaped multi-well docking enhanced heat exchange structure, comprising a vertical well, a first insulation cylinder and a second insulation cylinder, wherein the upper end of the first insulation cylinder is snapped and fixed to the second insulation cylinder, the first insulation cylinder and the second insulation cylinder are sleeved on the vertical well, a drill bit is fixed to the lower end of the first insulation cylinder, and multiple docking wells are provided around the vertical well, the lower end of each docking well is connected to a horizontal well, and each docking well is connected to the vertical well through the horizontal well;

[0011] The first insulation cylinder has an inner cylinder coaxial with it. A fixing component is slidably connected to the inner wall of the first insulation cylinder. Insulation cotton is provided between the first insulation cylinder and the inner cylinder and is fixed to the fixing component. The fixing component includes an upper fixing ring and a lower fixing ring distributed vertically. Multiple connecting rods are slidably connected between the upper fixing ring and the lower fixing ring. Baffles are fixed to the left and right sides of the multiple connecting rods. One end of a spring is fixed to the center of the side of the multiple connecting rods opposite to the inner cylinder. The other end of the spring is fixedly connected to the outer wall of the inner cylinder. The insulation cotton is located between the baffle and the inner cylinder. Multiple snap fasteners are fixed to the upper end of the upper fixing ring.

[0012] The internal structure of the second insulation cylinder is the same as that of the first insulation cylinder. The upper end of the first insulation cylinder is provided with multiple first snap-fit ​​grooves, the upper end of the second insulation cylinder is provided with multiple second snap-fit ​​grooves, and the lower end of the second insulation cylinder is fixed with multiple buckles. The second insulation cylinder is snapped and fixed to the first snap-fit ​​grooves of the first insulation cylinder by the buckles.

[0013] Preferably, the upper fixing ring and the lower fixing ring are two concentric rings with different diameters, and a fixing rod is provided between the two concentric rings with different diameters. The lower end of the fixing rod of the upper fixing ring has a groove, and the upper end of the fixing rod of the lower fixing ring has a sliding groove. The connecting rod is slidably connected to the upper fixing ring and the lower fixing ring through the groove of the upper fixing ring and the sliding groove of the lower fixing ring.

[0014] Preferably, a first guide block is symmetrically fixed to the outer wall of the upper fixing ring, and a second guide block is symmetrically fixed to the outer wall of the lower fixing ring. The first guide block and the second guide block are located on the same vertical line. Guide grooves are symmetrically opened on the inner wall of the first insulation cylinder. The upper fixing ring and the lower fixing ring are slidably connected to the guide grooves of the first insulation cylinder through the first guide block and the second guide block.

[0015] Preferably, the number of the snap-fit, the slide, the connecting rod, and the spring are the same.

[0016] Preferably, the upper end of the inner cylinder is fixedly connected to the upper fixing ring, the lower end of the inner cylinder is fixedly connected to the lower fixing ring, and the inner cylinder is sleeved on the outer wall of the vertical well and slidably connected.

[0017] Preferably, both the first and second insulation cylinders have a vacuum chamber inside.

[0018] Preferably, the drill bit is a frustum-shaped cylinder with openings at the top and bottom, the size of which is the same as the diameter of the vertical well. Multiple drill teeth are fixed at the lower end of the drill bit, and multiple chip removal strips are fixed on the inclined surface of the drill bit. The lower end of the chip removal strips corresponds to the drill teeth, and the upper end of the chip removal strips extends to the outer wall of the first insulation cylinder.

[0019] Preferably, the snap fastener is two mirror-shaped characters, the distance between the upper ends of the snap fastener is less than the distance from the slide groove to the edge of its fixing rod, and the upper end of the snap fastener is chamfered.

[0020] Preferably, the diameter of the vertical well is larger than the diameter of the docking well.

[0021] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0022] 1. By increasing the number of docking wells, the medium inside the pipe, after entering the docking well, flows out through different docking wells and horizontal wells, and the medium converges in the vertical well. This ensures that there are many heat exchange channels throughout the process, increases the contact area with the formation, and increases the circulating water volume on the ground source side of the system, which can effectively improve the downhole heat exchange efficiency.

[0023] 2. By installing a first and a second insulation cylinder on the outer wall of the vertical well, the problem of temperature drop when hot water rises to the ground can be effectively mitigated. By splicing the first and second insulation cylinders together, the insulation distance from the vertical well to the ground can be adjusted according to seasonal changes. Fixing the insulation cotton with a fixing component ensures that the insulation cotton fits tightly to the outer wall of the vertical well, guaranteeing the insulation effect of the fixing component, slowing down the temperature drop during the process of hot water rising to the ground, and facilitating the replacement of the insulation cotton. Drilling with a drill bit allows for adjustment of the insulation distance from the vertical well to the ground.

[0024] 3. Setting up multiple connecting wells for water intake increases the system's ground source-side circulating water volume. Under the premise of meeting the same water volume requirements, it reduces the number of vertical wells, reduces the land area occupied, and saves well drilling costs. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the vertical well of the present invention;

[0027] Figure 3 This is a schematic diagram of the combination of the first and second insulation cylinders of the present invention;

[0028] Figure 4 This is a schematic diagram of the first heat-insulating cylinder of the present invention;

[0029] Figure 5 This is a schematic diagram of the overall fixing component of the present invention;

[0030] Figure 6 This is a cross-sectional schematic diagram of the outer shell of the first heat-insulating cylinder of the present invention;

[0031] Figure 7 This is a schematic cross-sectional view of the first heat-insulating cylinder of the present invention;

[0032] Figure 8 This is a schematic diagram of the second heat-insulating cylinder of the present invention.

[0033] The diagram is labeled as follows: 1. Vertical well; 2. First insulation cylinder; 3. Second insulation cylinder; 4. Drill bit; 5. Inner cylinder; 6. Fixing component; 7. Insulation cotton; 101. Connecting well; 102. Horizontal well; 201. First locking groove; 202. Guide groove; 203. Vacuum chamber; 301. Buckle; 302. Second locking groove; 401. Drill teeth; 402. Chip removal bar; 601. Upper fixing ring; 602. Lower fixing ring; 603. Connecting rod; 604. Baffle; 605. Spring; 6011. Locking buckle; 6012. First guide block; 6021. Slide groove; 6022. Second guide block. Detailed Implementation

[0034] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0035] In the description of this invention, unless otherwise stated, "a plurality of" means two or more; the terms "upper," "lower," "left," "right," "inner," "outer," "front end," "rear end," "head," "tail," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," "third," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0036] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0037] Please see Figure 1 , Figure 2 , Figure 3 and Figure 8A U-shaped multi-well docking enhanced heat exchange structure includes a vertical well 1, a first insulation cylinder 2, and a second insulation cylinder 3. The upper end of the first insulation cylinder 2 is snapped and fixed to the second insulation cylinder 3. The upper end of the first insulation cylinder 2 has multiple first snap-fit ​​grooves 201, and the upper end of the second insulation cylinder 3 has multiple second snap-fit ​​grooves 302. The lower end of the second insulation cylinder 3 is fixed with multiple buckles 301. The second insulation cylinder 3 is snapped and fixed to the first insulation cylinder 2's first snap-fit ​​grooves 201 via the buckles 301. Each buckle 301 has three teeth: two symmetrically opposite each other, and a third single tooth perpendicular to the two opposite teeth. The left and right sides of the first snap-fit ​​grooves 201 have grooves corresponding to the two symmetrically opposite teeth. The first locking groove 201 is stepped, and the individual teeth of the buckle 301 engage with the first locking groove 201. The symmetrically opposite teeth of the buckle 301 engage with the grooves on both sides of the first locking groove 201. The second locking groove 302 at the upper end of the second insulation cylinder 3 can be engaged and fixed with the buckle 301 on another second insulation cylinder 3, which facilitates the fixed connection of multiple second insulation cylinders 3 together. This allows for adjustment of the insulation distance from the vertical well 1 to the ground according to different regions or temperatures, solving the problem of temperature drop when hot water rises to the ground. The first insulation cylinder 2 and the second insulation cylinder 3 are sleeved on the vertical well 1. Multiple connecting wells 101 are provided around the periphery of the vertical well 1, and the lower end of each connecting well 101 is connected to a horizontal well. 102, the diameter of the vertical well 1 is larger than the diameter of the docking well 101. All docking wells 101 are connected to the vertical well 1 via horizontal wells 102. Multiple docking wells 101 are provided, and the lower ends of all docking wells 101 are connected to the vertical well 1 via horizontal wells 102. After the medium enters the docking well 101, it converges with the medium in the horizontal wells 102 through different docking wells 101 and flows out into the vertical well 1. This ensures multiple heat exchange channels throughout the process, increases the contact area with the formation, and increases the circulating water volume on the ground source side of the system, effectively improving downhole heat exchange efficiency. Simultaneously, the connections between the multiple horizontal wells 102 and the vertical well 1 are staggered to prevent convection of the medium inside the multiple docking wells 101, which could lead to mutual impact and cause expansion of the pipe wall of the vertical well 1. A drill bit 4 is fixed to the lower end of the insulation cylinder 2. The drill bit 4 is a frustum-shaped cylinder with openings at the top and bottom, the size of which is the same as the diameter of the vertical well 1. Multiple drill teeth 401 are fixed to the lower end of the drill bit 4, and multiple chip removal strips 402 are fixed to the inclined surface of the drill bit 4. The lower end of the chip removal strips 402 corresponds to the drill teeth 401, and the upper end of the chip removal strips 402 extends to the outer wall of the first insulation cylinder 2. When the drill bit 4 is rotated clockwise, it drives the first insulation cylinder 2 deeper into the ground through the drill teeth 401. At the same time, the chip removal strips 402 on the inclined surface of the drill bit 4 can effectively remove the soil cut by the drill teeth 401, thereby rapidly increasing the insulation depth of the vertical well 1 to the ground. When rotated counterclockwise, the chip removal strips 402 move the soil at the edge of the first insulation cylinder 2 downwards.This fills the gaps with soil, preventing the formation of a gap between the first insulation cylinder 2 and the ground, which would affect the fixation of the first insulation cylinder 2. Both the first and second insulation cylinders 2 and 3 have vacuum chambers 203 inside, which provide insulation and effectively prevent heat loss from the medium flowing inside the vertical well 1. The internal structure of the second insulation cylinder 3 is the same as that of the first insulation cylinder 2, ensuring that the internal components of the second insulation cylinder 3 and the first insulation cylinder 2 correspond to each other, facilitating connection between the first and second insulation cylinders 2 and 3, and enabling quick and easy maintenance of both insulation cylinders 2 and 3.

[0038] Please see Figure 4 , Figure 5 , Figure 6 and Figure 7The first insulation cylinder 2 has an inner cylinder 5 coaxial with it. The upper end of the inner cylinder 5 is fixedly connected to the upper fixing ring 601, and the lower end of the inner cylinder 5 is fixedly connected to the lower fixing ring 602. The inner cylinder 5 is sleeved on the outer wall of the vertical well 1 and slidably connected. The inner cylinder 5 is coaxially arranged with the first insulation cylinder 2, so that the distance between the inner cylinder 5 and the first insulation cylinder 2 is equal. At the same time, the upper and lower ends of the inner cylinder 5 are fixedly connected to the corresponding upper fixing ring 601 and lower fixing ring 602, respectively, to ensure that the thickness of the insulation cotton 7 is consistent and to prevent inconsistent insulation cotton 7 filling thickness, which would lead to inconsistent insulation effect. The inner cylinder 5 is slidably connected to the vertical well 1, which facilitates the removal of the inner cylinder 5 to replace the insulation cotton 7. A fixing component 6 is slidably connected to the inner wall of the first insulation cylinder 2. Insulation cotton 7 is provided between the first insulation cylinder 2 and the inner cylinder 5 and is fixed to the fixing component 6. The fixing component 6 includes an upper fixing ring 601 and a lower fixing ring 602 distributed vertically. A first guide block 6012 is symmetrically fixed to the outer wall of the upper fixing ring 601. The upper fixing ring 601 is slidably connected to the guide groove 202 through the first guide block 6012, which facilitates the sliding removal of the fixing component 6 from the inside of the first insulation cylinder 2 for maintenance. A second guide block 6022 is symmetrically fixed to the outer wall of the lower fixing ring 602. The first guide block 6012 and the second guide block 6022 are located on the same vertical line. The inner wall of the first insulation cylinder 2 is symmetrically provided with guides. The upper fixing ring 601 and the lower fixing ring 602 are slidably connected to the guide groove 202 of the first insulation cylinder 2 via a first guide block 6012 and a second guide block 6022. The second guide block 6022 is slidably connected to the guide groove 202 to ensure that the lower fixing ring 602 slides up and down in the guide groove 202. The first guide block 6012 and the second guide block 6022 are set on the same vertical line to facilitate the vertical correspondence between the upper fixing ring 601 and the lower fixing ring 602, thereby ensuring their smooth sliding. The number of the snap fastener 6011, the slide groove 6021, the connecting rod 603 and the spring 605 are the same. The snap fastener 6011 is two mirror-placed 7-shaped objects. The distance between the upper ends of the snap fastener 6011 is less than that between the slide groove 6021 and the upper end of the snap fastener 6011. The distance to the edge of its fixing rod is such that the upper end of the snap fastener 6011 is chamfered, and multiple snap fasteners 6011 are fixed to the upper end of the upper fixing ring 601. By setting the number of snap fasteners 6011, slide grooves 6021, connecting rods 603 and springs 605 to be consistent, it is easy to make them correspond one-to-one. At the same time, the distance of the upper end of the snap fastener 6011 is less than the distance from the slide groove 6021 to the edge of its fixing rod. The upper end of the snap fastener 6011 is chamfered to facilitate the snap fastener 6011 to snap onto the lower fixing ring 602 inside another second insulation cylinder 3, so that the fixing components 6 inside the two second insulation cylinders 3 can be connected to each other. At the same time, the distance of the upper end of the snap fastener 6011 is set to be less than the distance from the slide groove 6021 to the edge of its fixing rod.To facilitate the engagement and connection of the fixing component 6 inside the second insulation cylinder 3 without affecting the sliding of the connecting rod 603 in the other fixing component 6, and to allow for the replacement of the insulation cotton 7 without removing the first insulation cylinder 2 and the second insulation cylinder 3, the fixing component 6 can be slid out from inside the first insulation cylinder 2 and the second insulation cylinder 3, thus enabling the replacement of the insulation cotton 7 and the maintenance of the fixing component 6. Multiple connecting rods 603 are slidably connected between the upper fixing ring 601 and the lower fixing ring 602, with the left and right sides of the multiple connecting rods 603... Each of the connecting rods 603 is fixed with a baffle 604. A spring 605 is fixed to the center of each connecting rod 603 on the side opposite to the inner cylinder 5. The other end of each spring 605 is fixedly connected to the outer wall of the inner cylinder 5. The insulation cotton 7 is located between the baffle 604 and the inner cylinder 5. The lower end of each connecting rod 603 is slidably connected to the groove 6021 at the upper end of the lower fixing ring 602, and the upper end of each connecting rod 603 is slidably connected to the lower end of the upper fixing ring 601. The baffles 604 fixed on the left and right sides of the connecting rod 603 provide support for the insulation cotton 7. The spring 605 pulls the connecting rod 603 towards the inner cylinder 5. The connecting rod 603 and the baffle 604 squeeze the insulation cotton 7 closer to the inner cylinder 5, so that the insulation cotton 7 is firmly attached to the inner cylinder 5, ensuring the insulation performance of the insulation cotton 7 and reducing the heat loss of the medium inside the vertical well 1. The upper fixing ring 601 and the lower fixing ring 602 are two concentric rings with different diameters. A fixing rod is provided between the two concentric rings with different diameters. The lower end of the fixing rod of the upper fixing ring 601 has a groove, and the upper end of the fixing rod of the lower fixing ring 602 has a groove. The upper and lower fixing rings 602 are provided with a sliding groove 6021. The connecting rod 603 is slidably connected to the upper fixing ring 601 and the lower fixing ring 602 through the groove of the upper fixing ring 601 and the sliding groove 6021. The connecting rod 603 is slidably connected to the lower fixing ring 602 through the groove 6021. The upper fixing ring 601 and the lower fixing ring 602 are both set as two concentric rings with different diameters, which facilitates the replacement of the insulation cotton 7 after the fixing component 6 is removed.

[0039] When using this invention:

[0040] First, based on the specific usage, set an appropriate number of docking wells 101, then set a vertical well 1, and connect the docking wells 101 to the vertical well 1 through the horizontal well 102;

[0041] Then, the first insulation cylinder 2 is fitted onto the outer wall of the vertical well 1. The first insulation cylinder 2 is rotated clockwise using external equipment. The drill teeth 401 at the lower end of the drill bit 4 create a cutting effect on the ground. As the drill bit 4 rotates clockwise, it gradually penetrates deeper into the ground. Simultaneously, the soil formed by the drill teeth 401 is discharged upwards through the chip removal strip 402. When the upper end of the first insulation cylinder 2 is flush with the ground, a second insulation cylinder 3 is installed on top of the first insulation cylinder 2. The second insulation cylinder 3 is secured to the first insulation cylinder 1 by a clip 301. In the first snap-fit ​​groove 201 at the upper end of the heat-insulating cylinder 2, the fixing components 6 inside the first heat-insulating cylinder 2 and the second heat-insulating cylinder 3 are snapped together by the snap-fit ​​buckle 6011 to form a fixed connection. Then, the second heat-insulating cylinder 3 is rotated clockwise to make it continue to go deeper into the ground. When the height of the second heat-insulating cylinder 3 is not enough, another second heat-insulating cylinder 3 can be added to the upper end of the second heat-insulating cylinder 3 until the specified height is reached.

[0042] Next, a heat pump is connected to the upper end of vertical well 1, which is connected to a water pump. The water pump is connected to docking well 101 to form a closed loop. When the water pump is started, the medium inside vertical well 1, docking well 101, and horizontal well 102 flows. The medium located at the lower end of docking well 101 and in horizontal well 102 exchanges heat with the geothermal reservoir, causing the medium to heat up. By cooperating with multiple docking wells 101 and horizontal well 102, the area between the medium and the geothermal reservoir is increased, improving the heat exchange efficiency between the medium and the geothermal reservoir. The heated medium flows out through vertical well 1 and enters the heat pump for heat exchange. The heat is used for heating or other purposes. The cold medium re-enters docking well 101 through the water pump and flows into the lower end of docking well 101 and horizontal well 102 to exchange heat with the geothermal reservoir, forming a cycle.

[0043] Finally, when the hot medium in the vertical well 1 rises near the ground, the cold ground temperature causes the medium temperature to drop, resulting in heat loss. By installing the first insulation cylinder 2 and the second insulation cylinder 3 near the ground end of the vertical well 1, heat loss can be reduced. At the same time, the insulation height of this insulation component can be adjusted according to seasonal temperature changes. When the outside temperature is low, the second insulation cylinder 3 can be turned clockwise to allow the drill bit 4 to drive the first insulation cylinder 2 and the second insulation cylinder 3 to continue to go deeper underground. A new second insulation cylinder 3 can be added to the top of the second insulation cylinder 3. When the outside temperature is high, the second insulation cylinder 3 can be turned counterclockwise to allow the drill bit 4 to drive the first insulation cylinder 2 and the second insulation cylinder 3 to move upwards. The second insulation cylinder 3 can then be removed. This allows the insulation height of the vertical well 1 to be adjusted. When replacing the insulation cotton 7, simply slide the fixing component 6 out of the inside of the first insulation cylinder 2 and the second insulation cylinder 3 to replace and maintain the insulation cotton 7.

[0044] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A U-shaped multi-well docking enhanced heat exchange structure, characterized in that: It includes a vertical well (1), a first insulation cylinder (2) and a second insulation cylinder (3). The upper end of the first insulation cylinder (2) is snapped and fixed to the second insulation cylinder (3). The first insulation cylinder (2) and the second insulation cylinder (3) are sleeved on the vertical well (1). A drill bit (4) is fixed at the lower end of the first insulation cylinder (2). Multiple docking wells (101) are provided around the vertical well (1). The lower end of each docking well (101) is connected to a horizontal well (102). Each docking well (101) is connected to the vertical well (1) through the horizontal well (102). The first insulation cylinder (2) has an inner cylinder (5) coaxial with it. A fixing component (6) is slidably connected to the inner wall of the first insulation cylinder (2). Insulation cotton (7) is provided between the first insulation cylinder (2) and the inner cylinder (5) and fixed to the fixing component (6). The fixing component (6) includes an upper fixing ring (601) and a lower fixing ring (602) distributed vertically. A slidable connection is provided between the upper fixing ring (601) and the lower fixing ring (602). Multiple connecting rods (603) are provided, with baffles (604) fixed on the left and right sides of each connecting rod (603). One end of a spring (605) is fixed to the center of the side of each connecting rod (603) opposite to the inner cylinder (5). The other end of each spring (605) is fixedly connected to the outer wall of the inner cylinder (5). The insulation cotton (7) is located between the baffles (604) and the inner cylinder (5). Multiple snap fasteners (6011) are fixed to the upper end of the upper fixing ring (601). The internal structure of the second insulation cylinder (3) is the same as that of the first insulation cylinder (2). The upper end of the first insulation cylinder (2) is provided with multiple first snap-fit ​​grooves (201), the upper end of the second insulation cylinder (3) is provided with multiple second snap-fit ​​grooves (302), and the lower end of the second insulation cylinder (3) is fixed with multiple buckles (301). The second insulation cylinder (3) is snapped and fixed to the first snap-fit ​​grooves (201) of the first insulation cylinder (2) by the buckles (301).

2. The U-shaped multi-well docking enhanced heat exchange structure according to claim 1, characterized in that: The upper fixing ring (601) and the lower fixing ring (602) are two concentric rings with different diameters. A fixing rod is provided between the two concentric rings with different diameters. The lower end of the fixing rod of the upper fixing ring (601) is provided with a groove, and the upper end of the fixing rod of the lower fixing ring (602) is provided with a sliding groove (6021). The connecting rod (603) is slidably connected to the upper fixing ring (601) and the lower fixing ring (602) through the groove of the upper fixing ring (601) and the sliding groove (6021) of the lower fixing ring (602).

3. The U-shaped multi-well docking enhanced heat exchange structure according to claim 1, characterized in that: The outer wall of the upper fixing ring (601) is symmetrically fixed with a first guide block (6012), and the outer wall of the lower fixing ring (602) is symmetrically fixed with a second guide block (6022). The first guide block (6012) and the second guide block (6022) are located on the same vertical line. The inner wall of the first heat insulation cylinder (2) is symmetrically provided with guide grooves (202). The upper fixing ring (601) and the lower fixing ring (602) are slidably connected to the guide grooves (202) of the first heat insulation cylinder (2) through the first guide block (6012) and the second guide block (6022).

4. The U-shaped multi-well docking enhanced heat exchange structure according to claim 1, characterized in that: The number of the snap-fit ​​(6011), slide (6021), connecting rod (603) and spring (605) is the same.

5. The U-shaped multi-well docking enhanced heat exchange structure according to claim 1, characterized in that: The upper end of the inner cylinder (5) is fixedly connected to the upper fixing ring (601), and the lower end of the inner cylinder (5) is fixedly connected to the lower fixing ring (602). The inner cylinder (5) is sleeved on the outer wall of the vertical well (1) and is slidably connected.

6. The U-shaped multi-well docking enhanced heat exchange structure according to claim 1, characterized in that: The first insulation cylinder (2) and the second insulation cylinder (3) both have a vacuum chamber (203) inside.

7. The U-shaped multi-well docking enhanced heat exchange structure according to claim 1, characterized in that: The drill bit (4) is a frustum-shaped opening at the top and bottom, and the size of the opening is the same as the diameter of the vertical well (1). Multiple drill teeth (401) are fixed at the lower end of the drill bit (4), and multiple chip removal strips (402) are fixed on the inclined surface of the drill bit (4). The lower end of the chip removal strips (402) corresponds to the drill teeth (401), and the upper end of the chip removal strips (402) extends to the outer wall of the first insulation cylinder (2).

8. The U-shaped multi-well docking enhanced heat exchange structure according to claim 1, characterized in that: The snap fastener (6011) is two mirror-image 7-shaped fasteners. The distance between the upper ends of the snap fasteners (6011) is less than the distance from the slide groove (6021) to the edge of its fixing rod. The upper end of the snap fastener (6011) is chamfered.

9. The U-shaped multi-well docking enhanced heat exchange structure according to claim 1, characterized in that: The diameter of the vertical well (1) is larger than the diameter of the docking well (101).

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