Single well heat exchange system and control method

Abstract

The invention relates to a single well heat exchange system and a control method, and belongs to the technical field of geothermal energy development. The single well heat exchange system comprises an inner pipe, an outer pipe and a heat exchanger, the inner pipe is sleeved with the outer pipe, a water inlet channel is formed between the outer wall of the inner pipe and the inner wall of the outer pipe, a water outlet channel is formed in the inner pipe, and the top end of the water outlet channel is connected with one end of the heat exchanger through a pipeline. The top end of the water inlet channel is connected with the other end of the heat exchanger through a pipeline and a circulating pump; water in the water inlet channel enters the inner pipe from the bottom end of the inner pipe; the section of the inner pipe is square, the inner pipe is provided with four side faces, and a control cable through hole is formed in the intersection of the two side faces. The geothermal energy in the middle section of the well is utilized, the utilization rate of the geothermal energy in the middle layer is increased, and geothermal energy storage in the deep layer is increased.

Description

Technical Field

[0001] The present invention belongs to the technical field of geothermal energy development, and in particular relates to a single well heat exchange system and a control method. Background Art

[0002] The large-scale development and utilization of geothermal heating has played an important role in clean winter heating and weather relief in northern regions. The development and utilization of medium and deep geothermal energy mainly uses the exploitation of geothermal water as a traditional heating method. Its utilization direction is geothermal hot springs, mineral water development, hot spring therapy, and the use of heat pump technology for heating. This heating method is currently widely used at home and abroad. Generally, geothermal energy is developed by drilling geothermal wells or re-perforating abandoned oil exploration wells to exploit geothermal water. This heating method is relatively mature. The amount of geothermal resources depends on the deep geothermal field and geological and hydrogeological conditions. It is greatly affected by regional geological conditions and has the significant characteristic of uneven resource distribution. When the well layer is deep, this method has a large demand for pump power and forms a large power consumption. On the other hand, there is a problem of lack of utilization of middle-layer geothermal energy. Summary of the invention

[0003] The purpose of the present invention is to provide a single well heat exchange system and control method, which reduces the delivery power of the circulation pump by adjusting the height difference of the circulating water, saves energy, and rationally utilizes the geothermal energy in the middle section of the well, improves the utilization rate of the middle-layer geothermal energy, and increases the geothermal energy storage in the deep layer.

[0004] A single well heat exchange system comprises an inner tube, an outer tube and a heat exchanger, wherein the outer tube is sleeved outside the inner tube, a water inlet channel is formed between the outer wall of the inner tube and the inner wall of the outer tube, a water outlet channel is formed inside the inner tube, the top of the water outlet channel is connected to one end of the heat exchanger through a pipeline, the top of the water inlet channel is connected to the other end of the heat exchanger through a pipeline and a circulation pump, and water in the water inlet channel enters the inner tube at the bottom end of the inner tube; The cross section of the inner tube is a square, the inner tube has four side surfaces, and control cable holes are arranged at the intersection of two side surfaces.

[0005] Optionally, the direction in which the outer tube extends in the well is the Y direction, and the direction perpendicular to the Y direction is the X direction, where the Y direction is the vertical extension of the outer tube in the well.

[0006] Optionally, a movable plate is provided at the bottom end of the inner tube, and one end of the movable plate is rotatably connected to the inner wall of the inner tube. When the work station is opened, the movable plate is close to the inner wall of the inner tube or parallel to the inner wall of the inner tube. At this time, water can enter the inner tube from the bottom end of the inner tube; when the work station is closed, the movable plate is perpendicular to the inner wall of the inner tube to close the bottom end of the inner tube. At this time, water cannot enter the inner tube from the bottom end of the inner tube; the controller located on the ground controls the opening and closing of the movable plate through the control cable, and the control cable is passed through the control cable through-hole.

[0007] Optionally, a slot is provided on the side wall of the inner tube, and slide rails are provided on both sides of the slot. The slide plate is mounted on the slide rails and covers the slot, and the slide plate can slide along the slide rails. After the slide plate slides a preset distance toward one side of the slide rail, the slot is not covered, and the inner cylinder is connected with the outer cylinder through the slot; when the slide plate cover is arranged on the slot, the slot is covered, and the inner cylinder cannot be connected with the outer cylinder through the slot.

[0008] Optionally, in the Y direction, a plurality of groups of slots are arranged on the inner cylinder.

[0009] Optionally, each group of slots is arranged on one side or multiple side surfaces of the inner cylinder in the X direction.

[0010] Optionally, the bottom end of the inner tube is open and not closed.

[0011] Optionally, at least one group of grid holes and a rotating plate are provided on the side wall of the inner tube, and one end of the rotating plate is rotatably connected to the side wall of the inner tube. When the work station is opened, the rotating plate is close to the inner wall of the inner tube or parallel to the inner wall of the inner tube and closes the grid holes. At this time, water cannot enter the inner tube from the network holes on the side wall of the inner tube; when the work station is closed, the rotating plate is perpendicular to the inner wall of the inner tube to close the inner tube. At this time, water cannot pass through the rotating plate from the bottom end of the inner tube upward, and water in the water inlet channel enters the inner tube from the opened grid holes.

[0012] Optionally, a controller located on the ground controls the opening and closing of the rotating plate via a control cable.

[0013] A control method for a single well heat exchange system comprises the following steps: In the initial state, the controller opens the movable plate and closes the slot, and the water in the water inlet channel enters the inner tube from the bottom end of the inner tube. At this time, the controller records the water temperature at the top outlet of the water outlet channel as the reference water temperature; The movable plate is closed, and the controller opens a group of slots within a preset length interval of the inner tube, and the water in the water inlet channel enters the inner tube from the opened slots. The controller compares the difference percentage between the water temperature at the top outlet of the water outlet channel and the reference water temperature. If the difference percentage is within the preset threshold, the current state is maintained; If the difference percentage exceeds a preset threshold, the controller opens multiple groups of slots within a preset length interval of the inner tube to increase geothermal heat exchange until the difference percentage is within the preset threshold.

[0014] A control method for a single well heat exchange system comprises the following steps: S1. In the initial state, the controller makes the rotating plate in the open position to close the grid holes and the openings, and the water in the water inlet channel enters the inner tube from the bottom end of the inner tube. At this time, the controller records the water temperature at the top outlet of the water outlet channel as the reference water temperature; S2. The controller places the rotating plate in the closing position to open a group of grid holes or openings within a preset length range of the inner tube. The water in the water inlet channel enters the inner tube from the opened grid holes or openings. The controller compares the difference percentage between the water temperature at the top outlet of the water outlet channel and the reference water temperature. If the difference percentage is within the preset threshold, the current state is maintained. At this time, the height difference of the circulating water changes, which can reduce the delivery power of the circulating pump, save energy, and reasonably utilize the geothermal energy in the middle section of the well, thereby improving the utilization rate of the geothermal energy in the middle section.

[0015] The preset length interval may be an interval of 0-500 meters from the bottom end of the inner tube, an interval of 500-1000 meters from the bottom end of the inner tube, or two intervals of 500-1000 meters or 1500-2500 meters from the bottom end of the inner tube, which is not limited in the present invention.

[0016] The preset threshold may be 4%-10%, which is not limited in the present invention.

[0017] S3. If the difference percentage exceeds the preset threshold, the controller converts the rotating plate in step S2 to the open position, and the controller sequentially traverses to make other rotating plates within the preset length interval of the inner tube in the closed position to open the corresponding grid holes or openings, and the water in the water inlet channel enters the inner tube from the opened grid holes or openings. The controller compares the difference percentage between the water temperature at the top outlet of the water outlet channel and the reference water temperature, and stops the traversal steps when the difference percentage is within the preset threshold.

[0018] S4. If the difference percentage still exceeds the preset threshold after the traversal in step S3 is completed, the controller places the rotating plate in the open position to close the grid holes and the openings, and the water in the water inlet channel enters the inner tube from the bottom end of the inner tube to exchange heat from the deep layer of the well.

[0019] Beneficial technical effects: By adjusting the height difference of the circulating water, the delivery power of the circulating pump is reduced, electricity consumption is saved, and the geothermal energy in the middle section of the well is rationally utilized, the utilization rate of the middle-layer geothermal energy is improved, and the deep geothermal energy storage is increased. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present invention. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings: Figure 1 This is a diagram of a single well heat exchange system according to an embodiment of the present invention.

[0021] Figure 2 It is a schematic diagram of the bottom water heat exchange cycle of the invention embodiment.

[0022] Figure 3 It is a schematic diagram of the inner tube cross section of an embodiment of the invention.

[0023] Figure 4 Schematic diagram of the circulating water height difference adjustment process according to an embodiment of the present invention.

[0024] Figure 5 This is a schematic diagram of the circulating water height difference adjustment process according to another embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] It should be noted that, in this article, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprises a ..." does not exclude the existence of other identical elements in the process, method, article or device including the element. Example

[0027] like Figures 1 to 4 As shown, a single well heat exchange system comprises an inner tube 1, an outer tube 2 and a heat exchanger 3. The outer tube 2 is sleeved outside the inner tube 1, a water inlet channel is formed between the outer wall of the inner tube 1 and the inner wall of the outer tube 2, a water outlet channel is formed inside the inner tube 1, the top of the water outlet channel is connected to one end of the heat exchanger 3 through a pipeline, the top of the water inlet channel is connected to the other end of the heat exchanger 3 through a pipeline and a circulation pump, and the water in the water inlet channel enters the inner tube 1 at the bottom end of the inner tube 1 to realize the circulation of water or other media.

[0028] Optionally, the direction in which the outer tube 2 extends in the well is the Y direction, and the direction perpendicular to the Y direction is the X direction; preferably, the Y direction is the vertical extension of the outer tube 2 in the well.

[0029] Optionally, in the X direction, the cross section of the inner tube 1 is a square, that is, the inner tube 1 is a square tube, and the inner tube 1 has four side surfaces, and a control cable through hole is provided at the intersection of two side surfaces.

[0030] A movable plate 11 is provided at the bottom end of the inner tube 1, and one end of the movable plate 11 is rotatably connected to the inner wall of the inner tube 1. When the work station is opened, the movable plate 11 is close to the inner wall of the inner tube 1 or parallel to the inner wall of the inner tube 1, and water can enter the inner tube 1 from the bottom end of the inner tube 1; when the work station is closed, the movable plate 11 is perpendicular to the inner wall of the inner tube 1 to close the bottom end of the inner tube 1, and water cannot enter the inner tube 1 from the bottom end of the inner tube 1; the controller located on the ground controls the opening and closing of the movable plate 11 through the control cable, and it can be understood that the control cable is passed through the control cable through hole; optionally, the controller is located in a control box (not shown) on the ground.

[0031] Preferably, the cross section of the movable plate 11 in the X direction is a square.

[0032] Optionally, in the X direction, the cross-sectional area of ​​the movable plate 11 is smaller than or equal to the cross-sectional area of ​​the inner tube 1 .

[0033] Preferably, a slot 12 is provided on the side wall of the inner tube 1 , and slide rails are provided on both sides of the slot 12 . A slide plate 13 is installed on the slide rails and covers the slot 12 , and the slide plate 13 can slide along the slide rails.

[0034] After the slide plate 13 slides a preset distance toward one side of the slide rail, the slot 12 is not covered, and the inner cylinder 1 is connected to the outer cylinder 2 through the slot 12; when the slide plate 13 is covered on the slot 12, the slot 12 is covered, and the inner cylinder 1 cannot be connected to the outer cylinder 2 through the slot 12. The controller located on the ground controls the opening and closing of the slide plate 13 through the control cable. It can be understood that the control cable is passed through the control cable through hole; optionally, the controller is located in a control box (not shown) on the ground.

[0035] Preferably, in the Y direction, the inner tube 1 is provided with a plurality of groups of slots 12. For example, the inner tube 1 is 3000 meters long. In the interval between 2500 meters and 3000 meters, a group of slots 12 is provided every 100 meters, that is, a group of slots 12 is provided at 2500 meters, 2600 meters, 2700 meters, 2800 meters and 2900 meters respectively; in the interval between 1500 meters and 2500 meters, a group of slots 12 is provided every 200 meters, that is, a group of slots 12 is provided at 1 A group of slots 12 is set at 500 meters, 1700 meters, 1900 meters, 2100 meters and 2300 meters respectively; in the range of 500 meters to 1500 meters, a group of slots 12 is set every 300 meters, that is, a group of slots 12 is set at 500 meters, 800 meters, 1100 meters and 1400 meters respectively, that is, the distances between adjacent slots 12 are equal or unequal, or the distances between adjacent slots 12 are set in arithmetic progression or in equal proportion.

[0036] Preferably, each group of slots 12 is arranged on one or more sides of the inner tube 1 in the X direction, that is, the inner tube 1 has four sides, and at each set length, for example, at 2500 meters, 2600 meters, 2700 meters, 2800 meters and 2900 meters, slots 12 are arranged on one side, two sides, three sides or four sides of the inner tube 1, that is, at the set length, slots 12 are arranged on one or more sides of the inner tube 1.

[0037] Optionally, the bottom end of the outer tube 2 is further provided with a plurality of hydraulically fractured segmented fissures, into which thermally conductive glue can be injected.

[0038] Optionally, a cement protective layer is further provided on the outside of the outer tube 2, and the supporting strength of the segmented fracture layer of the outer tube 2 is improved by the cement protective layer.

[0039] A control method for a single well heat exchange system comprises the following steps: In the initial state, the controller opens the movable plate 11 and closes the slot 12, and the water in the water inlet channel enters the inner tube 1 from the bottom end of the inner tube 1. At this time, the controller records the water temperature at the top outlet of the water outlet channel as the reference water temperature; Close the movable plate 11, and the controller opens a group of slots 12 within a preset length range of the inner tube 1. The water in the water inlet channel enters the inner tube 1 from the opened slots 12. The controller compares the difference percentage between the water temperature at the top outlet of the water outlet channel and the reference water temperature. If the difference percentage is within the preset threshold, the current state is maintained. At this time, the height difference of the circulating water changes, which can reduce the delivery power of the circulating pump, save energy, and rationally utilize the geothermal energy in the middle section of the well, thereby improving the utilization rate of the geothermal energy in the middle section.

[0040] The preset length interval can be an interval of 0-500 meters from the bottom end of the inner tube 1, an interval of 500-1000 meters from the bottom end of the inner tube 1, or two intervals of 500-1000 meters or 1500 meters-2500 meters from the bottom end of the inner tube 1, which is not limited by the present invention; or the preset length interval is located in the middle layer section of the well.

[0041] The preset threshold value may be 2%-8%, which is not limited in the present invention.

[0042] If the difference percentage exceeds a preset threshold, the controller opens multiple groups of slots 12 within a preset length interval of the inner tube 1 to increase geothermal exchange until the difference percentage is within the preset threshold.

[0043] This embodiment adjusts the height difference of the circulating water, reduces the delivery power of the circulating pump, saves energy, and rationally utilizes the geothermal energy in the middle section of the well, improves the utilization rate of the middle-layer geothermal energy, and increases the geothermal energy storage in the deep layer. Example

[0044] This embodiment is an improvement on the first embodiment.

[0045] like Figure 5 As shown, a single-well heat exchange system, the bottom end of the inner tube 1 is open, that is, the bottom end of the inner tube 1 is not provided with a movable plate 11. It can be understood that the bottom end of the inner tube 1 is not closed.

[0046] Optionally, at least one group of grid holes 15 and a rotating plate 14 are provided on the side wall of the inner tube 1, and one end of the rotating plate is rotatably connected to the side wall of the inner tube 1. When the work station is opened, the rotating plate 14 is close to the inner wall of the inner tube 1 or parallel to the inner wall of the inner tube 1 and closes the grid holes 15. At this time, water cannot enter the inner tube 1 from the grid holes 15 on the side wall of the inner tube 1; when the work station is closed, the rotating plate 14 is perpendicular to the inner wall of the inner tube 1 to close the inner tube 1. At this time, water cannot pass through the rotating plate 14 from the bottom end of the inner tube 1 upward, and water in the water inlet channel enters the inner tube 1 from the opened grid holes 15.

[0047] Optionally, at least one group of openings 16 and a rotating plate 14 are provided on the side wall of the inner tube 1, and one end of the rotating plate is rotatably connected to the side wall of the inner tube 1. When the work station is opened, the rotating plate 14 is close to the inner wall of the inner tube 1 or parallel to the inner wall of the inner tube 1 and closes the opening 16. At this time, water cannot enter the inner tube 1 from the opening 16 on the side wall of the inner tube 1; when the work station is closed, the rotating plate 14 is perpendicular to the inner wall of the inner tube 1 to close the inner tube 1. At this time, water cannot pass through the rotating plate 14 from the bottom end of the inner tube 1 upward, and water in the water inlet channel enters the inner tube 1 from the opened opening 16.

[0048] Optionally, multiple groups of grid holes 15 and openings 16 are arranged adjacently or at intervals, and each group of grid holes 15 and openings 16 is provided with a corresponding group of rotating plates 14. The controller located on the ground controls the opening and closing of the rotating plates 14 through a control cable. It can be understood that the control cable is passed through the control cable through hole; optionally, the controller is located in a control box (not shown) on the ground.

[0049] Preferably, the cross section of the rotating plate 14 in the X direction is a square.

[0050] Optionally, in the X direction, the cross-sectional area of ​​the rotating plate 14 is smaller than or equal to the cross-sectional area of ​​the inner tube 1 .

[0051] A control method for a single well heat exchange system comprises the following steps: S1. In the initial state, the controller makes the rotating plate 14 in the open position to close the grid holes 15 and the openings 16, and the water in the water inlet channel enters the inner tube 1 from the bottom end of the inner tube 1. At this time, the controller records the water temperature at the top outlet of the water outlet channel as the reference water temperature; S2. The controller places the rotating plate 14 in the closing position to open a group of grid holes 15 or openings 16 within a preset length interval of the inner tube 1. The water in the water inlet channel enters the inner tube 1 from the opened grid holes 15 or openings 16. The controller compares the difference percentage between the water temperature at the top outlet of the water outlet channel and the reference water temperature. If the difference percentage is within the preset threshold, the current state is maintained. At this time, the height difference of the circulating water changes, which can reduce the delivery power of the circulating pump, save energy, and reasonably utilize the geothermal energy in the middle section of the well, thereby improving the utilization rate of the geothermal energy in the middle section.

[0052] The preset length interval may be an interval of 0-500 meters from the bottom end of the inner tube 1, an interval of 500-1000 meters from the bottom end of the inner tube 1, or two intervals of 500-1000 meters or 1500-2500 meters from the bottom end of the inner tube 1, which is not limited in the present invention.

[0053] The preset threshold may be 4%-10%, which is not limited in the present invention.

[0054] S3. If the difference percentage exceeds the preset threshold, the controller switches the rotating plate 14 in step S2 to the open position, and the controller sequentially traverses to make other rotating plates 14 in the preset length interval of the inner tube 1 in the closed position to open the corresponding grid holes 15 or openings 16, and the water in the water inlet channel enters the inner tube 1 from the opened grid holes 15 or openings 16. The controller compares the difference percentage between the water temperature at the top outlet of the water outlet channel and the reference water temperature, and stops the traversal steps when the difference percentage is within the preset threshold.

[0055] S4. If the difference percentage still exceeds the preset threshold after the traversal in step S3 is completed, the controller places the rotating plate 14 in the open position to close the grid holes 15 and the openings 16, and the water in the water inlet channel enters the inner tube 1 from the bottom end of the inner tube 1 to exchange heat from the deep layer of the well.

[0056] This embodiment adjusts the height difference of the circulating water by only controlling the rotation of one set of rotating plates 14 each time, which not only reduces the operating steps, but also reduces the delivery power of the circulating pump, saves energy, and rationally utilizes the geothermal energy in the middle section of the well, improves the utilization rate of the middle-layer geothermal energy, and increases the geothermal energy storage in the deep layer.

[0057] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in terms of function in the above description. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the present invention.

[0058] It should be noted that the serial numbers of the embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0059] The above are only preferred embodiments of the present invention, and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, and any combination of embodiments or schemes are also included in the patent protection scope of the present invention.

Claims

1. A single well heat exchange system, characterized in that: It includes an inner tube, an outer tube and a heat exchanger, the outer tube is sleeved outside the inner tube, a water inlet channel is formed between the outer wall of the inner tube and the inner wall of the outer tube, a water outlet channel is formed inside the inner tube, the top of the water outlet channel is connected to one end of the heat exchanger through a pipeline, the top of the water inlet channel is connected to the other end of the heat exchanger through a pipeline and a circulation pump, and the water in the water inlet channel enters the inner tube at the bottom end of the inner tube; The cross section of the inner tube is a square, the inner tube has four side surfaces, and control cable holes are arranged at the intersection of two side surfaces.

2. The single well heat exchange system according to claim 1, characterized in that: The direction in which the outer tube extends in the well is the Y direction, and the direction perpendicular to the Y direction is the X direction. The Y direction is the vertical extension of the outer tube in the well.

3. The single well heat exchange system according to claim 2, characterized in that: A movable plate is provided at the bottom end of the inner tube, and one end of the movable plate is rotatably connected to the inner wall of the inner tube. When the work station is opened, the movable plate is close to the inner wall of the inner tube or parallel to the inner wall of the inner tube, and water can enter the inner tube from the bottom end of the inner tube; when the work station is closed, the movable plate is perpendicular to the inner wall of the inner tube to close the bottom end of the inner tube, and water cannot enter the inner tube from the bottom end of the inner tube; a controller located on the ground controls the opening and closing of the movable plate through a control cable, and the control cable is passed through the control cable through-hole.

4. The single well heat exchange system according to claim 3, characterized in that: A slot is provided on the side wall of the inner tube, and slide rails are provided on both sides of the slot. The slide plate is installed on the slide rail and covers the slot, and the slide plate can slide along the slide rail. After the slide plate slides a preset distance toward one side of the slide rail, the slot is not covered, and the inner cylinder is connected with the outer cylinder through the slot; when the slide plate cover is arranged on the slot, the slot is covered, and the inner cylinder cannot be connected with the outer cylinder through the slot.

5. The single well heat exchange system according to claim 4, characterized in that: In the Y direction, a plurality of groups of slots are arranged on the inner cylinder.

6. The single well heat exchange system according to claim 5, characterized in that: Each group of slots is arranged on one side or multiple side surfaces of the inner cylinder in the X direction.

7. The single well heat exchange system according to claim 2, characterized in that: The bottom end of the inner tube is open, and the bottom end of the inner tube is not closed.

8. The single well heat exchange system according to claim 7, characterized in that: At least one group of grid holes and a rotating plate are provided on the side wall of the inner tube, and one end of the rotating plate is rotatably connected to the side wall of the inner tube. When the work station is opened, the rotating plate is close to the inner wall of the inner tube or parallel to the inner wall of the inner tube and closes the grid holes. At this time, water cannot enter the inner tube from the network holes on the side wall of the inner tube; when the work station is closed, the rotating plate is perpendicular to the inner wall of the inner tube to close the inner tube. At this time, water cannot pass through the rotating plate from the bottom end of the inner tube upward, and water in the water inlet channel enters the inner tube from the opened grid holes.

9. The single well heat exchange system according to claim 8, characterized in that: The controller located on the ground controls the opening and closing of the rotating plate through the control cable.

10. A control method for a single well heat exchange system according to any one of claims 1 to 5, comprising the following steps: In the initial state, the controller opens the movable plate and closes the slot, and the water in the water inlet channel enters the inner tube from the bottom end of the inner tube. At this time, the controller records the water temperature at the top outlet of the water outlet channel as the reference water temperature; The movable plate is closed, and the controller opens a group of slots within a preset length interval of the inner tube, and the water in the water inlet channel enters the inner tube from the opened slots. The controller compares the difference percentage between the water temperature at the top outlet of the water outlet channel and the reference water temperature. If the difference percentage is within the preset threshold, the current state is maintained; If the difference percentage exceeds a preset threshold, the controller opens multiple groups of slots within a preset length interval of the inner tube to increase geothermal heat exchange until the difference percentage is within the preset threshold.

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