Device for extracting and utilizing geothermal energy

Abstract

The invention relates to the technical field of geothermal energy extraction, and discloses a geothermal energy extraction and utilization device which is characterized in that a water outlet is formed in the top end of a sleeve, and a rotary drill bit is arranged at the bottom end; the water inlet pipe is arranged in the sleeve, and a plurality of first partition plates are arranged between the water inlet pipe and the inner wall of the sleeve; the annular pipes are arranged on the sleeve in a sleeving mode, first through holes connected with the annular pipes are formed in the positions, above and below the first partition plates, of the sleeve, a second partition plate is arranged between every two first through holes in the annular pipes, and second through holes are formed in the positions, above and below the second partition plates, of the outer side walls of the annular pipes; each group of heat removal pipes is hinged to the annular pipe, a second partition plate is arranged in each heat removal pipe in the length direction of the corresponding heat removal pipe, and a third through hole is formed in the position, away from the annular pipe, of each second partition plate; according to the device for extracting and utilizing the geothermal energy, on the basis that it is guaranteed that more heat is carried by cold water in unit time, arrangement can be rapidly completed in heat extraction wells of different sizes, the overall adaptability of the device is high, the arrangement difficulty is low, and the heat extraction efficiency is high.

Description

Technical Field

[0001] The present invention relates to the technical field of geothermal energy extraction, and particularly relates to a device and method for extracting and utilizing geothermal energy. Background Art

[0002] Geothermal energy, as a renewable energy source, has good economic and social benefits. Currently, the direct development and utilization of geothermal fluid through artificial drilling is the main body of current geothermal exploration and development.

[0003] In the prior art, most of the devices for extracting and utilizing geothermal energy are straight-tube types. When extracting geothermal energy, cold water is pumped into the device from the outside. During the flowing process, the cold water exchanges heat with the external geothermal energy through the pipe wall, thereby heating the cold water into hot water, and then discharging the hot water out of the device for storage or utilization. However, during the heat extraction process of this kind of device, since the water inside is continuously flowing, the heating time of the cold water in the device is short, and the heat carried after heat exchange is relatively small, so the heat extraction efficiency of a single device is low.

[0004] In view of the above problems, there have also appeared some geothermal energy extraction devices with heat conducting members outside the pipe wall in the prior art. When this kind of geothermal energy extraction device extracts heat, more heat in the geothermal well can be conducted to the pipe wall through the heat conducting members perpendicular to the pipe wall for heat exchange with cold water. Compared with the straight-tube type heat extraction device, this kind of geothermal energy extraction device with heat conducting members outside the pipe wall can make the cold water in the device carry more heat per unit time to improve the heat extraction efficiency of a single heat exchange well. However, due to the heat conducting members, the overall volume of this kind of geothermal energy extraction device with heat conducting members outside the pipe wall is large, and the heat conducting members will frequently interfere with the well wall during the process of lowering the device into the well, and it can only be quickly installed in vertical wells with a larger diameter, which leads to poor adaptability and great installation difficulty of this kind of heat extraction device. Summary of the Invention

[0005] The present invention provides a device for extracting and utilizing geothermal energy to solve the above deficiencies in the prior art. The device for extracting and utilizing geothermal energy can ensure that cold water carries more heat per unit time, can be installed in heat extraction wells of different sizes, has strong overall adaptability, low installation difficulty, and high heat extraction efficiency.

[0006] The technical solution of the present invention is: A device for extracting and utilizing geothermal energy, comprising:

[0007] A casing, with a water outlet at the top end and a rotary drill bit at the bottom end of the casing;

[0008] An inlet pipe, arranged inside the casing, and a plurality of horizontal first partitions are provided between the inlet pipe and the inner wall of the casing, and the plurality of first partitions are longitudinally distributed;

[0009] Multiple annular tubes are all sleeved on the sleeve. The annular tubes are rotatably connected to the sleeve. The multiple annular tubes correspond to the multiple first partitions one by one. Above and below each of the first partitions on the sleeve, there are first through holes connected to the annular tubes. Between the two first through holes in the annular tube, there is a second partition. On the outer side wall of the annular tube, there are two second through holes, and the two second through holes are respectively located above and below the second partition.

[0010] Multiple groups of heat extraction tubes correspond to the multiple annular tubes one by one. Each group of heat extraction tubes is hinged on the annular tube. Along the length direction of the heat extraction tube, there is a third partition inside the heat extraction tube. At a position on the third partition far from the annular tube, there is a third through hole; when the heat extraction tube is perpendicular to the sleeve, the second through hole is communicated with the heat extraction tube.

[0011] In at least one embodiment of the present invention, an outlet pipe is sleeved outside the water inlet pipe at the top end of the sleeve. The water outlet is located inside the outlet pipe. The top end of the outlet pipe is connected with an end cover. The water inlet pipe penetrates through the end cover, and a connecting pipe is communicated with the side of the end cover.

[0012] In at least one embodiment of the present invention, a first heat insulation layer is provided on the water inlet pipe inside the outlet pipe, and a second heat insulation layer is provided on the water inlet pipe inside the sleeve.

[0013] In at least one embodiment of the present invention, the number of each group of heat extraction tubes is four. The four heat extraction tubes are evenly distributed on the annular tube. At the contact end of each heat extraction tube and the annular tube, there is a sealing gasket.

[0014] In at least one embodiment of the present invention, the outer side wall of the annular tube is arc-shaped. At the contact end of the heat extraction tube and the annular tube, there is an arc-shaped cover. The inner wall of the arc-shaped cover is provided with a sealing layer, and the sealing layer is attached to the annular tube; when the heat extraction tube is in a contracted state downward, the sealing layer is attached to the second through hole.

[0015] In at least one embodiment of the present invention, the multiple heat extraction tubes are all annular tubes. On each heat extraction tube, there are multiple connecting rings evenly arranged, and on each connecting ring, there are multiple heat conduction fins evenly distributed.

[0016] In at least one embodiment of the present invention, the rotary drill bit is provided with spiral blades, and one end of the multiple heat extraction tubes far from the annular tube is sharp.

[0017] In at least one embodiment of the present invention, a circulation tank is provided on the top of the end cover. The water inlet pipe penetrates into the circulation tank. The connecting pipe is connected with a heat exchanger, and the connecting pipe passes through the heat exchanger and is communicated with the circulation tank. At the bottom end of the water inlet pipe inside the sleeve, there is a one-way valve, and the one-way valve is used to limit the water in the sleeve from flowing back into the water inlet pipe.

[0018] The present invention also discloses a method for extracting and utilizing geothermal energy, comprising the following steps:

[0019] S1: Connect corresponding heat exchange pipes to the water outlet and the water inlet pipe, and adjust multiple heat extraction pipes on the casing to a downwardly contracting state, and gradually lower the device into the heat extraction well in this state;

[0020] S2: Rotate the device forward and backward multiple times so that the multiple heat extraction pipes are opened by centrifugal force and abut against the inner wall of the heat extraction well. Subsequently, continuously rotate the device forward so that the rotary drill bit on the casing gradually screws into the bottom of the heat extraction well, thereby enabling the multiple heat extraction pipes to be grouted and inserted into the well wall of the heat extraction well, and making the heat extraction pipes perpendicular to the casing;

[0021] S3: Pass cold water into the water inlet pipe. The cold water flows into the casing, passes through the first through-hole and the second through-hole and flows into the heat extraction pipes, and finally flows back into the casing through the third through-hole, the second through-hole and the first through-hole in the heat extraction pipes. The cold water is gradually heated after passing through the multiple heat extraction pipes and finally discharged from the water outlet.

[0022] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0023] 1. The present invention is provided with a rotary drill bit at the bottom of the casing and a ring pipe with multiple heat extraction pipes hinged thereon. During the layout process of the device, multiple heat extraction pipes can be folded on the side wall of the casing, enabling the device to be smoothly lowered into heat extraction wells of various sizes, and at the same time avoiding interference between the heat extraction pipes and the side wall of the heat extraction well during the process of lowering into the well. When the device reaches the bottom of the heat extraction well, the centrifugal force generated by rotating the device makes the multiple heat extraction pipes abut against the well wall of the heat extraction well. Subsequently, continuously rotate the casing so that the rotary drill bit gradually penetrates into the bottom of the heat extraction well and is fixed. During the process of the casing descending along with the rotary drill bit, the multiple heat extraction pipes gradually extend into the well wall and are perpendicular to the casing, thereby completing the layout of the heat extraction device; and the present invention is provided with a water inlet pipe in the casing to connect the heat extraction pipes through the ring pipe. During the heat extraction process, cold water is passed into the water inlet pipe. The cold water flows into the casing, passes through the first through-hole and the second through-hole and flows into the heat extraction pipes, and finally flows back into the casing through the third through-hole, the second through-hole and the first through-hole in the heat extraction pipes. The cold water is gradually heated after passing through the multiple heat extraction pipes and finally discharged from the water outlet. In summary, compared with the prior art, the device for extracting and utilizing geothermal energy can be smoothly laid out in heat extraction wells of different sizes on the basis of ensuring that cold water carries more heat per unit time. The device has strong adaptability, low layout difficulty and high heat extraction efficiency.

[0024] 2. The present invention is provided with multiple connecting rings with heat conducting fins on each heat extraction pipe. During the heat extraction process of the device, the heat conducting fins further increase the heat exchange area of the device and improve the geothermal energy extraction efficiency.

[0025] 3. By providing a first heat insulation layer and a second heat insulation layer on the outer wall of the water inlet pipe, the present invention can prevent heat loss of hot water during the flow through the water outlet pipe during the heat extraction process, thereby improving the utilization rate of geothermal energy. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a front view structural schematic diagram of the present invention;

[0027] Figure 2 is a front view sectional structural schematic diagram of the present invention;

[0028] Figure 3 is a partial front view sectional structural schematic of the present invention Figure 1 ;

[0029] Figure 4 is a partial front view sectional structural schematic of the present invention Figure 2 ;

[0030] Figure 5 is of the present invention Figure 4 A detailed structural schematic diagram;

[0031] Figure 6 is a structural schematic diagram of the present invention in the working state.

[0032] Description of the reference numerals:

[0033] 1. Casing; 11. Water outlet; 12. Rotary drill bit; 13. First through hole; 2. Water inlet pipe; 21. First partition; 22. First heat insulation layer; 23. Second heat insulation layer; 24. Check valve; 3. Annular pipe; 31. Second partition; 32. Second through hole; 4. Heat extraction pipe; 41. Third partition; 411. Third through hole; 42. Sealing gasket; 43. Arc-shaped cover; 5. Water outlet pipe; 51. End cover; 52. Connecting pipe; 6. Circulation tank; 7. Heat exchanger. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0034] The drawings in the present invention are not strictly drawn according to the actual ratio, and the specific dimensions and quantities of each structure can be determined according to actual needs. The drawings described in the present invention are only structural schematic diagrams.

[0035] To make the objectives, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings of the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the described embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0036] Unless otherwise defined, the technical terms or scientific terms used herein shall have the ordinary meanings as understood by those of ordinary skill in the art to which this invention pertains. The terms "first", "second" and similar terms used in this invention do not denote any order, quantity or importance, but are only used to distinguish different components. Words such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Terms such as "inside", "outside", "above", "below", "far", "near", "front", "rear", etc. are only used to indicate relative positional relationships. When the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0037] In the prior art, there is a geothermal extraction device with heat-conducting elements outside the pipe wall. When this geothermal extraction device extracts heat, more heat in the geothermal well can be conducted to the pipe wall through the heat-conducting elements perpendicular to the pipe wall for heat exchange with cold water. Compared with a straight-pipe type heat extraction device, this geothermal extraction device with heat-conducting elements outside the pipe wall can make the cold water in the device carry more heat per unit time to improve the heat extraction efficiency of a single heat exchange well. However, due to the heat-conducting elements, the overall volume of this geothermal extraction device is relatively large. During the process of lowering the device into the well, the heat-conducting elements will frequently interfere with the well wall, and it can only be quickly installed in a vertical well with a relatively large diameter, resulting in poor adaptability and great installation difficulty of this heat extraction device.

[0038] In view of this, the present invention provides a device for extracting and utilizing geothermal energy. This device for extracting and utilizing geothermal energy can ensure that cold water carries more heat per unit time, can be installed in heat extraction wells of different sizes, has strong overall adaptability, low installation difficulty, and high heat extraction efficiency.

[0039] Combined with Figures 1 to 6 As shown, a device for extracting and utilizing geothermal energy includes:

[0040] The top end of the casing 1 is provided with a water outlet 11, and the bottom end of the casing 1 is provided with a rotary drill bit 12; a spiral blade is arranged outside the rotary drill bit 12;

[0041] The water inlet pipe 2 is arranged inside the casing 1. A plurality of horizontal first partitions 21 are arranged between the water inlet pipe 2 and the inner wall of the casing 1, and the plurality of first partitions 21 are longitudinally distributed; the plurality of first partitions 21 are used to divide the annular space between the water inlet pipe 2 and the casing 1 into a plurality of chambers;

[0042] A plurality of annular tubes 3 are all sleeved on the sleeve 1. The annular tubes 3 are rotatably connected to the sleeve 1. The plurality of annular tubes 3 correspond one by one to the plurality of first partition plates 21. Above and below each first partition plate 21 on the sleeve 1, there are first through holes 13 connected to the annular tubes 3. Between the two first through holes 13 in the annular tube 3, there is a second partition plate 31. On the outer side wall of the annular tube 3, there are two second through holes 32, and the two second through holes 32 are respectively located above and below the second partition plate 31;

[0043] Multiple groups of heat extraction tubes 4 correspond one by one to the plurality of annular tubes 3. Each group of heat extraction tubes 4 is hinged on the annular tube 3. Inside the heat extraction tube 4, along the length direction of the heat extraction tube 4, there is a third partition plate 41. At a position on the third partition plate 41 far from the annular tube 3, there is a third through hole 411; when the heat extraction tube 4 is perpendicular to the sleeve 1, the second through hole 32 is communicated with the heat extraction tube 4.

[0044] As an alternative embodiment, an outlet pipe 5 is sleeved outside the inlet pipe 2 at the top end of the sleeve 1. The water outlet 11 is located inside the outlet pipe 5. The top end of the outlet pipe 5 is connected with an end cap 51. The inlet pipe 2 passes through the end cap 51, and a connecting pipe 52 is communicated with the side of the end cap 51; the connecting pipe 52 is used to be connected with a heat exchange device for the utilization of hot water.

[0045] As an alternative embodiment, a first heat insulation layer 22 is provided on the inlet pipe 2 inside the outlet pipe 5, and a second heat insulation layer 23 is provided on the inlet pipe 2 inside the sleeve 1; the settings of the first heat insulation layer 22 and the second heat insulation layer 23 prevent heat loss during the flow of hot water in the outlet pipe 5 and improve the utilization rate of geothermal energy.

[0046] As an alternative embodiment, the number of each group of heat extraction tubes 4 is four. The four heat extraction tubes 4 are evenly distributed on the annular tube 3. At the contact end of each heat extraction tube 4 and the annular tube 3, there is a sealing gasket 42; the setting of the sealing gasket 42 avoids the leakage of the extracted hot water at this place.

[0047] As an alternative embodiment, the outer side wall of the annular tube 3 is arc-shaped. At the contact end of the heat extraction tube 4 and the annular tube 3, there is an arc-shaped cover 43. The inner wall of the arc-shaped cover 43 is provided with a sealing layer, and the sealing layer is attached to the annular tube 3; when the heat extraction tube 4 is in a downward and contracted state, the sealing layer is attached to the second through hole 33 to avoid the leakage of the second through hole 33 when the heat extraction tube 4 is in a folded state and impurities enter the annular tube 3 during the layout process of the device, thereby causing blockage of the water flow channel.

[0048] As an alternative embodiment, the multiple heat extraction tubes 4 are all annular tubes. On each heat extraction tube 4, a plurality of connecting rings are evenly provided, and a plurality of heat conduction fins are evenly distributed on each connecting ring; the heat conduction fins further increase the heat exchange area of the device and improve the geothermal energy extraction efficiency.

[0049] As an alternative embodiment, the rotary drill bit 12 is provided with spiral blades, and the ends of the plurality of heat extraction pipes 4 away from the annular pipe 3 are sharp, and the sharp ends of the heat extraction pipes 4 are designed to be better fixed on the inner wall of the heat extraction well.

[0050] As an alternative embodiment, a circulation tank 6 is provided on the top of the end cover 51, the water inlet pipe 2 penetrates into the circulation tank 6, the connecting pipe 52 is connected to the heat exchanger 7, the connecting pipe 52 passes through the heat exchanger 7 and is communicated with the circulation tank 6, and a check valve 24 is provided at the bottom end of the water inlet pipe 2 in the sleeve 1, and the check valve 24 is used to limit the water in the sleeve 1 from flowing back into the water inlet pipe 2.

[0051] The present invention also discloses a method for extracting and utilizing geothermal energy, including the following steps:

[0052] S1: Connect the corresponding heat exchange pipelines to the water outlet 11 and the water inlet pipe 2, and adjust the plurality of heat extraction pipes 4 on the sleeve 1 to a downwardly contracted state, and gradually lower the device into the heat extraction well in this state;

[0053] S2: Rotate the device forward and backward multiple times so that the plurality of heat extraction pipes 4 are opened by centrifugal force and abut against the inner wall of the heat extraction well, and then continuously rotate the device forward so that the rotary drill bit 12 on the sleeve 1 gradually screws into the bottom of the heat extraction well, so that the plurality of heat extraction pipes 4 are grouted and inserted into the heat extraction well wall, and the heat extraction pipes 4 are perpendicular to the sleeve 1;

[0054] S3: Pass cold water into the water inlet pipe 2, the cold water flows into the sleeve 1, flows into the heat extraction pipes 4 through the first through hole 13 and the second through hole 31, and finally flows back into the sleeve 1 through the third through hole 411, the second through hole 31 and the first through hole 13 in the heat extraction pipes 4. The cold water is gradually heated after passing through the plurality of heat extraction pipes 4 and finally discharged from the water outlet 11 into the water outlet pipe 5;

[0055] S3: The water in the water outlet pipe 5 flows into the heat exchanger 7 through the connecting pipe 52 provided on the end cover 51 for heat utilization, and the water whose heat has been utilized flows back into the circulation tank 6 through the connecting pipe 52 and re-enters the water inlet pipe 2 through the circulation phase 6 for heat extraction.

[0056] The above embodiments are only specific implementation manners of the present invention patent, which are used to illustrate the technical solutions of the present invention patent, rather than limiting it. The protection scope of the present invention patent is not limited thereto. Although the present invention patent has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: any person skilled in the art within the technical scope disclosed by the present invention can still modify the technical solutions recorded in the foregoing embodiments, or can easily think of changes, or perform equivalent replacements on some of the technical features; and these modifications, changes or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions implemented by the present invention patent, and should all be covered within the protection scope of the present invention.

Claims

1. A device for extracting and utilizing geothermal energy, characterized in that: include: A casing (1) having a water outlet (11) at the top and a rotary drill bit (12) at the bottom; A water inlet pipe (2) is arranged in the casing (1), and a plurality of horizontal first baffles (21) are arranged between the water inlet pipe (2) and the inner wall of the casing (1), and the plurality of first baffles (21) are distributed longitudinally; A plurality of annular tubes (3) are sleeved on the sleeve (1), the annular tubes (3) are rotatably connected to the sleeve (1), the plurality of annular tubes (3) correspond to the plurality of first baffles (21) one by one, a first through hole (13) connected to the annular tube (3) is provided above and below each of the first baffles (21) on the sleeve (1), a second baffle (31) is provided between two of the first through holes (13) in the annular tube (3), two second through holes (32) are provided on the outer wall of the annular tube (3), and the two second through holes (32) are respectively located above and below the second baffle (31); A plurality of groups of heat extraction tubes (4) correspond one to one with the plurality of annular tubes (3); each group of the heat extraction tubes (4) is hinged on the annular tube (3); a third partition (41) is provided inside the heat extraction tube (4) along the length direction of the heat extraction tube (4); a third through hole (411) is provided on the third partition (41) at a position away from the annular tube (3); when the heat extraction tube (4) is perpendicular to the sleeve (1), the second through hole (32) is connected to the heat extraction tube (4).

2. The device for extracting and utilizing geothermal energy according to claim 1, characterized in that: A water outlet pipe (5) is mounted on the water inlet pipe (2) at the top end of the sleeve (1); the water outlet (11) is located inside the water outlet pipe (5); the top end of the water outlet pipe (5) is connected to an end cover (51); the water inlet pipe (2) passes through the end cover (51); and the side of the end cover (51) is connected to a connecting pipe (52).

3. The device for extracting and utilizing geothermal energy according to claim 2, characterized in that: A first heat insulation layer (22) is provided on the water inlet pipe (2) inside the water outlet pipe (5), and a second heat insulation layer (23) is provided on the water inlet pipe (2) inside the casing (1).

4. The device for extracting and utilizing geothermal energy according to claim 1, characterized in that: The number of the heat extraction tubes (4) in each group is four, and the four heat extraction tubes (4) are evenly distributed on the annular tube (3). A sealing gasket (42) is provided at the contact end between each heat extraction tube (4) and the annular tube (3).

5. The device for extracting and utilizing geothermal energy according to claim 1, characterized in that: The outer side wall of the annular tube (3) is arc-shaped, the contact end of the heat extraction tube (4) and the annular tube (3) is provided with an arc-shaped cover (43), the inner wall of the arc-shaped cover (43) is provided with a sealing layer, and the sealing layer is in contact with the annular tube (3); when the heat extraction tube (4) is in a contracted state facing downward, the sealing layer is in contact with the second through hole (32).

6. The device for extracting and utilizing geothermal energy according to claim 1, characterized in that: The plurality of heat extraction pipes (4) are all annular pipes, and each of the heat extraction pipes (4) is evenly provided with a plurality of connecting rings, and each of the connecting rings is evenly distributed with a plurality of heat conducting sheets.

7. The device for extracting and utilizing geothermal energy according to claim 1, characterized in that: The rotary drill bit (12) is provided with spiral blades, and the ends of the plurality of heat extraction pipes (4) away from the annular pipe (3) are sharp.

8. The device for extracting and utilizing geothermal energy according to claim 2, characterized in that: A circulation box (6) is provided on the top of the end cover (51), the water inlet pipe (2) penetrates into the circulation box (6), the connecting pipe (52) is connected to the heat exchanger (7), the connecting pipe (52) passes through the heat exchanger (7) and is connected to the circulation box (6), and a one-way valve (24) is provided at the bottom end of the water inlet pipe (2) in the casing (1), and the one-way valve (24) is used to limit the water in the casing (1) from flowing back into the water inlet pipe (2).

9. A method for extracting and utilizing geothermal energy, based on the device for extracting and utilizing geothermal energy as claimed in claim 1, characterized in that: The steps include: S1: Connecting corresponding heat exchange pipes to the water outlet (11) and the water inlet pipe (2), adjusting the multiple heat extraction pipes (4) on the casing (1) to a downwardly contracted state, and gradually lowering the device into the heat extraction well in this state; S2: rotating the device forward and reverse several times so that the plurality of heat extraction pipes (4) are opened by centrifugal force and abut against the inner wall of the heat extraction well, and then continuously rotating the device forward so that the rotary drill bit (12) on the casing (1) is gradually screwed into the bottom of the heat extraction well, thereby grouting the plurality of heat extraction pipes (4) into the wall of the heat extraction well, and making the heat extraction pipes (4) and the casing (1) in a vertical state; S3: cold water is introduced into the water inlet pipe (2), the cold water flows into the sleeve (1), passes through the first through hole (13) and the second through hole (31), flows into the heat extraction pipe (4), and finally passes through the third through hole (411), the second through hole (31) and the first through hole (13) in the heat extraction pipe (4), and flows back into the sleeve (1). After passing through a plurality of heat extraction pipes (4), the cold water is gradually heated and finally discharged from the water outlet (11).

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