Large-diameter geothermal well closing valve and large-diameter geothermal well closing depth adjusting method

Abstract

The invention provides a large-diameter geothermal well closing valve and a large-diameter geothermal well closing depth adjusting method. The closing valve comprises a top pressing disc, a middle pressing disc, an elastic sealing ring and a bottom pressing disc. The top pressure disc is a concave elastic metal disc, and a plurality of radial notches are uniformly formed in a disc body of the top pressure disc; the middle pressure plate and the bottom pressure plate are planar metal discs; the elastic sealing ring is a planar high-temperature-resistant rubber sealing ring; the middle positions of the top pressure plate, the middle pressure plate, the elastic sealing ring and the bottom pressure plate are respectively provided with a central hole for the heat-conducting medium pipe to pass through; a plurality of studs are symmetrically and fixedly arranged on a plate body of the bottom pressure plate, and each stud sequentially penetrates through a small hole in the elastic sealing ring, a small hole in the middle pressure plate and a strip-shaped hole in the top pressure plate and then is in threaded connection with a nut; through nut spinning, the top pressure plate is pressed and deformed to clamp the well wall of the geothermal well, and meanwhile, the middle pressure plate and the bottom pressure plate extrude the elastic seal. The closing valve can isolate the low-temperature part in the large-diameter geothermal well, and the influence of the low-temperature part of the geothermal well on heat collection is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of geothermal well heating, and in particular to a large-diameter geothermal well closing valve and a large-diameter geothermal well closing depth adjustment method. Background Art

[0002] As an efficient, environmentally friendly and sustainable way to utilize geothermal energy, geothermal wells have broad application prospects and development potential. The characteristic of geothermal wells is that the temperature inside the well increases with the depth of the well. During the use of geothermal wells, if the lower temperature part of the well is not isolated, the heat exchange medium will lose some heat when passing through the lower temperature part of the well wall, and even cause some substances to precipitate, which will inevitably affect the heat extraction efficiency. For this reason, it is necessary to isolate the lower temperature parts in the geothermal well and adjust them according to the actual changes.

[0003] Installing a shut-off valve at a certain depth in a geothermal well can reduce the impact of low temperature on heat extraction and ensure a more ideal heat extraction temperature. If a fault occurs in the well, the shut-off valve needs to be removed to repair the geothermal well.

[0004] Therefore, we designed a large-diameter geothermal well closing valve with adjustable position and a large-diameter geothermal well closing depth adjustment method. Summary of the invention

[0005] The present invention aims to provide a large-diameter geothermal well closing valve and a method for adjusting the closing depth of a large-diameter geothermal well. The large-diameter geothermal well closing valve is suitable for a fully enclosed U-shaped geothermal well with a diameter of more than 200 mm. The closing valve is installed at a certain depth in a large-diameter geothermal well, which can reduce the impact of the excessively low temperature of the geothermal well on heat extraction, and can adjust its position in the geothermal well according to the temperature changes in the geothermal well.

[0006] In order to achieve the above object, the present invention adopts the following technical solution: The present invention provides a large-caliber geothermal well closing valve, comprising a top pressure plate, a middle pressure plate, an elastic sealing ring, and a bottom pressure plate which are coaxially arranged from top to bottom; The top pressure plate is a concave elastic metal disc, and a plurality of radial notches are evenly arranged on the disc body; The middle pressure plate and the bottom pressure plate are both flat metal discs; The elastic sealing ring is a flat high temperature resistant rubber sealing ring; The middle positions of the top pressure plate, the middle pressure plate, the elastic sealing ring, and the bottom pressure plate are all provided with a central hole for the heat transfer medium pipe to pass through; A plurality of studs are symmetrically fixed on the body of the bottom pressure plate, and each stud is sequentially passed through the small hole on the elastic sealing ring, the small hole on the middle pressure plate, and the strip hole on the top pressure plate to be threadedly connected to a nut; a plurality of studs are symmetrically fixed on the body of the bottom pressure plate, and each stud is sequentially passed through the small hole on the elastic sealing ring, the small hole on the middle pressure plate, and the strip hole on the top pressure plate to be threadedly connected to a nut; through the spinning of the nut, the top pressure plate is compressed and deformed to clamp the wall of the geothermal well, and at the same time, the elastic sealing ring is squeezed and deformed by the middle pressure plate and the bottom pressure plate to seal the wall of the geothermal well and the heat transfer medium pipe.

[0007] Furthermore, the initial diameters of the top pressure plate, the middle pressure plate, the elastic sealing ring, and the bottom pressure plate are all smaller than the diameter of the geothermal well, and the pressure-bearing diameters of the top pressure plate and the elastic sealing ring are all larger than the diameter of the geothermal well.

[0008] Furthermore, an anti-dropping washer is sleeved on the stud, and the anti-dropping washer is located between the nut and the top pressure plate.

[0009] Furthermore, the large-diameter geothermal well closing valve also includes a temperature detection device, which is located above the top pressure plate. The temperature detection device is fixed to the middle pressure plate through a column passing through one of the radial notches.

[0010] Preferably, the temperature detection device includes a shell and a microprocessor, a temperature sensor, a power module, and a communication module arranged in the shell, and the microprocessor is electrically connected to the temperature sensor, the power module, and the communication module respectively.

[0011] Preferably, the microprocessor adopts the STM32 series, the temperature sensor adopts PT100, the communication module adopts a 4G / 5G communication module, and the power module adopts a sealed battery.

[0012] The present invention also provides a method for adjusting the sealing depth of a large-diameter geothermal well, using the above-mentioned large-diameter geothermal well sealing valve, comprising: S1: After the closing valve with the nut loosened is placed in the geothermal well at the initial closing depth, the nut is spun to make the top pressure plate gradually deform under pressure so that its diameter becomes larger and stuck on the well wall of the geothermal well, and the middle pressure plate and the bottom pressure plate squeeze the elastic sealing ring to make it thinner so that its diameter becomes larger and seals the well wall and the heat transfer medium pipe; S2: When the sealing depth needs to be adjusted, the heat transfer medium in the geothermal well is released through the heat transfer medium pipe, the pressure is gradually released, and then the nut is loosened to release the pressure of the top pressure plate on the well wall, and then the sealing valve is moved to the specified position, and the nut is tightened again to complete the sealing depth adjustment.

[0013] Beneficial technical effects of the present invention: The large-diameter geothermal well closing valve of the present invention is suitable for fully enclosed U-shaped geothermal wells with a diameter of more than 200 mm. By installing the closing valve of the present invention in a large-diameter geothermal well, the lower-temperature portion in the well can be isolated, reducing the impact of the excessively low-temperature portion of the geothermal well on heat extraction, and being able to realize timely adjustment of its position in the geothermal well according to the temperature change of the excessively low-temperature portion in the geothermal well. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 A three-dimensional diagram of a large-caliber geothermal well closing valve of the present invention; Figure 2 A top view of a large-caliber geothermal well closing valve of the present invention; Figure 3 It is a front view of a large-diameter geothermal well closing valve of the present invention; Figure 4 for Figure 1 A three-dimensional view of the middle top pressure plate; Figure 5 for Figure 1 Top view of the middle platen; Figure 6 for Figure 1 A top view of the middle elastic sealing ring; Figure 7 for Figure 1 Side view of the midsole pressure plate; Figure 8 for Figure 1 Control principle diagram of the medium temperature detection device; Fig. 9 for Figure 1 Installation diagram of a large-diameter geothermal well shut-off valve; Figure markings: 1-top pressure plate, 2-middle pressure plate, 3-elastic sealing ring, 4-bottom pressure plate, 401-stud, 5-nut, 6-anti-falling gasket, 7-temperature detection device, 701-microprocessor, 702-temperature sensor, 703-power module, 704-communication module. DETAILED DESCRIPTION

[0015] The technical solution of the present invention will be described clearly and completely in conjunction with the embodiments below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0016] like Figure 1-8As shown, the present invention provides a large-caliber geothermal well closing valve, comprising a top pressure plate 1, a middle pressure plate 2, an elastic sealing ring 3, and a bottom pressure plate 4 which are coaxially arranged from top to bottom; the top pressure plate 1 is a concave elastic metal disc, and a plurality of radial notches are evenly arranged on its disc body; the middle pressure plate 2 and the bottom pressure plate 4 are both planar metal discs; the elastic sealing ring 3 is a planar high-temperature resistant rubber sealing ring; a center hole for a heat transfer medium pipe to pass through is arranged in the middle positions of the top pressure plate 1, the middle pressure plate 2, the elastic sealing ring 3, and the bottom pressure plate 4; a plurality of studs 401 are symmetrically fixed on the disc body of the bottom pressure plate 4, and each stud 401 passes through the small hole on the elastic sealing ring 3, the small hole on the middle pressure plate 2, and the strip hole on the top pressure plate 1 in turn, and then is threadedly connected to a nut 5; through the spinning of the nut 5, the top pressure plate 1 is compressed and deformed to clamp the well wall of the geothermal well, and at the same time, the elastic sealing ring 3 is squeezed and deformed by the middle pressure plate 2 and the bottom pressure plate 4 to seal the well wall of the geothermal well and the heat transfer medium pipe.

[0017] Specifically, the initial diameter of the top pressure plate 1 is smaller than the diameter of the geothermal well, and the pressure diameter of the top pressure plate 1 is larger than the diameter of the geothermal well. When the nut 5 is spun, the top pressure plate 1 is deformed by pressure, and the diameter of the top pressure plate 1 becomes larger and stuck on the wall of the geothermal well. The diameters of the middle pressure plate 2, the elastic sealing ring 3, and the bottom pressure plate 4 are all smaller than the diameter of the geothermal well. By spinning the nut 5, the middle pressure plate 2 and the bottom pressure plate 4 squeeze the elastic sealing ring 3 to make it thinner and larger in diameter, ensuring the sealing between the well wall and the heat transfer medium pipe.

[0018] Specifically, the stud 401 is also provided with an anti-dropping washer 6, which is located between the nut 5 and the top pressure plate 1. In this embodiment, the anti-dropping washer 6 can be a washer with a threaded inner hole. After the anti-dropping washer 6 is assembled on the stud 401, the anti-dropping washer 6 will not fall off when the nut 5 is not installed, so that the top pressure plate 1, the middle pressure plate 2, the elastic sealing ring 3, and the bottom pressure plate 4 are connected together to prevent them from falling off during disassembly.

[0019] Specifically, the temperature detection device 7 is located above the top pressure plate 1, and the temperature detection device 7 is fixed to the middle pressure plate 2 through a column passing through one of the radial notches. The temperature detection device 7 includes a shell and a microprocessor 701, a temperature sensor 702, a power module 703, and a communication module 704 arranged in the shell. The microprocessor 701 is electrically connected to the temperature sensor 702, the power module 703, and the communication module 704, respectively.

[0020] In this embodiment, the microprocessor 701 adopts the STM32 series, such as STM32F103, STM32F407; the temperature sensor 702 adopts PT100, the communication module 704 adopts 4G / 5G communication module 704, and the power module 703 adopts a sealed battery. The power module 703 is used for power supply, and the temperature sensor 702 collects the temperature data above the top pressure plate 1 in the geothermal well and uploads it to the microprocessor 701, and then uploads it to the ground control center through the communication module 704.

[0021] The present invention also provides a method for adjusting the sealing depth of a large-diameter geothermal well, using the above-mentioned large-diameter geothermal well sealing valve, comprising: S1: After the closing valve with the nut 5 loosened is placed in the geothermal well at the initial closing depth, the nut 5 is screwed to make the top pressure plate 1 gradually deform under pressure so that its diameter becomes larger and stuck on the well wall of the geothermal well, and the middle pressure plate 2 and the bottom pressure plate 4 squeeze the elastic sealing ring 3 to make it thinner so that its diameter becomes larger and seals the well wall and the heat transfer medium pipe; S2: When the sealing depth needs to be adjusted, the heat transfer medium in the geothermal well is released through the heat transfer medium pipe, the pressure is gradually released, and then the nut 5 is loosened to release the pressure of the top pressure plate 1 on the well wall, and then the sealing valve is moved to the specified position, and the nut 5 is tightened again to complete the sealing depth adjustment.

[0022] Through this method, the position of the closing valve in the well can be adjusted in time to achieve the closing depth adjustment of the geothermal well, so as to achieve the purpose of controlling the temperature in the well and improving the heat extraction efficiency.

[0023] In the traditional ESG geothermal collection system, the closing valve can be installed in the recovery well; in the U-shaped well, it can be installed in the input and output wells respectively, or only in the output well.

[0024] The large-caliber geothermal well closing valve of the present invention is particularly suitable for fully enclosed U-shaped geothermal wells with a diameter of more than 200 mm. The closing valve can be installed as needed, and the number is not limited.

[0025] The closing valve of the present invention can isolate the lower temperature part in the well, reduce the influence of the too low temperature part of the geothermal well on heat extraction, and can realize timely adjustment of its position in the geothermal well according to the temperature change of the too low temperature part in the geothermal well.

[0026] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the technical solution and conceptual invention of the present invention should be included in the protection scope of the present invention.

Claims

1. A large-caliber geothermal well closing valve, characterized in that: It includes a top pressure plate, a middle pressure plate, an elastic sealing ring and a bottom pressure plate which are coaxially arranged from top to bottom; The top pressure plate is a concave elastic metal disc, and a plurality of radial notches are evenly arranged on the disc body; The middle pressure plate and the bottom pressure plate are both flat metal discs; The elastic sealing ring is a flat high temperature resistant rubber sealing ring; The middle positions of the top pressure plate, the middle pressure plate, the elastic sealing ring, and the bottom pressure plate are all provided with a central hole for the heat transfer medium pipe to pass through; A plurality of studs are symmetrically fixed on the plate body of the bottom pressure plate, and each stud passes through the small hole on the elastic sealing ring, the small hole on the middle pressure plate, and the strip hole on the top pressure plate in turn and is threadedly connected to a nut; through the spinning of the nut, the top pressure plate is compressed and deformed to clamp the wall of the geothermal well, and at the same time, the elastic sealing ring is squeezed and deformed by the middle pressure plate and the bottom pressure plate to seal the wall of the geothermal well and the heat transfer medium pipe.

2. A large-caliber geothermal well closing valve according to claim 1, characterized in that: The initial diameters of the top pressure plate, the middle pressure plate, the elastic sealing ring and the bottom pressure plate are all smaller than the diameter of the geothermal well, and the pressure-bearing diameters of the top pressure plate and the elastic sealing ring are all larger than the diameter of the geothermal well.

3. A large-caliber geothermal well closing valve according to claim 1, characterized in that: The stud is also sleeved with an anti-dropping washer, which is located between the nut and the top pressure plate.

4. A large-caliber geothermal well closing valve according to claim 1, characterized in that: The large-diameter geothermal well closing valve also includes a temperature detection device, which is located above the top pressure plate and is fixed to the middle pressure plate via a column passing through one of the radial notches.

5. A large-caliber geothermal well closing valve as claimed in claim 4, characterized in that: The temperature detection device comprises a shell and a microprocessor, a temperature sensor, a power module and a communication module arranged in the shell. The microprocessor is electrically connected to the temperature sensor, the power module and the communication module respectively.

6. A large-caliber geothermal well closing valve as claimed in claim 5, characterized in that: The microprocessor adopts the STM32 series, the temperature sensor adopts PT100, the communication module adopts a 4G / 5G communication module, and the power module adopts a sealed battery.

7. A method for adjusting the sealing depth of a large-diameter geothermal well, using the large-diameter geothermal well sealing valve according to any one of claims 1 to 6, comprising: S1: After the closing valve with the nut loosened is placed in the geothermal well at the initial closing depth, the nut is spun to make the top pressure plate gradually deform under pressure so that its diameter becomes larger and stuck on the well wall of the geothermal well, and the middle pressure plate and the bottom pressure plate squeeze the elastic sealing ring to make it thinner so that its diameter becomes larger and seals the well wall and the heat transfer medium pipe; S2: When the sealing depth needs to be adjusted, the heat transfer medium in the geothermal well is released through the heat transfer medium pipe, the pressure is gradually released, and then the nut is loosened to release the pressure of the top pressure plate on the well wall, and then the sealing valve is moved to the specified position, and the nut is tightened again to complete the sealing depth adjustment.

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