Compressed nitrogen energy storage device for oil field and use method

Abstract

The invention discloses a compressed nitrogen energy storage device for an oil field and a using method, and relates to the technical field of nitrogen energy storage. An energy storage cylinder is welded in the outer cylinder, an isolation cavity is formed between the outer cylinder and the energy storage cylinder, a piston is slidably arranged in the energy storage cylinder, connecting grooves are formed in the upper end and the lower end of the energy storage cylinder, an air inlet pipe is welded to one side of a connecting assembly connected with the top end connecting groove, and a hydraulic pipe is welded to one side of a connecting assembly connected with the bottom end connecting groove. A connecting assembly is embedded in each connecting groove, and an opening and closing mechanism is installed at the top end of each connecting assembly. By installing opening and closing mechanisms at the air inlet end and the hydraulic end and replacing a traditional air bag with a piston, the speed of entering and discharging compressed nitrogen into the energy storage cylinder can be controlled, so that the internal pressure of the energy storage cylinder can be controlled, and when the compressed nitrogen is discharged, the influence of retraction of the air bag on the discharging speed of the compressed nitrogen can be avoided; and the use safety of the compressed nitrogen is improved.

Description

Technical Field

[0001] This invention relates to the field of nitrogen energy storage technology, and more specifically, to a compressed nitrogen energy storage device and its usage method for oil fields. Background Technology

[0002] Currently, conventional membrane nitrogen generation and injection equipment used in oilfields typically employs a screw air compressor to obtain low-pressure air, which is then processed into low-pressure nitrogen gas through an air treatment system and a membrane separation system. This low-pressure nitrogen gas is then compressed and boosted to the required pressure (generally below 35 MPa) by a reciprocating piston booster. However, given the urgent need for high-pressure nitrogen gas (above 50 MPa) in current oilfield operations, particularly in advanced processes such as shale gas development and acid fracturing, traditional membrane nitrogen generation and injection systems are clearly insufficient to meet this technological challenge. Therefore, it is necessary to develop new ultra-high-pressure nitrogen injection equipment to meet the needs of oilfield operations. Furthermore, after nitrogen compression, it is essential to utilize an energy storage device for preservation, allowing for the release of high-pressure nitrogen gas for use when needed.

[0003] Patent application publication number CN106368991A discloses an airbag-type accumulator, including a shell, an inner cavity, an airbag, a buffer frame, a liquid flow control device, a liquid flow circulation device, and a spring assembly. The interior of the shell is an inner cavity, in which an airbag is placed. The airbag is connected to a connecting end via an air inlet pipe. The lower end of the inner cavity is provided with a buffer frame, a liquid flow control device, and a liquid flow circulation device. The buffer frame and the liquid flow circulation device are connected as a whole, and the lower end of the buffer frame and the liquid flow circulation device is vertically provided with a corresponding spring assembly. The bottom end of the shell is connected to the liquid flow pipe via a connecting outer shell. This airbag accumulator modifies the structure of existing airbag accumulators by branching the gas inlet pipe and incorporating a spring assembly in the bottom buffer structure. A liquid flow control device is also included to ensure proper pressure control within the cavity, improving its practicality. However, this accumulator also has significant drawbacks in actual use. While the bottom buffer structure controls the liquid flow, it reduces the internal space and flatness of the casing. This uneven contact during continuous pressurization can easily lead to rupture at the bottom of the airbag. Furthermore, the short lifespan of the airbag results in a relatively short overall lifespan for this accumulator.

[0004] Therefore, there is an urgent need for a compressed nitrogen energy storage device for oil fields that can ensure the stability of the internal pressure of the energy storage device, improve the service life of the energy storage device, and enhance the safety of use. Summary of the Invention

[0005] The purpose of this invention is to provide a compressed nitrogen energy storage device and its usage method for oil fields, which can improve the compressive strength of the energy storage device, thereby increasing the energy storage capacity of compressed nitrogen, improving the impact resistance, reducing the influence of external temperature on the internal pressure of the energy storage device, ensuring the stability of the internal pressure of the energy storage device, and improving the service life and safety of the energy storage device, thereby overcoming the shortcomings of the existing energy storage devices, such as the short service life.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] An oilfield compressed nitrogen energy storage device includes an outer cylinder; an energy storage cylinder is installed inside the outer cylinder, forming an isolation chamber between the outer cylinder and the energy storage cylinder; a piston is slidably installed inside the energy storage cylinder; connecting grooves are provided at the upper and lower ends of the energy storage cylinder, and connecting components are embedded in the connecting grooves; an air inlet pipe is welded to one side of the connecting component of the connecting groove at the upper end of the energy storage cylinder, and a hydraulic pipe is welded to one side of the connecting component of the connecting groove at the lower end of the energy storage cylinder; an opening and closing mechanism for controlling the opening and closing of the connecting components is installed on the connecting components; the opening and closing mechanism is installed at both the air inlet end and the hydraulic end and uses a piston configuration, which can control the rate at which compressed nitrogen enters and exits into the energy storage cylinder, thereby controlling the internal pressure of the energy storage cylinder.

[0008] Furthermore, the connecting assembly includes a connecting cylinder; a first flange is provided at the top of the connecting cylinder, the connecting cylinder is welded to one side of the connecting seat, and the other side of the connecting seat is screwed into the corresponding connecting groove; a conical groove is provided inside the connecting seat, and a shaft hole is provided at the upper end of the connecting cylinder, the shaft hole is provided with a shaft seal, which is to prevent gas or liquid from entering the device from the outside of the shaft hole, and also to prevent gas or liquid inside the device from leaking into the external environment. An inlet and outlet cavity is provided at the lower end of the connecting cylinder, and one end of the inlet and outlet cavity is connected to the shaft hole, and the other end is connected to the conical groove; the purpose of providing the inlet and outlet cavity is to control the inlet and outlet cavity to communicate with the inside of the energy storage cylinder through the conical groove during the operation of the opening and closing structure, so as to allow compressed nitrogen to be filled in and discharged.

[0009] Furthermore, the inlet and outlet chambers of the connecting assembly that connects the air inlet pipe to the connecting groove at the upper end of the energy storage cylinder are connected, and the inlet and outlet chambers of the connecting assembly that connects the hydraulic pipe to the connecting groove at the lower end of the energy storage cylinder are connected, and valves are installed at the ends of both the air inlet pipe and the hydraulic pipe.

[0010] Furthermore, the opening and closing mechanism includes a hydraulic pump and a hydraulic rod; the hydraulic pump is connected to the top of the corresponding connecting cylinder, and a second flange is provided on the outer wall of the hydraulic pump, which is connected to the first flange. One end of the hydraulic rod passes through the second flange and connects to the hydraulic pump, while the other end passes through the shaft hole and the inlet / outlet cavity and is inserted into the conical groove and fitted with a sealing plug. The shape of the sealing plug matches the conical groove, and the maximum diameter of the bottom of the sealing plug is smaller than the maximum inner diameter of the conical groove. When controlling the opening and closing of the connection between the air inlet pipe or hydraulic pipe and the inside of the energy storage cylinder, the hydraulic pump operates, enabling the hydraulic rod to push and pull the sealing plug, thereby allowing the conical groove to connect or close with the inlet / outlet cavity, thus achieving opening and closing control. Furthermore, by controlling the ejection distance of the sealing plug, the connection section between the conical groove and the inlet / outlet cavity is controlled, thereby controlling the rate of pressure change inside the energy storage cylinder.

[0011] Furthermore, end plates are provided on both the upper and lower sides of the outer cylinder, and pressure plates are connected to the outer side of the end plates. The pressure plates are pressed into the connecting components.

[0012] Furthermore, a sleeve hole is provided in the middle of the pressure plate. The inner diameter of the sleeve hole is larger than the diameter of the first flange, and smaller than the diameter of the connecting seat. The connecting seat is connected to the connecting groove. The tapered groove after connection is connected to the inner wall of the energy storage cylinder. The pressure plate is used to press and fix the connecting seat, thereby improving the stability of the connecting seat installation and the sealing performance of the energy storage cylinder.

[0013] Furthermore, the outer cylinder and the energy storage cylinder are integrally molded structures, with their bottoms connected and an annular opening formed at the top. A sealing ring is provided on the annular opening, and the sealing ring is flush with the top surface of the connected end plate. The isolation cavity is filled with aerogel. Filling the internal isolation cavity with aerogel not only improves the compressive strength of the energy storage cylinder, but also provides thermal insulation, reducing the impact of external temperature on the inside of the energy storage cylinder, ensuring the stability of the internal pressure, and improving impact resistance. The outer cylinder protects the internal energy storage cylinder.

[0014] Furthermore, the sealing ring is provided with injection holes through which aerogel is injected. A set screw is screwed into the injection hole, which is mainly used to seal the two injection holes, preventing the aerogel in the isolation cavity from overflowing and thus providing a reinforcement effect.

[0015] Furthermore, a support ring is provided on the outside of the outer cylinder, and multiple support legs are installed on the support ring, with the multiple support legs arranged evenly in a circle.

[0016] Furthermore, the present invention also provides a method for using a compressed nitrogen energy storage device for oil fields, specifically including the following steps:

[0017] The air inlet pipe is connected to the compressed nitrogen input terminal, and the hydraulic pipe is connected to the hydraulic connection terminal.

[0018] During energy storage, when compressed nitrogen is input from the inlet pipe, the piston slides down under the pressure of compressed nitrogen, which reduces the pressure inside the energy storage cylinder. Hydraulic oil is discharged from the hydraulic pipe. Through the operation of the hydraulic pump, the hydraulic rod extends, causing the sealing plug of the hydraulic rod to push inward, so that the conical groove connects with the inlet and outlet chambers, allowing both inlet and outlet chambers to connect with the inside of the energy storage cylinder and be filled with compressed nitrogen.

[0019] After charging is complete, the hydraulic pump operates, causing the hydraulic rods to contract. This pulls the sealing plug outward, closing the conical groove and the inlet / outlet cavity. The sealing plug fits into the conical groove to seal the energy storage cylinder and store energy.

[0020] During use, the operation of two hydraulic pumps causes the hydraulic rod to push the sealing plug inward. The conical groove connects with the inlet and outlet chambers, allowing both inlet and outlet chambers to connect with the energy storage cylinder. Hydraulic oil is injected into the energy storage cylinder through the hydraulic pipe, causing the piston to move upward under pressure, increasing the internal pressure of the energy storage cylinder. The compressed nitrogen gas inside the energy storage cylinder is then discharged through the air inlet pipe.

[0021] Compared with the prior art, the present invention has the following beneficial technical effects:

[0022] This invention provides a compressed nitrogen energy storage device for oil fields. By installing opening and closing mechanisms at both the inlet and hydraulic ends, and replacing the traditional air bladder with a piston, compared with the prior art, the opening and closing mechanisms at both ends can control the speed of compressed nitrogen entering and exiting the energy storage cylinder, thereby controlling the internal pressure of the energy storage cylinder. Furthermore, when expelling compressed nitrogen, the impact of air bladder retraction on the speed of compressed nitrogen discharge can be avoided, thus reducing the exhaust impact on the inlet end and improving the safety of compressed nitrogen use. Moreover, by replacing the air bladder with a piston, there is no need to worry about the impact of air bladder rupture, thereby increasing the service life of the energy storage device.

[0023] This invention connects the connecting seat to the connecting groove and sets up a pressure plate on the connecting seat. Compared with the prior art, by improving the fixation of the structural connection at both ends of the energy storage cylinder, the connection at both ends is prevented from being pushed out by the high pressure inside the energy storage cylinder, thereby improving the compressive strength and increasing the maximum pressure that compressed nitrogen can store, thus further improving the safety of the device.

[0024] This invention fills the isolation cavity between the outer cylinder and the energy storage cylinder with aerogel and welds a sealing ring to the connection between the outer cylinder and the energy storage cylinder. Compared with existing technologies, the aerogel filling isolates the energy storage cylinder from the outside environment, thereby reducing the impact of external temperature on the compressed nitrogen inside the energy storage cylinder and ensuring the stability of the internal pressure. At the same time, the energy storage cylinder is integrally connected to the outer cylinder, further improving the compressive strength of the energy storage cylinder and thus further improving the safety of compressed nitrogen energy storage. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the overall structure of the compressed nitrogen energy storage device for oil fields in an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of the top structure of the outer cylinder in an embodiment of the present invention.

[0027] Figure 3 This is a schematic diagram of the cross-sectional structure of the outer cylinder and the energy storage cylinder in an embodiment of the present invention.

[0028] Figure 4 This is a schematic diagram of the cross-sectional structure of the sealing ring in an embodiment of the present invention.

[0029] Figure 5 This is a schematic diagram of the cooperation structure between the connecting component and the opening / closing mechanism in an embodiment of the present invention.

[0030] Figure 6 This is a schematic diagram of the cross-sectional structure of the connecting component in an embodiment of the present invention.

[0031] Figure 7 This is a schematic diagram of the opening and closing mechanism in an embodiment of the present invention.

[0032] In the diagram, 1. Outer cylinder; 2. Support ring; 3. Support leg; 4. End plate; 5. Connecting assembly; 501. Connecting cylinder; 502. Connecting seat; 503. Tapered groove; 504. Inlet / outlet cavity; 505. Shaft hole; 506. First flange; 6. Air inlet pipe; 7. Opening / closing mechanism; 701. Hydraulic pump; 702. Second flange; 703. Hydraulic rod; 704. Sealing plug; 8. Pressure plate; 9. Hydraulic pipe; 10. Sealing ring; 11. Set screw; 12. Connecting groove; 13. Energy storage cylinder; 14. Isolation cavity; 15. Piston. Detailed Implementation

[0033] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0034] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0035] This invention provides a compressed nitrogen energy storage device for oil fields. By installing opening and closing mechanisms at both the inlet and hydraulic ends, and replacing the traditional air bladder with a piston, the speed at which compressed nitrogen enters and exits the energy storage cylinder can be controlled through the opening and closing mechanisms at both ends. This allows for control of the internal pressure of the energy storage cylinder. Furthermore, when discharging compressed nitrogen, the impact of air bladder retraction on the discharge speed can be avoided, thereby reducing the exhaust impact on the inlet end and improving the safety of compressed nitrogen use.

[0036] Example 1

[0037] See Figures 1 to 4 The system includes an outer cylinder 1; an energy storage cylinder 13 is welded inside the outer cylinder 1, forming an isolation cavity 14 between the outer cylinder 1 and the energy storage cylinder 13. A piston 15 is slidably disposed inside the energy storage cylinder 13. Connecting grooves 12 are provided at the upper and lower ends of the energy storage cylinder 13, and connecting components 5 are embedded in each connecting groove 12. An air inlet pipe 6 is welded to one side of the connecting component 5 at the upper end of the connecting groove 12 of the energy storage cylinder 13, and a hydraulic pipe 9 is welded to one side of the connecting component 5 at the lower end of the connecting groove 12 of the energy storage cylinder 13. The connecting component 5 is equipped with an opening and closing mechanism 7 for controlling the opening and closing of the connecting component 5. The component 5 works in conjunction with the opening and closing mechanism 7. Opening the opening and closing mechanism 7 allows compressed nitrogen to enter the energy storage cylinder 13 from the inlet pipe 6. After the compressed nitrogen has been filled, the opening and closing mechanism 7 is closed to achieve a seal, thereby storing the compressed nitrogen. When compressed nitrogen is needed, the opening and closing mechanism 7 is opened and hydraulic oil is injected into the energy storage cylinder 13 from the hydraulic pipe 9. By controlling the rate at which the hydraulic oil is injected into the energy storage cylinder 13, the moving speed of the piston 15 is controlled, thereby controlling the internal pressure of the energy storage cylinder 13 and further controlling the rate at which the compressed nitrogen is discharged.

[0038] The outer cylinder 1 has end plates 4 welded to both its upper and lower sides. Each end plate 4 is connected to a pressure plate 8, which is press-fitted with the corresponding connecting component 5. The pressure plate 8 has a sleeve hole in its center. The inner diameter of the sleeve hole is larger than the diameter of the first flange 506, but smaller than the diameter of the connecting seat 502. This allows the pressure plate 8 to be stably placed on the connecting seat 502 and press-fitted with the corresponding connecting component 5. This improves the stability of the structure at both ends of the energy storage cylinder 13 and prevents the connection at both ends of the energy storage cylinder 13 from being affected by the internal pressure of the energy storage cylinder 13. Excessive influence will cause it to be pushed out, thereby increasing the compressive strength of the energy storage cylinder 13 and increasing the maximum pressure of the compressed nitrogen that the energy storage cylinder 13 can store, thereby further improving the safety of the device during use; the outer cylinder 1 and the energy storage cylinder 13 are integrally formed structures, the bottom of the outer cylinder 1 and the energy storage cylinder 13 are connected, and an annular opening is formed at the top, and a sealing ring 10 is welded on the annular opening. The sealing ring 10 is flush with the top surface of the connecting end plate 4. The isolation cavity 14 is filled with aerogel. The sealing ring 10 is provided with an injection hole, and a screw-on connection is made in the injection hole. There is a set screw 11, through which aerogel is injected. The set screw 11 mainly seals the injection hole, preventing the aerogel in the isolation chamber 14 from overflowing and providing reinforcement. During energy storage, the aerogel filling the isolation chamber 14 isolates the energy storage cylinder 13 from the outside environment, preventing the influence of external temperature on the compressed nitrogen inside the energy storage cylinder 13. This prevents the compressed nitrogen from expanding due to heat, ensuring the stability of the internal pressure of the energy storage cylinder 13, thereby improving the safety of compressed nitrogen energy storage. When injecting compressed nitrogen for energy storage... When piston 15 moves downward, the pressure inside energy storage cylinder 13 decreases, connecting component 5 and opening / closing mechanism 7 open, hydraulic oil flows out from bottom hydraulic pipe 9, and compressed nitrogen is charged in. Then connecting component 5 and opening / closing mechanism 7 close, realizing compressed nitrogen energy storage. During the use of compressed nitrogen, hydraulic oil is charged into energy storage cylinder 13 from bottom hydraulic pipe 9 by opening connecting component 5 and opening / closing mechanism 7. The moving speed of piston 15 is controlled by the hydraulic oil charging rate, thereby controlling the internal pressure of energy storage cylinder 13 and the speed of compressed nitrogen discharge.

[0039] Example 2

[0040] See Figures 5 to 7Based on Embodiment 1, the connecting assembly 5 includes a connecting cylinder 501; a first flange 506 is welded to the top of the connecting cylinder 501, the connecting cylinder 501 is welded to one side of the connecting seat 502, and a connecting groove 12 is screwed onto the other side of the connecting seat 502; a tapered groove 503 is formed inside the connecting seat 502, and the connecting seat 502 is connected to the connecting groove 12. After connection, the tapered groove 503 is connected to the inner wall of the energy storage cylinder 13, and the pressure plate 8 is used to press the connecting seat 502 firmly, thereby improving the connection efficiency. The connecting sleeve 502 is installed to ensure stability and improve the sealing of the energy storage cylinder 13. A shaft hole 505 is opened at the upper end of the connecting sleeve 501, and a shaft seal is installed inside the shaft hole 505. The shaft seal prevents gas or liquid from entering the device from the outside of the shaft hole, and also prevents gas or liquid from leaking into the external environment. An inlet / outlet cavity 504 is opened at the lower end of the connecting sleeve 501, with one end of the inlet / outlet cavity 504 communicating with the shaft hole 505 and the other end communicating with the tapered groove 503. The inlet / outlet cavity 504 is connected to the shaft hole 505 at one end and to the conical groove 503 at the other end. The purpose of the inlet / outlet cavity 504 is to allow the inlet / outlet cavity 504 to communicate with the inside of the energy storage cylinder 13 through the conical groove 503 during the operation of the opening and closing mechanism, thereby enabling the filling and discharge of compressed nitrogen. The opening and closing mechanism 7 includes a hydraulic pump 701 and a hydraulic rod 703. The hydraulic pump 701 is connected to the top of the corresponding connecting cylinder 501, and a second flange is welded to the outer wall of the hydraulic pump 701. 702, and the second flange 702 is connected to the first flange 506. One end of the hydraulic rod 703 passes through the second flange 702 and is connected to the hydraulic pump 701. The other end passes through the shaft hole 505 and the inlet / outlet cavity 504 and is inserted into the tapered groove 503 and is fitted with a sealing plug 704. The shape of the sealing plug 704 matches the tapered groove 503 and the maximum diameter of the bottom of the sealing plug 704 is smaller than the maximum inner diameter of the tapered groove 503 to ensure that the sealing plug 704 can fit the tapered groove 503 to achieve the sealing function.

[0041] During energy storage, when compressed nitrogen is input through the inlet pipe 6, the hydraulic pumps 701 within the two connecting components 5, in conjunction with the installed opening and closing mechanisms 7, operate, causing the hydraulic rods 703 to extend. This pushes the sealing plugs 704 inward into the energy storage cylinder 13, thus connecting both inlet and outlet chambers 504 with the interior of the energy storage cylinder 13. As compressed nitrogen fills the inlet pipe 6, the piston 15 slides down under the pressure of the compressed nitrogen, causing the hydraulic oil at its bottom to be discharged from the hydraulic pipe 9, allowing the energy storage cylinder 13 to store the compressed nitrogen. After storage is complete, the two opening and closing mechanisms 7 operate again, causing the two sealing plugs 704 to seal the corresponding conical grooves 503, thereby storing the compressed nitrogen. When compressed nitrogen is used, the two opening and closing mechanisms 7 are operated to open the two conical grooves 503. The hydraulic pipe 9 at the bottom fills the energy storage cylinder 13 with hydraulic oil. The movement speed of the piston 15 is controlled by the hydraulic oil filling rate, thereby controlling the internal pressure of the energy storage cylinder 13 and the speed of compressed nitrogen discharge. During the filling of hydraulic oil, the piston 15 moves upward and discharges the compressed nitrogen from the inlet pipe 6. During the use of compressed nitrogen, the internal pressure of the energy storage cylinder 13 can also be controlled by the operation of the hydraulic pump 701 in the opening and closing mechanism 7 installed on the connecting assembly 5 connected to the hydraulic pipe 9, thereby controlling the extension of the hydraulic rod 703 and controlling the communication section between the inlet / outlet chamber 504 and the conical groove 503.

[0042] This invention also provides a method for using a compressed nitrogen energy storage device for oil fields, specifically including the following steps:

[0043] The air inlet pipe 6 is connected to the compressed nitrogen input terminal, and the hydraulic pipe 9 is connected to the hydraulic connection terminal;

[0044] During energy storage, when compressed nitrogen is input from the inlet pipe 6, the piston 15 slides down under the pressure of compressed nitrogen, which reduces the internal pressure of the energy storage cylinder 13. Hydraulic oil is discharged from the hydraulic pipe 9. Through the operation of the hydraulic pump 701, the hydraulic rod 703 extends, causing the sealing plug 704 of the hydraulic rod 703 to push inward, so that the conical groove 503 is connected to the inlet and outlet chambers 504, allowing both inlet and outlet chambers 504 to be connected to the inside of the energy storage cylinder 13 and filled with compressed nitrogen.

[0045] After the filling is completed, the hydraulic rods 703 contract due to the operation of the hydraulic pump 701, which pulls the sealing plug 704 outward, and the conical groove 503 and the inlet / outlet cavity 504 close. The sealing plug 704 fits against the conical groove 503 to seal the energy storage cylinder 13 and store energy.

[0046] In use, the operation of two hydraulic pumps 701 causes the hydraulic rod 703 to push the sealing plug 704 inward. The conical groove 503 is connected to the inlet and outlet chambers 504, so that both inlet and outlet chambers 504 are connected to the energy storage cylinder 13. Hydraulic oil is injected into the energy storage cylinder 13 through the hydraulic pipe 9, which causes the piston 15 to move upward under pressure, thereby increasing the internal pressure of the energy storage cylinder 13. The compressed nitrogen gas inside the energy storage cylinder 13 is discharged from the air inlet pipe 6.

[0047] During the use of compressed nitrogen, the internal pressure of the energy storage cylinder 13 can be controlled by the operation of the hydraulic pump 701 in the opening and closing mechanism 7 installed on the connecting assembly 5 connected to the hydraulic pipe 9, thereby controlling the extension of the hydraulic rod 703 and controlling the communication section between the inlet / outlet chamber 504 and the conical groove 503.

[0048] During the assembly of the energy storage device, a sealing ring 10 is welded onto the annular opening formed at the top of the integrally connected outer cylinder 1 and the energy storage cylinder 13. Then, the two set screws 11 installed on the sealing ring 10 are opened, and aerogel is injected into the isolation chamber 14. Then, the piston 15 is placed in the energy storage cylinder 13. The two sets of connecting components 5 and the connecting seat 502 at the bottom of the opening and closing mechanism 7 are screwed into the corresponding connecting groove 12. By installing the pressure plate 8, the outside of the connecting seat 502 is further squeezed, thereby improving the fixation of the connection between the connecting component 5 and the connecting groove 12, thereby improving the pressure resistance of the entire energy storage device.

[0049] Finally, the following points should be noted: First, in the description of this invention, it should be noted that, unless otherwise specified and limited, the terms "installation", "connection", and "linkage" should be interpreted broadly, and can refer to mechanical connection or electrical connection, or internal connection between two components, or direct connection. "Up", "down", "left", "right", etc. are only used to indicate relative positional relationship. When the absolute position of the object being described changes, the relative positional relationship may change.

[0050] Secondly: The accompanying drawings of the embodiments disclosed in this invention only involve the structures involved in the embodiments disclosed in this invention. Other structures can refer to the general design. In the absence of conflict, the same embodiment and different embodiments of this invention can be combined with each other.

[0051] In conclusion, 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, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A compressed nitrogen energy storage device for oil fields, characterized by, The utility model provides an energy storage device, including outer tube (1), be provided with energy storage cylinder (13) inside outer tube (1), and the isolation chamber (14) is formed between outer tube (1) and energy storage cylinder (13), the piston (15) is slidably arranged inside energy storage cylinder (13), and the connecting groove (12) is arranged on the both ends of energy storage cylinder (13), the connecting groove (12) all in-embed has connecting assembly (5), the connecting assembly (5) one side of connecting groove (12) on the upper end of energy storage cylinder (13) is welded with air inlet pipe (6), and the connecting assembly (5) one side of connecting groove (12) on the lower end of energy storage cylinder (13) is welded with hydraulic pipe (9), and the opening and closing mechanism (7) of controlling connecting assembly (5) is installed on connecting assembly (5).

2. The compressed nitrogen energy storage device for oilfield use according to claim 1, characterized by, The connecting assembly (5) includes a connecting cylinder (501), a first flange (506) is arranged at the top end of the connecting cylinder (501), the connecting cylinder (501) is arranged on one side of a connecting seat (502), the other side of the connecting seat (502) is screwed with the connecting groove (12), a tapered groove (503) is formed in the connecting seat (502), an axial hole (505) is formed at the upper end of the connecting cylinder (501), a shaft seal is arranged in the axial hole (505), an inlet and outlet cavity (504) is formed at the lower end of the connecting cylinder (501), one end of the inlet and outlet cavity (504) is communicated with the axial hole (505), and the other end is communicated with the tapered groove (503).

3. The compressed nitrogen energy storage device for oilfield use according to claim 2, characterized by, The inlet and outlet cavity (504) of the connecting assembly (5) connected with the connecting groove (12) at the upper end of the energy storage cylinder (13) is communicated with the air inlet pipe (6), the inlet and outlet cavity (504) of the connecting assembly (5) connected with the connecting groove (12) at the lower end of the energy storage cylinder (13) is communicated with the hydraulic pipe (9), and valves are installed at the ends of the air inlet pipe (6) and the hydraulic pipe (9).

4. The compressed nitrogen energy storage device for oilfield use of claim 2, wherein, The opening and closing mechanism (7) includes a hydraulic pump (701) and a hydraulic rod (703), the hydraulic pump (701) is connected with the top end of the corresponding connecting cylinder (501), a second flange (702) is arranged on the outer wall of the hydraulic pump (701), the second flange (702) is connected with the first flange (506), one end of the hydraulic rod (703) penetrates through the second flange (702) and is connected with the hydraulic pump (701), the other end penetrates through the axial hole (505) and the inlet and outlet cavity (504) and is inserted into the tapered groove (503) and is provided with a sealing plug (704), the sealing plug (704) is matched with the tapered groove (503) in shape, and the maximum diameter size of the bottom of the sealing plug (704) is smaller than the maximum inner diameter size of the tapered groove (503).

5. The compressed nitrogen energy storage device for oilfield use of claim 2, wherein, End discs (4) are arranged on the upper and lower sides of the outer tube (1), pressure discs (8) are connected to the outer sides of the end discs (4), and the pressure discs (8) are press-fitted with the connecting assemblies (5).

6. The compressed nitrogen energy storage device for oilfield use of claim 5, wherein, A sleeve hole is formed in the middle of the pressure disc (8), the inner diameter size of the sleeve hole is greater than the diameter size of the first flange (506), and the inner diameter size of the sleeve hole is smaller than the diameter size of the connecting seat (502).

7. The compressed nitrogen energy storage device for oilfield use of claim 5, wherein, The outer cylinder (1) and the energy storage cylinder (13) are integrally formed, the bottom of the outer cylinder (1) and the energy storage cylinder (13) are connected, the top is formed with an opening, and a sealing ring (10) is arranged on the opening, the sealing ring (10) is flush with the top surface of the connected end disc (4), and the isolation cavity (14) is filled with aerogel.

8. The compressed nitrogen energy storage device for oilfield use of claim 1, wherein, The sealing ring (10) is provided with an injection hole, and a top screw (11) is screwed in the injection hole.

9. The compressed nitrogen energy storage device for oilfield use of claim 1, wherein, The outer cylinder (1) is provided with a support ring (2) outside, a plurality of supporting legs (3) are installed on the support ring (2), and the plurality of supporting legs (3) are uniformly arranged in a circle.

10. The method of using a compressed nitrogen energy storage device for oilfield use of claim 4, wherein, The method comprises the following steps: The air inlet pipe (6) is connected to the compressed nitrogen input end, and the hydraulic pipe (9) is connected to the hydraulic connection end; During energy storage, when the compressed nitrogen is input from the air inlet pipe (6), the piston (15) slides under the pressure of the compressed nitrogen, the pressure inside the energy storage cylinder (13) becomes smaller, the hydraulic oil is discharged from the hydraulic pipe (9), the hydraulic rod (703) is elongated through the operation of the hydraulic pump (701), the sealing plug (704) of the hydraulic rod (703) is pushed inward, the conical groove (503) is communicated with the inlet and outlet cavity (504), and the two inlet and outlet cavities (504) are communicated with the energy storage cylinder (13) and filled with compressed nitrogen; After filling is completed, the hydraulic rod (703) is retracted through the operation of the hydraulic pump (701), the sealing plug (704) of the hydraulic rod (703) is pulled outward, the conical groove (503) and the inlet and outlet cavity (504) are closed, the sealing plug (704) is attached to the conical groove (503) to seal the energy storage cylinder (13), and energy storage is performed; During use, the sealing plug (704) of the hydraulic rod (703) is pushed inward through the operation of the two hydraulic pumps (701), the conical groove (503) is communicated with the inlet and outlet cavity (504), the two inlet and outlet cavities (504) are communicated with the energy storage cylinder (13), the hydraulic oil is filled into the energy storage cylinder (13) from the hydraulic pipe (9) to make the piston (15) move upward under the pressure, the pressure inside the energy storage cylinder (13) becomes larger, and the compressed nitrogen in the energy storage cylinder (13) is discharged from the air inlet pipe (6).

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