Simulation experiment device for hydrogen-doped natural gas pipeline

Abstract

The utility model discloses a simulation experiment device for a hydrogen-doped natural gas pipeline, and relates to the technical field of hydrogen-doped natural gas pipeline production, the simulation experiment device comprises a device main body, the top of the device main body is connected with an isolation cabin, and the outer surface of the isolation cabin is connected with a second sealing door; a servo motor and a guide rod are installed on the two sides of the interior of the isolation bin correspondingly, and the output end of the servo motor is connected with a lead screw. Through the arrangement of the isolation bin, the dowel bar, the corrugated pipe, the sealing ring, the sealing gasket and the hoop, the execution structure and the transmission structure are both arranged in the isolation bin, the execution structure and the transmission structure are prevented from making contact with hydrogen, and the initial cost and the subsequent maintenance cost are reduced; the dowel bar penetrates through the device main body and the isolation bin and transmits force conveyed by the execution structure and the transmission structure to the tension sensor so as to stretch the pipeline sample; an execution structure and a transmission structure are independently separated for sealing, hydrogen embrittlement resistance treatment is not needed, and the initial input cost and the replacement cost when a subsequent structure is abraded and damaged are reduced.

Description

Technical Field

[0001] This utility model relates to the field of hydrogen-blended natural gas pipeline production technology, specifically a simulation experimental device for hydrogen-blended natural gas pipelines. Background Technology

[0002] Blending hydrogen with natural gas and transporting it through existing natural gas pipelines and their distribution networks is currently the best potential way to safely, efficiently, on a large scale, and over long distances deliver hydrogen to end users. However, the pipelines are subject to hydrogen embrittlement risks, so simulation experiments are needed during the production and development of hydrogen-blended natural gas pipelines.

[0003] Simulation experiments on hydrogen-blended natural gas pipelines are a crucial step in verifying their technical feasibility, safety, and economy. They cover a wide range of research areas, including material properties, fluid dynamics, combustion characteristics, and gas separation. Examples include hydrogen embrittlement tests, permeability tests, fluid dynamics simulations, and leakage diffusion simulations. Among these, hydrogen embrittlement tests are further divided into slow strain rate tests, high-pressure hydrogen environment tests, and hydrogen permeation tests.

[0004] Existing slow strain rate simulation experimental devices for hydrogen-blended natural gas pipelines require stretching the pipeline at a constant low strain rate in a hydrogen environment to simulate the long-term stress state of the pipeline in a hydrogen environment. The tensile force is usually applied by a linear motion actuator or an actuator plus a transmission structure, and the working environment is in a hydrogen environment. Not only do the transmission components need to have hydrogen embrittlement resistance, but the actuators such as motors, cylinders, electric cylinders, and hydraulic cylinders also need to be treated to resist hydrogen embrittlement. First, they need to be specially customized, resulting in high initial investment costs. Second, the replacement costs during subsequent wear and maintenance are also high. Utility Model Content

[0005] Therefore, the purpose of this utility model is to provide a simulation experimental device for hydrogen-blended natural gas pipelines to solve the technical problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a simulation experimental device for a hydrogen-blended natural gas pipeline, comprising a main body, an isolation chamber connected to the top of the main body, and a second sealing door connected to the outer surface of the isolation chamber; a servo motor and a guide rod are respectively installed on both sides inside the isolation chamber, and a lead screw is connected to the output end of the servo motor; a support plate is connected between the lead screw and the guide rod, and a force transmission rod is connected to the bottom of the support plate; a corrugated pipe is connected to the outside of the force transmission rod through a sealing ring, and a sealing gasket is connected to the top of the corrugated pipe; a clamp is provided on the outside of the corrugated pipe.

[0007] By adopting the above technical solution, the servo motor, lead screw, guide rod, and other structures are set inside the isolation chamber, avoiding contact between the actuator and transmission structures and hydrogen, thus reducing initial and subsequent maintenance costs. To prevent hydrogen from entering the isolation chamber along the force transmission rod, a bellows is used to shield the space between the force transmission rod and the main body of the device, and sealing rings and gaskets are used to fill the gaps between the bellows, the force transmission rod, and the main body of the device to prevent hydrogen permeation. The bellows can deform when the force transmission rod moves up and down, and the L-shaped stainless steel bellows has high pressure resistance, hydrogen embrittlement resistance, fatigue resistance, and long service life.

[0008] Furthermore, the support plate is slidably connected to the guide rod via a linear bearing, and the support plate is threadedly connected to the lead screw via a lead screw nut.

[0009] By adopting the above technical solution, after the servo motor starts, the output end drives the lead screw to rotate. After the lead screw rotates, it drives the support plate and the force transmission rod to move upward. The upward movement of the force transmission rod causes the tension sensor, the mounting base and the flange plate to move upward.

[0010] Furthermore, both the bellows and the force transmission rod are made of 316L stainless steel.

[0011] By adopting the above technical solution, the space between the force transmission rod and the main body of the device is blocked by the corrugated pipe, and the 316L stainless steel corrugated pipe has the characteristics of high pressure resistance, hydrogen embrittlement resistance, strong fatigue resistance and long service life.

[0012] Furthermore, the sealing ring and sealing gasket are made of metal-graphite composite material.

[0013] By adopting the above technical solution, using metal such as stainless steel as the base material and graphite material on the sealing surface, the gaps between the bellows, the force transmission rod, and the main body of the device can be effectively filled by sealing rings and gaskets, thus preventing hydrogen permeation.

[0014] Furthermore, the top end of the bellows and the sealing gasket are detachably connected to the main body of the device by bolts, and the bottom end of the bellows and the sealing ring are detachably connected to the force transmission rod by clamps.

[0015] By adopting the above technical solution, the staff closes the first sealing door and removes the pipe sample from the flange plate. Then, the staff removes the clamps and the bolts that fasten the bellows and gaskets, and the bellows, sealing rings and gaskets can be replaced.

[0016] Furthermore, a first sealing door is connected to the outer surface of the main body of the device, and an air inlet, a first air inlet, and an air outlet are respectively connected to both sides of the main body of the device.

[0017] By adopting the above technical solution, after the preparation work is completed, the staff closes the first sealing door and turns on the servo motor. During this period, the first air inlet is closed, while the air inlet fills the main body of the device with hydrogen, and the air outlet is opened to replace and expel the air that was originally in the main body of the device. After a period of time, the air outlet is closed, which increases the gas pressure of hydrogen inside the main body of the device. When the external pressure gauge detects that the hydrogen pressure reaches a certain value, the air inlet is closed to stop the input of hydrogen, so that the pipe sample is subjected to tensile force in a hydrogen environment, simulating the long-term stress state of a hydrogen-blended natural gas pipeline in a hydrogen environment. When the pipe sample breaks and the experiment is completed, the air outlet and the first air inlet are opened. The first air inlet inputs fresh air into the main body of the device, while the air outlet sends the hydrogen away for unified treatment to avoid the random release of hydrogen and the risk of explosion.

[0018] Furthermore, a tension sensor is installed at the bottom of the force transmission rod, and mounting bases are connected to the bottom of the tension sensor and the lower part of the device body. A flange plate is connected to one end of each of the two mounting bases, and a pipe sample is connected between the two flange plates.

[0019] By adopting the above technical solution, the workers use bolts to fasten the flange plate of the corresponding size of the pipe sample to the mounting base, and then use bolts to fasten the pipe sample to the flange plate.

[0020] Furthermore, the pipe sample is detachably connected to two flange plates by bolts, and the two flange plates are detachably connected to two mounting seats by bolts respectively.

[0021] By adopting the above technical solution, the staff uses bolts to fasten the flange plate of the corresponding size of the pipe sample to the mounting base, and then uses bolts to fasten the pipe sample to the flange plate.

[0022] Furthermore, a hydrogen sensor is installed at the bottom inside the isolation chamber, and a second air inlet is connected to the top of one side of the isolation chamber.

[0023] By adopting the above technical solution, when the bellows, sealing ring, or sealing gasket is damaged during the experiment, the hydrogen sensor detects that cleaning has entered the isolation chamber. At this time, the second air inlet and outlet open, and the servo motor shuts down to stop applying tension to the pipe sample. After the second air inlet opens, fresh air is introduced into the isolation chamber. Then, the fresh air enters the main body of the device, and the hydrogen is discharged through the outlet. The fresh air replaces the hydrogen, avoiding hydrogen embrittlement caused by long-term exposure of the actuator and transmission structure to the high-pressure hydrogen environment.

[0024] In summary, the present invention has the following main advantages:

[0025] This invention utilizes an isolation chamber, a force transmission rod, a bellows, a sealing ring, a sealing gasket, and a clamp. Both the execution and transmission structures are housed inside the isolation chamber, preventing contact between them and hydrogen, thus reducing initial and subsequent maintenance costs. The force transmission rod penetrates the main body of the device and the isolation chamber, transmitting the force from the execution and transmission structures to the tension sensor for stretching the pipe sample. To prevent hydrogen from entering the isolation chamber along the force transmission rod, a bellows shields the space between the force transmission rod and the main body of the device. A sealing ring and a sealing gasket fill the gaps between the bellows, the force transmission rod, and the main body, preventing hydrogen permeation. The bellows deforms when the force transmission rod moves up and down. 316L stainless steel bellows is characterized by high pressure resistance, hydrogen embrittlement resistance, fatigue resistance, and long service life. Compared to dynamic sealing rings, bellows provides shielding through ductile deformation. The sealing ring and gasket, as static seals, experience no frictional loss, allowing for longer service life and reducing replacement frequency. Furthermore, dynamic sealing rings are prone to aggravated wear or even direct damage when the pipe sample is broken due to radial impact loads, while bellows itself has lateral displacement compensation capabilities, resulting in almost no damage and preventing hydrogen leakage caused by radial impact. Separating the execution and transmission structures for sealing eliminates the need for hydrogen embrittlement prevention treatment, reducing initial investment costs and subsequent replacement costs due to structural wear and damage. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of this utility model;

[0027] Figure 2 This is a cross-sectional structural diagram of the present invention;

[0028] Figure 3 For the present utility model Figure 2 Enlarged view of the structure at point A in the image;

[0029] Figure 4 This is a schematic diagram of the corrugated pipe structure of this utility model.

[0030] In the diagram: 1. Main body of the device; 2. First sealing door; 3. Air inlet; 4. First air inlet; 5. Air outlet; 6. Isolation chamber; 7. Second sealing door; 8. Hydrogen sensor; 9. Servo motor; 10. Lead screw; 11. Guide rod; 12. Support plate; 13. Force transmission rod; 14. Tension sensor; 15. Mounting base; 16. Flange plate; 17. Pipe sample; 18. Bellows; 19. Sealing ring; 20. Sealing gasket; 21. Clamp; 22. Second air inlet. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0032] The embodiments of this utility model will be described below based on its overall structure.

[0033] Example 1:

[0034] A simulation experimental device for a hydrogen-blended natural gas pipeline, such as Figures 1-4 As shown, the device includes a main body 1, with an isolation chamber 6 connected to the top of the main body 1. A second sealing door 7 is connected to the outer surface of the isolation chamber 6. A servo motor 9 and a guide rod 11 are respectively installed on both sides inside the isolation chamber 6. A lead screw 10 is connected to the output end of the servo motor 9. A support plate 12 is connected between the lead screw 10 and the guide rod 11. The support plate 12 is slidably connected to the guide rod 11 through a linear bearing. The support plate 12 is threadedly connected to the lead screw 10 through a lead screw nut. A force transmission rod 13 is connected to the bottom of the support plate 12. After the servo motor 9 is started, the output end drives the lead screw 10 to rotate. After the lead screw 10 rotates, it drives the support plate 12 and the force transmission rod 13 to move upward. The upward movement of the force transmission rod 13 drives the tension sensor 14, the mounting base 15, and the flange plate 16 to move upward, so that the pipeline sample 17 is subjected to tension in a hydrogen environment, simulating the long-term stress state of a hydrogen-blended natural gas pipeline in a hydrogen environment. The tension sensor 14 monitors the tension on the pipeline sample 17.

[0035] The force transmission rod 13 is externally connected to a bellows 18 via a sealing ring 19. Both the bellows 18 and the force transmission rod 13 are made of 316L stainless steel. A sealing gasket 20 is connected to the top of the bellows 18. The sealing ring 19 and the sealing gasket 20 are made of metal-graphite composite material. The top of the bellows 18 and the sealing gasket 20 are detachably connected to the main body 1 of the device via bolts. A clamp 21 is provided on the outside of the bellows 18. The bottom of the bellows 18 and the sealing ring 19 are detachably connected to the force transmission rod 13 via the clamp 21. The servo motor 9, lead screw 10, guide rod 11, and other structural components are also included. Inside the isolation chamber 6, the actuator and transmission structures are prevented from coming into contact with hydrogen, reducing initial and subsequent maintenance costs. To prevent hydrogen from entering the isolation chamber 6 along the force transmission rod 13, the space between the force transmission rod 13 and the main body 1 is blocked by a bellows 18, and the gaps between the bellows 18, the force transmission rod 13, and the main body 1 are filled by a sealing ring 19 and a sealing gasket 20 to prevent hydrogen infiltration. The bellows 18 can deform when the force transmission rod 13 moves up and down, and the 316L stainless steel bellows 18 has high pressure resistance, hydrogen embrittlement resistance, fatigue resistance, and long service life.

[0036] See Figure 1 and Figure 2In the above embodiment, a first sealing door 2 is connected to the outer surface of the device body 1. An air inlet 3, a first air inlet 4, and an air outlet 5 are respectively connected to both sides of the device body 1. A tension sensor 14 is installed at the bottom of the force transmission rod 13. Mounting seats 15 are connected to the bottom of the tension sensor 14 and the lower interior of the device body 1. A flange plate 16 is connected to one end of each of the two mounting seats 15. The two flange plates 16 are detachably connected to the two mounting seats 15 by bolts. A pipe sample 17 is connected between the two flange plates 16. The pipe sample 17 is detachably connected to the two flange plates 16 by bolts. The operator uses bolts to fasten the flange plate 16 of the corresponding size of the pipe sample 17 to the mounting seat 15, and then uses bolts to fasten the pipe sample 17 to the flange plate 16. After the work is completed, the staff closes the first sealing door 2 and turns on the servo motor 9. During this period, the first air inlet 4 is closed, while the air inlet 3 fills the main body 1 with hydrogen gas, and the air outlet 5 is opened to replace and discharge the air that was originally in the main body 1. After a period of time, the air outlet 5 is closed, which increases the hydrogen pressure inside the main body 1. When the external pressure gauge detects that the hydrogen pressure has reached a certain value, the air inlet 3 is closed to stop the input of hydrogen gas. When the pipe sample 17 breaks and the experiment is completed, the air outlet 5 and the first air inlet 4 are opened. The first air inlet 4 inputs fresh air into the main body 1, while the air outlet 5 sends the hydrogen gas away for unified treatment to prevent the random discharge of hydrogen gas from causing an explosion. After the hydrogen gas is discharged, the staff opens the first sealing door 2 and removes the broken pipe sample 17.

[0037] Example 2:

[0038] Based on the above embodiment 1, in order to prevent structural damage from causing hydrogen to enter the isolation chamber 6, the following settings are now implemented.

[0039] See Figure 1 and Figure 2 In the above embodiment, a hydrogen sensor 8 is installed at the bottom inside the isolation chamber 6, and a second air inlet 22 is connected to the top of one side of the isolation chamber 6. When the bellows 18, sealing ring 19 or sealing gasket 20 is damaged during the experiment, the hydrogen sensor 8 detects that cleaning has entered the isolation chamber 6. At this time, the second air inlet 22 and the air outlet 5 are opened, and the servo motor 9 is turned off and stops applying tension to the pipe sample 17. After the second air inlet 22 is opened, fresh air is introduced into the isolation chamber 6. Then the fresh air enters the main body 1 of the device, and the hydrogen is discharged through the air outlet 5. The fresh air replaces the hydrogen, avoiding hydrogen embrittlement caused by long-term exposure of the actuator and transmission structure to the high-pressure hydrogen environment.

[0040] The implementation principle of this utility model is as follows: First, the operator uses bolts to fasten the flange plate 16 of the corresponding size of the pipe sample 17 to the mounting base 15, and then uses bolts to fasten the pipe sample 17 to the flange plate 16; after the preparation work is completed, the operator closes the first sealing door 2 and turns on the servo motor 9; during this period, the first air inlet 4 is closed, while the air inlet 3 fills the device body 1 with hydrogen gas, and the air outlet 5 is opened to replace and discharge the air that was originally in the device body 1. After a period of time, the air outlet 5 is closed, so that the air inside the device body 1 is discharged. When the hydrogen pressure increases, the inlet 3 closes and stops the input of hydrogen after the external pressure gauge detects that the hydrogen pressure has reached a certain value. After the servo motor 9 starts, the output end drives the lead screw 10 to rotate. After the lead screw 10 rotates, it drives the support plate 12 and the force transmission rod 13 to move upward. The upward movement of the force transmission rod 13 drives the tension sensor 14, the mounting base 15 and the flange plate 16 to move upward, so that the pipeline sample 17 is subjected to tension in the hydrogen environment, simulating the long-term stress state of the hydrogen-blended natural gas pipeline in the hydrogen environment. The tension sensor 14 monitors the tension on the pipeline sample 17.

[0041] The servo motor 9, lead screw 10, guide rod 11, and other structures are located inside the isolation chamber 6 to prevent the actuator and transmission structures from contacting hydrogen, thus reducing initial and subsequent maintenance costs. To prevent hydrogen from entering the isolation chamber 6 along the force transmission rod 13, the space between the force transmission rod 13 and the main body 1 is blocked by a bellows 18, and the gaps between the bellows 18, the force transmission rod 13, and the main body 1 are filled by a sealing ring 19 and a sealing gasket 20 to prevent hydrogen permeation. The bellows 18 can deform when the force transmission rod 13 moves up and down, and the 316L stainless steel bellows 18 has high pressure resistance, hydrogen embrittlement resistance, fatigue resistance, and long service life.

[0042] Compared to setting a dynamic sealing ring 19, the bellows 18 provides shielding through ductile deformation. The sealing ring 19 and the sealing gasket 20, as static seals, have no frictional loss and can be used for a longer period of time, reducing the frequency of replacement. Furthermore, the dynamic sealing ring 19 is prone to aggravated wear or even direct damage when the pipe sample 17 is pulled apart by radial impact loads. In contrast, the bellows 18 itself has lateral displacement compensation capabilities, so there is almost no damage. This avoids the phenomenon of hydrogen leakage caused by radial impact leading to seal damage.

[0043] When the bellows 18, sealing ring 19, or sealing gasket 20 is damaged during the experiment, the hydrogen sensor 8 detects that cleaning has entered the isolation chamber 6. At this time, the second air inlet 22 and the air outlet 5 open, and the servo motor 9 closes and stops applying tension to the pipe sample 17. After the second air inlet 22 opens, fresh air is introduced into the isolation chamber 6. Then, the fresh air enters the main body 1 of the device, and the hydrogen is discharged through the air outlet 5. The fresh air replaces the hydrogen, avoiding hydrogen embrittlement caused by long-term exposure of the actuator and transmission structure to the high-pressure hydrogen environment. Afterward, the staff closes the first sealing door 2 and removes the pipe sample 17 from the flange plate 16. Then, the staff removes the clamp 21 and the bolts that fasten the bellows 18 and sealing gasket 20, and the bellows 18, sealing ring 19, and sealing gasket 20 can be replaced.

[0044] After the pipe sample 17 breaks and the experiment is completed, the outlet 5 and the first air inlet 4 are opened. The first air inlet 4 introduces fresh air into the main body 1 of the device, while the outlet 5 sends the hydrogen away for unified treatment to prevent the random release of hydrogen from causing an explosion. After the hydrogen is released, the staff opens the first sealing door 2 to remove the broken pipe sample 17. When it is necessary to maintain the execution structure and transmission structure, the staff can open the second sealing door 7 to perform the operation.

[0045] Although embodiments of the present invention have been shown and described, these specific embodiments are merely explanations of the present invention and are not intended to limit the invention. The specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. After reading this specification, those skilled in the art may make modifications, substitutions, and variations to the embodiments as needed without departing from the principles and spirit of the present invention, provided that such modifications, substitutions, and variations are within the scope of the claims of the present invention and are protected by patent law.

Claims

1. A simulation experimental device for a hydrogen-blended natural gas pipeline, comprising a main body (1), characterized in that: The main body (1) of the device is connected to an isolation chamber (6) at the top, and a second sealing door (7) is connected to the outer surface of the isolation chamber (6); a servo motor (9) and a guide rod (11) are respectively installed on both sides inside the isolation chamber (6), and a lead screw (10) is connected to the output end of the servo motor (9); a support plate (12) is connected between the lead screw (10) and the guide rod (11), and a force transmission rod (13) is connected to the bottom of the support plate (12); a bellows (18) is connected to the outside of the force transmission rod (13) through a sealing ring (19), and a sealing gasket (20) is connected to the top of the bellows (18), and a clamp (21) is provided on the outside of the bellows (18).

2. The simulation experimental apparatus for hydrogen-blended natural gas pipelines according to claim 1, characterized in that: The support plate (12) is slidably connected to the guide rod (11) via a linear bearing, and the support plate (12) is threadedly connected to the lead screw (10) via a lead screw nut.

3. The simulation experimental apparatus for hydrogen-blended natural gas pipelines according to claim 1, characterized in that: Both the corrugated pipe (18) and the force transmission rod (13) are made of 316L stainless steel.

4. The simulation experimental apparatus for hydrogen-blended natural gas pipelines according to claim 1, characterized in that: The sealing ring (19) and sealing gasket (20) are made of metal-graphite composite material.

5. The simulation experimental apparatus for hydrogen-blended natural gas pipelines according to claim 4, characterized in that: The top end of the corrugated pipe (18) and the sealing gasket (20) are detachably connected to the main body of the device (1) by bolts, and the bottom end of the corrugated pipe (18) and the sealing ring (19) are detachably connected to the force transmission rod (13) by clamp (21).

6. The simulation experimental apparatus for hydrogen-blended natural gas pipelines according to claim 1, characterized in that: The outer surface of the main body (1) of the device is connected to a first sealing door (2), and the two sides of the main body (1) are respectively connected to an air inlet (3), a first air inlet (4) and an air outlet (5).

7. The simulation experimental apparatus for hydrogen-blended natural gas pipelines according to claim 6, characterized in that: A tension sensor (14) is installed at the bottom of the force transmission rod (13), and a mounting base (15) is connected to the bottom of the tension sensor (14) and the lower part of the device body (1). A flange plate (16) is connected to one end of each of the two mounting bases (15), and a pipe sample (17) is connected between the two flange plates (16).

8. The simulation experimental apparatus for hydrogen-blended natural gas pipelines according to claim 7, characterized in that: The pipe sample (17) is detached from two flange plates (16) by bolts, and the two flange plates (16) are detached from two mounting seats (15) by bolts respectively.

9. The simulation experimental apparatus for hydrogen-blended natural gas pipelines according to claim 1, characterized in that: A hydrogen sensor (8) is installed at the bottom inside the isolation chamber (6), and a second air inlet (22) is connected to the top of one side of the isolation chamber (6).

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