Buried natural gas pipeline leakage flow detection system

Abstract

The utility model provides a buried natural gas pipeline leakage flow detection system, and belongs to the technical field of urban gas safety. Comprising a sealing device which can be placed on the ground and is used for collecting leakage gas of a buried pipeline, a flow meter which is connected with the sealing device and is used for metering gas flow, a sucking pump which is used for providing negative pressure to convey the leakage gas, a gas analyzer which is used for analyzing data of the leakage gas, and a connecting device which is used for connecting the sealing device, the flow meter and the sucking pump, a hose of the gas analyzer; by means of the buried natural gas pipeline leakage flow detection system, a more ideal semi-closed space can be formed, and the detection accuracy and effectiveness are improved; the methane / ethane analyzer arranged in the detection system adopts an infrared absorption spectrum technology and has the advantages of high precision, high sensitivity, high frequency, short response time and low power consumption, acquired data are more real and reliable, and leakage quantification is more accurate.

Description

Technical Field

[0001] This utility model belongs to the field of urban gas safety technology, specifically relating to a buried natural gas pipeline leakage flow detection system. Background Technology

[0002] Urban gas operators are increasingly focusing on identifying safety hazards in pipeline transmission and distribution systems and assessing methane emissions. Portable methane / ethane gas analyzers are among the most widely used detection devices. High-flow-rate enclosed sampling detection using these devices is a common method for quantifying methane emissions from leak points. The principle is as follows: the enclosed detection device forms a semi-enclosed space with an inlet and a sampling interface. A vacuum pump captures gas from the sampling interface and introduces it into the analyzer. Finally, the methane leak flow rate is calculated based on the sampled flow rate and the measured concentration data.

[0003] However, due to the special nature of buried gas pipelines, which are buried underground, ordinary sealing devices cannot collect leaked natural gas through the surface to achieve the desired sealing effect. Utility Model Content

[0004] The purpose of this utility model is to provide a buried natural gas pipeline leakage flow detection system for capturing and analyzing gas in space, and calculating methane leakage flow based on the gas sampling flow and the measured concentration data. The buried natural gas pipeline leakage flow detection system includes a sealing device that can be placed on the ground to collect leaked gas from the buried pipeline, a flow meter connected to the sealing device for measuring the gas flow, a vacuum pump for providing negative pressure to transport the leaked gas, a gas analyzer for analyzing the leaked gas data, and a hose for connecting the sealing device, the flow meter, the vacuum pump, and the gas analyzer.

[0005] The enclosure includes a semi-enclosed space enclosed by a shell and is hollow inside; one end of the enclosure is an open surface that communicates with the interior of the enclosure; a gas sampling port is provided on the shell of the enclosure, and a flexible hose is connected to the gas sampling port; a pump is used to extract leaked gas from the semi-enclosed space, which is then delivered to a gas analyzer after passing through a flow meter; the flow meter is used to measure the gas sampling flow rate, and the gas analyzer is used to detect the concentration of methane and / or ethane gas.

[0006] Preferably, the enclosure is rectangular in shape, with the side length of the bottom surface being greater than the side length of the sides; the top, front, rear, left, and right sides of the enclosure are all provided with panels, while the bottom surface is open;

[0007] The gas sampling interface is located on the top surface and can be connected to a hose; the sealing device can be placed on the ground, with the opening of the sealing device facing the ground, and the shell of the sealing device forming a relatively enclosed space with the ground.

[0008] Preferably, the sealing device is cylindrical or frustum-shaped, with a closed shell on the top and sides, forming a semi-closed space, and the bottom is open; the gas sampling interface is located on the top surface.

[0009] Preferably, the sealing device, flow meter, air pump, and gas analyzer are connected in sequence; the buried natural gas pipeline leakage flow detection system includes three hoses, which are respectively installed between the sealing device and the inlet of the flow meter, between the outlet of the flow meter and the inlet of the air pump, and between the outlet of the air pump and the inlet of the gas analyzer.

[0010] Preferably, the buried natural gas pipeline leakage flow detection system further includes a mobile power supply, which is connected to the air pump and the gas analyzer to provide power to the air pump and the gas analyzer.

[0011] Preferably, the flow meter is a dry gas flow meter, which is used to measure the gas sampling flow rate; the gas analyzer is a portable infrared absorption spectroscopy methane / ethane analyzer, which uses infrared absorption spectroscopy to detect and analyze the concentrations of methane and ethane.

[0012] Preferably, the buried natural gas pipeline leakage flow detection system further includes a ground insertion rod, and a connecting column is provided inside the sealing device;

[0013] The ground insertion rod is a hollow column with its proximal end connected to the connecting post and its distal end having a pointed tip. The side of the ground insertion rod has multiple air holes, which are connected to the hollow cavity inside the ground insertion rod. A portion of the distal end of the ground insertion rod can be inserted into the ground through the ground surface.

[0014] When the ground stake is inserted into the ground, air holes are provided in both the area inside the ground and the area outside the ground surface.

[0015] Preferably, the inner side of the enclosure device is provided with multiple connecting posts, and at least one grounding rod is connected to these connecting posts; the axis of the grounding rod is perpendicular to the top surface of the enclosure device.

[0016] Preferably, the connecting post is provided with an external thread, and the near end of the grounding rod is provided with an internal thread that matches the external thread, and the connecting post and the grounding rod are connected by threads.

[0017] As described above, the beneficial technical effects of the buried natural gas pipeline leakage flow detection system of this utility model are as follows:

[0018] The sealing device is designed based on the characteristics of buried pipeline leakage scenarios, and can form a more ideal semi-enclosed space, improving the accuracy and effectiveness of detection;

[0019] The methane / ethane analyzer equipped in the detection system uses infrared absorption spectroscopy technology, which has the advantages of high accuracy, high sensitivity, high frequency, fast response time and low power consumption, and the data obtained is more real and reliable, and the leakage quantification is more accurate.

[0020] The buried natural gas pipeline leakage flow detection system is simple, portable, easy to operate, and highly practical. Attached Figure Description

[0021] The present invention will be more fully understood through the following detailed description and in conjunction with the accompanying drawings, wherein similar elements are numbered in a similar manner, wherein:

[0022] Figure 1 This is a schematic diagram of the usage status of the buried natural gas pipeline leakage flow detection system according to an embodiment of this utility model;

[0023] Figure 2 This is a schematic diagram of the sealing device of the buried natural gas pipeline leakage flow detection system according to an embodiment of the present invention;

[0024] Figure 3 This is a schematic diagram of the bottom of the sealing device of the buried natural gas pipeline leakage flow detection system according to an embodiment of the present invention;

[0025] Figure 4 This is a schematic diagram of the use status of the sealing device of the buried natural gas pipeline leakage flow detection system according to an embodiment of this utility model;

[0026] Figure 5 This is a cross-sectional view and an airflow diagram of the sealing device of the buried natural gas pipeline leakage flow detection system according to an embodiment of the present invention.

[0027] Figure 6 This is a schematic diagram of the installation of the ground insertion rod of the rectangular enclosed device of the buried natural gas pipeline leakage flow detection system according to an embodiment of this utility model;

[0028] Figure 7 This is a schematic diagram of the connecting column of the cuboid-shaped sealing device of the buried natural gas pipeline leakage flow detection system according to an embodiment of this utility model;

[0029] Figure 8 This is a schematic diagram of the connecting column of the frustum-shaped sealing device of the buried natural gas pipeline leakage flow detection system according to an embodiment of this utility model;

[0030] Figure 9 This is a schematic diagram of the installation of the ground insertion rod of the frustum-shaped enclosed device of the buried natural gas pipeline leakage flow detection system according to an embodiment of this utility model;

[0031] Figure 10This is a cross-sectional view and an airflow diagram of the buried natural gas pipeline leakage flow detection system with a ground insertion rod in use, according to an embodiment of the present invention.

[0032] In the diagram: 1. Sealing device; 11. Gas sampling interface; 2. Flow meter; 3. Gas pump; 4. Gas analyzer; 5. Hoses; 6. Power supply; 7. Ground insertion pole; 71. Connecting column; 72. Gas vent; 81. Gas pipeline; 82. Ground structure; 9. Counterweight. Detailed Implementation

[0033] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings, but this utility model is not limited to the following embodiments.

[0034] Urban gas operators are increasingly emphasizing the investigation of safety hazards in pipeline transmission and distribution systems and the assessment of methane emissions. Portable methane / ethane gas analyzers are among the most widely used detection devices. High-flow-rate enclosed sampling detection using this device is a common method for quantifying methane emissions at leak points. The principle is as follows: the enclosed detection device forms a semi-enclosed space with an inlet and a sampling interface 11. A vacuum pump 3 captures gas from the sampling interface 11 and introduces it into the analyzer. Finally, the methane leak flow rate is calculated based on the sampled flow rate and the measured concentration data.

[0035] However, due to the special nature of buried gas pipelines 81, which are buried underground, ordinary sealing devices cannot collect leaked natural gas through the surface to achieve the ideal sealing effect.

[0036] To address the aforementioned issues, this utility model provides a buried natural gas pipeline leakage flow detection system for capturing and analyzing gas within a space. The system calculates the methane leakage flow based on the collected gas flow rate and measured concentration data. The buried natural gas pipeline leakage flow detection system includes a sealed device 1 that can be placed on the ground to collect leaked gas from the buried pipeline; a flow meter 2 connected to the sealed device 1 for measuring gas flow; a vacuum pump 3 for providing negative pressure to transport the leaked gas; a gas analyzer 4 for analyzing leaked gas data; and a flexible hose 5 for connecting the sealed device 1, the flow meter 2, the vacuum pump 3, and the gas analyzer 4.

[0037] The sealing device 1 includes a semi-enclosed space enclosed by a shell and is hollow inside; one end of the sealing device 1 is an open surface that communicates with the interior of the sealing device 1; a gas sampling interface 11 is provided on the shell of the sealing device 1, and a flexible hose 5 is connected to the gas sampling interface 11; a vacuum pump 3 is used to extract leaked gas in the semi-enclosed space, which is then transported to a gas analyzer 4 after passing through a flow meter 2; the flow meter 2 is used to measure the gas sampling flow rate, and the gas analyzer 4 is used to detect the concentration of methane and / or ethane gas.

[0038] In this embodiment, as Figure 1 As shown, a buried natural gas pipeline leakage flow detection system is applicable to the quantitative detection of leaks in buried gas pipelines 81. It consists of a sealing device 1, a rubber hose 5, a dry gas flow meter 2, a vacuum pump 3, a gas analyzer 4, and a portable power supply 6. The sealing device 1 is rectangular in shape, with a completely open bottom and closed sides. A gas sampling interface 11 is located on the top surface. The sealing device 1 is used to seal off the ground space at the leak point. The gas hose 5 connects the sealing device 1, flow meter 2, pump 3, and analyzer in sequence, forming a flow channel for the sampled gas. The dry gas flow meter 2 is used to accurately measure the gas sampling flow. The vacuum pump 3 is used to extract gas from the semi-enclosed space and deliver it to the gas analyzer 4. The gas analyzer 4 is a portable infrared absorption spectroscopy methane / ethane analyzer, capable of highly accurate detection of methane and ethane concentrations in the collected gas. The portable power supply 6 powers the vacuum pump 3 and the gas analyzer 4.

[0039] The sealing device 1 in this embodiment can form a relatively sealed space on the ground surface. The leaked natural gas can be collected by the sealing device after overflowing through the ground surface. The air pump 3 can form a negative pressure in the sealing device 1, which is conducive to collecting the natural gas that overflows through the ground surface.

[0040] It should be noted that negative pressure means that the pressure inside the sealed device 1 is lower than the external pressure, which is a relatively negative pressure environment. While the air pump 3 extracts the gas inside the sealed device 1, air can still enter through the gap between the sealed device 1 and the ground.

[0041] The sealing device 1 of the buried natural gas pipeline leakage flow detection system in this embodiment is designed based on the characteristics of buried pipeline leakage scenarios, and can form a more ideal semi-enclosed space, improving the accuracy and effectiveness of detection. The methane / ethane analyzer equipped with the detection system adopts infrared absorption spectroscopy technology, which has the advantages of high accuracy, high sensitivity, high frequency, fast response time and low power consumption, and the acquired data is more realistic and reliable, and the leakage quantification is more accurate. Moreover, the equipment is simple, portable, easy to operate, has low learning curve, and is highly practical.

[0042] In the actual implementation process, when carrying out detection tasks, it is first necessary to identify the location of the leak point, and then perform the following operations in sequence:

[0043] (1) Turn on the gas analyzer 4 and detect it away from the leak point for 5 minutes to obtain the ambient background methane concentration;

[0044] (2) Cover the ground at the leak point with the sealing device 1, and connect the dry flow meter 2 and the vacuum pump 3 in sequence through the gas hose 5;

[0045] (3) After connecting the power supply, turn on the vacuum pump 3 and continuously extract high-concentration methane gas in the semi-enclosed space for 5 minutes.

[0046] (4) Connect the outlet of the vacuum pump 3 and the inlet of the gas analyzer 4 through the gas hose 5 to form a complete buried natural gas pipeline leakage flow detection system. Detect for 5-10 minutes and record the methane concentration data during this period.

[0047] (5) Turn off methane gas analyzer 4 and dismantle the system.

[0048] Furthermore, the enclosure device 1 is rectangular in shape, with the side length of the bottom surface being greater than the side length of the sides; the top surface, front side, rear side, left side, and right side of the enclosure device 1 are all provided with panels, while the bottom surface is open.

[0049] The gas sampling interface 11 is located on the top surface and can be connected to the hose 5; the sealing device 1 can be placed on the ground, with the opening of the sealing device 1 facing the ground, and the shell of the sealing device 1 forming a relatively enclosed space with the ground.

[0050] In this embodiment, as Figure 2 , Figure 3 As shown, the enclosure device 1 is rectangular in shape. The top, front, rear, left and right sides of the enclosure device 1 are enclosed by a panel to form a semi-enclosed structure, while the bottom is open. When in use, the bottom is in contact with the ground.

[0051] Enclosure 1 in use, as shown Figure 4 , Figure 5 As shown, natural gas overflowing from the ground surface can be collected by the sealing device 1. In some preferred embodiments, the top surface of the sealing device 1 is flat, and a counterweight 9 can be placed on the top surface to ensure that the sealing device 1 is stably placed on the ground.

[0052] airflow diagram as shown Figure 5 As shown, the dotted line indicates the flow direction of the leaking natural gas. The leaking natural gas from the gas pipeline 81 overflows from the gap in the ground structure 82. The sealing device 1 is placed on the ground near the leak point to collect the leaking natural gas. The hose 5 connected to the gas sampling port 11 can suck out the natural gas collected in the sealing device 1.

[0053] Furthermore, the sealing device 1 is cylindrical or frustum-shaped, with a closed shell on the top and sides, forming a semi-closed space, and the bottom is open; the gas sampling interface 11 is located on the top surface.

[0054] In some embodiments, the enclosure device 1 may be cylindrical or frustum-shaped, and enclosure devices 1 with different shapes can be matched to adapt to different working environments.

[0055] A frustum-shaped enclosed device 1, as shown Figure 8 as well as Figure 9As shown, the cylindrical sealing device 1 is similar, the only difference being the angle between the side and the top surface. The gas intake port 11 of the cylindrical or frustum-shaped sealing device 1 is located on the top surface.

[0056] Furthermore, the sealing device 1, flow meter 2, air pump 3, and gas analyzer 4 are connected in sequence; the buried natural gas pipeline leakage flow detection system includes three hoses 5, which are respectively installed between the sealing device 1 and the inlet of the flow meter 2, between the outlet of the flow meter 2 and the inlet of the air pump 3, and between the outlet of the air pump 3 and the inlet of the gas analyzer 4.

[0057] The buried natural gas pipeline leakage flow detection system also includes a mobile power supply 6, which is connected to the air pump 3 and the gas analyzer 4 to provide power to the air pump 3 and the gas analyzer 4.

[0058] The flow meter 2 is a dry gas flow meter 2, which is used to measure the gas sampling flow rate; the gas analyzer 4 is a portable infrared absorption spectroscopy methane / ethane analyzer, which uses infrared absorption spectroscopy technology to detect and analyze the concentration of methane and ethane.

[0059] Furthermore, the buried natural gas pipeline leakage flow detection system also includes a ground insertion rod 7, and a connecting column 71 is provided inside the sealing device 1;

[0060] The ground insertion rod 7 is a hollow column with its proximal end connected to the connecting post 71 and its distal end having a pointed tip. The side of the ground insertion rod 7 has multiple air holes 72, which are connected to the hollow cavity inside the ground insertion rod 7. A portion of the distal end of the ground insertion rod 7 can be inserted into the ground through the ground surface.

[0061] When the ground insertion rod 7 is inserted into the ground, air holes 72 are provided in both the area inside the ground and the area outside the ground surface of the ground insertion rod 7.

[0062] In this embodiment, as Figure 6 , Figure 7 , Figure 8 as well as Figure 9 As shown, ground insertion rod 7 is a hollow rod, allowing for internal ventilation, such as... Figure 10 As shown, the dotted line indicates the flow direction of the leaked natural gas. The leaked natural gas from the gas pipeline 81 seeps into the gaps in the ground structure 82. The vents 72 on the circumferential surface of the ground plug 7 can serve as either air intake or exhaust. The vents 72 in the area of ​​the ground plug 7 within the ground surface serve as air intake, capable of extracting some of the natural gas that is still inside the ground and has not yet overflowed. The vents 72 in the area of ​​the ground plug 7 outside the ground surface serve as air exhaust, capable of outputting the gas into the sealed device 1.

[0063] Furthermore, the inner side of the enclosure device 1 is provided with a plurality of connecting posts 71, and at least one grounding rod 7 is connected to these connecting posts 71 of the enclosure device 1; the axis of the grounding rod 7 is perpendicular to the top surface of the enclosure device 1.

[0064] The connecting column 71 can be set at the center or around the perimeter of the enclosure device 1. In the specific implementation process, it can be set according to the surface material and its softness.

[0065] Furthermore, the connecting post 71 is provided with an external thread, and the near end of the grounding rod 7 is provided with an internal thread that matches the external thread. The connecting post 71 and the grounding rod 7 are connected by threads.

[0066] The connecting post 71 and the grounding rod 7 can be connected by plugging or by thread.

[0067] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A buried natural gas pipeline leakage flow detection system, used to capture and analyze gas in a space, and calculate methane leakage flow based on the gas sampling flow rate and measured concentration data, characterized in that: The buried natural gas pipeline leakage flow detection system includes a sealing device (1) that can be placed on the ground to collect leaked gas from the buried pipeline, a flow meter (2) connected to the sealing device (1) for measuring the gas flow, a vacuum pump (3) for providing negative pressure to transport the leaked gas, a gas analyzer (4) for analyzing the leaked gas data, and a hose (5) for connecting the sealing device (1), the flow meter (2), the vacuum pump (3), and the gas analyzer (4). The sealing device (1) includes a semi-enclosed space enclosed by a shell and is hollow inside; one end of the sealing device (1) is an open surface that is connected to the interior of the sealing device (1); a gas sampling interface (11) is provided on the shell of the sealing device (1), and a hose (5) is connected to the gas sampling interface (11); a gas pump (3) is used to extract the leaked gas in the semi-enclosed space, which is then transported to the gas analyzer (4) after passing through the flow meter (2); the flow meter (2) is used to measure the gas sampling flow rate, and the gas analyzer (4) is used to detect the concentration of methane and / or ethane gas.

2. The buried natural gas pipeline leakage flow detection system according to claim 1, characterized in that: The enclosure device (1) is rectangular in shape, with the side length of the bottom surface being greater than the side length of the side surface; the top surface, front side, rear side, left side and right side of the enclosure device (1) are all provided with panels, and the bottom surface is open; The gas sampling interface (11) is set on the top surface and can be connected to the hose (5); the sealing device (1) can be placed on the ground, the opening of the sealing device (1) on the ground faces the ground, and the shell of the sealing device (1) forms a relatively closed space with the ground.

3. The buried natural gas pipeline leakage flow detection system according to claim 1, characterized in that: The sealing device (1) is cylindrical or frustum-shaped, with a closed shell on the top and sides, forming a semi-closed space, and the bottom is open; the gas sampling interface (11) is located on the top surface.

4. A buried natural gas pipeline leakage flow detection system according to any one of claims 1 to 3, characterized in that: The sealing device (1), flow meter (2), air pump (3), and gas analyzer (4) are connected in sequence; the buried natural gas pipeline leakage flow detection system includes three hoses (5), which are respectively set between the sealing device (1) and the inlet of the flow meter (2), between the outlet of the flow meter (2) and the inlet of the air pump (3), and between the outlet of the air pump (3) and the inlet of the gas analyzer (4).

5. The buried natural gas pipeline leakage flow detection system according to claim 4, characterized in that: The buried natural gas pipeline leakage flow detection system also includes a mobile power supply (6), which is connected to the air pump (3) and the gas analyzer (4) to provide power to the air pump (3) and the gas analyzer (4).

6. A buried natural gas pipeline leakage flow detection system according to any one of claims 1 to 3, characterized in that: The flow meter (2) is a dry gas flow meter, which is used to measure the gas sampling flow rate; the gas analyzer (4) is a portable infrared absorption spectroscopy methane / ethane analyzer, which uses infrared absorption spectroscopy to detect and analyze the concentration of methane and ethane.

7. The buried natural gas pipeline leakage flow detection system according to claim 1, characterized in that: The buried natural gas pipeline leakage flow detection system also includes a ground insertion rod (7), and a connecting column (71) is provided inside the sealing device (1); The ground insertion rod (7) is a hollow column with its proximal end connected to the connecting column (71) and its distal end having a pointed tip; the ground insertion rod (7) has multiple air holes (72) on its side, and the air holes (72) are connected to the hollow cavity inside the ground insertion rod (7); a part of the distal end of the ground insertion rod (7) can be inserted into the ground through the ground surface; When the ground insertion rod (7) is inserted into the ground, air holes (72) are provided in both the area inside the ground and the area outside the ground surface.

8. The buried natural gas pipeline leakage flow detection system according to claim 7, characterized in that: The inner side of the enclosure device (1) is provided with a plurality of connecting posts (71), and at least one grounding rod (7) is connected to the connecting posts (71) of the enclosure device (1); the axis of the grounding rod (7) is perpendicular to the top surface of the enclosure device (1).

9. A buried natural gas pipeline leakage flow detection system according to claim 7, characterized in that: The connecting post (71) is provided with an external thread, and the near end of the ground insertion rod (7) is provided with an internal thread that matches the external thread. The connecting post (71) and the ground insertion rod (7) are connected by threads.

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