A natural gas sampling and detection device used in natural gas pipelines

Abstract

The present invention discloses a natural gas sampling and detection device applied to a natural gas pipeline, which belongs to the technical field of natural gas sampling and comprises a sampling barrel arranged on the natural gas pipeline, wherein the bottom end of the sampling barrel is connected with the natural gas pipeline, a sealing plate is arranged at the bottom of the sampling barrel, an air inlet hole is opened on the sealing plate, a pull rod is movably arranged at the top end of the sampling barrel, a first piston plate is rotatably mounted at one end of the pull rod, a sealing block matching the size of the air inlet hole is fixed at the bottom of the first piston plate; a plurality of sampling boxes are fixed on the side wall of the sampling barrel, and a sampling hole is opened at one end of the sampling box close to the sampling barrel; the present invention prevents residual gas from existing in the sampling barrel, ensures the purity and independence of the next sampling, and avoids the error caused by the mutual influence between the residual natural gas and the new sampled gas in the traditional sampling method.

Description

Technical Field

[0001] The invention relates to the technical field of natural gas sampling, and in particular to a natural gas sampling and detection device applied to a natural gas pipeline. Background Art

[0002] Natural gas is stored in underground porous rock formations, including oilfield gas, gas field gas, coalbed methane, mud volcano gas and biogas, and a small amount is also found in coal seams. It is a high-quality fuel and chemical raw material. The main use of natural gas is as fuel. It can be used to make carbon black, chemicals and liquefied petroleum gas. Propane and butane produced from natural gas are important raw materials for modern industry. Natural gas is mainly composed of a mixture of gaseous low-molecular hydrocarbons and non-hydrocarbon gases. When using natural gas, it needs to be transported by pipelines. At the same time, it is necessary to sample and test the natural gas in the pipeline to conduct gas quality analysis.

[0003] At present, when sampling natural gas, a sampling device is generally installed on the pipeline. For example, the patent with publication number CN212432689U discloses a natural gas pipeline that is convenient for sampling and detection, including a natural gas pipeline, a limiting mechanism, a conveying mechanism and a placing mechanism. The limiting mechanism is arranged on the top of the natural gas pipeline, the conveying mechanism is arranged on the limiting mechanism, and the placing mechanism is arranged on the conveying mechanism.

[0004] The above patent still has some shortcomings: when sampling, natural gas will enter the fixed shell. After one sampling is completed, some natural gas will remain in the fixed shell. When the next sampling is carried out, the new natural gas will be mixed with the previous residual natural gas, resulting in errors in the sampling composition, which in turn affects the test results. Summary of the invention

[0005] The purpose of the present invention is to provide a natural gas sampling and detection device applied to a natural gas pipeline to solve the following technical problem: after the existing sampling and detection device completes a sampling, some natural gas still remains inside. When the next sampling is performed, the new natural gas will mix with the previously remaining natural gas, resulting in errors in the sampling composition, which in turn affects the detection results.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A natural gas sampling and detection device applied to a natural gas pipeline comprises a sampling cylinder arranged on the natural gas pipeline, the bottom end of the sampling cylinder is connected to the natural gas pipeline, a blocking plate is arranged at the bottom of the sampling cylinder, an air inlet hole is opened on the blocking plate, a pull rod is movably arranged at the top end of the sampling cylinder, a first piston plate is rotatably mounted on one end of the pull rod, and a blocking block matching the size of the air inlet hole is fixed at the bottom of the first piston plate;

[0008] A plurality of sampling boxes are fixed on the side wall of the sampling barrel, a sampling hole is opened on one end of the sampling box close to the sampling barrel, a screw is threadedly connected on the side wall of the sampling box away from the sampling barrel, a piston block is rotatably mounted on one end of the screw, a branch pipe is connected to the bottom of the sampling box, a sampling test tube is also fixed on the bottom of the sampling box, and one end of the branch pipe extends into the sampling test tube;

[0009] The side wall of the sampling tube is also connected with a pressure relief pipe, and a valve is arranged on the pressure relief pipe.

[0010] As a further solution of the present invention: a handle is installed at one end of the screw rod away from the piston block, and an exhaust pipe is connected to the bottom of the sampling box.

[0011] As a further solution of the present invention: a nut block is fixed to the bottom of the sampling box, and the nut block is located outside the branch pipe, and a thread matching the nut block is arranged on the outer wall of the sampling test tube mouth.

[0012] As a further solution of the present invention: a rubber sealing sheet is arranged in the tube mouth of the sampling test tube, and a cross-shaped opening is arranged on the rubber sealing sheet.

[0013] As a further solution of the present invention: a handwheel is installed at one end of the pull rod away from the first piston plate, a vertical rod is fixed to one side of the top wall of the sampling tube, a limiting bolt is threadedly connected to the vertical rod, and the limiting bolt contacts the upper surface of the handwheel.

[0014] As a further solution of the present invention: a limit block is symmetrically arranged on the inner wall of the sampling cylinder, a second piston plate is sleeved on the pull rod, a rotary seal is arranged at the sleeve joint of the pull rod and the second piston plate, the rotary seal consists of a rubber ring and a slip ring rotatably arranged on the rubber ring, the rubber ring is fixedly connected to the second piston plate, the slip ring is sleeved on the pull rod, and the second piston plate is located above the limit block, an annular storage bag is arranged above the second piston plate, both sides of the storage bag are connected to a discharge pipe, and one end of the discharge pipe passes through the second piston plate and extends to the bottom of the second piston plate, sealant is arranged in the storage bag, the discharge pipe is a rubber hose, and the discharge pipe is sealed and fixedly connected to the second piston plate.

[0015] As a further solution of the present invention: the cross section of the limit block is an isosceles triangle structure, and the limit block is provided with a groove matching the discharge pipe.

[0016] As a further solution of the present invention: a scraper rod is symmetrically installed at the bottom end of the pull rod, a circular slide groove is opened on the top of the sampling barrel, a slider is slidably connected in the circular slide groove, an arc-shaped telescopic tube is connected to one side of the slider, a connecting tube is connected to the top of the sampling barrel, one end of the connecting tube extends into the circular slide groove and is connected to one end of the telescopic tube, and the connecting point between the connecting tube and the sampling barrel is located above the second piston plate, and a force-bearing rod is fixed on the pull rod, and the force-bearing rod is in contact with the slider.

[0017] Beneficial effects of the present invention:

[0018] (1) The present invention provides a sealable sealing plate at the bottom of the sampling tube, and a movable pull rod and a first piston plate structure at the top, so that there will be no residual gas in the sampling tube, ensuring the purity and independence of the next sampling, avoiding the error caused by the mutual influence of residual natural gas and new sampled gas in the traditional sampling method, and at the same time, by providing multiple sampling boxes, multiple sampling is achieved, thereby improving the representativeness of the sampling data and the efficiency of detection;

[0019] (2) The present invention provides a sampling tube and a sealing rubber sheet. When natural gas enters the sampling box, the piston block moves to allow the natural gas to automatically enter the sampling tube. After sampling is completed, the sampling tube is removed to obtain the required sample. The rubber sealing sheet can prevent natural gas leakage.

[0020] (3) The present invention provides structures such as a limit block, a second piston plate, a storage bag, and a discharge pipe. Since the first piston plate frequently rubs against the inner wall of the sampling tube during sampling, in order to avoid continuous leakage of natural gas caused by wear of the first piston plate, when natural gas leaks, the internal air pressure of the sampling tube increases, pushing the second piston plate to move, squeezing out the sealant in the storage bag to fill the worn area, thereby avoiding continuous leakage of natural gas and improving safety. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described below in conjunction with the accompanying drawings.

[0022] Figure 1 It is a schematic diagram of the structure of the present invention;

[0023] Figure 2 It is a schematic diagram of the structure of the sampling tube of the present invention from a first viewing angle;

[0024] Figure 3 It is a schematic diagram of the structure of the sampling tube of the present invention from a second viewing angle;

[0025] Figure 4 It is a schematic diagram of the internal structure of the sampling tube of the present invention;

[0026] Figure 5 It is a schematic diagram of the internal structure of the sampling box of the present invention;

[0027] Figure 6 It is a three-dimensional structural schematic diagram of the sampling box and the sampling test tube of the present invention;

[0028] Figure 7 It is a schematic structural diagram of the second piston plate and the storage bag of the present invention;

[0029] Figure 8 It is a structural schematic diagram of the limit block of the present invention;

[0030] Fig. 9 yes Figure 3 The enlarged view of point A in the middle;

[0031] Fig.10 It is a structural schematic diagram of the pull rod, the second piston plate and the rotary seal of the present invention.

[0032] In the figure: 1. sampling cylinder; 2. sampling box; 201. sampling hole; 202. screw; 203. piston block; 204. handle; 205. exhaust pipe; 206. branch pipe; 207. nut block; 208. sampling test tube; 209. rubber sealing sheet; 3. pull rod; 4. first piston plate; 5. blocking block; 6. blocking plate; 7. hand wheel; 8. pressure relief pipe; 9. vertical pole; 10. limit bolt; 11. second piston plate; 12. limit block; 13. storage bag; 14. discharge pipe; 15. groove; 16. scraper rod; 17. force rod; 18. circular slide groove; 19. telescopic tube; 20. slider; 21. connecting pipe; 22. rotary seal.

[0033] The drawings are only used for illustrative purposes and are not to be construed as limitations of the present invention. To better illustrate the present embodiment, some parts of the drawings may be omitted, enlarged, or reduced in size, and do not represent the size and shape of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions may be omitted in the drawings. DETAILED DESCRIPTION

[0034] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] See also Figure 1-Figure 6As shown, the present invention is a natural gas sampling and detection device applied to a natural gas pipeline, comprising a sampling tube 1 arranged on the natural gas pipeline, the bottom end of the sampling tube 1 is connected to the natural gas pipeline, a blocking plate 6 is arranged at the bottom of the sampling tube 1, an air inlet hole is opened on the blocking plate 6, a pull rod 3 is movably arranged at the top of the sampling tube 1, a first piston plate 4 is rotatably installed at one end of the pull rod 3, and a blocking block 5 matching the size of the air inlet hole is fixed at the bottom of the first piston plate 4; a plurality of sampling boxes 2 are fixed on the side wall of the sampling tube 1 A sampling hole 201 is provided at one end of the sampling box 2 close to the sampling cylinder 1, a screw 202 is threadedly connected to the side wall of the sampling box 2 away from the sampling cylinder 1, a piston block 203 is rotatably installed at one end of the screw 202, a branch pipe 206 is connected to the bottom of the sampling box 2, a sampling test tube 208 is also fixed to the bottom of the sampling box 2, and one end of the branch pipe 206 extends into the sampling test tube 208; a pressure relief pipe 8 is also connected to the side wall of the sampling cylinder 1, and a valve is provided on the pressure relief pipe 8; in the initial state, the first piston plate 4 and the sealing The first piston plate 4 is in contact with the sealing plate 6, and the piston block 203 is located on the side close to the sampling cylinder 1, so as to ensure that there is no residual natural gas in the sampling cylinder 1 and the sampling box 2. When sampling is required, the valve on the pressure relief pipe 8 is opened first, and the operator manually pulls the pull rod 3 upward to make the first piston plate 4 and the blocking block 5 separate from the blocking plate 6, and the natural gas in the natural gas pipeline will enter the sampling cylinder 1. According to the required sampling amount, the first piston plate 4 is lifted to a suitable height, and then the screw 202 is rotated to make the piston block 203 move to the side away from the sampling cylinder 1. The natural gas will enter the sampling box 2 by moving it sideways, and enter the sampling tube 208 through the branch pipe 206. Then, the screw rod 202 is rotated in the opposite direction to reset the piston block 203, and the natural gas in the sampling box 2 is completely discharged. The sampling tube 208 is removed to complete the sampling. If multiple samplings are required, the operation can be repeated. After the sampling is completed, the pull rod 3 is pressed down to reset the first piston plate 4, and the natural gas in the sampling cylinder 1 is completely discharged, which is convenient for the next sampling. The natural gas in the sampling tube 208 can be tested with corresponding instruments.

[0036] See also Figure 5 A handle 204 is installed at one end of the screw rod 202 away from the piston block 203, and an exhaust pipe 205 is connected to the bottom of the sampling box 2; the exhaust pipe 205 is used to exhaust the air in the sampling box 2 when the piston block 203 moves, and the handle 204 is convenient for the operator to turn the screw rod 202.

[0037] See also Figure 5 and Figure 6 A nut block 207 is fixed at the bottom of the sampling box 2, and the nut block 207 is located outside the branch pipe 206. A thread matching the nut block 207 is provided on the outer wall of the mouth of the sampling test tube 208; the sampling test tube 208 is installed in a threaded connection manner, which is simple and easy to operate.

[0038] See also Figure 5 and Figure 6A rubber sealing sheet 209 is provided in the tube mouth of the sampling test tube 208, and a cross-shaped opening is provided on the rubber sealing sheet 209; the setting of the rubber sealing sheet 209 prevents natural gas leakage after the sampling is completed, and the cross-shaped opening facilitates the insertion of the branch pipe 206.

[0039] See also Figure 2 A handwheel 7 is installed at one end of the pull rod 3 away from the first piston plate 4, and a vertical rod 9 is fixed to one side of the top wall of the sampling tube 1. The vertical rod 9 is threadedly connected with a limiting bolt 10, and the limiting bolt 10 contacts the upper surface of the handwheel 7; the handwheel 7 is convenient for the operator to pull the pull rod 3, and the limiting bolt 10 can be used to limit the height of the handwheel 7 to ensure that the first piston plate 4 is affected and does not move during the non-sampling time.

[0040] See also Figure 4 , Figure 7 and Fig.10 , a limited block 12 is symmetrically arranged on the inner wall of the sampling tube 1, a second piston plate 11 is sleeved on the pull rod 3, a rotary seal 22 is arranged at the sleeve joint of the pull rod 3 and the second piston plate 11, and the rotary seal 22 is composed of a rubber ring and a slip ring rotatably arranged on the rubber ring, the rubber ring is fixedly connected to the second piston plate 11, and the slip ring is sleeved on the pull rod 3 to ensure the airtightness between the second piston plate 11 and the pull rod 3 and the inner wall of the sampling tube 1, and will not affect the movement of the second piston plate 11, and at the same time, the tightness of the parts does not block the pull rod 3 Relative to the rotation of the second piston plate 11, and the second piston plate 11 is located above the limit block 12, an annular storage bag 13 is arranged above the second piston plate 11, both sides of the storage bag 13 are connected with discharge pipes 14, and one end of the discharge pipe 14 passes through the second piston plate 11 and extends to the bottom of the second piston plate 11, a sealant is arranged in the storage bag 13, the discharge pipe 14 is a rubber hose, and the discharge pipe 14 is sealed and fixedly connected to the second piston plate 11; since the first piston plate 4 frequently rubs against the inner wall of the sampling cylinder 1 during sampling, in order to avoid continuous leakage of natural gas caused by wear of the first piston plate 4, when natural gas leaks, the air pressure between the first piston plate 4 and the second piston plate 11 increases, and the second piston plate 11 moves upward under the influence of the air pressure, thereby squeezing the storage bag 13 and squeezing out the sealant, and the sealant falls onto the first piston plate 4 through the discharge pipe 14, thereby filling and sealing the worn area, avoiding further leakage of natural gas, and improving safety.

[0041] See also Figure 7 and Figure 8 The cross section of the limit block 12 is an isosceles triangle structure, and a groove 15 matching the discharge pipe 14 is provided on the limit block 12; under normal conditions, the discharge pipe 14 is inserted into the groove 15 to prevent the sealant from contacting with the outside air and oxidizing.

[0042] See also Figure 4 , Figure 7 and Fig. 9 , a scraper rod 16 is symmetrically installed at the bottom end of the pull rod 3, a circular slide groove 18 is opened on the top of the sampling tube 1, a slider 20 is slidably connected in the circular slide groove 18, and an arc-shaped telescopic tube 19 is connected to one side of the slider 20. A connecting tube 21 is connected to the top of the sampling tube 1, one end of the connecting tube 21 extends into the circular slide groove 18 and is connected to one end of the telescopic tube 19, and the connecting point between the connecting tube 21 and the sampling tube 1 is located above the second piston plate 11, and a force rod 17 is fixed on the pull rod 3, and the force rod 17 is in contact with the slider 20; in order to allow the sealant to quickly fill the gap, when the second After the piston plate 11 rises to above the connection point between the connecting pipe 21 and the sampling cylinder 1, the natural gas will enter the telescopic tube 19 through the connecting pipe 21, the telescopic tube 19 will stretch and push the slider 20 to move, the slider 20 will move along the circular slide groove 18, thereby pushing the force-bearing rod 17 and the pull rod 3 to rotate, the rotation of the pull rod 3 drives the scraper rod 16 at the bottom to rotate, and the sealant fallen on the first piston plate 4 will be scraped along the inner wall of the sampling cylinder 1 to improve the sealing effect. When the operator comes to take samples and finds that the length of the telescopic tube 19 has changed, it can be known that there has been a leak inside the sampling cylinder 1, and maintenance can be carried out.

[0043] Working principle of the present invention: In the initial state, the first piston plate 4 is in contact with the blocking plate 6, and the piston block 203 is located on the side close to the sampling tube 1, so as to ensure that there is no residual natural gas in the sampling tube 1 and the sampling box 2. When sampling is required, the valve on the pressure relief pipe 8 is first opened, and the limit bolt 10 is turned to release the restriction on the hand wheel 7. The operator manually pulls the pull rod 3 upward to make the first piston plate 4 and the blocking block 5 separate from the blocking plate 6, and the natural gas in the natural gas pipeline will enter the sampling tube 1. According to the required sampling amount, the first piston plate 4 is lifted to a suitable height, and then the screw 20 is turned. 2 makes the piston block 203 move toward the side away from the sampling cylinder 1, and the natural gas will enter the sampling box 2 and enter the sampling test tube 208 through the branch pipe 206. Then, the screw rod 202 is rotated in the opposite direction to reset the piston block 203, and the natural gas in the sampling box 2 is completely discharged. The sampling test tube 208 is removed to complete the sampling. If multiple samplings are required, the operation can be repeated. After the sampling is completed, the pull rod 3 is pressed down to reset the first piston plate 4, and the natural gas in the sampling cylinder 1 is completely discharged. The valve is closed to reset the limit bolt 10, and finally the natural gas in the sampling test tube 208 can be tested with a corresponding instrument;

[0044] Since the first piston plate 4 frequently rubs against the inner wall of the sampling tube 1 during sampling, in order to avoid the first piston plate 4 from being worn out and causing continuous leakage of natural gas, when natural gas leaks, the air pressure between the first piston plate 4 and the second piston plate 11 increases, and the second piston plate 11 moves upward under the influence of the air pressure, thereby squeezing the storage bag 13 and squeezing out the sealant, and the sealant falls onto the first piston plate 4 through the discharge pipe 14. When the second piston plate 11 rises to above the connection between the connecting pipe 21 and the sampling tube 1, the natural gas will enter the telescopic tube 19 through the connecting pipe 21, and the telescopic tube 19 will extend and push the slider 20 to move. The slider 20 moves along the circular slide groove 18, thereby pushing the force rod 17 and the pull rod 3 to rotate. The rotation of the pull rod 3 drives the scraper rod 16 at the bottom to rotate, and the sealant falling on the first piston plate 4 will be scraped evenly along the inner wall of the sampling tube 1 to improve the sealing effect. When the operator comes to take samples, it is found that the length of the telescopic tube 19 has changed, and it can be known that there has been a leak inside the sampling tube 1, and then maintenance is carried out.

[0045] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A natural gas sampling and detection device applied to a natural gas pipeline, comprising a sampling cylinder (1) arranged on the natural gas pipeline, characterized in that: The bottom end of the sampling tube (1) is connected to the natural gas pipeline, a blocking plate (6) is provided at the bottom of the sampling tube (1), an air inlet hole is provided on the blocking plate (6), a pull rod (3) is movably provided at the top end of the sampling tube (1), a first piston plate (4) is rotatably mounted on one end of the pull rod (3), and a blocking block (5) matching the size of the air inlet hole is fixed at the bottom of the first piston plate (4); A plurality of sampling boxes (2) are fixed on the side wall of the sampling cylinder (1); a sampling hole (201) is provided on one end of the sampling box (2) close to the sampling cylinder (1); a screw rod (202) is threadedly connected to the side wall of the sampling box (2) away from the sampling cylinder (1); a piston block (203) is rotatably mounted on one end of the screw rod (202); a branch pipe (206) is connected to the bottom of the sampling box (2); a sampling test tube (208) is also fixed to the bottom of the sampling box (2); one end of the branch pipe (206) extends into the sampling test tube (208); A pressure relief pipe (8) is also connected to the side wall of the sampling tube (1), and a valve is provided on the pressure relief pipe (8); A limit block (12) is symmetrically arranged on the inner wall of the sampling cylinder (1), a second piston plate (11) is sleeved on the pull rod (3), a rotary seal (22) is arranged at the sleeve joint between the pull rod (3) and the second piston plate (11), the rotary seal (22) is composed of a rubber ring and a slip ring rotatably arranged on the rubber ring, the rubber ring is fixedly connected to the second piston plate (11), the slip ring is sleeved on the pull rod (3), and the second piston plate (11) is located above the limit block (12), an annular storage bag (13) is arranged above the second piston plate (11), both sides of the storage bag (13) are connected to a discharge pipe (14), and one end of the discharge pipe (14) passes through the second piston plate (11) and extends to the bottom of the second piston plate (11), a sealant is arranged in the storage bag (13), the discharge pipe (14) is a rubber hose, and the discharge pipe (14) is sealed and fixedly connected to the second piston plate (11).

2. A natural gas sampling and detection device applied to a natural gas pipeline according to claim 1, characterized in that: A handle (204) is installed at one end of the screw rod (202) away from the piston block (203), and an exhaust pipe (205) is connected to the bottom of the sampling box (2).

3. A natural gas sampling and detection device applied to a natural gas pipeline according to claim 1, characterized in that: A nut block (207) is fixed to the bottom of the sampling box (2), and the nut block (207) is located outside the branch pipe (206). A thread matching the nut block (207) is provided on the outer wall of the tube mouth of the sampling test tube (208).

4. A natural gas sampling and detection device applied to a natural gas pipeline according to claim 1, characterized in that: A rubber sealing sheet (209) is arranged in the tube mouth of the sampling test tube (208), and a cross-shaped opening is arranged on the rubber sealing sheet (209).

5. A natural gas sampling and detection device for use in a natural gas pipeline according to claim 1, characterized in that: A handwheel (7) is installed at one end of the pull rod (3) away from the first piston plate (4), and a vertical rod (9) is fixed to one side of the top wall of the sampling tube (1). A limit bolt (10) is threadedly connected to the vertical rod (9), and the limit bolt (10) is in contact with the upper surface of the handwheel (7).

6. A natural gas sampling and detection device for use in a natural gas pipeline according to claim 1, characterized in that: The cross section of the limit block (12) is an isosceles triangle structure, and the limit block (12) is provided with a groove (15) that matches the discharge pipe (14).

7. A natural gas sampling and detection device for use in a natural gas pipeline according to claim 1, characterized in that: A scraper rod (16) is symmetrically mounted at the bottom end of the pull rod (3), a circular groove (18) is provided at the top of the sampling tube (1), a slider (20) is slidably connected in the circular groove (18), one side of the slider (20) is connected to an arc-shaped telescopic tube (19), a connecting tube (21) is connected to the top of the sampling tube (1), one end of the connecting tube (21) extends into the circular groove (18) and is connected to one end of the telescopic tube (19), and the connecting point between the connecting tube (21) and the sampling tube (1) is located above the second piston plate (11), and a force-bearing rod (17) is fixed on the pull rod (3), and the force-bearing rod (17) is in contact with the slider (20).

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