A device for hydrogen permeation testing of non-metallic composite pipes

Abstract

This utility model discloses a device suitable for hydrogen permeation testing of non-metallic composite pipes, including an upper clamp, a lower clamp, an inlet pipe, an outlet pipe, and a waste gas treatment system. Both the upper and lower clamps are arc-shaped structures, with the upper clamp coaxially fitted inside the lower clamp and screwed together. A placement groove is coaxially formed on the outer circumferential surface of the upper clamp, and the pipe sample is placed in the placement groove. An upper arc-shaped groove communicating with the placement groove is formed coaxially at the middle position of the outer circumferential surface of the upper clamp relative to the inner arc surface of the placement groove, and a lower arc-shaped groove is coaxially formed on the inner circumferential surface of the lower clamp. The inlet pipe is located directly above the upper clamp, with one end connected to a hydrogen source and the other end extending into the upper clamp and communicating with the upper arc-shaped groove. The outlet pipe is located directly below the lower clamp, with one end connected to the waste gas treatment system and the other end extending into the lower clamp and communicating with the lower arc-shaped groove. This utility model can accurately detect the permeation performance of the composite pipe wall.

Description

Technical Field

[0001] This utility model relates to the field of non-metallic composite pipe technology, specifically to a device suitable for hydrogen permeation testing of non-metallic composite pipes. Background Technology

[0002] Non-metallic composite pipes for hydrogen transportation are a new type of product, and hydrogen / gas permeability testing is required before use. Currently, the common method is to seal both ends of the composite pipe with metal joints before conducting the hydrogen / gas permeability test. However, this method has several drawbacks: 1) The measured hydrogen / gas permeation is the sum of the permeation within the pipe body and at the pipe ends, thus failing to accurately detect the pipe body's hydrogen / gas permeability; 2) It requires a certain length of pipe with external metal joints, high sealing requirements at the pipe ends, and is difficult to operate. It also requires a large amount of hydrogen / gas and a large test chamber. The high gas demand also leads to a long vacuuming and filling time, increasing testing costs and safety hazards; 3) Under high-pressure gas, the composite pipe expands, reducing the volume of the low-pressure chamber (annular space). The measured gas pressure on the low-pressure side includes the pressure resulting from the reduced volume of the annular space due to pipe expansion, thus reducing the accuracy of the pipeline's gas permeability measurement.

[0003] Therefore, how to accurately test the permeation rate of composite pipes has become an urgent problem to be solved. Utility Model Content

[0004] The technical problem to be solved by this utility model is to provide a device suitable for hydrogen permeation testing of non-metallic composite pipes. It is simple to operate and convenient to use, reduces gas consumption and test time, reduces sealing difficulty, and can accurately detect the permeability performance of the composite pipe wall, thereby improving work efficiency.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The present invention provides a device for hydrogen permeation testing of non-metallic composite tubes, the innovation of which lies in: including an upper clamp, a lower clamp, an inlet pipe, an outlet pipe, and a waste gas treatment system; both the upper and lower clamps are horizontally and longitudinally arranged arc-shaped structures, and the upper clamp is coaxially sleeved within the lower clamp, and the two are screwed together for fixation; a placement groove matching the tube sample is coaxially embedded in the middle position of the outer circumference of the upper clamp, and the placement groove does not extend beyond the two end faces and front and rear end faces of the upper clamp, and the tube sample is placed in the placement groove; the upper clamp... The lower clamp has an upper arc-shaped groove that is coaxially embedded in the middle of its outer circumference and relative to the inner arc surface of the placement groove, and is connected to the placement groove. A lower arc-shaped groove that matches the upper arc-shaped groove is also coaxially embedded in the inner circumference of the lower clamp relative to the position of the upper arc-shaped groove. The air inlet pipe is located directly above the upper clamp, with one end connected to a hydrogen source via a pipeline, and the other end extending radially along the upper clamp into its interior and communicating with the upper arc-shaped groove. The air outlet pipe is located directly below the lower clamp, with one end connected to the waste gas treatment system via a pipeline, and the other end extending radially along the lower clamp into its interior and communicating with the lower arc-shaped groove.

[0006] Preferably, the curvature of the upper clamp and the lower clamp are consistent with the curvature of the tube, and their arc lengths are matched and both are greater than the arc length of the tube; the outer diameter of the upper clamp is consistent with the inner diameter of the lower clamp, and the inner arc surface of the upper clamp is set upward and coaxially sleeved in the lower clamp; the longitudinal width of the upper clamp is consistent with the longitudinal width of the lower clamp, and both are greater than the longitudinal width of the tube.

[0007] Preferably, it also includes locking bolts and nuts; both ends of the upper and lower clamps are horizontally flanged outwards, ensuring that the two flanges of the upper clamp are respectively aligned with the corresponding flanges of the lower clamp; locking bolts are also vertically screwed onto the two flanges of the upper clamp, and the screw end of each locking bolt extends vertically downwards from the corresponding flange of the lower clamp, and is screwed onto the corresponding nut, thereby coaxially connecting and fixing the upper and lower clamps together through the cooperation of the locking bolts and nuts.

[0008] Preferably, the curvature of the upper and lower arc-shaped grooves are consistent with the curvature of the tube, and the arc lengths of the upper and lower arc-shaped grooves are consistent and both less than the arc length of the placement groove; the longitudinal widths of the upper and lower arc-shaped grooves are both less than the longitudinal width of the placement groove, and the upper arc-shaped groove does not extend beyond the inner circumferential surface of the upper clamp, and the lower arc-shaped groove does not extend beyond the outer circumferential surface of the lower clamp.

[0009] Preferably, it also includes a wire mesh and a metal support; a matching metal support is coaxially arranged on the outer side of the lower arc-shaped groove, and a matching wire mesh is coaxially arranged on the inner side of the lower arc-shaped groove. Thus, the tube sample placed in the placement groove is supported by the cooperation of the wire mesh and the metal support, and it is ensured that neither the wire mesh nor the metal support affects the permeation of hydrogen.

[0010] Preferably, it also includes sealing ring III and sealing ring IV; a circular groove III matching sealing ring III is also embedded in the middle of the inner circumferential surface of the lower clamp relative to the outer side of the lower arc groove, and a circular groove IV matching sealing ring IV is also embedded in the middle of the inner circumferential surface of the lower clamp relative to the inner side of the circular groove III, ensuring that the circular groove IV, the circular groove III and the lower arc groove are not interconnected; the sealing ring III is coaxially placed in the circular groove III, and the sealing ring IV is coaxially placed in the circular groove IV, ensuring that the sealing ring III and the sealing ring IV are tightly fitted to the outer circumferential surface of the tube, thereby sealing the lower arc groove.

[0011] Preferably, it further includes sealing ring I and sealing ring II; a circular groove I matching sealing ring I is also embedded in the outer circumferential surface of the upper clamp relative to the outer side of the upper arc groove and relative to the inner arc surface of the placement groove, and the setting position of the circular groove I corresponds to the setting position of the circular groove III; a circular groove II matching sealing ring II is also embedded in the middle position of the outer circumferential surface of the upper clamp relative to the inner side of the circular groove I, and the setting position of the circular groove II corresponds to the setting position of the circular groove IV, and it is ensured that the circular groove II, the circular groove I and the upper arc groove are not interconnected; sealing ring I is coaxially placed in the circular groove I, and sealing ring II is coaxially placed in the circular groove II, and it is ensured that sealing ring I and sealing ring II are tightly fitted to the inner circumferential surface of the tube, thereby sealing the upper arc groove.

[0012] Preferably, the longitudinal width and arc length of the lower arc groove are both smaller than the inner diameter of the sealing ring IV, and the longitudinal width and arc length of the upper arc groove are both smaller than the inner diameter of the sealing ring II.

[0013] Preferably, it also includes valve I, valve II, valve III, a pressure gauge, and valve IV; valve III, the pressure gauge, and valve I are sequentially and intermittently connected in the pipeline located between the inlet pipe and the hydrogen source, and valve IV is also connected in the pipeline located between the outlet pipe and the waste gas treatment system; one end of valve II is connected to the nitrogen source through a pipeline, and the other end is connected to the pipeline located between the pressure gauge and valve I through a pipeline, thereby switching between nitrogen purging and hydrogen testing by alternately opening and closing valve I and valve II.

[0014] The beneficial effects of this utility model are:

[0015] (1) This utility model is simple to operate and easy to use, reduces the amount of gas used and the test time, reduces the sealing difficulty, and can accurately detect the pipe wall permeability of the composite pipe, thus improving work efficiency;

[0016] (2) This utility model does not require the use of metal joints, and only a small section of the tube sample needs to be cut to test the gas permeability of the tube, thereby reducing the testing cost and reducing the amount of test gas required, thus increasing safety.

[0017] (3) By setting up a metal wire screen and metal support, this utility model can not only ensure the stability of the tubular structure under high pressure, but also does not affect the permeation of hydrogen. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of the structure of a device for hydrogen permeation testing of non-metallic composite tubes according to the present invention.

[0020] Figure 2 for Figure 1 An enlarged schematic diagram of part A in the middle.

[0021] Among them, 1-locking bolt; 2-inlet pipe; 3-upper clamp; 4-pipe sample; 5-sealing ring I; 6-sealing ring II; 7-metal wire mesh; 8-outlet pipe; 9-metal support; 10-lower clamp; 11-hydrogen source; 12-nitrogen source; 13-valve I; 14-valve II; 15-valve III; 16-pressure gauge; 17-valve IV; 18-exhaust gas treatment system; 19-upper arc groove; 20-sealing ring III; 21-sealing ring IV. Detailed Implementation

[0022] The technical solution of this utility model will be clearly and completely described below through specific embodiments.

[0023] This utility model discloses a device for hydrogen permeation testing of non-metallic composite tubes, comprising an upper clamp 3, a lower clamp 10, an inlet pipe 2, an outlet pipe 8, and a waste gas treatment system 18; the specific structure is as follows: Figure 1 , Figure 2As shown, both the upper clamp 3 and the lower clamp 10 are horizontally longitudinally arranged arc-shaped structures, with the upper clamp 3 coaxially sleeved inside the lower clamp 10 and the two screwed together for fixation. A placement groove matching the tube sample 4 is coaxially embedded in the middle of the outer circumference of the upper clamp 3, and the placement groove does not extend beyond the two end faces and the front and rear end faces of the upper clamp 3, and the tube sample 4 is placed in the placement groove. An upper arc-shaped groove 19 communicating with the placement groove is also coaxially embedded in the middle of the outer circumference of the upper clamp 3 and relative to the inner arc surface of the placement groove, and is located in the lower clamp. The inner circumferential surface of fixture 10 is coaxially embedded with a lower arc-shaped groove that matches the upper arc-shaped groove 19. The air inlet pipe 2 is located directly above the upper clamp 3, and one end of it is connected to the hydrogen source 11 through a pipeline. The other end of it extends radially along the upper clamp 3 into the interior of the upper clamp 3 and is connected to the upper arc-shaped groove 19. The air outlet pipe 8 is located directly below the lower clamp 10, and one end of it is connected to the waste gas treatment system 18 through a pipeline. The other end of it extends radially along the lower clamp 10 into the interior of the lower clamp 10 and is connected to the lower arc-shaped groove.

[0024] The curvature of the upper clamp 3 and the lower clamp 10 are consistent with the curvature of the tube sample 4, and their arc lengths are matched and both are greater than the arc length of the tube sample 4; the outer diameter of the upper clamp 3 is consistent with the inner diameter of the lower clamp 10, and the inner arc surface of the upper clamp 3 is set upward and coaxially sleeved inside the lower clamp 10; the longitudinal width of the upper clamp 3 is consistent with the longitudinal width of the lower clamp 10, and both are greater than the longitudinal width of the tube sample 4.

[0025] like Figure 1 , Figure 2 As shown, both ends of the upper clamp 3 and the lower clamp 10 are horizontally flanged outwards, ensuring that the two flanges of the upper clamp 3 are aligned with the corresponding flanges of the lower clamp 10. Locking bolts 1 are vertically screwed onto the two flanges of the upper clamp 3, and the screw end of each locking bolt 1 extends vertically downwards to the corresponding flange of the lower clamp 10 and is screwed onto the corresponding nut. Thus, through the cooperation of the locking bolts 1 and the nut, the upper clamp 3 and the lower clamp 10 are coaxially sleeved and fixed together.

[0026] like Figure 1 , Figure 2 As shown, the curvature of the upper arc groove 19 and the lower arc groove are consistent with the curvature of the tube sample 4, and the arc length of the upper arc groove 19 and the lower arc groove are consistent and both are less than the arc length of the placement groove; the longitudinal width of the upper arc groove 19 and the lower arc groove are both less than the longitudinal width of the placement groove, and the upper arc groove 19 does not extend beyond the inner circumferential surface of the upper clamp 3, and the lower arc groove does not extend beyond the outer circumferential surface of the lower clamp 10.

[0027] like Figure 1 , Figure 2As shown, a matching metal support 9 is coaxially provided on the outer side of the lower arc-shaped groove, and a matching metal wire mesh 7 is coaxially provided on the inner side of the lower arc-shaped groove. Thus, the tube sample 4 placed in the placement groove is supported by the cooperation of the metal wire mesh 7 and the metal support 9, and it is ensured that neither the metal wire mesh 7 nor the metal support 9 affects the permeation of hydrogen.

[0028] like Figure 1 , Figure 2 As shown, a circular groove Ⅲ matching the sealing ring Ⅲ20 is embedded in the middle of the inner circumferential surface of the lower clamp 10 relative to the outer side of the lower arc groove. A circular groove Ⅳ matching the sealing ring Ⅳ21 is also embedded in the middle of the inner circumferential surface of the lower clamp 10 relative to the inner side of the circular groove Ⅲ. It is ensured that the circular groove Ⅳ, the circular groove Ⅲ, and the lower arc groove are not connected to each other. The sealing ring Ⅲ20 is placed coaxially in the circular groove Ⅲ, and the sealing ring Ⅳ21 is placed coaxially in the circular groove Ⅳ. It is ensured that the sealing ring Ⅲ20 and the sealing ring Ⅳ21 are tightly fitted to the outer circumferential surface of the tube sample 4, thereby sealing the lower arc groove.

[0029] like Figure 1 , Figure 2 As shown, a circular groove I matching the sealing ring I5 is embedded in the outer circumferential surface of the upper clamp 3, relative to the outer side of the upper arc groove 19 and relative to the inner arc surface of the placement groove. The position of the circular groove I corresponds to the position of the circular groove III. A circular groove II matching the sealing ring II6 is embedded in the middle position of the outer circumferential surface of the upper clamp 3, relative to the inner side of the circular groove I. The position of the circular groove II corresponds to the position of the circular groove IV. It is ensured that the circular groove II, the circular groove I, and the upper arc groove 19 are not interconnected. The sealing ring I5 is placed coaxially in the circular groove I, and the sealing ring II6 is placed coaxially in the circular groove II. It is ensured that the sealing ring I5 and the sealing ring II6 are tightly fitted against the inner circumferential surface of the tube sample 4, thereby sealing the upper arc groove 19.

[0030] The longitudinal width and arc length of the lower arc groove of this utility model are both smaller than the inner diameter of the sealing ring IV, and the longitudinal width and arc length of the upper arc groove 19 are both smaller than the inner diameter of the sealing ring II.

[0031] like Figure 1 As shown, valve III 15, pressure gauge 16, and valve I 13 are sequentially and intermittently connected to the pipeline between the inlet pipe 2 and the hydrogen source 11, and valve IV 17 is also connected to the pipeline between the outlet pipe 8 and the exhaust gas treatment system 18; one end of valve II 14 is connected to the nitrogen source 12 through a pipeline, and the other end is connected to the pipeline between pressure gauge 16 and valve I 13 through a pipeline. Thus, the switching between nitrogen purging and hydrogen testing is achieved by alternately opening and closing valve I 13 and valve II 14.

[0032] The working principle of this utility model is as follows: First, sealing ring I5 and sealing ring II6 are respectively installed in the corresponding circular slots I and II of the upper clamp 3, and sealing ring III20 and sealing ring IV21 are respectively installed in the corresponding circular slots III and IV of the lower clamp 10. The metal support 9 and the metal wire mesh 7 are coaxially installed in the lower arc groove of the lower clamp 10. Then, a tube sample 4 matching the placement groove is cut from the composite tube, the thickness of the tube sample is recorded, and the tube sample 4 is coaxially placed in the placement groove. After the upper clamp 3 and the lower clamp 10 are coaxially sleeved together, the two are screwed together and fixed with locking bolts 1. At this time, the tube sample 4 isolates the upper arc groove 19 and the lower arc groove into two independent spaces and is supported on the metal wire mesh 7.

[0033] Then, the entire device is placed in a closed system. First, valves II14, III15, and IV17 are opened, while valve I13 is closed. Nitrogen gas is then introduced for purging. After the air in the upper clamp 3 and lower clamp 10 is replaced, valves II14 and IV17 are closed, while valve I13 is opened. Hydrogen gas is then introduced. When the hydrogen pressure loaded on the tube sample 4 reaches the test pressure, the pressure increase is stopped and maintained at the test pressure. Then, the test pressure, test temperature, and test time are recorded. Then, valve IV17 is slowly opened. The wall permeability performance of the composite tube can be obtained by observing the change curve of the concentration of discharged hydrogen gas versus the test time.

[0034] The beneficial effects of this utility model are:

[0035] (1) This utility model is simple to operate and easy to use, reduces the amount of gas used and the test time, reduces the sealing difficulty, and can accurately detect the pipe wall permeability of the composite pipe, thus improving work efficiency;

[0036] (2) This utility model does not require the use of metal joints, and only a small section of the tube sample 4 needs to be cut to test the gas permeability of the tube, thereby reducing the testing cost and reducing the amount of test gas required, thus increasing safety.

[0037] (3) By setting up a metal wire screen 7 and a metal support 9, this utility model can not only ensure the stability of the structure of the tube sample 4 under high pressure, but also does not affect the permeation of hydrogen.

[0038] The embodiments described above are merely preferred embodiments of the present utility model and are not intended to limit the concept and scope of the present utility model. Without departing from the design concept of the present utility model, all modifications and improvements made by those skilled in the art to the technical solutions of the present utility model should fall within the protection scope of the present utility model. The technical content for which protection is sought in the present utility model has been fully recorded in the technical requirements.

Claims

1. A device suitable for hydrogen permeation testing of non-metallic composite pipes, characterized in that: The system includes an upper clamp, a lower clamp, an inlet pipe, an outlet pipe, and an exhaust gas treatment system. Both the upper and lower clamps are horizontally and longitudinally arranged arc-shaped structures. The upper clamp is coaxially fitted into the lower clamp and the two are screwed together. A placement groove matching the tube sample is coaxially embedded in the middle of the outer circumference of the upper clamp, and the placement groove does not extend beyond the two end faces and front and rear end faces of the upper clamp. The tube sample is placed in the placement groove. A further coaxially embedded section is located in the middle of the outer circumference of the upper clamp, relative to the inner arc surface of the placement groove. The upper arc-shaped groove is connected to the placement groove, and a lower arc-shaped groove matching the upper arc-shaped groove is coaxially embedded on the inner circumferential surface of the lower clamp relative to the position of the upper arc-shaped groove; the air inlet pipe is located directly above the upper clamp, and one end of it is connected to the hydrogen source through a pipeline, and the other end extends radially along the upper clamp into the interior of the upper clamp and is connected to the upper arc-shaped groove; the air outlet pipe is located directly below the lower clamp, and one end of it is connected to the waste gas treatment system through a pipeline, and the other end extends radially along the lower clamp into the interior of the lower clamp and is connected to the lower arc-shaped groove.

2. The device for hydrogen permeation testing of non-metallic composite pipes according to claim 1, characterized in that: The curvature of both the upper and lower clamps matches the curvature of the tubular sample, and their arc lengths are matched and both are greater than the arc length of the tubular sample. The outer diameter of the upper clamp matches the inner diameter of the lower clamp, and the inner arc surface of the upper clamp faces upward and is coaxially fitted inside the lower clamp. The longitudinal width of the upper clamp matches the longitudinal width of the lower clamp, and both are greater than the longitudinal width of the tubular sample.

3. The apparatus of claim 2, wherein: It also includes locking bolts and nuts; both ends of the upper and lower clamps are horizontally flanged outwards, ensuring that the two flanges of the upper clamp are respectively aligned with the corresponding flanges of the lower clamp; locking bolts are also vertically screwed onto the two flanges of the upper clamp, and the screw end of each locking bolt extends vertically downwards from the corresponding flange of the lower clamp, and is screwed onto the corresponding nut, thereby coaxially connecting and fixing the upper and lower clamps together through the cooperation of the locking bolts and nuts.

4. The apparatus of claim 1, wherein: The curvature of the upper and lower arc-shaped grooves is consistent with the curvature of the tube, and the arc lengths of the upper and lower arc-shaped grooves are consistent and both less than the arc length of the placement groove; the longitudinal widths of the upper and lower arc-shaped grooves are both less than the longitudinal width of the placement groove, and the upper arc-shaped groove does not extend beyond the inner circumference of the upper clamp, and the lower arc-shaped groove does not extend beyond the outer circumference of the lower clamp.

5. The apparatus of claim 4, wherein: It also includes a wire mesh screen and a metal support; a matching metal support is coaxially arranged on the outer side of the lower arc-shaped groove, and a matching wire mesh screen is coaxially arranged on the inner side of the lower arc-shaped groove. Thus, the tube sample placed in the placement groove is supported by the cooperation of the wire mesh screen and the metal support, and it is ensured that the wire mesh screen and the metal support do not affect the permeation of hydrogen.

6. The apparatus of claim 1, wherein: It also includes sealing ring III and sealing ring IV; a circular groove III matching sealing ring III is embedded in the middle of the inner circumferential surface of the lower clamp relative to the outer side of the lower arc groove, and a circular groove IV matching sealing ring IV is embedded in the middle of the inner circumferential surface of the clamp relative to the inner side of the circular groove III, ensuring that the circular groove IV, the circular groove III, and the lower arc groove are not interconnected; the sealing ring III is coaxially placed in the circular groove III, and the sealing ring IV is coaxially placed in the circular groove IV, ensuring that the sealing ring III and the sealing ring IV are tightly fitted to the outer circumferential surface of the tube, thereby sealing the lower arc groove.

7. The apparatus of claim 6, wherein: It also includes sealing ring I and sealing ring II; a circular groove I matching sealing ring I is also embedded in the outer circumferential surface of the upper clamp relative to the outer side of the upper arc groove and relative to the inner arc surface of the placement groove, and the setting position of the circular groove I corresponds to the setting position of the circular groove III; a circular groove II matching sealing ring II is also embedded in the middle position of the outer circumferential surface of the upper clamp relative to the inner side of the circular groove I, and the setting position of the circular groove II corresponds to the setting position of the circular groove IV, and it is ensured that the circular groove II, the circular groove I and the upper arc groove are not interconnected; sealing ring I is coaxially placed in the circular groove I, and sealing ring II is coaxially placed in the circular groove II, and it is ensured that sealing ring I and sealing ring II are tightly fitted to the inner circumferential surface of the tube, thereby sealing the upper arc groove.

8. The apparatus of claim 7, wherein: The longitudinal width and arc length of the lower arc groove are both smaller than the inner diameter of the sealing ring IV, and the longitudinal width and arc length of the upper arc groove are both smaller than the inner diameter of the sealing ring II.

9. The apparatus of claim 1, wherein: It also includes valve I, valve II, valve III, pressure gauge, and valve IV; valve III, pressure gauge, and valve I are sequentially and intermittently connected in the pipeline located between the inlet pipe and the hydrogen source, and valve IV is also connected in the pipeline located between the outlet pipe and the waste gas treatment system; one end of valve II is connected to the nitrogen source through a pipeline, and the other end is connected to the pipeline located between the pressure gauge and valve I through a pipeline, thereby switching between nitrogen purging and hydrogen testing by alternately opening and closing valve I and valve II.

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