Pipeline welding joint air tightness detection equipment and detection method

Abstract

The embodiment of the invention provides pipeline welding joint air tightness detection equipment and a detection method. The pipeline welding joint airtightness detection equipment comprises a plugging device, a load loading device, a gas pipeline and an air pressure measuring instrument, the plugging device comprises at least two plugging assemblies, the plugging assemblies can move and are used for plugging and releasing a pipe orifice of the pipeline, and the load loading device is used for applying a load to a welding joint of the pipeline. The gas pipeline penetrates through the plugging assembly and is used for inflating the plugged pipeline, and the gas pressure measuring instrument is arranged on the gas pipeline. According to the pipeline welding joint air tightness detection equipment provided by the embodiment of the invention, the air leakage condition can be avoided in the detection process, and the accurate detection result can be obtained. Meanwhile, the load loading device is used for applying a load to the welding joint and simulating the condition that the pipeline is subjected to an external force during installation and use so as to judge the air tightness condition of the welding joint subjected to the external force, so that the detection result has high reliability.

Description

Technical Field

[0001] The invention relates to the field of pipeline detection, and in particular to an air tightness detection device and a detection method for pipeline welding joints. Background Art

[0002] When the pipeline is transporting hydrogen-blended natural gas, hydrogen molecules will be adsorbed on the metal material of the pipeline and dissociate into hydrogen atoms to invade the metal, causing hydrogen damage to the metal material and causing the metal structure to fail. Since the organizational structure and mechanical properties of the welded joint are quite different from those of the steel matrix of the pipeline, the welded joint is the part most prone to failure. In the related art, a detection cylinder is set around the weld on the outside of the pipeline, gas is filled into the detection cylinder, and the air pressure is monitored to determine the air tightness of the weld. However, it is difficult to completely seal the detection cylinder with the outer wall of the pipeline, and the detection result has errors. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0004] To this end, an embodiment of the present invention provides a pipeline welding joint air tightness detection device.

[0005] An embodiment of the present invention further provides a method for detecting air tightness of a pipeline welding joint.

[0006] The pipeline welding joint air tightness detection device according to the embodiment of the present invention comprises:

[0007] A plugging device, the plugging device comprising at least two plugging components, the plugging components being movable and used to plug and release the pipe opening of the pipeline;

[0008] A load-applying device, the load-applying device being used to apply a load to the welded joint of the pipeline;

[0009] A gas pipeline, which is passed through the blocking component and is used to inflate the blocked pipe;

[0010] An air pressure measuring instrument is arranged on the gas pipeline.

[0011] In the pipeline welding joint air tightness detection device of the embodiment of the present invention, the plugging assembly of the plugging device is used to plug and release the pipe mouth of the pipeline, the gas pipeline is installed in the plugging assembly and inflated into the pipeline for detection, and during the gas pipeline inflation process, the plugging assembly and the pipeline are completely sealed, thereby avoiding air leakage and obtaining accurate detection results. At the same time, the load loading device is used to apply a load to the welding joint to simulate the situation where the pipeline is subjected to external force during installation and use, so as to determine the air tightness of the welding joint after being subjected to external force, so that the detection result has a higher reliability.

[0012] In some embodiments, the plugging assembly includes a plugging head and a sealing ring, at least a portion of the outer circumferential surface of the plugging head extends axially along the plugging head and is inclined along the radial direction of the plugging head, the sealing ring is sleeved on at least a portion of the inclined outer circumferential surface of the plugging head, and is used to connect between the plugging head and the wall of the pipe mouth.

[0013] In some embodiments, the load loading device includes at least two pressure applying parts, which are arranged in sequence along a ring and can be telescopically moved relative to the axis of the ring, and are used to surround the outer circumference of the weld joint and apply a load along the radial direction of the pipe to the weld joint.

[0014] In some embodiments, the load loading device also includes a position sensor, a load sensor and at least two force controllers, at least two of the force controllers are connected one-to-one with at least two of the pressure-applying parts to drive the pressure-applying parts to telescope and move, the pressure-applying parts are provided with the position sensor and the load sensor, and the position sensor and the load sensor are electrically connected to the force controller connected to the same pressure-applying part.

[0015] In some embodiments, the first end of the gas pipeline is passed through the blocking assembly, and the second end of the gas pipeline is provided with a first branch and a second branch, the first branch is connected to a gas supply device, and the second branch is connected to a gas extraction device.

[0016] The pipeline welded joint air tightness detection method of the embodiment of the present invention is implemented by using the pipeline welded joint air tightness detection device described in any of the above embodiments, and the detection method includes:

[0017] S1. The plugging device plugs the pipe opening of the pipeline;

[0018] S2. The gas pipeline purges the interior of the pipeline;

[0019] S3. The gas pipeline is filled with hydrogen-blended natural gas into the pipeline, and a first determination is made as to whether the welded joint of the pipeline is leaking based on the pressure value of the pressure measuring instrument;

[0020] S4. After the result of the first judgment is that the weld joint is not leaking, the pipeline filled with hydrogen-blended natural gas is left to stand for a period of time, and then a second judgment is made on whether the weld joint is leaking according to the air pressure value of the air pressure measuring instrument;

[0021] S5. After the result of the second judgment is that the welding joint is not leaking, the load loading device applies a load to the welding joint, and makes a third judgment on whether the welding joint is leaking according to the air pressure value of the air pressure measuring instrument. When the result of the third judgment is that the welding joint is not leaking, the pipeline is qualified.

[0022] The pipeline welded joint air tightness detection method of the embodiment of the present invention is implemented by using the pipeline welded joint air tightness detection device of the embodiment of the present invention to obtain accurate and reliable detection results. At the same time, the detection method makes a first judgment after filling with hydrogen-blended natural gas and obtains the air tightness of the welded joint under the conveying gas pressure, makes a second judgment after filling with hydrogen-blended natural gas and standing for a period of time and obtains the air tightness of the welded joint after hydrogen atom invasion, and makes a third judgment after the load is applied by the load loading device and obtains the air tightness of the welded joint after hydrogen atom invasion and load, so as to fully detect the welded joints of the pipeline, thereby obtaining comprehensive, accurate and reliable detection results.

[0023] In some embodiments, the step S1 further comprises: after sealing the pipe opening of the pipe, measuring the original diameter of the welded joint of the pipe;

[0024] The step S5 also includes: after the result of the third judgment is that the weld joint has no leakage, measuring the loaded diameter of the weld joint, judging whether the pipeline is qualified according to the loaded diameter and the original diameter, or judging whether the pipeline is qualified according to the loaded diameter and the cracking condition of the weld joint.

[0025] In some embodiments, the pipeline welding joint air tightness detection method further includes:

[0026] Steps S1 to S5 are performed on multiple pipelines of the same specification. The ratio of hydrogen to natural gas in the hydrogen-blended natural gas filled into each pipeline in step S3 is different. When all the pipelines are qualified, the specifications of the pipelines are qualified.

[0027] In some embodiments, the step S1 further includes: before sealing the pipe opening of the pipe, cleaning the pipe and drying the pipe.

[0028] In some embodiments, step S2 specifically includes:

[0029] S2-1. The gas pipeline is filled with an inert gas into the interior of the pipeline;

[0030] S2-2. The gas pipeline extracts the gas inside the pipeline;

[0031] S2-3. Repeat steps S2.1 and S2.2 at least twice. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 Schematic diagram of a pipeline welding joint air tightness detection device according to an embodiment of the present invention.

[0033] Reference numerals:

[0034] 1. Sealing device; 11. Sealing assembly; 111. Sealing head; 112. Sealing ring; 2. Load applying device; 21. Pressure applying part; 3. Gas pipeline; 4. Air pressure measuring instrument. DETAILED DESCRIPTION

[0035] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0036] Reference below Figure 1 The invention describes an air tightness detection device and a detection method for pipeline welding joints according to an embodiment of the invention.

[0037] like Figure 1 As shown, the pipeline welding joint air tightness detection equipment of the embodiment of the present invention includes a sealing device 1, a load loading device 2, a gas pipeline 3 and an air pressure measuring instrument 4.

[0038] The plugging device 1 comprises at least two plugging components 11, which are movable and used to plug and release the pipe opening of the pipeline. Figure 1 As shown, the pipeline has two pipe openings, and two plugging components 11 are used to plug the two pipe openings one by one, thereby sealing the inside of the pipeline. It can be understood that the pipe openings and plugging components 11 of the pipeline are not limited to two, and can also be three or more.

[0039] The gas pipeline 3 is arranged in the blocking component 11 and is used to inflate the blocked pipe. Figure 1 As shown, the gas pipeline 3 is passed through one of the blocking components 11 and communicates with the interior of the pipeline when the pipe opening of the pipeline is blocked to inflate the interior of the pipeline.

[0040] The air pressure measuring instrument 4 is provided in the gas pipeline 3. The air pressure measuring instrument 4 is used to measure the air pressure in the gas pipeline 3. Since the gas pipeline 3 is connected to the inside of the pipeline, the air pressure in the gas pipeline 3 is the same as the internal air pressure of the pipeline, so the air pressure inside the pipeline is measured by the air pressure measuring instrument 4.

[0041] The load applying device 2 is used to apply a load to the welded joint of the pipeline. The load can be understood as an external force or as pressure.

[0042] In the pipeline welding joint air tightness detection device of the embodiment of the present invention, the plugging assembly of the plugging device is used to plug and release the pipe mouth of the pipeline, the gas pipeline is installed in the plugging assembly and inflated into the pipeline for detection, and during the gas pipeline inflation process, the plugging assembly and the pipeline are completely sealed, thereby avoiding air leakage and obtaining accurate detection results. At the same time, the load loading device is used to apply a load to the welding joint to simulate the situation where the pipeline is subjected to external force during installation and use, so as to determine the air tightness of the welding joint after being subjected to external force, so that the detection result has a higher reliability.

[0043] In some embodiments, the plugging assembly 11 includes a plugging head 111 and a sealing ring 112. At least a portion of the outer circumferential surface of the plugging head 111 extends along the axial direction of the plugging head 111 and is inclined along the radial direction of the plugging head 111. The sealing ring 112 is sleeved on at least a portion of the inclined outer circumferential surface of the plugging head 111 and is used to connect between the plugging head 111 and the wall of the pipe mouth.

[0044] like Figure 1 As shown, the plugging assembly 11 includes a plugging head 111 and a sealing ring 112. The plugging head 111 is preferably but not limited to a frustum shape. The outer peripheral surface of the plugging head 111 extends along its axial direction and is inclined along its radial direction. In other words, the cross-sectional area of ​​the outer peripheral surface of the plugging head 111 decreases along the axial direction, and the sealing ring 112 is sleeved on the outer peripheral surface of the plugging head 111.

[0045] During detection, the plugging assembly 11 is arranged in one-to-one correspondence with the pipe orifice, the axial direction of the plugging assembly 11 coincides with the center line of the pipe orifice, and the cross-sectional area of ​​the outer peripheral surface of the plugging head 111 decreases in the direction toward the pipe orifice. In other words, the end of the plugging head 111 with a smaller outer diameter is arranged toward the pipe orifice. The plugging assembly 11 can move toward the pipe orifice to block the pipe orifice. When blocking the pipe orifice, the end of the plugging head 111 with a smaller outer diameter is located inside the pipe, and the end of the plugging head 111 with a larger outer diameter is located outside the pipe. The sealing ring 112 is connected between the outer peripheral surface of the plugging head 111 and the wall surface of the pipe orifice. The wall surface of the pipe orifice can be the inner peripheral surface of the pipe orifice, or it can be the end surface of the pipe orifice along the axial direction of the pipe, preferably the end surface of the pipe orifice along the axial direction of the pipe. The plugging assembly 11 can move away from the pipe orifice to release the pipe orifice.

[0046] The sealing ring 112 is used to seal the plugging head 111 to the wall of the pipe mouth to avoid air leakage between the plugging head 111 and the wall of the pipe mouth. The outer peripheral surface of the plugging head 111 is inclined so that it can be suitable for pipe mouths of different diameters, so that the plugging assembly 11 is suitable for plugging pipes of various sizes.

[0047] Furthermore, the sealing ring 112 is detachably connected to the plugging head 111. The sealing ring 112 has multiple sealing rings with different diameters. By replacing the sealing rings 112 with different diameters on the plugging head 111 to plug pipe openings with different diameters, the plugging assembly 11 is suitable for plugging pipes of various sizes.

[0048] Furthermore, the sealing ring 112 is elastic so that it can expand and contract along its circumference. The sealing ring 112 can move axially along the plugging head 111 relative to the plugging head 111. When the sealing ring 112 is moved axially along the plugging head 111, the diameter of the sealing ring 112 changes due to the interaction between the outer diameter of the plugging head 111 and the elasticity of the sealing ring 112, so as to be able to block pipe openings of different diameters, thereby making the plugging assembly 11 suitable for blocking pipes of various sizes.

[0049] It can be understood that the plugging head is not limited to being a frustum shape. In other embodiments, the plugging head includes a straight section and an inclined section. The inclined section is a frustum shape, and the straight section is arranged at the end with a smaller outer diameter or the end with a larger outer diameter of the inclined section, and extends in a cylindrical shape in a direction away from the inclined section.

[0050] In such Figure 1 In the specific example shown, there are two plugging assemblies 11 arranged opposite to each other in the up-down direction, the cross-sectional area of ​​the outer peripheral surface of the plugging head 111 of the upper plugging assembly 11 decreases from top to bottom, and the cross-sectional area of ​​the outer peripheral surface of the plugging head 111 of the lower plugging assembly 11 decreases from bottom to top, the pipeline is used to be placed between the two plugging assemblies 11, and the upper and lower ends of the pipeline are provided with pipe openings, the two plugging assemblies 11 can be relatively close to block the pipe openings and fix the pipeline, and can be relatively far away to release the pipe openings and loosen the pipeline. The two plugging assemblies 11 are preferably, but not limited to, arranged on a frame (not shown in the figure), and the frame is provided with a first movable bracket connected to the plugging assembly 11 and driving the plugging assembly 11 to move in the vertical direction.

[0051] In some embodiments, the load loading device 2 includes at least two pressure applying parts 21, which are arranged in sequence along a ring and can be telescopically moved relative to the axis of the ring, and are used to surround the outer circumference of the weld joint and apply a load along the radial direction of the pipe to the weld joint.

[0052] like Figure 1 As shown, the number of the pressure applying parts 21 is preferably, but not limited to, two, and the pressure applying parts 21 are arc-shaped, and the two pressure applying parts 21 are arranged in sequence along the ring. In other words, the two pressure applying parts 21 are arranged at intervals around the vertical direction, and in other words, the two pressure applying parts 21 are arranged around the axial direction of the pipe. Both pressure applying parts 21 are telescopically movable relative to the axis of the ring. In other words, the two pressure applying parts 21 can move toward and away from the pipe in the horizontal direction, so as to apply a load along the radial direction of the pipe to the welded joint.

[0053] During the inspection, the pipeline is located between the two pressure-applying parts 21, and the pressure-applying parts 21 are arranged opposite to the welding joint of the pipeline. Then, the two pressure-applying parts 21 move toward the pipeline and abut against the outer peripheral surface of the welding joint, further applying a load along the radial direction of the pipeline to the welding joint, and then the two pressure-applying parts 21 move away from the pipeline and detach from the outer peripheral surface of the welding joint.

[0054] It should be noted that when the two pressure-applying parts 21 are separated from the outer circumferential surface of the welded joint, the two pressure-applying parts 21 are arranged at intervals along the circumference of the pipe; when the two pressure-applying parts 21 are in contact with the outer circumferential surface of the welded joint but no load is applied, the two pressure-applying parts 21 are arranged at intervals along the circumference of the pipe; when the two pressure-applying parts 21 are in contact with the outer circumferential surface of the welded joint and a load has been applied, the two pressure-applying parts 21 can be arranged at intervals along the circumference of the pipe, or can be connected to form a ring along the circumference of the pipe, preferably arranged at intervals along the circumference of the pipe.

[0055] At least two pressure applying parts 21 are arranged along the circumference of the pipeline to apply loads to the weld joint at multiple positions along the circumference of the pipeline, so that the weld joint is fully deformed to obtain accurate detection results.

[0056] Furthermore, the pressure-applying part 21 is preferably but not limited to being arranged on a frame (not shown in the figure), and the frame is provided with a second movable bracket connected to the pressure-applying part 21 and driving the pressure-applying part 21 to move in the vertical direction. The second movable bracket adjusts the position of the pressure-applying part 21 in the vertical direction so that the pressure-applying part 21 is arranged opposite to the welding joint. In other words, the pressure-applying part 21 and the welding joint are arranged with intervals in the horizontal direction.

[0057] Furthermore, the longitudinal section of the pressure-applying part 21 is T-shaped, and the pressure-applying part 21 includes a vertical extension part and a horizontal extension part, the horizontal extension part is connected to the outer end of the vertical extension part away from the pipe, and is connected to the middle of the vertical extension part in the vertical direction, and the vertical extension part is used to abut the welded joint toward the inner end of the pipe. Since the vertical extension part has a certain height in the vertical direction, it can ensure that it overlaps with the welded joint in the vertical direction, thereby ensuring that the welded joint is fully loaded and deformed. Preferably, the weld of the welded joint is located in the middle of the vertical extension part in the horizontal direction.

[0058] It can be understood that the pressure-applying part is not limited to applying a load along the radial direction of the pipe to the welding joint. In other embodiments, the pipe includes three sub-pipes connected as a tee, and the connection between any two sub-pipes is a welding joint. In this case, the direction of the load applied by the pressure-applying part to the welding joint is not orthogonal to the axial direction of the corresponding two sub-pipes, and only one pressure-applying part can be set at this time.

[0059] In some embodiments, the load loading device 2 also includes a position sensor (not shown in the figure), a load sensor (not shown in the figure) and at least two force controllers (not shown in the figure). The at least two force controllers are connected to at least two pressure-applying parts 21 in a one-to-one correspondence to drive the pressure-applying parts 21 to telescope and move. The pressure-applying parts 21 are provided with a position sensor and a load sensor, and the position sensor and the load sensor are electrically connected to the force controller connected to the same pressure-applying part 21.

[0060] Specifically, the force controller is arranged in a one-to-one correspondence with the pressure-applying part 21. One end of the force controller is preferably but not limited to being arranged on the frame, and the other end of the force controller is provided with a corresponding pressure-applying part 21, which is used to drive the pressure-applying part 21 to move toward the pipeline relative to the frame and apply a preset load to the welding joint, and drive the pressure-applying part 21 to move away from the pipeline relative to the frame.

[0061] The pressure part 21 is provided with a position sensor and a load sensor, and the position sensor and the load sensor are electrically connected to the force controller connected to the same pressure part 21. In other words, the force controller is electrically connected to the position sensor and the load sensor on the connected pressure part 21. The position sensor is used to obtain the moving position of the pressure part 21 and transmit it to the force controller, and the load sensor is used to obtain the real-time load applied by the pressure part 21 on the welding joint and transmit it to the force controller. The force controller drives the pressure part 21 to move according to the received moving position and real-time load to ensure that the pressure part 21 accurately applies a preset load to the welding joint.

[0062] In some embodiments, the first end of the gas pipeline 3 is passed through the sealing assembly 11, and the second end of the gas pipeline 3 is provided with a first branch (not shown in the figure) and a second branch (not shown in the figure), the first branch is connected to the gas supply device (not shown in the figure), and the second branch is connected to the gas extraction device (not shown in the figure).

[0063] like Figure 1 As shown, the gas pipeline 3 has a first end and a second end that are arranged opposite to each other. The first end of the gas pipeline 3 is inserted into the plugging head 111 of the lower plugging assembly 11, and can extend from the upper end surface of the plugging head 111, or can be flush with the upper end surface of the plugging head 111. The second end of the gas pipeline 3 is provided with a first branch and a second branch. The first branch is connected to a gas supply device to provide gas to the pipeline. The gas supply device is preferably but not limited to a gas tank, a gas cylinder, etc. The gas supply device can also provide only one gas, or can provide at least two gases. Preferably, the gas supply device provides two gases, hydrogen-blended natural gas and nitrogen. The second branch is connected to a vacuum device to extract the gas in the pipeline. The vacuum device is preferably but not limited to a vacuum pump.

[0064] The air pressure measuring instrument 4 is disposed in the gas pipeline 3 and is located between the plugging head 111 and the second end of the gas pipeline 3 . The air pressure measuring instrument 4 is preferably, but not limited to, a barometer.

[0065] It can be understood that the second end of the gas pipeline is not limited to being provided with a first branch and a second branch. In other embodiments, the second end of the gas pipeline is connected to a gas supply device for filling the pipeline with gas. In this case, the gas pipeline serves as an air inlet pipeline, and the sealing head of the lower sealing assembly is passed through an air outlet pipeline. The air outlet pipeline is provided with an openable and closable exhaust device. The gas enters the pipeline through the air inlet pipeline and is then discharged through the air outlet pipeline of the opened exhaust device.

[0066] Reference below Figure 1 A method for detecting air tightness of a pipeline welding joint according to an embodiment of the present invention is described.

[0067] like Figure 1 As shown, the method for detecting the air tightness of a pipeline welded joint is implemented using the pipeline welded joint air tightness detection device of the embodiment of the present invention, and the method for detecting the air tightness of a pipeline welded joint includes S1. The plugging device 1 plugs the pipe mouth of the pipeline. S2. The gas pipeline 3 purges the inside of the pipeline. S3. The gas pipeline 3 fills the pipeline with hydrogen-blended natural gas, and makes a first judgment on whether the welded joint of the pipeline is leaking according to the air pressure value of the air pressure measuring instrument 4. S4. After the result of the first judgment is that the welded joint is not leaking, the pipeline filled with hydrogen-blended natural gas is left to stand for a period of time, and then a second judgment is made on whether the welded joint is leaking according to the air pressure value of the air pressure measuring instrument 4. S5. After the result of the second judgment is that the welded joint is not leaking, the load loading device 2 applies a load to the welded joint, and makes a third judgment on whether the welded joint is leaking according to the air pressure value of the air pressure measuring instrument 4. When the result of the third judgment is that the welded joint is not leaking, the pipeline is qualified.

[0068] The pipeline welded joint air tightness detection method of the embodiment of the present invention is implemented by the pipeline welded joint air tightness detection equipment of the embodiment of the present invention to obtain accurate and reliable detection results. At the same time, the detection method makes a first judgment after filling with hydrogen-blended natural gas and obtains the air tightness of the welded joint under the conveying gas pressure, makes a second judgment after filling with hydrogen-blended natural gas and standing for a period of time and obtains the air tightness of the welded joint after hydrogen atom invasion, and makes a third judgment after the load is applied by the load-loading device and obtains the air tightness of the welded joint after hydrogen atom invasion and load, so as to fully detect the welded joints of the pipeline, thereby obtaining comprehensive, accurate and reliable detection results. Loading means being subjected to load, which can be understood as being subjected to external force, and can also be understood as being subjected to pressure.

[0069] In some embodiments, step S1 specifically includes selecting the size model of the sealing ring 112 according to the size specification of the pipe mouth of the pipeline, and sleeve the sealing ring 112 on the outer peripheral surface of the plugging head 111 one by one, and then drive the plugging assembly 11 to move toward the pipe mouth one by one until the end with a smaller outer diameter of the plugging head 111 extends out of the pipe mouth, and the sealing ring 112 is connected between the outer peripheral surface of the plugging head 111 and the wall surface of the pipe mouth, thereby blocking the pipe mouth of the pipeline and sealing the interior of the pipeline, such as Figure 1 shown.

[0070] In some embodiments, step S2 specifically includes S2-1. The gas pipeline 3 fills the inside of the pipeline with inert gas. S2-2. The gas pipeline 3 extracts the gas inside the pipeline. S2-3. Repeat steps S2.1 and S2.2 at least twice.

[0071] like Figure 1 The first end of the gas pipeline 3 is passed through the plugging assembly 11 on the lower side, and the first branch of the second end of the gas pipeline 3 is connected to the gas supply device, which is used to provide two gases, hydrogen-blended natural gas and inert gas. The inert gas is preferably but not limited to nitrogen, and the second branch of the second end of the gas pipeline 3 is connected to the exhaust device.

[0072] After the sealing components 11 seal the pipe openings one by one, the gas pipeline 3 provided on the lower sealing component 11 is connected to the interior of the pipeline, the nitrogen outlet of the gas supply device is opened, the hydrogen-blended natural gas outlet of the gas supply device is closed, and the exhaust device is closed, and the gas pipeline 3 fills nitrogen into the interior of the pipeline. Preferably, when filling with nitrogen, the air pressure inside the pipeline is observed and obtained through the air pressure measuring instrument 4 until the air pressure inside the pipeline reaches a certain value. It can be understood that in other embodiments, nitrogen can also be filled into the pipeline for a certain period of time.

[0073] Then close the nitrogen outlet of the gas supply device, close the hydrogen-blended natural gas outlet of the gas supply device, and start the vacuum device, which extracts the gas inside the pipeline through the gas pipeline 3, preferably until a vacuum is formed inside the pipeline. It can be understood that in other embodiments, the gas can also be extracted for a certain time.

[0074] Then, the steps of filling the pipeline with nitrogen and extracting the gas inside the pipeline are repeated, preferably but not limited to twice. In other words, the steps of filling the pipeline with nitrogen and extracting the gas inside the pipeline need to be performed preferably but not limited to three times to ensure that the inside of the pipeline is purged clean.

[0075] It can be understood that, in step S2, the gas in the pipeline is not limited to being extracted from the gas pipeline. In other embodiments, the gas in the pipeline is discharged from the gas outlet pipeline.

[0076] In some embodiments, step S3 specifically includes opening the hydrogen-blended natural gas outlet of the gas supply device, closing the nitrogen outlet of the gas supply device, and closing the exhaust device, and the gas pipeline 3 is filled with hydrogen-blended natural gas into the pipeline. During the process of filling with hydrogen-blended natural gas, the air pressure value displayed by the air pressure measuring instrument 4 is observed, and it is judged for the first time whether the welding joint is leaking.

[0077] If the air pressure value displayed by the air pressure measuring instrument 4 is significantly lower than the supply pressure of the hydrogen-blended natural gas or the air pressure value displayed by the air pressure measuring instrument 4 continues to decrease, then there is leakage in the welded joint of the pipeline; if the air pressure value displayed by the air pressure measuring instrument 4 is substantially consistent with the supply pressure of the hydrogen-blended natural gas or the air pressure value displayed by the air pressure measuring instrument 4 is substantially constant, then there is no leakage in the welded joint of the pipeline.

[0078] Preferably, the air pressure value displayed by the air pressure measuring instrument 4 is significantly lower than the gas supply pressure of the hydrogen-blended natural gas, that is, the difference between the air pressure value displayed by the air pressure measuring instrument 4 and the gas supply pressure of the hydrogen-blended natural gas is greater than or equal to 5% of the gas supply pressure of the hydrogen-blended natural gas. The air pressure value displayed by the air pressure measuring instrument 4 is substantially consistent with the gas supply pressure of the hydrogen-blended natural gas, that is, the difference between the air pressure value displayed by the air pressure measuring instrument 4 and the gas supply pressure of the hydrogen-blended natural gas is less than 5% of the gas supply pressure of the hydrogen-blended natural gas. The air pressure value displayed by the air pressure measuring instrument 4 is substantially constant, that is, the air pressure value displayed by the air pressure measuring instrument 4 is within the range of ±3% of the gas supply pressure of the hydrogen-blended natural gas.

[0079] The first judgment is used to detect the air tightness of the welded joint under the delivery gas pressure when the pipeline is transporting hydrogen-blended natural gas. The gas supply pressure of the hydrogen-blended natural gas is preferably but not limited to the delivery gas pressure of the hydrogen-blended natural gas.

[0080] When leakage occurs in the welded joint of the pipeline in the first judgment, the pipeline is unqualified. The gas in the pipeline is extracted, and the gas supply device and the gas extraction device are closed, and the plugging assembly 11 is driven to move away from the pipe mouth one by one and release the pipe mouth and the pipeline, so as to facilitate the inspection of the next pipeline.

[0081] In some embodiments, step S4 specifically includes closing the hydrogen-blended natural gas outlet of the gas supply device, closing the nitrogen outlet of the gas supply device, and closing the exhaust device after the result of the first judgment is that the welding joint is not leaking, and the pipeline is left to stand for a period of time in a state filled with hydrogen-blended natural gas, and then observing the air pressure value displayed by the air pressure measuring instrument 4, and judging whether the welding joint is leaking for a second time.

[0082] If the air pressure value displayed by the air pressure measuring instrument 4 is significantly lower than the supply pressure of the hydrogen-blended natural gas or significantly lower than the air pressure in the pipeline before standing still, there is air leakage in the welded joint of the pipeline; if the air pressure value displayed by the air pressure measuring instrument 4 is roughly consistent with the supply pressure of the hydrogen-blended natural gas or roughly consistent with the air pressure in the pipeline before standing still, there is no air leakage in the welded joint of the pipeline.

[0083] Preferably, the air pressure value displayed by the air pressure measuring instrument 4 is significantly lower than the air pressure in the pipeline before standing still, which means that the air pressure value displayed by the air pressure measuring instrument 4 is lower than the air pressure in the pipeline before standing still by more than or equal to 5%. If the air pressure value displayed by the air pressure measuring instrument 4 is substantially consistent with the air pressure in the pipeline before standing still, which means that the air pressure value displayed by the air pressure measuring instrument 4 is lower than the air pressure in the pipeline before standing still by less than 5%.

[0084] The second judgment is used to detect the air tightness of the welded joints after hydrogen atoms invade during the process of transporting hydrogen-blended natural gas in the pipeline.

[0085] When leakage occurs in the welded joint of the pipeline in the second judgment, the pipeline is unqualified. The gas in the pipeline is extracted, and the gas supply device and the gas extraction device are closed, and the plugging assembly 11 is driven to move away from the pipe mouth one by one and release the pipe mouth and the pipeline, so as to facilitate the inspection of the next pipeline.

[0086] In some embodiments, step S5 specifically includes, after the result of the second judgment is that the welding joint is not leaking, the force controller drives the pressure-applying part 21 to move toward the pipeline to abut the outer peripheral surface of the welding joint and apply a load. During the movement of the pressure-applying part 21, the force controller ensures that the load applied to the welding joint is consistent with the preset load through the data transmitted by the position sensor and the load sensor. After the pressure-applying part 21 applies the preset load to the welding joint, the pressure-applying part 21 can be quickly detached from the welding joint and reset under the drive of the force controller, or it can abut against the welding joint for a period of time and then detach from the welding joint and reset.

[0087] While the pressure applying part 21 applies a load to the weld joint, the air pressure value displayed by the air pressure measuring instrument 4 is observed, and it is determined for the third time whether the weld joint is leaking.

[0088] If the air pressure value displayed by the air pressure measuring instrument 4 is significantly lower than the supply pressure of the hydrogen-blended natural gas, or is significantly lower than the air pressure in the pipeline before the load is applied, or the air pressure value displayed by the air pressure measuring instrument 4 continues to decrease, then there is leakage in the welded joint of the pipeline; if the air pressure value displayed by the air pressure measuring instrument 4 is substantially consistent with the supply pressure of the hydrogen-blended natural gas, or is substantially consistent with the air pressure in the pipeline before the load is applied, or the air pressure value displayed by the air pressure measuring instrument 4 is substantially constant, then there is no leakage in the welded joint of the pipeline.

[0089] Preferably, the air pressure value displayed by the air pressure measuring instrument 4 is significantly lower than the air pressure in the pipeline before the load is applied, which means that the air pressure in the pipeline is reduced by 5% or more compared with the air pressure in the pipeline before the load is applied. The air pressure value displayed by the air pressure measuring instrument 4 is substantially consistent with the air pressure in the pipeline before the load is applied, which means that the air pressure value displayed by the air pressure measuring instrument 4 is reduced by less than 5% compared with the air pressure in the pipeline before the load is applied.

[0090] The third judgment is used to detect the air tightness of the welded joint after hydrogen atoms invade and are subjected to external forces such as impact, vibration, and compression during transportation. Further, the air tightness of the welded joint can be detected after hydrogen atoms invade and are deformed under external forces. It is used to simulate the actual conditions of the pipeline when transporting hydrogen-blended natural gas to avoid idealization of the test results.

[0091] When leakage occurs in the welding joint of the pipeline in the third judgment, the pipeline is unqualified. The gas in the pipeline is extracted, and the gas supply device and the gas extraction device are closed, and the plugging assembly 11 is driven to move away from the pipe mouth one by one and release the pipe mouth and the pipeline, so as to facilitate the inspection of the next pipeline.

[0092] When there is no leakage at the welding joint of the pipeline in the third judgment, the pipeline is qualified.

[0093] Therefore, based on the first judgment, the second judgment and the third judgment performed in sequence, it is finally judged whether the air tightness of the pipeline welding joint is qualified, and then it is judged whether the pipeline with the same welding joint and welded by the same process as the welding joint is suitable for the transportation of hydrogen-blended natural gas.

[0094] In some embodiments, step S1 further includes measuring the original diameter of the welded joint of the pipeline after the pipe opening of the pipeline is blocked. Step S5 further includes measuring the loaded diameter of the welded joint after the result of the third judgment is that the welded joint is not leaking, and judging whether the pipeline is qualified according to the loaded diameter and the original diameter, or judging whether the pipeline is qualified according to the loaded diameter and the cracking condition of the welded joint.

[0095] Specifically, in step S1, after the plugging components 11 seal the pipe openings one by one and seal the interior of the pipeline, the welded joints of the pipeline are measured to obtain the original diameters of the welded joints.

[0096] Then, step S2, step S3, step S4 and step S5 are performed in sequence.

[0097] In step S5, when the welding joint of the pipeline leaks in the third judgment, the pipeline is unqualified. The gas in the pipeline is extracted, and the gas supply device and the gas extraction device are closed, and the plugging assembly 11 is driven to move away from the pipe opening one by one and release the pipe opening and the pipeline, so as to facilitate the inspection of the next pipeline.

[0098] When the welded joint of the pipeline is not leaking in the third judgment, the welded joint of the pipeline is measured again to obtain the loaded diameter of the welded joint, in other words, the diameter of the welded joint after the load is applied by the load loading device 2 is measured.

[0099] Then, the qualification of the pipeline can be judged based on the loaded diameter and the original diameter. For example, the cross-sectional dimension change curve and / or the load-displacement curve of the welded joint can be obtained based on the loaded diameter and the original diameter, and compared with the corresponding theoretical curve to judge whether the pipeline is qualified.

[0100] It is also possible to judge whether the pipeline is qualified based on the loaded diameter and the cracking condition of the welded joint. For example, the deformation of the loaded diameter and the cracking size of the welded joint are analyzed and compared with the corresponding theoretical values, or the ratio of the deformation of the loaded diameter and the cracking size of the welded joint is obtained and compared with the corresponding theoretical ratio, so as to judge whether the pipeline is qualified.

[0101] When the pipeline is judged to be unqualified based on the loaded diameter and the original diameter or the loaded diameter and the cracking condition of the welded joint, the gas in the pipeline is extracted, and the gas supply device and the gas extraction device are closed, and the sealing assembly 11 is driven to move away from the pipe mouth one by one and release the pipe mouth and the pipeline to facilitate the inspection of the next pipeline.

[0102] In some embodiments, the method for detecting air tightness of pipeline welded joints in an embodiment of the present invention further includes performing steps S1 to S5 on multiple pipelines of the same specifications, and the ratio of hydrogen and natural gas in the hydrogen-blended natural gas filled into each pipeline in step S3 is different. When all pipelines are qualified, the specifications of the pipelines are qualified.

[0103] Specifically, steps S1 to S5 are performed simultaneously or sequentially on multiple pipelines of the same specification. The ratio of hydrogen to natural gas in the hydrogen-blended natural gas filled into each pipeline in step S3 is different. In other words, multiple pipelines correspond one-to-one to hydrogen-blended natural gas with various ratios of hydrogen to natural gas, so as to judge whether the pipelines of the same specification are qualified in hydrogen-blended natural gas environments with different ratios. When all pipelines are qualified, in other words, when pipelines of the same specification are qualified in hydrogen-blended natural gas environments with various ratios, the pipeline specification is qualified, in other words, the air tightness of the welding structure of the pipeline of this specification is qualified, so that pipelines of the same size, with the same welding joints and welded by the same process as the welding joints are suitable for the transportation of hydrogen-blended natural gas.

[0104] It should be noted that the specifications of the pipeline preferably include, but are not limited to, the inner diameter of the pipeline, the outer diameter of the pipeline, the width of the welding structure and the process. Multiple pipelines of the same specifications have the same length when being tested.

[0105] Testing multiple pipes of the same specification is to conduct multi-sample testing on the pipes to fully test the pipes of that specification, thereby obtaining more accurate results and avoiding deviations in the test results due to individual differences in the pipes.

[0106] In some embodiments, step S1 further includes cleaning and drying the pipeline before plugging the pipeline opening.

[0107] Specifically, in step S1, the pipeline is first placed in acetone for ultrasonic cleaning, then the cleaned pipeline is blown dry, and then the plugging component 11 is driven to plug the pipe opening and seal the inside of the pipeline, thereby preventing debris and pollutants on the pipeline from affecting the spacing result.

[0108] In the description of the present invention, it is necessary to understand that the terms "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0109] In addition, the terms "first" and "second" are only used for distinction, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0110] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0111] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0112] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0113] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A pipeline welding joint air tightness detection device, characterized in that: include: A plugging device (1), the plugging device (1) comprising at least two plugging components (11), the plugging components (11) being movable and used for plugging and releasing the pipe opening of a pipeline; A load-applying device (2), the load-applying device (2) being used to apply a load to the welded joint of the pipeline; A gas pipeline (3), the gas pipeline (3) being arranged through the blocking component (11) and used for inflating gas into the blocked pipeline; An air pressure measuring instrument (4), wherein the air pressure measuring instrument (4) is arranged on the gas pipeline (3).

2. The pipeline welding joint air tightness detection equipment according to claim 1 is characterized in that: The plugging assembly (11) comprises a plugging head (111) and a sealing ring (112); at least part of the outer peripheral surface of the plugging head (111) extends along the axial direction of the plugging head (111) and is arranged obliquely along the radial direction of the plugging head (111); the sealing ring (112) is sleeved on at least part of the outer peripheral surface of the plugging head (111) that is arranged obliquely, and is used to connect between the plugging head (111) and the wall surface of the pipe mouth.

3. The pipeline welding joint air tightness detection equipment according to claim 1 is characterized in that: The load-applying device (2) comprises at least two pressure-applying parts (21), which are arranged in sequence along a ring and are telescopically movable relative to the axis of the ring, and are used to surround the outer circumference of the weld joint and apply a load along the radial direction of the pipeline to the weld joint.

4. The pipeline welding joint air tightness detection equipment according to claim 3 is characterized in that: The load loading device (2) further comprises a position sensor, a load sensor and at least two force controllers, wherein the at least two force controllers are connected to the at least two pressure applying parts (21) in a one-to-one correspondence so as to drive the pressure applying parts (21) to telescope and move, and the pressure applying parts (21) are provided with the position sensor and the load sensor, and the position sensor and the load sensor are electrically connected to the force controller connected to the same pressure applying part (21).

5. The pipeline welding joint air tightness detection equipment according to claim 1 is characterized in that: The first end of the gas pipeline (3) is inserted into the blocking assembly (11), and the second end of the gas pipeline (3) is provided with a first branch and a second branch, wherein the first branch is connected to a gas supply device and the second branch is connected to a gas extraction device.

6. A method for detecting air tightness of pipeline welding joints, characterized in that: The detection method is implemented by using the pipeline welding joint air tightness detection device according to any one of claims 1 to 5, and comprises: S1. A plugging device (1) plugs the pipe opening of the pipeline; S2. The gas pipeline (3) purges the interior of the pipeline; S3. The gas pipeline (3) is filled with hydrogen-mixed natural gas into the pipeline, and a first judgment is made on whether the welded joint of the pipeline is leaking according to the air pressure value of the air pressure measuring instrument (4); S4. After the result of the first judgment is that the weld joint is not leaking, the pipeline filled with hydrogen-blended natural gas is left to stand for a period of time, and then a second judgment is made on whether the weld joint is leaking according to the air pressure value of the air pressure measuring instrument (4); S5. After the result of the second judgment is that the welding joint is not leaking, the load loading device (2) applies a load to the welding joint, and performs a third judgment on whether the welding joint is leaking based on the air pressure value of the air pressure measuring instrument (4). When the result of the third judgment is that the welding joint is not leaking, the pipeline is qualified.

7. The method for detecting air tightness of pipeline welding joints according to claim 6, characterized in that: The step S1 further comprises: after sealing the pipe opening of the pipeline, measuring the original diameter of the welded joint of the pipeline; The step S5 also includes: after the result of the third judgment is that the weld joint has no leakage, measuring the loaded diameter of the weld joint, judging whether the pipeline is qualified according to the loaded diameter and the original diameter, or judging whether the pipeline is qualified according to the loaded diameter and the cracking condition of the weld joint.

8. The method for detecting air tightness of pipeline welding joints according to claim 6, characterized in that: Also includes: Steps S1 to S5 are performed on multiple pipelines of the same specification. The ratio of hydrogen to natural gas in the hydrogen-blended natural gas filled into each pipeline in step S3 is different. When all the pipelines are qualified, the specifications of the pipelines are qualified.

9. The method for detecting air tightness of pipeline welding joints according to claim 6, characterized in that: The step S1 further includes: before sealing the pipe opening of the pipe, cleaning the pipe and drying the pipe.

10. The method for detecting air tightness of pipeline welding joints according to claim 6, characterized in that: The step S2 specifically includes: S2-1. The gas pipeline (3) is filled with an inert gas into the interior of the pipeline; S2-2. The gas pipeline (3) extracts the gas inside the pipeline; S2-3. Repeat steps S2.1 and S2.2 at least twice.

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