Gas pipeline leakage on-line monitoring and positioning test device and control method thereof

Abstract

The invention discloses a gas pipeline leakage on-line monitoring and positioning test device and a control method thereof. The gas pipeline leakage on-line monitoring and positioning test device comprises a test pipeline and a data terminal, the test pipeline is used for transmitting gas and providing a data source for the data terminal, and comprises a supply section, a test section and a discharge section; the test section comprises the monitoring device, a leakage simulation device and an observation device, the longitudinal and transverse propagation rules of gas leakage in the pipeline are researched by simulating and testing pipeline leakage and analyzing monitored data, and a leakage positioning formula and a leakage severity degree judgment model are established. According to the verifiable test device, accurate positioning of the simulation leakage device on the longitudinal and cross sections of the pipeline and judgment of the leakage severity can be achieved, support is provided for practical application of a monitoring and positioning device for urban gas pipeline leakage, and the online monitoring and positioning level of fluid pipeline leakage is effectively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of signal monitoring and analysis, and relates to an online monitoring test device and a control method thereof, and in particular to an online monitoring and positioning test device for gas pipeline leakage and a control method thereof. Background Art

[0002] With the improvement of living standards, gas pipeline transportation is widely used in various fields of the national economy. However, as the age of the pipeline increases, gas pipeline leakage is often caused by corrosion, weld defects, vibration and wear, external force damage, etc., which not only affects the normal operation of the pipeline, but also poses a huge potential threat to production safety, social stability, soil, environment, ecology, etc. At present, when a gas pipeline leaks, manual methods are mostly used to find the leak point along the line, which focuses on the experience of the leak detection personnel, has low accuracy, and is time-consuming and labor-intensive.

[0003] At present, online gas pipeline leakage detection is mostly based on negative pressure wave method, acoustic wave method, flow balance method and distributed optical fiber method, among which negative pressure wave method is the most widely used. The negative pressure wave method can determine whether a leak occurs by monitoring the change trend of the pressure sensors installed along the gas pipeline, and conduct positioning alarm, which can cope with sudden leakage conditions. However, for small holes, micropores, multi-point and slow leaks caused by corrosion, traditional negative pressure wave technology usually cannot monitor the changes in pressure gradient, and the detection and positioning effects are poor.

[0004] Based on the strain effect of the resistance strain gauge, as well as its high measurement sensitivity and accuracy (its minimum strain reading is 1με), wide measurement range (1-20000με can be measured), good frequency response (can measure dynamic strain from static to hundreds of thousands of Hz), small size and light weight of the strain gauge (the smallest strain gauge grid length can be as short as 0.1mm), it can be measured in various complex environments (such as high temperature, low temperature, high-speed rotation, strong magnetic field and other environmental measurements), etc., it can effectively capture the micro-strain caused by the pressure difference before and after the strain gauge and the deformation change caused by the fluid impact, and can convert it into an electrical signal output. Due to the continuity of the fluid, the change in fluid velocity in the pipeline caused by the leakage lags behind the pressure change. Due to the existence of this time difference, it is possible to capture the transient pressure drop and the average flow velocity of the section after the leakage with the same set of resistance strain gauges. Based on the directionality of gas propagation caused by the leakage, a resistance strain gauge group is set along the circumference of the pipeline. The approximate position of the leakage point in the pipeline cross section can be judged according to the position of the resistance strain gauge that first captures the transient deformation value, and the severity of the leakage can be judged according to the change in the cross-sectional flow velocity before and after the leakage.

[0005] Based on the above assumptions, it is necessary to use experimental testing to study the correspondence between strain gauge deformation and pressure and flow rate, and to verify whether the test device can accurately locate the leakage point on the longitudinal and cross-sections of the pipeline and determine the severity of the leakage. Summary of the invention

[0006] (I) Purpose of the invention: In order to solve the problems existing in the above-mentioned prior art, the purpose of the present invention is to build a set of test equipment for testing and studying the corresponding relationship between the deformation of strain gauges and the pressure and flow rate in urban gas pipelines, and to verify that the test equipment can achieve accurate positioning of leakage points on the longitudinal and cross-sectional surfaces of urban gas pipelines and judgment of the severity of leakage.

[0007] (II) Technical solution: In order to solve the above technical problems, the present technical solution provides a gas pipeline leakage online monitoring and positioning test device, including a test pipeline and a data terminal; the test pipeline is used to transmit gas and provide a data source for the data terminal, which includes a supply section, a test section, and a discharge section; the test section includes the monitoring device, a simulated leakage device and an observation device.

[0008] The supply section sends the real-time pressure and real-time flow rate to the data terminal; the discharge section sends the real-time pressure and real-time flow rate to the data terminal; the monitoring device sends the real-time deformation data of the strain gauge in the test section pipeline to the data terminal.

[0009] The analysis and processing unit of the data terminal obtains a continuous waveform diagram corresponding to each strain gauge in the test section pipeline according to the real-time pressure and real-time flow rate of the supply section and the discharge section, and the real-time deformation data of the strain gauge in the test section pipeline; after the observation device determines that the monitoring device is in good condition, the simulated leakage device simulates leakage, and the data terminal processes and analyzes the instantaneous deformation value and the time interval of occurrence collected by the monitoring device, locates the position of the simulated leakage device of the simulated leakage, and establishes a leakage location formula.

[0010] The analysis and processing unit of the data terminal establishes a leakage severity judgment model based on the correspondence between the real-time deformation data and the real-time pressure and real-time flow rate in the continuous waveform diagram, and the real-time deformation data of the strain gauge collected by the monitoring device after the simulated leakage device performs simulated leakage.

[0011] Furthermore, the monitoring device includes three groups of equipment, each group consists of a flange, a strain gauge and a strain gauge data transmission line, each group is connected to the test pipeline through a flange, and is arranged at both ends and the middle of the test section.

[0012] Furthermore, the flange is of the same specification and model as the flange used for connecting the test pipe, and a radial through groove is opened on one side of the vertical surface of the flange, and the width and depth of the groove are greater than the width and thickness of the strain gauge and the strain gauge data transmission line; one end of the strain gauge connected to the strain gauge data transmission line is placed in the groove, adhered with insulating glue, and the groove is filled, and the other end of the strain gauge extends into the test pipe and is evenly distributed along the inner circumference of the test pipe; the width of the strain gauge is greater than or equal to the minimum leakage hole diameter, and the distance between the front end of the strain gauge extending into the test pipe and the inner wall of the test pipe is greater than or equal to 0.125 times the inner circumference diameter of the test pipe.

[0013] Furthermore, the simulated leakage device includes two groups of equipment, each group consisting of a number of leakage holes and leakage hole control valves with different apertures, one group is arranged upstream of the monitoring device close to the supply section side, and the other group is arranged between the monitoring device close to the supply section side and the monitoring device in the middle position.

[0014] Furthermore, the leakage hole is obtained by drilling a hole in the test pipe, inserting a hollow tube into the interior of the test pipe and welding it to the test pipe. A leakage hole control valve is provided on each leakage hole to control opening and closing. The maximum aperture of the leakage hole is less than or equal to 0.2 times the diameter of the test pipe, and the width of the strain gauge is greater than or equal to the minimum aperture of the leakage hole.

[0015] Furthermore, the observation device includes three groups of equipment, each group consists of an endoscope and an endoscope, and each group is respectively arranged on one side of the three groups of monitoring devices close to the supply section. The group of observation devices close to the supply section is located between the simulated leakage device close to the supply section and the monitoring device close to the supply section. The endoscope is a drilled hole in the test pipe, which passes through the side wall of the test pipe. The diameter of the endoscope is 0.2 times that of the endoscope lens.

[0016] Furthermore, the supply section includes an air source, a pressure regulating device, a pressure transmitting device and a flow transmitting device; the discharge section includes a pressure transmitting device, a flow transmitting device and a pressure relief device.

[0017] Furthermore, the analysis and processing unit is respectively connected to the pressure transmitter, the flow transmitter and the monitoring device to collect data information monitored online in the test pipeline. The analysis and processing unit compares the pressure and flow rate data in the test pipeline monitored by the pressure transmitter and the flow transmitter with the deformation data monitored by the monitoring device to analyze and establish the corresponding relationship between the deformation and the pressure and flow rate.

[0018] Furthermore, the gas source, pressure regulating device, pressure transmitting device, flow transmitting device, monitoring device, observation device, simulated leakage device and pressure relief device are all installed on the test pipeline; the test section, supply section and discharge section of the test pipeline are connected by flanges, and the test pipelines of each part are straight pipelines with the same material and diameter.

[0019] A control method for a gas pipeline leakage online monitoring and positioning test device is applicable to a gas pipeline leakage online monitoring and positioning test device including a test pipeline and a data terminal. The test pipeline is used to transmit gas and provide a data source for the data terminal, including a supply section, a test section, and a discharge section. The test section includes a monitoring device, a simulated leakage device, and an observation device. Specifically, the method includes the following steps: Step 1: Assemble the test pipe of the test device; Step 2: gas is transported to the test pipeline, and the real-time pressure and flow rate of the supply section and the discharge section, as well as the real-time deformation data of the strain gauge in the pipeline of the test section are transmitted to the data terminal; Step 3: According to the data transmitted to the data terminal in step 2, a continuous waveform of the real-time pressure, real-time flow rate and real-time deformation data corresponding to each strain gauge in the test section pipeline is obtained; after the observation device determines that the monitoring device is in good condition, the simulated leakage device simulates leakage; the data terminal processes and analyzes the instantaneous deformation value and the time interval of occurrence collected by the monitoring device, locates the position of the simulated leakage device of the simulated leakage, and establishes a leakage location formula; Step 4: The data terminal establishes a leakage severity judgment model based on the correspondence between the real-time deformation data and the real-time pressure and real-time flow rate in the continuous waveform diagram, and the real-time deformation data of the strain gauge collected by the monitoring device after the simulated leakage device simulates leakage.

[0020] (III) Beneficial effects: The monitoring and positioning test device of the present invention can verify that the test device can accurately locate the leakage point on the longitudinal and transverse sections of the pipeline and judge the severity of the leakage through leakage tests under different preset working conditions. The test data can be used to study the longitudinal and transverse propagation laws of gas leakage in the pipeline, establish leakage positioning formulas and leakage severity judgment models, and provide support for the practical application of gas pipeline leakage monitoring and positioning devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of a gas pipeline leakage online monitoring and positioning test device of the present invention; Figure 2 This is a schematic diagram of the vertical structure of the monitoring device in Example 1 of the present invention; Figure 3This is a schematic diagram of the top view of the lower half of the monitoring device in Example 1 of the present invention; Figure 4 It is a schematic diagram of the leakage hole of the present invention; Figure 5 is a schematic cross-sectional view of a monitoring device in Example 2 of the present invention; Figure 6 It is a schematic longitudinal section diagram of the monitoring device in Example 2 of the present invention.

[0022] Figure markings: 1-gas source; 2-pressure regulating device; 3-first pressure transmitting device; 4-first flow transmitting device; 51-first simulated leakage device; 52-second simulated leakage device; 61-first observation device; 62-second observation device; 63-third observation device; 71-first monitoring device; 72-second monitoring device; 73-third monitoring device; 8-second pressure transmitting device; 9-second flow transmitting device; 10-connecting rod; 11-load ball; 15-pressure relief device; 16-analysis and processing unit; 17-display unit; 18-flange; 19-strain gauge data transmission line; 20-flange hole; 21-groove; 22-strain gauge; 23-leakage hole; 24-leakage hole control valve; 25-test pipeline; A1-supply section, A2-test section, A3-discharge section. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with preferred embodiments. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0024] The accompanying drawings are schematic diagrams of embodiments of the present invention. It should be noted that the drawings are only examples and are not drawn to scale, and should not be used to limit the actual protection scope of the present invention.

[0025] Example 1

[0026] Reference Figure 1~Figure 4 , which is the first embodiment of the present invention, and provides a gas pipeline leakage online monitoring and positioning test device, including a test pipeline and a data terminal; Figure 1 As shown, the test pipeline includes three parts: a supply section A1, a test section A2, and a discharge section A3, which are used to transport gas and provide a data source for the data terminal; the data terminal includes an analysis and processing unit 16 and a display unit 17, which are used to collect the real-time pressure in the test pipeline, analyze flow rate fluctuations and display them.

[0027] The supply section A1 is placed at the upstream position of the test device, and includes a gas source 1, a pressure regulating device 2, a first pressure transmitter 3, and a first flow transmitter 4. The gas source 1 is placed at one end of the supply section A1, away from the test section A2, to block one end of the test pipe 25 and provide test gas to the test pipe 25. Preferably, the gas source 1 uses inert industrial gas or compressed air, which is supplied by an industrial gas cylinder or an air compressor. The pressure regulating device 2 is placed on the side of the gas source close to the test section A2, and regulates the pressure of the test gas provided by the gas source 1 so that the test pipe 25 reaches a predetermined test pressure. The first pressure transmitter 3 is placed on the side of the pressure regulating device 2 close to the test section A2, and is connected to the analysis and processing unit 16 through a circuit; the first flow transmitter 4 is placed on the side of the first pressure transmitter 3 close to the test section A2, and is connected to the analysis and processing unit 16 through a circuit. The first pressure transmitter 3 and the first flow transmitter 4 monitor the gas pressure, flow and flow rate data in the supply section A1 online, and transmit the collected data to the analysis and processing unit 16.

[0028] The test section A2 is placed in the midstream of the test device and includes a monitoring device, an observation device and a simulated leakage device.

[0029] like Figure 1-3 As shown, the monitoring device includes three groups of equipment, namely, the first monitoring device 71, the second monitoring device 72, and the third monitoring device 73. Each group consists of a flange 18, a strain gauge 22, and a strain gauge data transmission line 19. Each group is connected to the test pipeline 25 through the flange. The first monitoring device 71 is arranged on the side of the test section A2 close to the supply section A1, the second monitoring device 72 is arranged in the middle position of the test section A2, and the third monitoring device 73 is arranged on the side of the test section A2 close to the discharge section A3. The monitoring device is used to collect deformation data of the strain gauge 22. One end of the strain gauge data transmission line 19 is connected to the strain gauge 22, and the other end is connected to the analysis and processing unit 16. The specifications and sizes of the strain gauges 22 selected in each group of the monitoring device are the same. The width of the selected strain gauge 22 is greater than the minimum aperture of the leakage hole, so as to cover the cross section of the leakage gas propagation path of the leakage hole, and is used to determine the approximate orientation of the leakage hole in the pipeline cross section to reduce the lateral effect. The length of the strain gauge 22 should be selected so that the end of the strain gauge 22 extending into the test pipe is located inside the average flow velocity position when the fluid flow velocity in the test pipe is fully developed, so as to detect the average cross-sectional flow velocity after the fluid flow velocity at the monitoring point in the test pipe is fully developed after the leakage occurs, while reducing the impact on the fluid flow. Preferably, the width of the strain gauge 22 is greater than or equal to the minimum leakage hole diameter of the simulated leakage device on the test pipe 25, and the length of the strain gauge 22 is greater than or equal to 0.125 times the inner diameter of the test pipe 25.

[0030] The flange 18 includes a flange hole 20 and a groove 21. The flange 18 has the same specifications as the flange on the test pipe 25 for connecting the monitoring device. According to the data and size of the installed strain gauge, a plurality of radial through grooves 21 are opened on one side of the vertical surface of the flange 18. The grooves 21 are evenly distributed on the flange 18. The depth and width of the grooves are greater than the width and thickness of the strain gauge and the strain gauge data transmission line. One end of the strain gauge 22 connected to the strain gauge data transmission line 19 is placed in the groove 21, and is pasted with insulating glue to fill the groove 21. The other end of the strain gauge 22 extends into the test pipe 25 and is evenly distributed along the inner circumference of the test pipe 25.

[0031] like Figure 4 As shown, the simulated leakage device includes two groups of equipment, namely the first simulated leakage device 51 and the second simulated leakage device 52. Each group consists of a number of leakage holes 23 with different apertures and leakage hole control valves 24. Here, four leakage holes 23 and leakage hole control valves 24 are used as examples for explanation. The first simulated leakage device 51 is arranged on the side of the first monitoring device 71 close to the supply section A1, and the second simulated leakage device 52 is arranged between the first monitoring device 71 and the second monitoring device 72, and is used to affect the pressure and flow rate in the test pipe 25 by opening and closing to simulate leakage. The leakage hole 23 is formed by drilling a hole in the test pipe 25 to extend a hollow tube into the test pipe and weld it to the test pipe 25. A leakage hole control valve 24 is arranged on each leakage hole 23 to control opening and closing. The maximum aperture of the leakage hole 23 is less than or equal to 0.2 times the diameter of the test pipe 25, and the width of the strain gauge 22 is greater than or equal to the minimum aperture of the leakage hole 23.

[0032] The observation device includes three groups of equipment, namely, the first observation device 61, the second observation device 62, and the third observation device 63. Each group consists of an endoscope and an endoscope. The first observation device 61 is located between the first simulated leakage device 51 and the first monitoring device 71. The second observation device 62 is arranged on the side of the second monitoring device 72 close to the supply section A1. The third observation device 63 is arranged on the side of the third monitoring device 73 close to the supply section A1. The endoscope is a drilled hole of the test pipe 25, which passes through the side wall of the test pipe 25. The diameter of the endoscope is 0.2 times that of the endoscope lens, so that the selected endoscope can be smoothly inserted into the pipe to observe the state of the strain gauge.

[0033] The discharge section A3 is placed at the downstream position of the test device, and includes a second pressure transmitter 8, a second flow transmitter 9 and a pressure relief device 15. The pressure relief device 15 is placed at one end of the discharge section A3, away from the side of the test section A2, to block one end of the test pipe 25, and by adjusting the opening of the pressure relief device 15, cooperates with the pressure regulating device 2 of the supply section A1 to make the test pipe 25 reach the predetermined test pressure and flow rate value. The pressure relief device 15 can be an adjustable pressure relief valve, which is not specifically limited here. The second flow transmitter 9 is placed on the side of the pressure relief device 15 close to the test section A2, and is connected to the analysis and processing unit 16 through a circuit; the second pressure transmitter 8 is placed on the side of the second flow transmitter 9 close to the test section A2, and is connected to the analysis and processing unit 16 through a circuit. The second pressure transmitter 8 and the second flow transmitter 9 monitor the gas pressure, flow and flow rate data in the discharge section A3 online.

[0034] The data terminal includes an analysis and processing unit 16 and a display unit 17. The data terminal adopts an industrial-grade computer. One end of the analysis and processing unit 16 is connected to the first pressure transmitter 3, the first flow transmitter 4, the second pressure transmitter 8, the second flow transmitter 9 and the monitoring device, and the other end is connected to the display unit 17. The analysis and processing unit 16 includes a data acquisition module, a serial port server, data acquisition software and a data processing module, which realizes the acquisition and analysis of the data monitored in the test pipeline 25, and locates the position of the leakage point on the longitudinal and cross-sectional surfaces of the pipeline. The display unit 17 displays the processing results of the analysis and processing unit 16 in real time.

[0035] The test pipes 25 between the supply section A1, the test section A2 and the discharge section A3 are connected by flanges, and the test pipes 25 between the parts are straight pipes with the same material and the same diameter.

[0036] The gas source 1 , the pressure regulating device 2 , the first pressure transmitting device 3 , the first flow transmitting device 4 , the monitoring device, the observation device, the simulated leakage device, the second pressure transmitting device 8 , the second flow transmitting device 9 and the pressure relief device 15 are all installed on the test pipeline 25 .

[0037] The pressure regulating device 2, the first pressure transmitting device 3, the first flow transmitting device 4, the second pressure transmitting device 8 and the second flow transmitting device 9 are determined according to the outlet pressure of the gas source 1 and the required test pressure and flow rate conditions. Preferably, large-range and high-precision equipment are selected.

[0038] Before installing the monitoring device, the pressure regulating device 2, the first pressure transmitting device 3, the first flow transmitting device 4, the second pressure transmitting device 8 and the second flow transmitting device 9, the test pipeline 25 should be purged. After the test device is installed, the air tightness and strength test should be carried out.

[0039] Specifically, the test can be generally divided into two situations: static pressure and dynamic pressure. The static pressure test is to open the gas source 1 through the pressure regulating device 2 until the predetermined test pressure is reached in the test pipeline 25, close the gas source 1, open the leakage hole control valve 24 on different simulated leakage devices to simulate leakage; the dynamic pressure test is to open the gas source 1 through the pressure regulating device 2 until the predetermined test pressure is reached in the test pipeline 25, open the pressure relief device 15 to a certain opening, make the gas flow rate in the test pipeline 25 reach a certain stable state, open the leakage hole control valve 24 on different simulated leakage devices to simulate leakage.

[0040] Each working condition was repeated more than three times to ensure the accuracy and repeatability of the test data.

[0041] After each or several tests, the integrity of each strain gauge of the monitoring device should be observed through an observation device using an endoscope.

[0042] In each test, the deformation data of each group of strain gauges of the monitoring device, as well as the monitoring data of the first pressure transmitter 3, the first flow transmitter 4, the second pressure transmitter 8, and the second flow transmitter 9 are collected and transmitted to the data terminal for analysis and storage, and a real-time waveform is displayed.

[0043] Analyze the monitored data, study the longitudinal and lateral propagation patterns of gas leakage in pipelines, and establish leakage location formulas and leakage severity judgment models.

[0044] Example 2

[0045] Reference Figure 5 , Figure 6 , which is the second embodiment of the present invention, and is different from the first embodiment in that: the monitoring device includes three groups of equipment, namely a first monitoring device 71, a second monitoring device 72, and a third monitoring device 73, each group is composed of a flange 18, a strain gauge 22, a strain gauge data transmission line 19, a connecting rod 10 and a load ball 11, each group is connected to the test pipe 25 through the flange 18, and is arranged at both ends and the middle position of the test section A2 to collect deformation data of the strain gauge 22.

[0046] The connecting rod 10 is a hollow L-shaped circular tube, which vertically passes through the flange 18. The straight end extends to the outside of the test pipe 25, and the elbow end extends to the inside of the test pipe 25. The end of the elbow is welded to the surface of the load ball 11. The outer diameter of the cross-sectional circle of the connecting rod 10 is smaller than the width of the strain gauge 22. The elbow end of the connecting rod 10 is placed toward the supply section A1, and the horizontal section of the elbow end of the connecting rod is parallel to the placement direction of the test pipe 25. The distance from the end of the straight end of the connecting rod 10 to the test pipe 25 is less than or equal to the length of the strain gauge 22, and the length of the horizontal section of the elbow end of the connecting rod 10 is equal to the length of the strain gauge 22. The hollow interior of the connecting rod 10 is used to pass the strain gauge data transmission line 19.

[0047] The load ball 11 is a hollow sphere, the center of which coincides with the center of the cross section of the test pipe, and the diameter of the load ball 11 is less than 1 / 2 of the inner diameter of the test pipe 25. The load ball 11 is used to provide a placement platform for the strain gauge 22, and the connection between the connecting rod 10 and the load ball 11 is hollow and connected. The inner hollow of the connecting rod 10 and the inner hollow of the load ball 11 are used to pass the strain gauge data transmission line 19, and the spherical setting of the load ball 11 can reduce air resistance. Preferably, the diameter of the load ball 11 is equal to 1 / 3 of the inner diameter of the test pipe 25.

[0048] The strain gauge 22 is located on the circumference of the cross section of the load ball 11. The cross section is a cross section passing through the center of the sphere that is perpendicular to the horizontal ground and perpendicular to the gas delivery direction in the test pipeline 25. The cross section is arranged in three groups. The three groups of cross sections pass through the center of the sphere, from the center of the sphere to 1 / 4 of the radius, and from the center of the sphere to 1 / 2 of the radius in sequence. The three groups of cross sections are all located on the hemisphere close to the supply section side, and the direction of the force-bearing surface of the strain gauge 22 is parallel to the cross section.

[0049] The number of the strain gauges 22 is greater than or equal to 6, and they are evenly spaced on the load ball 11. In the present invention, 8 are used as an example for explanation. The specifications and sizes of the strain gauges 22 are the same, the width is greater than or equal to the minimum leakage hole diameter of the simulated leakage device on the test pipe 25, and the length is greater than or equal to 0.2 times the diameter of the load ball 11. The number of strain gauges 22 on the three groups of cross sections is equal, and they are respectively arranged at the strain gauge gaps of adjacent cross sections.

[0050] A small hole is provided at the connection between the load ball 11 and each strain gauge 22 for passing the strain gauge data transmission line 19. One end of the strain gauge data transmission line 19 is connected to the strain gauge 22, and the other end passes through the inside of the load ball 11 and the connecting rod 10 and then connects to the analysis and processing unit 16. The size of the small hole is adapted to the strain gauge data transmission line 19, ensuring that the strain gauge data transmission line 19 can pass through and the aperture will not be too large to affect the data transmission efficiency.

[0051] Preferably, the connecting rod 10 and the load ball 11 are made of heat-resistant and corrosion-resistant materials.

[0052] The strain gauge 22 three-dimensionally monitors the pressure and flow rate in the test pipe 25 at different positions on the three groups of cross sections. The strain gauge 22 on each group of cross sections is displayed on the display unit using curves of different colors. The three-dimensional position monitoring expresses different data of the pressure and flow rate at different positions of the test device during the simulated leakage process, captures the tiny and detailed change process, and further accurately determines the position of the leakage hole.

[0053] A control method for a gas pipeline leakage online monitoring and positioning test device is applicable to a gas pipeline leakage online monitoring and positioning test device including a test pipeline and a data terminal. The test pipeline is used to transmit gas and provide a data source for the data terminal, including a supply section, a test section, and a discharge section. The test section includes a monitoring device, a simulated leakage device, and an observation device. Specifically, the method includes the following steps: Step 1: Assemble the test pipe of the test device; Step 2: gas is transported to the test pipeline, and the real-time pressure and flow rate of the supply section and the discharge section, as well as the real-time deformation data of the strain gauge in the pipeline of the test section are transmitted to the data terminal; Step 3: According to the data transmitted to the data terminal in step 2, a continuous waveform of the real-time pressure, real-time flow rate and real-time deformation data corresponding to each strain gauge in the test section pipeline is obtained; after the observation device determines that the monitoring device is in good condition, the simulated leakage device simulates leakage; the data terminal processes and analyzes the instantaneous deformation value and the time interval of occurrence collected by the monitoring device, locates the position of the simulated leakage device of the simulated leakage, and establishes a leakage location formula; Step 4: The data terminal establishes a leakage severity judgment model based on the correspondence between the real-time deformation data and the real-time pressure and real-time flow rate in the continuous waveform diagram, and the real-time deformation data of the strain gauge collected by the monitoring device after the simulated leakage device simulates leakage.

[0054] More specifically, the step 1 includes the following steps: Step 101: Select three straight pipes of the same material and diameter and connect them through flanges; Step 102: The supply section is placed upstream of the test device, and a gas source, a pressure regulating device, a first pressure transmitting device, and a first flow transmitting device are sequentially arranged on the test pipeline according to the gas delivery direction; Step 103: The test section is placed in the midstream position of the test device, and three groups of monitoring devices, three groups of observation devices and two groups of simulated leakage devices are set on the test pipeline. Among them, the first monitoring device is set on the side of the test section close to the supply section, the second monitoring device is set at the middle position of the test section, and the third monitoring device is set on the side of the test section close to the discharge section. The first simulated leakage device is set on the side of the first monitoring device close to the supply section, and the second simulated leakage device is set between the first monitoring device and the second monitoring device. The first observation device is located between the first simulated leakage device and the first monitoring device, the second observation device is set on the side of the second monitoring device close to the supply section, and the third observation device is set on the side of the third monitoring device close to the supply section; Step 104: The discharge section is placed downstream of the test device, and a second pressure transmitter, a second flow transmitter, and a pressure relief device are sequentially arranged on the test pipeline according to the gas delivery direction.

[0055] The step 2 specifically includes the following steps: Step 201: Turn on the gas source to transmit the test gas into the test pipeline; Step 202: The pressure regulating device regulates the pressure of the test gas transmitted by the gas source so that the test pipeline reaches a predetermined test pressure; Step 203: the first pressure transmitter and the first flow transmitter monitor the real-time pressure and real-time flow rate data of the gas in the supply section online, and transmit the data to the data terminal; Step 204: three sets of monitoring devices monitor the real-time deformation data of the strain gauges in the test section online and transmit the data to the data terminal; Step 205: The second pressure transmitter and the second flow transmitter monitor the real-time pressure and real-time flow rate data of the gas in the discharge section online, and transmit the data to the data terminal.

[0056] The step three specifically includes the following steps: Step 301: The data terminal generates a continuous waveform diagram of the real-time pressure, real-time flow rate and real-time deformation data corresponding to each strain gauge in the test section pipeline according to the received data; Step 302: according to the continuous waveform diagram of the real-time deformation data of each strain gauge of the three groups of monitoring devices, the maximum peak and trough values ​​are obtained, and they are preset as deformation thresholds; Step 303: During the test interval, the integrity of the strain gauge of the monitoring device is checked through the observation device; Step 304: When the predetermined pressure and flow rate are reached in the test pipeline, a leakage hole is opened. If the instantaneous deformation values ​​collected by the three groups of monitoring devices on the test section are all greater than or equal to the preset deformation threshold, and the time intervals of the instantaneous deformation values ​​detected successively are all less than or equal to the preset time interval threshold, it is determined that a valid instantaneous deformation value is detected; if not, return to step 303; Step 305: One group of monitoring devices first detects the effective instantaneous deformation value described in step 304, and compares the time intervals between the instantaneous deformation values ​​detected by the other two groups of monitoring devices; Step 306: when the first simulated leakage device is turned on, if the first monitoring device first detects the effective instantaneous deformation value described in step 304, and the second monitoring device and the third monitoring device successively detect the instantaneous deformation value at the same time interval, then it is determined that the test is effective; when the second simulated leakage device is turned on, if the monitoring device on the test section close to the simulated leakage device first detects the effective instantaneous deformation value described in step 304, and the other two groups of monitoring devices successively detect the instantaneous deformation value at different time intervals, then it is determined that the test is effective; if not, return to step 303; Step 307: According to step 306, if the test is determined to be effective, the time sequence of the instantaneous deformation values ​​detected by the inner circumference strain gauges on the monitoring device that first detects the effective instantaneous deformation value described in step 304 is compared to determine the position of the simulated leakage device on the cross section of the pipeline, and compared with the position of the leakage hole on the opened simulated leakage device; Step 308: According to step 306, if the test is determined to be effective. When the first simulated leakage device is turned on, the time interval of the instantaneous deformation value detected by the second monitoring device and the third monitoring device, and the preset distance between the two, are used to roughly obtain the propagation speed of the test gas. When the second simulated leakage device is turned on, the difference in the time interval of the instantaneous deformation value detected by the two sets of monitoring devices in succession, and the obtained propagation speed of the test gas, are used to determine the position of the leakage point in the longitudinal section of the pipeline, and compared with the position of the leakage hole on the opened simulated leakage device; Step 309: Establish a leakage location formula based on the comparison between the position of the leakage point determined in step 307 and step 308 in the transverse and longitudinal sections of the pipeline and the position of the leakage hole on the opened simulated leakage device.

[0057] The step 4 specifically includes the following steps: Step 401: The data terminal generates a corresponding relationship between real-time deformation data and real-time pressure and real-time flow rate according to the continuous waveform diagram obtained in step 301; Step 402: According to step 306, if the test is determined to be effective, the severity of the leakage can be determined based on the deformation value of the strain gauge that first detects the effective instantaneous deformation value in step 304. The larger the strain gauge deformation value, the more serious the leakage. According to the corresponding relationship between the real-time deformation data of the strain gauge and the real-time pressure and real-time flow rate established in step 401, the deformation value of the strain gauge before and after the leakage is compared, and the severity of the leakage can be quantitatively determined, and a leakage severity judgment model can be established.

[0058] To sum up, the present invention proposes an online monitoring and positioning test device for gas pipeline leakage and a control method thereof, which can verify that the test device can achieve accurate positioning of the leakage point on the longitudinal and cross-sections of the pipeline and determine the severity of the leakage, and provide support for the practical application of the gas pipeline leakage monitoring and positioning device. Its popularization and application will effectively improve the level of online monitoring and positioning of leakages in fluid pipelines such as water, gas, heat, and oil.

[0059] The above content is an explanation of the preferred embodiments of the present invention, which can help those skilled in the art to more fully understand the technical solution of the present invention. However, these embodiments are merely illustrative, and it cannot be determined that the specific implementation methods of the present invention are limited to the description of these embodiments. For ordinary technicians in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions and transformations can be made, which should be regarded as belonging to the protection scope of the present invention.

Claims

1. A gas pipeline leakage online monitoring and positioning test device, characterized in that: It includes a test pipeline and a data terminal; the test pipeline is used to transmit gas and provide a data source for the data terminal, and includes a supply section, a test section, and a discharge section; the test section includes the monitoring device, the simulated leakage device, and the observation device; The supply section sends the real-time pressure and real-time flow rate to the data terminal; the discharge section sends the real-time pressure and real-time flow rate to the data terminal; the monitoring device sends the real-time deformation data of the strain gauge in the test section pipeline to the data terminal; The analysis and processing unit of the data terminal obtains a continuous waveform corresponding to each strain gauge in the test section pipeline according to the real-time pressure and real-time flow rate of the supply section and the discharge section, and the real-time deformation data of the strain gauge in the test section pipeline; after the observation device determines that the monitoring device is in good condition, the simulated leakage device simulates leakage, and the data terminal processes and analyzes the instantaneous deformation value and the time interval of occurrence collected by the monitoring device, locates the position of the simulated leakage device of the simulated leakage, and establishes a leakage location formula; The analysis and processing unit of the data terminal establishes a leakage severity judgment model based on the correspondence between the real-time deformation data and the real-time pressure and real-time flow rate in the continuous waveform diagram, and the real-time deformation data of the strain gauge collected by the monitoring device after the simulated leakage device performs simulated leakage.

2. A gas pipeline leakage online monitoring and positioning test device according to claim 1, characterized in that: The monitoring device includes three groups of equipment, each group consists of a flange, a strain gauge and a strain gauge data transmission line, each group is connected to the test pipeline through a flange and is arranged at both ends and the middle of the test section.

3. A gas pipeline leakage online monitoring and positioning test device according to claim 2, characterized in that: The flange is of the same specification and model as the flange used for connecting the test pipe, and a radial through groove is opened on one side of the vertical surface of the flange, and the width and depth of the groove are greater than the width and thickness of the strain gauge and the strain gauge data transmission line; one end of the strain gauge connected to the strain gauge data transmission line is placed in the groove, adhered with insulating glue, and the groove is filled, and the other end of the strain gauge extends into the test pipe and is evenly distributed along the inner circumference of the test pipe; the width of the strain gauge is greater than or equal to the minimum leakage hole diameter, and the distance between the front end of the strain gauge extending into the test pipe and the inner wall of the test pipe is greater than or equal to 0.125 times the inner circumference diameter of the test pipe.

4. The on-line monitoring and positioning test device for gas pipeline leakage according to claim 1 is characterized by: The simulated leakage device includes two groups of equipment, each group consists of a number of leakage holes with different apertures and leakage hole control valves, one group is arranged upstream of the monitoring device close to the supply section side, and the other group is arranged between the monitoring device close to the supply section side and the monitoring device in the middle position.

5. A gas pipeline leakage online monitoring and positioning test device according to claim 4, characterized in that: The leakage hole is formed by drilling a hole in the test pipe, inserting a hollow tube into the interior of the test pipe and welding the hole to the test pipe. A leakage hole control valve is provided on each leakage hole to control the opening and closing. The maximum aperture of the leakage hole is less than or equal to 0.2 times the diameter of the test pipe, and the width of the strain gauge is greater than or equal to the minimum aperture of the leakage hole.

6. A gas pipeline leakage online monitoring and positioning test device according to claim 1, characterized in that: The observation device includes three groups of equipment, each group consists of an endoscope and an endoscope, and each group is respectively arranged on one side of the three monitoring devices close to the supply section. The group of observation devices close to the supply section is located between the simulated leakage device close to the supply section and the monitoring device close to the supply section. The endoscope is a drilled hole in the test pipe, which passes through the side wall of the test pipe. The diameter of the endoscope is 0.2 times that of the endoscope lens.

7. The on-line monitoring and positioning test device for gas pipeline leakage according to claim 1 is characterized by: The supply section includes an air source, a pressure regulating device, a pressure transmitting device and a flow transmitting device; the discharge section includes a pressure transmitting device, a flow transmitting device and a pressure relief device.

8. The on-line monitoring and positioning test device for gas pipeline leakage according to claim 7 is characterized by: The analysis and processing unit is respectively connected to the pressure transmitter, the flow transmitter and the monitoring device to collect data information monitored online in the test pipeline. The analysis and processing unit compares the pressure and flow rate data in the test pipeline monitored by the pressure transmitter and the flow transmitter with the deformation data monitored by the monitoring device to analyze and establish the corresponding relationship between the deformation and the pressure and flow rate.

9. A gas pipeline leakage online monitoring and positioning test device according to claim 7, characterized in that: The gas source, pressure regulating device, pressure transmitting device, flow transmitting device, monitoring device, observation device, simulated leakage device and pressure relief device are all installed on the test pipeline; the test section, supply section and discharge section of the test pipeline are connected by flanges, and the test pipelines of each part are straight pipelines with the same material and diameter.

10. A control method for an online monitoring and positioning test device for gas pipeline leakage, characterized in that: Applicable to a gas pipeline leakage online monitoring and positioning test device including a test pipeline and a data terminal, the test pipeline is used to transmit gas and provide a data source for the data terminal, including a supply section, a test section, and a discharge section. The test section includes a monitoring device, a simulated leakage device, and an observation device, specifically including the following steps: Step 1: Assemble the test pipe of the test device; Step 2: gas is transported to the test pipeline, and the real-time pressure and flow rate of the supply section and the discharge section, as well as the real-time deformation data of the strain gauge in the pipeline of the test section are transmitted to the data terminal; Step 3: According to the data transmitted to the data terminal in step 2, a continuous waveform of the real-time pressure, real-time flow rate and real-time deformation data corresponding to each strain gauge in the test section pipeline is obtained; after the observation device determines that the monitoring device is in good condition, the simulated leakage device simulates leakage; the data terminal processes and analyzes the instantaneous deformation value and the time interval of occurrence collected by the monitoring device, locates the position of the simulated leakage device of the simulated leakage, and establishes a leakage location formula; Step 4: The data terminal establishes a leakage severity judgment model based on the correspondence between the real-time deformation data and the real-time pressure and real-time flow rate in the continuous waveform diagram, and the real-time deformation data of the strain gauge collected by the monitoring device after the simulated leakage device simulates leakage.

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