Leakage signal detection device and method for high-pressure gas-liquid two-phase flow pipeline

Abstract

The application discloses a leakage signal detection device for a high-pressure gas-liquid two-phase flow pipeline, which comprises a gas-liquid mixing section, a third valve, a flow pattern visualization experiment section and a gas-liquid separation section which are sequentially connected; an experiment heating unit is arranged on a pipeline between the third valve and the flow pattern visualization experiment section; a leakage positioning experiment unit is arranged on a pipeline between the flow pattern visualization experiment section and the gas-liquid separation section; a temperature sensor is arranged on a pipeline between the experiment heating unit and the flow pattern visualization experiment section; a differential pressure transmitter is further arranged; a first high-frequency pressure sensor is arranged on a pipeline between the flow pattern visualization experiment section and the leakage positioning experiment unit, a second high-frequency pressure sensor and a condenser are arranged on a pipeline between the leakage positioning experiment unit and the gas-liquid separation section; and a data acquisition and display system is further arranged. The problems that it is difficult to stably measure experimental parameters of high-pressure gas-liquid two-phase flow are solved. A leakage signal detection method for the high-pressure gas-liquid two-phase flow pipeline is further provided.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of pipeline leakage detection, and particularly relates to a leakage signal detection device for a high-pressure gas-liquid two-phase flow pipeline and a leakage signal detection method for a high-pressure gas-liquid two-phase flow pipeline. BACKGROUND

[0002] Long-distance pipeline transportation technology is widely used in water conservancy engineering, petroleum and chemical industry, energy and power and other fields (Research Progress and Frontiers of Long-distance Water Transportation Hydraulic Control[J]. Journal of Hydraulic Engineering, 2016, 47(03): 424-435.), and is the preferred mode of water resources and oil and gas resources transportation. However, in the above engineering, the pipeline working pressure is high (MPa level), the transportation distance is long, the geological environment along the line is complex, and the factors such as pipeline corrosion and geological damage caused by long-term service are superimposed, which leads to pipeline leakage accidents, causing huge economic losses and environmental pollution and other major accidents (A comprehensive framework to evaluate hydraulic and water quality impacts of pipe breaks on water distribution systems[J]. Water Resources Research, 2018, 54(10): 8174-8195.). In particular, with the continuous upgrading of the intelligent operation of the long-distance pipeline system in China, higher requirements are put forward for the pipeline leakage positioning and detection technology.

[0003] The existing leakage detection technology is mainly applied to single-phase fluid transportation pipelines, and the detection method based on transient signal is an important way (Experimental investigation on blockage predictions in gas pipelines using the pressure pulse wave method[J]. Energy, 2021, 230: 120897.). The basic principle is to realize positioning by detecting the singular points of the transient leakage signal (mainly fluid pressure / differential pressure signal). However, in actual engineering, the fluid transportation pipeline is often in a gas-liquid two-phase flow state, and there are many flow patterns, which have a non-negligible influence on the propagation process of the leakage signal, and are the key factors restricting the accuracy improvement of the leakage positioning technology. Taking the long-distance water transportation system as an example, due to factors such as pump suction, negative pressure in the pipe, poor air valve exhaust and the like, air is inevitably mixed in the pipeline (especially at local high points and descending pipe sections), that is, gas-liquid two-phase flow is generated.

[0004] The two-phase flow system has complex flow characteristics such as wave phenomenon and interface disturbance, so that the propagation characteristics of the leakage signal under different flow patterns are quite different, the two-phase flow can cause a large amount of flow background noise, and the change of flow parameters under high pressure leakage condition is more severe, the difficulty of signal extraction and processing is upgraded, which makes the traditional single-phase leakage detection technology difficult to apply. Therefore, it is urgent to build an experimental device that can stably detect the leakage signal of high-pressure gas-liquid two-phase flow, so as to help explore the influence mechanism of two-phase flow pattern on the propagation of leakage signal.

[0005] There are many technical difficulties in building a leakage signal detection device for high-pressure gas-liquid two-phase flow pipeline and carrying out flow visualization and leakage signal detection, mainly manifested as:

[0006] (1) Design and process a visualized experimental section that can withstand high pressure, solve the problems of sealing, installation, shooting, etc. of quartz glass tube;

[0007] (2) The high-pressure gas-liquid two-phase flow system is prone to flow instability, and measures need to be taken to maintain stable gas-liquid two-phase flow rate and pressure.

[0008] Therefore, it is a difficult problem to be solved in the field to provide an experimental platform that is reliable in operation, low in test cost, wide in test measurement parameter range, and can accurately and synchronously measure the flow pattern and pressure, pressure difference and other data of high-pressure gas-liquid two-phase flow pipeline. SUMMARY

[0009] The first object of the present application is to provide a leakage signal detection device for high-pressure gas-liquid two-phase flow pipeline, which solves the problem of difficult stable measurement of high-pressure gas-liquid two-phase flow experimental parameters.

[0010] The second object of the present application is to provide a leakage signal detection method for high-pressure gas-liquid two-phase flow pipeline, which solves the problems that the influence of flow pattern on leakage signal is not considered in the traditional detection method, and it is difficult to simultaneously measure the image data of flow pattern and the leakage signal data such as pressure, pressure difference and other leakage signal data with high precision.

[0011] The first technical solution adopted by the present application is a leakage signal detection device for high-pressure gas-liquid two-phase flow pipeline, comprising a gas-liquid mixing section, a third valve, a flow pattern visualization experimental section and a gas-liquid separation section connected in sequence through a pipeline; the gas-liquid separation section supplies liquid for the gas-liquid mixing section; an experimental heating unit is arranged on the pipeline between the third valve and the flow pattern visualization experimental section;

[0012] A leakage positioning experiment unit is arranged on the pipeline between the flow pattern visualization experiment section and the gas-liquid separation section; a temperature sensor is arranged on the pipeline between the experiment heating unit and the flow pattern visualization experiment section; a differential pressure transmitter is further arranged, which is connected with the inlet end of the visualization experiment section and the outlet end of the visualization experiment section through two pipelines; a first high-frequency pressure sensor is arranged on the pipeline between the flow pattern visualization experiment section and the leakage positioning experiment unit, and a second high-frequency pressure sensor and a condenser are arranged on the pipeline between the leakage positioning experiment unit and the gas-liquid separation section, and the condenser is arranged close to the gas-liquid separation section; a plurality of high-speed cameras and a plurality of light sources are arranged around the visualization experiment section, and the high-speed cameras and the light sources are one-to-one corresponding and used in cooperation; a data acquisition and display system is further arranged, and the plurality of high-speed cameras, the gas-liquid mixing section, the temperature sensor, the differential pressure transmitter, the leakage positioning experiment unit, the first high-frequency pressure sensor and the second high-frequency pressure sensor are connected with the data acquisition and display system.

[0013] The application is further characterized in that,

[0014] The gas-liquid mixing section comprises a gas circuit unit, a gas-liquid mixer and a liquid circuit unit connected in sequence; the gas circuit unit comprises an air compressor, an air tank, a pressure stabilizing valve, an adjusting valve and an air flow meter connected in sequence; the air flow meter is further connected with the gas inlet of the gas-liquid mixer through a pipeline; the liquid circuit unit comprises a water tank, a first valve, a first filter, a high-pressure constant-flow pump, a second valve and a mass flow meter connected in sequence; the mass flow meter is further connected with the liquid inlet of the gas-liquid mixer through a pipeline; the gas-liquid two-phase flow fluid outlet of the gas-liquid mixer is further connected with a third valve through a pipeline; the gas-liquid separation section supplies liquid to the water tank; the air flow meter and the mass flow meter are connected with the data acquisition and display system.

[0015] The gas-liquid separation section comprises a gas-liquid separator, the gas outlet of the gas-liquid separator is connected with a second pipeline, and a second back pressure valve is further arranged on the second pipeline; the liquid outlet of the gas-liquid separator is connected with a first pipeline, and a second filter and a first back pressure valve are further arranged on the first pipeline, and the second filter is arranged close to the liquid outlet of the gas-liquid separator; the water tank is supplied with liquid through the first pipeline.

[0016] The visualized experimental section comprises a quartz tube, a first flange, a second flange, a third flange and a fourth flange, the first flange and the second flange are used in pairs, the first flange is installed at the pipeline end on one side of the first end of the quartz tube, the second flange is installed at the end of the first end of the quartz tube, and the first flange and the second flange are connected through bolted nuts; the third flange and the fourth flange are used in pairs, the third flange is installed at the pipeline end of the second end of the quartz tube, the fourth flange is installed at the pipeline end on one side of the second end of the quartz tube, and the third flange and the fourth flange are connected through bolted nuts; a quartz tube square shell with a through hole in the shape of a cuboid and with a through hole is further sleeved on the outer wall of the quartz tube between the second flange and the third flange, the quartz tube passes through the through hole of the quartz tube square shell, and the outer wall of the quartz tube is tightly combined with the inner wall of the through hole of the quartz tube square shell.

[0017] The first end of the quartz tube is provided with a first sealing ring, and the first sealing ring is located between the first flange and the second flange; the second end of the quartz tube is provided with a second sealing ring, and the second sealing ring is located between the third flange and the fourth flange.

[0018] The leakage positioning experimental unit comprises three parallel first branch pipes, a second branch pipe and a second branch pipe; one end of each of the first branch pipe, the second branch pipe and the second branch pipe is connected with a pipeline between the first high-frequency pressure sensor and the second high-frequency pressure sensor; the first branch pipe, the second branch pipe and the second branch pipe are respectively provided with a first electric valve, a second electric valve and a third electric valve; the first electric valve, the second electric valve and the third electric valve are connected with a data acquisition and display system.

[0019] The experimental heating unit comprises a first alternating pole plate and a second alternating pole plate arranged on a pipeline between the third valve and the flow pattern visualization experimental section; a transformer is connected between the first alternating pole plate and the second alternating pole plate through wires; the experimental heating unit further comprises an alternating current power supply and a voltage regulator forming a closed loop, and the voltage regulator and the transformer are connected in an electromagnetic induction mode, so that the heating power is transmitted to the first alternating pole plate, the second alternating pole plate, the third valve and the pipeline between the flow pattern visualization experimental section, so that a certain heat flux density is given to the pipeline between the two alternating pole plates.

[0020] The second technical solution adopted by the present application is a leakage signal detection method for a high-pressure gas-liquid two-phase flow pipeline, which adopts the above-mentioned leakage signal detection device for the high-pressure gas-liquid two-phase flow pipeline, and is implemented according to the following steps:

[0021] Step 1, check the circuit to ensure that there is no broken wire or leakage; turn on the data acquisition and display system to ensure that each sensor works normally;

[0022] Step 2, close the regulating valve, open the first valve, the second valve and the third valve; introduce deionized water into the water tank, set the required liquid mass flow on the high-pressure constant flow pump, start the high-pressure constant flow pump, and observe whether the pipeline is unobstructed and whether there is leakage; if the pipeline is unobstructed and there is no leakage problem, proceed to the next step;

[0023] Step 3, after the liquid completes 1-2 minutes of circulation in the test loop, open the air compressor to introduce high-pressure gas into the high-pressure gas storage tank; after the high-pressure gas storage tank is full of gas, slowly open the pressure stabilizing valve to adjust the outlet pressure, and after the outlet pressure is stable, slowly open the regulating valve to adjust the gas flow to the set flow, and obtain the gas-liquid two-phase fluid in the gas-liquid mixer;

[0024] Step 4, after the gas-liquid two-phase fluid completes 1-2 minutes of circulation in the test loop, adjust the first back pressure valve and the second back pressure valve to make the test loop reach the set pressure;

[0025] Step 5, adjust the pressure regulator of the experimental heating unit to control the stable heating power output of the transformer, so that the fluid temperature at the outlet of the experimental heating unit (14) reaches the preset initial pipe inlet temperature, and after the experimental data is stable, record the relevant experimental data measured by all monitoring instruments in the measurement device at this time (including the flow pattern data obtained by the first high-speed camera 32 and the first high-speed camera 34, the recorded data of the temperature sensor 15, the differential pressure sensor 17, the first high-frequency pressure sensor 19 and the second high-frequency pressure sensor 20);

[0026] Step 6, open the first electric valve in the leakage positioning experimental unit, and record the relevant experimental data before and after the opening time (0.1s-2s) of the electric valve. After the parameter recording is completed, close the first electric valve. After the experimental data is stable, repeat the above process: open the second electric valve and the third electric valve in turn, and record the data before and after the opening time (0.1s-2s) of the second electric valve or the third electric valve.

[0027] Step 7, change the gas flow by using the regulating valve, and after the test data is stable, observe the flow pattern at this time through the flow pattern visualization experimental section, and repeat the step to record the relevant parameters. Similarly, change the liquid flow by using the high-pressure constant flow pump, and repeat the above process;

[0028] Step 8, change the outlet temperature of the experimental heating unit by using the experimental heating unit, repeat the step and the step to obtain the relevant experimental data under different temperature conditions; change the pressure of the experimental loop by using the first back pressure valve and the second back pressure valve, repeat the step and the step to obtain the relevant experimental data under different pressure conditions.

[0029] Step 9, gradually reduce the heating power on the corresponding pipeline of the experimental heating unit, wait until the power is reduced to 0, and then turn off the transformer; adjust a back pressure valve and a second back pressure valve to reduce the test circuit pressure to normal pressure; turn off the air compressor to stop generating gas, and gradually adjust and close the pressure stabilizing valve and the regulating valve to stop delivering gas to the test circuit; turn off the high-pressure constant-flow pump, and the fluid stops circulating in the test circuit; finally, turn off the first valve, the second valve, the third valve, and the data acquisition and display system.

[0030] The beneficial effects of the present application are:

[0031] (1) The high-pressure gas-liquid two-phase flow pipeline leakage signal detection device provided by the present application has the greatest advantage that the test device is safe and reliable in operation, the experimental cost is low, the range of test measurement parameters is large, and the measurement parameters can be kept stable during the test process, thereby solving the problem of difficult stable measurement of high-pressure gas-liquid two-phase flow experimental parameters.

[0032] (2) The high-pressure gas-liquid two-phase flow pipeline leakage signal detection device provided by the present application can synchronously acquire gas-liquid two-phase flow pattern image and signal data in real time, which is conducive to observing the flow pattern of gas-liquid two-phase flow and facilitating the exploration of the change rule of leakage signals under different flow patterns.

[0033] (3) The high-pressure gas-liquid two-phase flow pipeline leakage signal detection device provided by the present application uses measurement instruments and data acquisition systems that have high sampling frequency and fast response, and can detect and save data in real time, and the related data can help explore the leakage rule and influencing factors under high-pressure gas-liquid two-phase flow conditions.

[0034] (4) The high-pressure gas-liquid two-phase flow pipeline leakage signal detection device provided by the present application is designed and processed with a high-pressure-resistant visual experiment section, which solves the problems of sealing, installation, and shooting of quartz glass pipes.

[0035] (5) The high-pressure gas-liquid two-phase flow pipeline leakage signal detection method provided by the present application considers the influence of flow pattern on leakage signals, solves the problem of synchronous collection of flow pattern image data and leakage signal data such as pressure and pressure difference, and can obtain accurate high-pressure gas-liquid two-phase flow pattern and leakage signal data. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 is a structural schematic diagram of the high-pressure gas-liquid two-phase flow pipeline leakage signal detection device of the present application;

[0037] Figure 2 is a structural schematic diagram of the flow pattern visual experiment section in the high-pressure gas-liquid two-phase flow pipeline leakage signal detection device of the present application.

[0038] Figure 3is a schematic diagram of a photographing mode of a flow pattern visualization experimental section in a leakage signal detection device of a high-pressure gas-liquid two-phase flow pipeline of the present application.

[0039] Figure 4 is a structural schematic diagram of a preheating section in the leakage signal detection device of the high-pressure gas-liquid two-phase flow pipeline of the present application;

[0040] Figure 5 is a pressure signal diagram of liquid flow and gas flow when the pressure is adjusted to 0.7 MPa and the temperature is adjusted to 25 DEG C in Example 1;

[0041] Figure 6 is a flow pattern image under the condition of Figure 5

[0042] Figure 7 is a pressure signal diagram when the liquid flow and the gas flow are respectively set to 10 g / s and 5 g / s and the pressure is set to 0.7 MPa in Example 1;

[0043] Figure 8 is a flow pattern image under the condition of Figure 7

[0044] Figure 9 is pressure signal change data when the liquid flow and the gas flow are respectively set to 10 g / s and 3.33 g / s and the pressure is set to 0.2 MPa in Example 1;

[0045] ​​1. air compressor, 2. high pressure air tank, 3. pressure stabilizing valve, 4. regulating valve, 5. air flow meter, 6. water tank, 7. first valve, 8. first filter, 9. high pressure constant flow pump, 10. second valve, 11. mass flow meter, 12. gas-liquid mixer, 13. third valve, 14. experimental heating unit, 15. temperature sensor, 16. flow pattern visualization experimental section, 17. differential pressure sensor, 18. leak location experimental unit, 19. first high frequency pressure sensor, 20. second high frequency pressure sensor, 21. gas-liquid separator, 22. second filter, 23. first back pressure valve, 24. second back pressure valve, 25. data acquisition and display system, 26. first flange, 27. second flange, 28. third flange, 29. fourth flange, 30. first sealing ring, 31. second sealing ring, 32. first high speed camera, 33. first light source, 34. second high speed camera, 35. second light source, 36. quartz tube, 37. quartz tube square shell, 38. first electric valve, 39. second electric valve, 40. third electric valve, 41. first alternating current electrode plate, 42. second alternating current electrode plate, 43. alternating current power supply, 44. voltage regulator, 45. transformer, 46. gas-liquid separator gas outlet, 47. gas-liquid separator liquid outlet, 48. gas-liquid mixing section, 49. gas-liquid separation section, 50. second pipe, 51. first pipe, 52. first branch pipe, 53. second branch pipe, 54. third branch pipe, 55. condenser. DETAILED DESCRIPTION

[0046] The present application will be described in detail below with reference to the drawings and specific embodiments.

[0047] The present application provides a leak signal detection device for high pressure gas-liquid two-phase flow pipe, such as Figures 1-5As shown, it comprises a gas-liquid mixing section 48, a third valve 13, a flow pattern visualization experiment section 16 and a gas-liquid separation section 49 connected in sequence through pipelines; the gas-liquid separation section 49 supplies liquid for the gas-liquid mixing section 48; an experiment heating unit 14 is arranged on the pipeline between the third valve 13 and the flow pattern visualization experiment section 16; a leakage positioning experiment unit 18 is arranged on the pipeline between the flow pattern visualization experiment section 16 and the gas-liquid separation section 49; a temperature sensor 15 is arranged on the pipeline between the experiment heating unit 14 and the flow pattern visualization experiment section 16; it further comprises a differential pressure transmitter 17 connected with the inlet end of the visualization experiment section 16 and the outlet end of the visualization experiment section 16 through two pipelines respectively; a first high-frequency pressure sensor 19 is arranged on the pipeline between the flow pattern visualization experiment section 16 and the leakage positioning experiment unit 18, and a second high-frequency pressure sensor 20 and a condenser 55 are arranged on the pipeline between the leakage positioning experiment unit 18 and the gas-liquid separation section 49, with the condenser 55 arranged close to the gas-liquid separation section 49; a plurality of high-speed cameras and a plurality of light sources are arranged around the visualization experiment section 16, with the high-speed cameras and the light sources corresponding to each other and used in cooperation; it further comprises a data acquisition and display system 25, and the plurality of high-speed cameras, the gas-liquid mixing section 48, the temperature sensor 15, the differential pressure transmitter 17, the leakage positioning experiment unit 18, the first high-frequency pressure sensor 19 and the second high-frequency pressure sensor 20 are connected with the data acquisition and display system 25. The entire device circuit is an open circulation, and the gas-liquid two-phase flow fluid is obtained in the gas-liquid mixing section 48 and flows out, flows into the gas-liquid separation section 49 after passing through the experiment heating unit 14, the flow pattern visualization experiment section 16, the leakage positioning experiment unit 18 and the condenser 55 and other related devices, and is separated into gas and liquid again, the gas is discharged to the atmosphere, and the liquid flows into the gas-liquid mixing section 48 for recycling. The experiment heating unit 14, the visualization experiment section 16, the leakage positioning experiment unit 18 and the related connecting pipelines are all wrapped with thermal insulation cotton to reduce heat loss.

[0048] As Figure 1As shown, the gas-liquid mixing section 48 includes a gas circuit unit, a gas-liquid mixer 12 and a liquid circuit unit connected in sequence; the gas circuit unit includes an air compressor 1, an air tank 2, a pressure stabilizing valve 3, a regulating valve 4 and an air flow meter 5 connected in sequence; the air flow meter 5 is also connected to the gas inlet of the gas-liquid mixer 12 through a pipeline; the liquid circuit unit includes a water tank 6, a first valve 7, a first filter 8, a high-pressure constant-flow pump 9, a second valve 10 and a mass flow meter 11 connected in sequence; the mass flow meter 11 is also connected to the liquid inlet of the gas-liquid mixer 12 through a pipeline; the gas-liquid two-phase flow fluid outlet of the gas-liquid mixer 12 is also connected to a third valve 13 through a pipeline; the gas-liquid separation section 49 supplies liquid to the water tank 6; the air flow meter 5 and the mass flow meter 11 are connected to a data acquisition and display system 25. In the gas circuit of the gas-liquid mixing section 48, the gas is made by the air compressor 1, then flows into the gas-liquid mixer 12 through the air tank 2, the pressure stabilizing valve 3, the regulating valve 4 and the air flow meter 5; in the liquid circuit, the water flows out of the water tank 6, then flows into the gas-liquid mixer 12 through the first valve 7, the first filter 8, the high-pressure constant-flow pump 9, the second valve 10 and the mass flow meter 11. The gas and the liquid are fully mixed in the gas-liquid mixer 12 to obtain the gas-liquid two-phase flow fluid. The air compressor 1 has a filtering device to filter impurities in the air, so as to stabilize the production and output of high-pressure gas; the air tank 2 can store high-pressure gas and preliminarily stabilize the gas pressure; the pressure stabilizing valve 3 can further stabilize the gas pressure and output the stabilized gas; the regulating valve 4 cooperates with the gas flow meter 5 to adjust the output flow of the gas. The first filter 8 can remove impurities in the water to protect the use safety of related instruments and equipment in the circulation circuit; the high-pressure constant-flow pump 9 can stably control the liquid flow to keep the flow stable during the experiment.

[0049] As shown, Figure 1 The gas-liquid separation section 49 includes a gas-liquid separator 21, the gas-liquid separator gas outlet 46 of the gas-liquid separator 21 is connected to a second pipeline 50, and the second pipeline 50 is also provided with a second back pressure valve 24; the gas-liquid separator liquid outlet 47 of the gas-liquid separator 21 is connected to a first pipeline 51, and the first pipeline 51 is also provided with a second filter 22 and a first back pressure valve 23, and the second filter 22 is arranged close to the gas-liquid separator liquid outlet 47 of the gas-liquid separator 21; the water tank 6 is supplied with liquid through the first pipeline 51. The gas flows out of the gas-liquid separator gas outlet 46, flows into the atmosphere through the second back pressure valve 24; the liquid flows out of the gas-liquid separator liquid outlet 47, flows into the gas-liquid mixing section 48 for recycling through the second filter 22 and the first back pressure valve 23. The first back pressure valve 23 and the second back pressure valve 24 are respectively used for stabilizing and adjusting the pressure of the liquid and the gas to ensure the pressure stability of the experimental circuit; the second filter 22 is used for removing impurities in the liquid to protect the use safety of related instruments and equipment in the circulation circuit.

[0050] AsFigures 2-3 As shown, the visualized experimental section 16 includes a quartz tube 36, a first flange 26, a second flange 27, a third flange 28 and a fourth flange 29. The first flange 26 and the second flange 27 are used in pairs, the first flange 26 is installed on the pipeline end on one side of the first end of the quartz tube 36, and the second flange 27 is installed on the end of the first end of the quartz tube 36. The first flange 26 and the second flange 27 are connected by bolted nuts. The third flange 28 and the fourth flange 29 are used in pairs, the third flange 28 is installed on the pipeline end of the second end of the quartz tube 36, and the fourth flange 29 is installed on the pipeline end on one side of the second end of the quartz tube 36. The third flange 28 and the fourth flange 29 are connected by bolted nuts. The quartz tube 36 is sleeved with a quartz tube square shell 37 with a through hole in the shape of a cuboid on the outer wall between the second flange 27 and the third flange 28. The quartz tube 36 passes through the through hole of the quartz tube square shell 37, and the outer wall of the quartz tube 36 is tightly fitted with the inner wall of the through hole of the quartz tube square shell 37. The first end of the quartz tube 36 is provided with a first sealing ring 30, and the first sealing ring 30 is located between the first flange 26 and the second flange 27. The second end of the quartz tube 36 is provided with a second sealing ring 31, and the second sealing ring 31 is located between the third flange 28 and the fourth flange 29. The first flange 26 is welded with the connecting pipeline, the first flange 26, the second flange 27 and the first sealing ring 30 are used in combination to connect one end of the quartz tube 36 with the stainless steel pipeline. The third flange 28 is welded with the stainless steel pipeline, and the third flange 28, the fourth flange 29 and the second sealing ring 31 are used in combination to connect the other end of the quartz tube 36 with the connecting pipeline. This way of connecting the quartz tube 36 with the stainless steel pipeline not only has small resistance, but also can withstand high temperature and high pressure. The first high-speed camera 32 and the second high-speed camera 34 respectively shoot the state of the fluid in the quartz tube 36 from the axial and longitudinal directions through the quartz tube square shell 37, and the first light source 33 and the second light source 35 respectively light the first high-speed camera 32 and the second high-speed camera 34. This shooting method can clearly shoot the fluid in the pipe from different angles, which is convenient for research and analysis.

[0051] As shown in the figure, Figure 1 As shown, the leakage positioning experimental unit 18 includes three parallel first branch pipes 52, second branch pipes 53 and third branch pipes 54. One end of each of the first branch pipes 52, the second branch pipes 53 and the third branch pipes 54 is connected with the pipeline between the first high-frequency pressure sensor 19 and the second high-frequency pressure sensor 20. The first branch pipes 52, the second branch pipes 53 and the third branch pipes 54 are respectively provided with first electric valves 38, second electric valves 39 and third electric valves 40. The first electric valves 38, the second electric valves 39 and the third electric valves 40 are connected with the data acquisition and display system, can be quickly opened and closed, simulate the pipeline leakage condition, and can quickly capture the instantaneous parameters at the moment of leakage in an instant when the valve is opened.

[0052] AsFigure 4 As shown, the preheating section 14 includes a first alternating pole plate 41 and a second alternating pole plate 42 arranged on the pipeline between the third valve 13 and the temperature sensor 15, a transformer 45 connected between the first alternating pole plate 41 and the second alternating pole plate 42 through a wire, and an alternating current power supply 43 and a voltage regulator 44 forming a closed loop, and the voltage regulator 44 and the transformer 45 are connected through electromagnetic induction to transmit power to the first alternating pole plate 41, the second alternating pole plate 42 and the pipeline, so as to give the pipeline between the two alternating pole plates a certain heat flux density.

[0053] The differential pressure sensor 17 used is a Rosemont 3051 pressure transmitter, the second high-frequency pressure sensor 19 and the second high-frequency pressure sensor 20 are PA-33 / 20bar, and the first filter 8 and the second filter 22 are Xiongchuan SS-216-30.

[0054] The temperature sensor 15 adopts a K-type armored thermocouple with a temperature measurement range of 0-300℃, the first back pressure valve 23 and the second back pressure valve 24 have a pressure regulation range of 0-10MPa, the high-pressure constant-flow pump 9 is a high-pressure-resistant (10MPa) constant-flow pump with stable output flow, and the data acquisition and display system 22 is an NI acquisition system with a case model of NI DAQ-9178, matched with NI 9203, NI 9213 and NI 9220 input modules, and a collection program of LABVIEW, which is used to collect relevant test data measured by all monitoring instruments in the test device.

[0055] The application also provides a leakage signal detection method for a high-pressure gas-liquid two-phase flow pipeline, which adopts the leakage signal detection device for the high-pressure gas-liquid two-phase flow pipeline and is implemented according to the following steps.

[0056] Step 1, check the circuit to ensure that there is no disconnection and no leakage, and open the data acquisition and display system 25 to ensure that each sensor works normally.

[0057] Step 2, close the regulating valve 4, open the first valve 7, the second valve 10 and the third valve 13, and introduce deionized water into the water tank, set the liquid mass flow required for the test on the high-pressure constant-flow pump 9, start the high-pressure constant-flow pump 9, and observe whether the pipeline is unobstructed and whether there is leakage; if the pipeline is unobstructed and there is no leakage problem, the next step is performed.

[0058] Step 3, after the liquid completes 1-2 minutes of circulation in the test loop, open the air compressor 1 to introduce high-pressure gas into the high-pressure gas storage tank 2, slowly open the pressure stabilizing valve 3 to adjust the outlet pressure after the high-pressure gas storage tank 2 is filled with gas, slowly open the regulating valve 4 to adjust the gas flow to the set flow, and obtain the gas-liquid two-phase fluid in the gas-liquid mixer 12.

[0059] Step 4, after the gas-liquid two-phase fluid completes 1-2 minutes circulation in the test loop, adjust the first back pressure valve 23 and the second back pressure valve 24 to make the test loop reach the set pressure;

[0060] Step 5, adjust the pressure regulator 44 of the experimental heating unit 14 to control the transformer 45 to output stable heating power, so that the fluid temperature at the outlet of the experimental heating unit 14 reaches the preset initial inlet temperature, and after the experimental data is stable, the related experimental data measured by all monitoring instruments in the measuring device (including the flow pattern data obtained by the first high-speed camera 32 and the first high-speed camera 34, the recorded data of the temperature sensor 15, the differential pressure sensor 17, the first high-frequency pressure sensor 19 and the second high-frequency pressure sensor 20) are recorded by the data acquisition and display system 25.

[0061] Step 6, open the first electric valve 38 in the leakage positioning experimental unit 18, and record the related experimental data before and after the electric valve opening time (0.1s-2s), after the parameter recording is completed, close the first electric valve 38; after the experimental data is stable, repeat the above process: open the second electric valve 39 and the third electric valve 40 in turn, and record the data before and after the second electric valve 39 or the third electric valve 40 opening time (0.1s-2s).

[0062] Step 7, change the gas flow by adjusting the valve 4, after the test data is stable, observe the flow pattern at this time through the flow pattern visualization experimental section 16, and repeat step 6 to record the related parameters. Similarly, change the liquid flow by using the high-pressure constant-flow pump 9, and repeat the above process;

[0063] Step 8, change the outlet temperature of the experimental heating unit 14 by using the experimental heating unit 14, repeat steps 6 and 7 to obtain the related experimental data under different temperature conditions; change the pressure of the experimental loop by using the first back pressure valve 23 and the second back pressure valve 24, repeat steps 6 and 7 to obtain the related experimental data under different pressure conditions.

[0064] Step 9, gradually reduce the heating power on the corresponding pipeline of the experimental heating unit 14, after the power is reduced to 0, close the transformer 45; adjust the first back pressure valve 23 and the second back pressure valve 24 to make the pressure of the test loop drop to normal pressure; close the air compressor 1 to stop generating gas, and gradually adjust and close the pressure stabilizing valve 3 and the adjusting valve 4 to stop delivering gas to the experimental loop; close the high-pressure constant-flow pump 9 to stop the fluid circulating in the experimental loop; finally, close the first valve 7, the second valve 10, the third valve 13 and the data acquisition and display system 25.

[0065] Example 1

[0066] Through the high-pressure gas-liquid two-phase flow pipeline leakage signal detection device provided by the application and the high-pressure gas-liquid two-phase flow pipeline leakage positioning method provided by the application, under the experimental conditions of a 6mm pipe diameter, the flow pattern and leakage signal of air-water two-phase flow fluid in a high-pressure pipeline are measured and obtained. The specific steps and results are as follows:

[0067] After the inspection work in step 1 is completed, steps 2 and 3 are performed, the liquid flow and the gas flow are respectively set to 8.33g / s and 3.33g / s, and the stable flow of the gas-liquid two-phase fluid is obtained; then, according to steps 4 and 5, the pressure is adjusted to 0.7MPa and the temperature is adjusted to 25℃, and the flow pattern image and the pressure signal at this time are obtained, as shown in Figures 5-6 Similarly, the liquid flow and the gas flow are respectively set to 10g / s and 5g / s, and the pressure is set to 0.7MPa, and the flow pattern image and the pressure signal at this time are obtained, as shown in Figures 7-8 The results prove that the application can accurately and real-time synchronously collect the flow pattern image and the pressure signal data.

[0068] According to steps 3-7, the liquid flow and the gas flow are respectively set to 10g / s and 3.33g / s, the pressure is set to 0.2MPa, the first electric valve is opened, and the pressure signal change data at this time is recorded, as shown in Figure 9 The results show that the method of the application can accurately measure the leakage signal under the condition of high-pressure gas-liquid two-phase flow.

Claims

1. A leakage signal detection device for a high pressure gas-liquid two-phase flow pipe, characterized by, The gas-liquid mixing section (48), the third valve (13), the flow pattern visualization experimental section (16) and the gas-liquid separation section (49) are sequentially connected; the gas-liquid separation section (49) supplies liquid for the gas-liquid mixing section (48); the experimental heating unit (14) is arranged on the pipeline between the third valve (13) and the flow pattern visualization experimental section (16); The leakage positioning experimental unit (18) is arranged on the pipeline between the flow pattern visualization experimental section (16) and the gas-liquid separation section (49); the temperature sensor (15) is arranged on the pipeline between the experimental heating unit (14) and the flow pattern visualization experimental section (16); the differential pressure transmitter (17) is connected with the inlet end of the flow pattern visualization experimental section (16) and the outlet end of the flow pattern visualization experimental section (16) through two pipelines; the first high-frequency pressure sensor (19) is arranged on the pipeline between the flow pattern visualization experimental section (16) and the leakage positioning experimental unit (18), the second high-frequency pressure sensor (20) and the condenser (55) are arranged on the pipeline between the leakage positioning experimental unit (18) and the gas-liquid separation section (49), and the condenser (55) is arranged close to the gas-liquid separation section (49); a plurality of high-speed cameras and a plurality of light sources are arranged around the flow pattern visualization experimental section (16), the high-speed cameras and the light sources are one-to-one corresponding and are used in cooperation; the data acquisition and display system (25) is further included, and the plurality of high-speed cameras, the gas-liquid mixing section (48), the temperature sensor (15), the differential pressure transmitter (17), the leakage positioning experimental unit (18), the first high-frequency pressure sensor (19) and the second high-frequency pressure sensor (20) are connected with the data acquisition and display system (25); The gas-liquid mixing section (48) includes a gas circuit unit, a gas-liquid mixer (12) and a liquid circuit unit which are sequentially connected; the gas circuit unit includes an air compressor (1), a gas storage tank (2), a pressure stabilizing valve (3), an adjusting valve (4) and an air flow meter (5) which are sequentially connected; the air flow meter (5) is further connected with the gas inlet of the gas-liquid mixer (12) through a pipeline; the liquid circuit unit includes a water tank (6), a first valve (7), a first filter (8), a high-pressure constant-flow pump (9), a second valve (10) and a mass flow meter (11) which are sequentially connected; the mass flow meter (11) is further connected with the liquid inlet of the gas-liquid mixer (12) through a pipeline; the gas-liquid two-phase flow fluid outlet of the gas-liquid mixer (12) is further connected with the third valve (13) through a pipeline; the gas-liquid separation section (49) supplies liquid for the water tank (6); the air flow meter (5) and the mass flow meter (11) are connected with the data acquisition and display system (25). The leakage positioning experiment unit (18) includes three parallel first branch pipes (52), second branch pipes (53) and third branch pipes (54); one end of the first branch pipes (52), the second branch pipes (53) and the third branch pipes (54) are connected with a pipeline between the first high-frequency pressure sensor (19) and the second high-frequency pressure sensor (20); the first branch pipes (52), the second branch pipes (53) and the third branch pipes (54) are respectively provided with the first electric valve (38), the second electric valve (39) and the third electric valve (40); the first electric valve (38), the second electric valve (39) and the third electric valve (40) are connected with the data acquisition and display system.

2. The apparatus for detecting a leak signal of a high-pressure gas-liquid two-phase flow pipe according to claim 1, characterized by, The gas-liquid separation section (49) includes a gas-liquid separator (21), the gas-liquid separator gas outlet (46) of the gas-liquid separator (21) is connected with a second pipeline (50), and the second pipeline (50) is further provided with a second back pressure valve (24); the gas-liquid separator liquid outlet (47) of the gas-liquid separator (21) is connected with a first pipeline (51), and the first pipeline (51) is further provided with a second filter (22) and a first back pressure valve (23); the second filter (22) is arranged close to the gas-liquid separator liquid outlet (47) of the gas-liquid separator (21); and the first pipeline (51) supplies liquid for the water tank (6).

3. The apparatus for detecting a leak signal of a high-pressure gas-liquid two-phase flow pipe according to claim 1, characterized by, The flow pattern visualization experiment section (16) includes a quartz tube (36), a first flange (26), a second flange (27), a third flange (28) and a fourth flange (29); the first flange (26) and the second flange (27) are used in pairs, the second flange (27) is installed at the first end of the quartz tube (36), and the first flange (26) and the second flange (27) are connected by bolt cooperation with a nut; the third flange (28) and the fourth flange (29) are used in pairs, the third flange (28) is installed at the second end of the quartz tube (36), and the third flange (28) and the fourth flange (29) are connected by bolt cooperation with a nut; the outer wall of the quartz tube (36) between the second flange (27) and the third flange (28) is further sleeved with a rectangular parallelepiped quartz tube square shell (37) with a through hole, the quartz tube (36) passes through the through hole of the quartz tube square shell (37), and the outer wall of the quartz tube (36) is tightly combined with the inner wall of the through hole of the quartz tube square shell (37).

4. The apparatus for detecting a leak signal of a high-pressure gas-liquid two-phase flow pipe according to claim 3, characterized by, The first end of the quartz tube (36) is provided with a first sealing ring (30), and the first sealing ring (30) is located between the first flange (26) and the second flange (27); the second end of the quartz tube (36) is provided with a second sealing ring (31), and the second sealing ring (31) is located between the third flange (28) and the fourth flange (29).

5. The apparatus for detecting a leak signal of a high-pressure gas-liquid two-phase flow pipe according to claim 1, characterized by, The experimental heating unit (14) comprises a first alternating current plate (41) and a second alternating current plate (42) arranged on the pipeline between the third valve (13) and the flow pattern visualization experimental section (16); the first alternating current plate (41) and the second alternating current plate (42) are connected with a transformer (45) through wires; the experimental heating unit (14) further comprises an alternating current power supply (43) and a voltage regulator (44) forming a closed loop, and the voltage regulator (44) and the transformer (45) are connected through electromagnetic induction, so that the heating power is transmitted to the first alternating current plate (41), the second alternating current plate (42) and the pipeline between the third valve (13) and the flow pattern visualization experimental section (16).

6. A method for detecting a leakage signal of a high-pressure gas-liquid two-phase flow pipe, characterized by, The leakage signal detection device of the high-pressure gas-liquid two-phase flow pipeline according to any one of claims 1-5 is implemented in the following steps: Step 1, check the circuit to ensure that there is no broken wire or leakage; turn on the data acquisition and display system (25) to ensure that each sensor is working properly; Step 2, close the regulating valve (4), open the first valve (7), the second valve (10) and the third valve (13); introduce deionized water into the water tank (6), set the required liquid mass flow on the high-pressure constant flow pump (9), start the high-pressure constant flow pump (9), and observe whether the pipeline is unobstructed and whether there is leakage; if the pipeline is unobstructed and there is no leakage problem, proceed to the next step; Step 3, after the liquid completes 1-2 minutes of circulation in the test loop, turn on the air compressor (1) to introduce high-pressure gas into the high-pressure gas storage tank (2); after the high-pressure gas storage tank (2) is filled with gas, slowly open the pressure stabilizing valve (3) to adjust the outlet pressure; after the outlet pressure is stable, slowly open the regulating valve (4) to adjust the gas flow to the set flow, and obtain the gas-liquid two-phase fluid in the gas-liquid mixer (12); Step 4, after the gas-liquid two-phase fluid completes 1-2 minutes of circulation in the test loop, adjust the first back pressure valve (23) and the second back pressure valve (24) to make the test loop reach the set pressure; Step 5, adjust the voltage regulator (44) of the experimental heating unit (14) to control the transformer (45) to output stable heating power, so that the fluid temperature at the outlet of the pipeline where the experimental heating unit (14) is located reaches the preset initial pipeline inlet temperature; after the experimental data is stable, record the relevant experimental data measured by all monitoring instruments in the measuring device at this time by using the data acquisition and display system (25); Step 6, open the first electric valve (38) in the leakage positioning experimental unit (18), and record the relevant experimental data before and after the electric valve opening time; after the parameter recording is completed, close the first electric valve (38); after the experimental data is stable, repeat the above process: open the second electric valve (39) and the third electric valve (40) in turn, and record the data before and after the second electric valve (39) or the third electric valve (40) is opened. Step 7, change the gas flow by adjusting valve (4), and after the test data is stable, observe the flow pattern through the flow pattern visualization experiment section (16), and repeat step (6), and record the related parameters; similarly, change the liquid flow by using the high-pressure constant flow pump (9), and repeat the above process; Step 8, change the outlet temperature of the experimental heating unit (14) by using the experimental heating unit (14), repeat steps (6) and (7), and obtain the related experimental data under different temperature conditions; change the pressure of the experimental loop by using the first back pressure valve (23) and the second back pressure valve (24), repeat steps (6) and (7), and obtain the related experimental data under different pressure conditions; Step 9, gradually reduce the heating power on the corresponding pipeline of the experimental heating unit (14), and after the power is reduced to 0, turn off the transformer (45); adjust the first back pressure valve (23) and the second back pressure valve (24) to reduce the pressure of the test loop to normal pressure; turn off the air compressor (1) to stop generating gas, and gradually adjust and close the pressure stabilizing valve (3) and the adjusting valve (4) to stop delivering gas to the experimental loop; turn off the high-pressure constant flow pump (9), and the fluid stops circulating in the experimental loop; finally, turn off the first valve (7), the second valve (10), the third valve (13) and the data acquisition and display system (25).

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