A method for testing the bubble resistance of a composite pipe

Abstract

The present application belongs to the technical field of composite pipe performance testing, and particularly relates to a method for testing the anti-bubbling performance of a whole composite pipe. The method for testing the anti-bubbling performance of a whole composite pipe comprises a device for testing the anti-bubbling performance of a whole composite pipe, which is composed of a gas distribution system, a test liquid filling system and a testing system. The gas distribution system and the test liquid filling system are respectively connected with the input end of the composite pipe to be tested. The testing system comprises a pressure measuring device connected with the composite pipe to be tested. The present application can simulate the use state of a whole composite pipe in complex application environments such as high temperature and high pressure. Compared with the prior art which only tests the permeability of the inner layer material of a composite pipe, the test result is more in line with the actual situation, and the test data is more convincing. The present application can simulate the failure forms such as bubbling, bulging and delamination of the inner liner after sudden pressure relief of the composite pipe. A gas recovery device is arranged for the toxic and harmful gas used in the test, so as to reduce the environmental pollution caused by the test.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of composite pipe performance testing, and particularly relates to a method for testing the anti-bubbling performance of a whole composite pipe. BACKGROUND

[0002] Fiber-reinforced composite pipes have the advantages of corrosion resistance, small expansion coefficient, wear resistance, low cost, and simple operation and maintenance, and are very good metal pipe replacement materials. With the rapid development of market economy, fiber-reinforced composite pipes have been widely used in oil extraction, gas extraction, gathering and transportation, water injection, and gas transportation fields. A fiber-reinforced composite pipe generally comprises an outer protective layer, a middle reinforcing layer, and a polymer inner lining layer. During use, the inner layer is in contact with the conveying medium. Small gas molecules in the medium penetrate into the pipe wall through adsorption and diffusion under the action of pressure difference. After a period of accumulation, the pressure of the accumulated gas in the pipe wall is equivalent to the pressure of the conveying medium, and tends to be balanced. When the pipe is suddenly shut down or a pipe leak occurs, the accumulated gas in the pipe wall rapidly expands, causing the polymer inner layer of the pipe to collapse, the inner layer and the reinforcing layer to separate, and the reinforcing layer and the outer protective layer to separate, thereby reducing the carrying capacity of the pipe and inducing pipe rupture and leakage accidents.

[0003] At present, patent documents WO2013143028A1, WO2012100630A1, CN101246095B, and CN106644886A disclose testing devices and methods for material gas permeability, but these devices are all for material-level film samples and cannot be used for whole pipe testing. Moreover, the testing conditions are generally low pressure (less than 0.2 MPa pressure difference) and low temperature (less than 100 DEG C), and cannot simulate the actual operating conditions and failure modes of composite pipes. SUMMARY

[0004] The present application aims to make up for the defects and deficiencies in the prior art, and provides a method for testing the anti-permeability of a composite pipe and evaluating the anti-bubbling performance of a whole composite pipe, which takes a whole pipe as a testing object and can simulate the actual operating conditions of a composite pipe and the failure modes such as bulging and delamination of the inner lining layer after sudden pressure relief of the pipe.

[0005] To achieve the above-mentioned purpose, the technical solution adopted by the present application is as follows: a device for testing the anti-bubbling performance of a whole composite pipe, mainly comprising a gas supply system, a test liquid filling system, and a testing system. The gas supply system and the test liquid filling system are respectively connected with the input end of the composite pipe to be tested. The testing system comprises a pressure measuring device connected with the composite pipe to be tested.

[0006] As a preferred mode of the present application, the gas supply system comprises a test gas booster pipeline and an air supply pipeline, which provide the required gas medium for the experimental testing system.

[0007] Further preferably, the test gas boosting pipeline mainly comprises a gas medium bottle group, a gas pipeline and a gas booster pump connected in sequence; a flame arrester and a controlled component for controlling the opening and closing and size of the gas pipeline are provided; and a plurality of sensors are provided.

[0008] Further preferably, the gas distribution system further comprises a supply fan, an exhaust fan and a gas detector connected with the control system.

[0009] Further preferably, the gas medium bottle group is connected with the gas booster pump through two branches, one of which is provided with a gas distribution tank; the gas distribution tank is used for mixing the mixed gas; and the other branch is used for conveying single-component gas.

[0010] Further preferably, the air supply pipeline mainly comprises an air compressor connected with the gas booster pump through a gas pipeline.

[0011] Further preferably, the test liquid filling system mainly comprises a test solution barrel, a liquid filling pump, a flow meter and a liquid pipeline; one end of the liquid filling pump is connected with the test solution barrel, and the other end is connected with the measured composite pipe through the liquid pipeline.

[0012] Further preferably, a constant-temperature environment adjusting system is further included, which mainly comprises a water tank and an electric heater; the water tank is connected with a water supplementing device through a pipeline; a remote liquid level meter and a remote thermometer connected with the control system are arranged on the water tank; and the measured composite pipe is arranged in the water tank.

[0013] Further preferably, a tail gas absorption system is further included, which is connected with the output end of the measured composite pipe; the tail gas absorption system comprises a plurality of tail gas absorption tanks connected in series; an air inlet and an absorption liquid outlet are arranged at the bottom of the tail gas absorption tank; an air outlet pipeline and an absorption liquid inlet are arranged at the top of the tail gas absorption tank; and a tail gas analyzer and a pipeline flame arrester are arranged on the air outlet pipeline of the last tail gas absorption tank.

[0014] Further preferably, an air distributor is arranged on the air inlet at the bottom of the tail gas absorption tank; and a remote pressure gauge and a liquid level meter are further arranged on the tank body.

[0015] Further preferably, a control system is further included, which is connected with a plurality of sensors and controlled components and gas detection sensors, and is used for controlling the work of the various sensors, controlled components and gas detection sensors.

[0016] Compared with the prior art, the test device for testing the whole-pipe anti-bubbling performance of the test composite pipe has the following beneficial effects:

[0017] 1. The test device can simulate the use state of the whole composite pipe in complex application environments such as high temperature and high pressure, compared with the existing technology which only tests the permeability of the inner layer material of the composite pipe, the test result is more close to the actual situation, and the test data is more convincing.

[0018] 2. The test medium can be single-component test gas, mixed medium test gas, liquid or gas-liquid two-phase medium.

[0019] 3. The test device can simulate the failure forms such as blistering, bulging and delamination of the inner liner after sudden pressure relief of the composite pipe.

[0020] 4. A gas recovery device is arranged for the toxic and harmful gas used in the test, so as to reduce the environmental pollution of the test.

[0021] 5. The flame arrester arranged in the gas pipeline has the effect of preventing backfire, and improves the safety of the test device. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is the overall structure diagram of the test device for testing the anti-bubbling performance of the whole composite pipe provided in the embodiment of the application;

[0023] Figure 2 It is the structure diagram of the gas distribution system;

[0024] Figure 3 It is the structure diagram of the tail gas absorption system;

[0025] Figure 4 It is the structure diagram of the test liquid filling system and the test system;

[0026] In the figure, 1, gas medium bottle group; 2, first gas pipeline; 3, electromagnetic valve; 4, first on-site pressure gauge; 5, first pressure regulating valve; 6, second pressure regulating valve; 7, third pressure regulating valve; 8, gas distribution tank; 9, pressure control valve; 10, first flame arrester; 11, electromagnetic valve; 12, booster pump; 13, stop valve; 14, second on-site pressure gauge; 15, high-pressure hose; 16, electric heater; 17, remote thermometer; 18, remote liquid level meter; 19, emptying valve; 20, first electromagnetic valve; 21, first remote pressure gauge; 22, to-be-tested composite pipeline one; 23, to-be-tested composite pipeline two; 24, second electromagnetic valve; 25, tail gas inlet pipeline control valve; 26, gas distributor; 27, first liquid level meter; 28, primary tail gas absorption tank; 29, second remote pressure gauge; 30, absorption liquid inlet; 31, tail gas outlet pipeline; 32, second liquid level meter; 33, secondary tail gas absorption tank; 34, third remote pressure gauge; 35, analysis instrument; 36, second flame arrester; 37, control valve; 38, second absorption liquid discharge outlet; 39, experimental solution barrel; 40, liquid feeding pump; 41, liquid pipeline; 42, water supplementing pump; 43, water supplementing barrel; 44, air blower; 45, air exhaustor; 46, gas detector; 47, air compressor; 48, second gas pipeline; 49, water tank; 50, liquid discharge valve; 51, first absorption liquid discharge outlet; 52, flow meter. DETAILED DESCRIPTION

[0027] In order to facilitate the understanding of the present application, the present application will be described in more detail below in conjunction with the drawings and specific embodiments. The preferred embodiments of the present application are shown in the drawings. However, the present application can be realized in many different forms and is not limited to the embodiments described in the specification. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0028] The test device for testing the whole-pipe anti-bubbling performance of a composite pipe provided by the present application, as shown in the figure, mainly consists of a gas distribution system, a test liquid filling system, a constant-temperature environment adjusting system, a testing system, a tail gas absorption system and a control system. Figure 1 The gas distribution system mainly includes a test gas booster pipeline and an air supply pipeline, which provide the required gas medium for the testing system.

[0029] The test gas booster pipeline mainly includes a gas medium bottle group 1, a first gas pipeline 2, a first flame arrester 10 and a gas booster pump 12. A plurality of sensors and controlled components for controlling the opening and closing of the gas path are arranged on the first gas pipeline 2, and the sensors and controlled components are connected to the control system.

[0030] The test gas booster pipeline mainly includes a gas medium bottle group 1, a first gas pipeline 2, a first flame arrester 10 and a gas booster pump 12. A plurality of sensors and controlled components for controlling the opening and closing of the gas path are arranged on the first gas pipeline 2, and the sensors and controlled components are connected to the control system.

[0031] The gas medium cylinder group 1 is used to store various test gases. It is connected to the first gas pipeline 2 through a high-pressure hose, and then connected in series with the solenoid valve 3, the first local pressure gauge 4, the first flame arrester 10, the solenoid valve 11, and the gas booster pump 12. After being boosted to the specified pressure by the gas booster pump 12, it is connected to the test system.

[0032] Among them, such as Figure 2 As shown, the first gas pipeline 2 downstream of the first local pressure gauge 4 splits into two branches. One branch is equipped with a first pressure regulating valve 5, which is directly connected to the gas booster pump 12 to deliver single-component gas media to the testing system. The other branch is equipped with a second pressure regulating valve 6, a gas mixing tank 8, and a third pressure regulating valve 7 in sequence, and then connects to the gas booster pump 12 to deliver mixed gas media. The gas mixing tank 8 is used to mix different gases uniformly. The gas mixing tank 8 is equipped with a pressure control valve 9 with alarm and recording functions. If the pressure in the gas mixing tank 8 is too high, the control valve 9 will automatically alarm. At the same time, the control system automatically adjusts the opening of the second pressure regulating valve 6 and the third pressure regulating valve 7 to regulate the pressure in the gas mixing tank 8.

[0033] The switching between these two branches is controlled by the first pressure regulating valve 5 and the second pressure regulating valve 6. When using the mixed test gas pipeline, the second pressure regulating valve 6 is in the "open" state and the first pressure regulating valve 5 is in the "closed" state. When using the single-component test gas pipeline, the second pressure regulating valve 6 is in the "closed" state and the first pressure regulating valve 5 is in the "open" state.

[0034] The air supply pipeline can be used to adjust the concentration of test gas and purge the pipeline of the test device. It mainly includes an air compressor 47, which is connected to the gas booster 12 through a second gas pipeline 48.

[0035] The gas distribution system is also equipped with a gas detector 46. If a gas leak occurs in the gas distribution system, the gas detector 46 will issue an alarm signal and automatically shut off the solenoid valve 3 through the control system. This will control the opening of the blower 44, exhaust fan 45, and air compressor 47 to adjust the system and prevent accidents and disasters.

[0036] The test solution filling system provides the liquid test medium to the test system and mainly includes a test solution tank 39, a filling pump 40, a flow meter 52, and a liquid pipeline 41. One end of the filling pump 40 is connected to the test solution tank 39, and the other end is connected to the liquid pipeline 41. The flow meter 52 is connected to the liquid pipeline 41, and the other end of the liquid pipeline 41 receives either the composite pipeline 1 to be tested 22 or the composite pipeline 2 to be tested 23. The controlled end of the filling pump 40 is connected to the control system.

[0037] The constant temperature environment regulating system provides constant temperature test environment for the experimental test system, and is mainly composed of a water tank 49, an electric heater 16, a remote temperature meter 17, a remote liquid level meter 18, a water supplement pump 42, a water supplement barrel 43 and the like. The temperature of water in the water tank can be automatically adjusted according to test requirements. The remote liquid level meter 18 has recording and alarm functions. If the liquid level exceeds the set range, an alarm signal can be sent, and the water supplement pump 42 can be stopped through the control system.

[0038] As shown in Figure 4 , the experimental test system comprises a first remote pressure gauge 21 and a first electromagnetic valve 20 connected in series at the input end of the composite pipe to be tested. The experimental test system takes the whole pipe of the composite pipe to be tested as the test sample. According to the actual use conditions of the composite pipe, test gas and / or test liquid are injected into the composite pipe to be tested. Under the conditions of set temperature and pressure, the pressure is maintained for a predetermined period of time, and then the composite pipe is rapidly depressurized at a rate of not less than 6.9 MPa / min, so as to evaluate the anti-bubbling performance of the composite pipe.

[0039] As shown in Figure 1 and Figure 4 , the input end of the composite pipe to be tested 22 is connected in series with a first remote pressure gauge 21 and a first electromagnetic valve 20, and then connected with a gas distribution system and / or a test liquid injection system. The output end of the composite pipe to be tested 22 is connected in series with a second electromagnetic valve 24, and then connected with a tail gas absorption system. The first remote pressure gauge 21 has recording and alarm functions. When the pressure exceeds the normal range, a signal is transmitted to the control system, and the control system automatically adjusts each control component on the gas path, so as to keep the pressure in the composite pipe to be tested stable. The first electromagnetic valve 20 is connected in parallel with a pipeline 19 with a control valve leading to the tail gas absorption system before the node, and is mainly used for recovering residual toxic and harmful gas in the pipeline of the gas distribution system to prevent environmental pollution. The second electromagnetic valve 24 is connected in parallel with a pipeline 50 with a control valve before the node, and is mainly used for recovering residual test liquid in the experimental pipeline.

[0040] As shown in Figure 3 , the tail gas absorption system mainly comprises a primary tail gas absorption tank 28 and a secondary tail gas absorption tank 33. The bottom of the primary tail gas absorption tank 28 is provided with a gas inlet pipeline control valve 25, a gas distributor 26 and a first absorption liquid discharge outlet 51 connected with the experimental test system. The top is provided with a tail gas outlet pipeline 31, an absorption liquid inlet 30 and a second remote pressure gauge 29. The tank body is provided with a first liquid level meter 27. The secondary tail gas absorption tank 33 is provided with a control valve 37, a second absorption liquid discharge outlet 38, a second liquid level meter 32, a third remote pressure gauge 34, an analysis instrument 35 and a second flame arrester 36. The analysis instrument 35 is used for analyzing whether the discharged tail gas is qualified.

[0041] The control system comprises a computer connected with various sensors and control components, gas leakage alarm, instruments and meters in the device, for controlling their start-stop, opening size, etc.

[0042] The method for testing the anti-bubbling performance of the whole pipe of the composite pipe by the test device of the application is as follows: the whole pipe of the composite pipe to be tested is connected to the test system, after the sealing test, the temperature of the water tank of the test system is adjusted according to the working condition, the test temperature is reached, the test gas and / or test liquid are selected, injected into the composite pipe to be tested, and pressurized to a predetermined pressure, after the temperature and pressure are stable, the temperature and pressure are kept unchanged, the timing experiment is started, after the predetermined experimental period is reached, the composite pipe to be tested is rapidly depressurized, the depressurization rate is not less than 6.9 MPa / min, after the whole system is thoroughly purged by the safety gas, the sample is taken out, and whether there is bubbling or the inner lining layer collapses on the inner wall of the sample is observed.

[0043] After the experiment is finished, the test gas enters the gas distributor 26 from the tail gas inlet pipeline control valve 25, is uniformly discharged into the absorption liquid in the primary tail gas absorption tank 28, the toxic and harmful gas fully reacts with the absorption liquid, the environmental pollution is reduced, and the safety and environmental protection of the device is improved, the test gas washed by the absorption liquid enters the tail gas outlet pipeline 31, and then enters the secondary tail gas absorption tank 33. Whether the discharged tail gas is qualified is analyzed by the analysis instrument 35, and the analysis result is fed back to the control system, for adjusting the tail gas absorption system.

Claims

1. A method for testing the anti-foaming performance of a composite pipe as a whole, comprising an apparatus for testing the anti-foaming performance of the composite pipe as a whole, the apparatus comprising a gas distribution system, a test solution injection system, and a testing system; characterized in that: The gas distribution system and the test liquid injection system are respectively connected to the input end of the composite pipe under test; the test system includes a pressure measuring device connected to the composite pipe under test; the entire composite pipe under test is connected to the test system, and after a sealing test, the temperature of the water tank in the test system is adjusted according to the operating conditions to reach the test temperature, the test gas and / or test liquid are selected and injected into the composite pipe under test, and pressurized to the predetermined pressure. After the temperature and pressure stabilize, the temperature and pressure are kept constant, and the timing test is started. After the predetermined test cycle is reached, the composite pipe under test is rapidly depressurized, and the depressurization rate is not less than 6.9 MPa / min; the sample is taken out, and the inner wall of the sample is observed to see if there are bubbles or the inner lining layer collapses.

2. The method for testing the overall anti-bubbling performance of composite pipes according to claim 1, characterized in that: The gas distribution system includes a test gas pressurization pipeline and an air supply pipeline, which provide the required gas medium for the test system.

3. The method for testing the overall anti-foaming performance of composite pipes according to claim 2, characterized in that: The test gas pressurization pipeline includes a gas medium bottle group, a gas pipeline and a gas pressurization pump connected in sequence; the gas pipeline is equipped with a flame arrester, a controlled component for controlling the on / off state and magnitude of the gas flow, and various sensors.

4. The method for testing the overall anti-bubbling performance of composite pipes according to claim 3, characterized in that: The gas medium cylinder group is connected to the gas booster pump through two branches, one of which is equipped with a gas distribution tank; the gas distribution tank is used for mixing the mixed gas; the other branch is used for transporting single-component gases.

5. The method for testing the overall anti-bubbling performance of composite pipes according to claim 3, characterized in that: The air supply pipeline includes an air compressor, which is connected to a gas booster pump via a gas pipeline.

6. The method for testing the overall anti-foaming performance of composite pipes according to claim 1, characterized in that: The test solution filling system includes a test solution tank, a filling pump, and a liquid pipeline; one end of the filling pump is connected to the test solution tank, and the other end is connected to the composite tube under test through the liquid pipeline.

7. The method for testing the overall anti-bubbling performance of composite pipes according to claim 1, characterized in that: It also includes a constant temperature environment control system, which consists of a water tank and an electric heater. The water tank is connected to a water replenishment device through a pipe. The composite pipe under test is placed inside the water tank.

8. The method for testing the anti-foaming performance of the entire composite pipe according to claim 1, characterized in that: It also includes an exhaust gas absorption system, which is connected to the output end of the composite tube being tested; the exhaust gas absorption system includes multiple exhaust gas absorption tanks connected in series.

9. The method for testing the overall anti-bubbling performance of a composite pipe according to claim 8, characterized in that: A gas distributor is provided at the bottom of the exhaust gas absorption tank.

10. The method for testing the anti-bubbling performance of a composite pipe as described in any one of claims 1-9, characterized in that: It also includes a control system, which is connected to a variety of sensors and control components to control the operation of the various sensors and control components.

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