Device and method for testing ultralow-temperature performance of multi-layer flexible composite pipe

Abstract

The invention discloses a multilayer flexible composite pipe ultralow temperature performance testing device which comprises a refrigeration device, the refrigeration device is connected with a low temperature test module through a pipeline, the outer wall of the low temperature test module is coated with a heat preservation module, and the low temperature test module is connected with a control module through a wire; in addition, the invention further discloses an ultralow-temperature performance testing method for the multi-layer flexible composite pipe, and the method comprises the steps that a pipe sample is cut out and pretreated; clamping the test pipe section; setting a test temperature, a test pressure and a test period, and adjusting the stress of the test pipe section; starting a refrigerating device; setting test temperature, test pressure and test period; and collecting and analyzing test data. According to the device and the method for testing the ultralow-temperature performance of the multi-layer flexible composite pipe, the blank that the overall performance of the multi-layer flexible composite pipe is not comprehensively evaluated in the prior art is filled up, a scientific and accurate performance evaluation means is provided for construction of the flexible composite pipe in a cold region, and the construction safety is improved.

Description

Technical Field

[0001] This invention belongs to the field of multilayer flexible composite performance testing and evaluation technology, and relates to a device for testing the ultra-low temperature performance of multilayer flexible composite tubes. This invention also relates to a method for testing the ultra-low temperature performance of multilayer flexible composite tubes. Background Technology

[0002] Crude oil gathering and transportation pipelines are a crucial component of surface gathering and transportation pipelines, and their safe and stable operation is fundamental to ensuring energy security. With the development of major oilfields in China, flexible composite pipes have become an important solution for corrosion protection and insulation of surface pipelines in oilfields due to their advantages such as low thermal conductivity, corrosion resistance, and resistance to scaling and wax buildup. However, in cold winter regions, the extreme climatic conditions, especially the ultra-low temperature environments during winter construction (reaching as low as -50 degrees Celsius), pose a significant challenge to the performance of multi-layer flexible composite pipes during laying and installation in these extreme conditions.

[0003] Currently, although the application of flexible composite pipes is becoming increasingly widespread, the performance testing and evaluation system for them under such low-temperature conditions is still imperfect. Changes in material properties and complex environmental factors under low-temperature conditions may lead to various failure risks for pipelines, such as brittle fracture, decreased toughness, and fatigue failure. Existing testing technologies and equipment have significant shortcomings in simulating ultra-low temperature environments and evaluating the performance of each layer of the composite pipe and the interlayer bonding strength, failing to accurately guide on-site construction and operations and posing safety hazards. Therefore, it is necessary to design an ultra-low temperature performance testing device for oil and gas composite pipelines. This testing device can comprehensively evaluate the performance and failure risks of pipelines under ultra-low temperatures, providing strong technical support and guidance for on-site work. Through the research and application of this laboratory, the operational safety and service life of oil and gas composite pipelines in ultra-low temperature environments can be significantly improved, reducing economic losses and environmental risks caused by pipeline failure. Summary of the Invention

[0004] The purpose of this invention is to provide a low-temperature performance testing device for multilayer flexible composite tubes, which solves the problem of the lack of comprehensive evaluation of the overall performance of multilayer flexible composite tubes in the prior art.

[0005] Another objective of this invention is to provide a method for testing the ultra-low temperature performance of multilayer flexible composite tubes.

[0006] The first technical solution adopted in this invention is a multi-layer flexible composite tube ultra-low temperature performance testing device, including a refrigeration device, a low temperature test module connected to the refrigeration device through a pipe, an insulation module covering the outer wall of the low temperature test module, and a control module connected to the low temperature test module through a wire.

[0007] The invention is further characterized by: The insulation module includes a thermal insulation layer, which covers the outer wall of the low-temperature test module, and a shell is sealed outside the thermal insulation layer.

[0008] The thermal insulation layer is made of silica aerogel.

[0009] The low-temperature test module includes a low-temperature test chamber, which is connected to a refrigeration device via pipes. Several clamps are fixed on the workbench inside the low-temperature test chamber, and each clamp is connected to a displacement sensor. The low-temperature test chamber is also equipped with a high-definition camera system, which is connected to the control module via wires.

[0010] The cryogenic test chamber is sequentially connected to an airflow circulation system, a temperature control system, a pressure simulation system, and a dynamic loading device; the temperature control system is connected to a temperature sensor; the pressure simulation system is connected to a pressure sensor; and the cryogenic test chamber is also connected to a gas recovery device.

[0011] The test sample held by the clamp is a test pipe section.

[0012] The control module is a control room, which houses the control system, data acquisition and analysis system, emergency stop device, and alarm system. The alarm system is connected to the temperature control system and pressure simulation system, and the emergency stop device is connected to the alarm system.

[0013] The data acquisition and analysis system is connected to the high-definition camera system.

[0014] A protective laboratory is located between the shell and the control room.

[0015] Another technical solution adopted in this invention is a method for testing the ultra-low temperature performance of multi-layer flexible composite pipes, which specifically includes the following steps: Step 1: Cut a pipe sample from the flexible composite pipe, pre-treat the pipe sample, and obtain a test pipe section; Step 2: Place the test tube section inside the low-temperature test chamber 7 and use clamps 8 to hold the test tube section; Step 3: Set the test temperature, test pressure and test cycle of the low temperature test chamber 7 through the control system 17, and adjust the stress on the test tube section through the dynamic loading device 4; Step 4: Turn on the refrigeration device 11 to cool down the low-temperature test chamber 7, and turn on the airflow circulation system 1 to make the temperature distribution in the low-temperature test chamber 7 uniform. Step 5: Conduct ultra-low temperature performance tests on the test tube section according to the set test temperature, test pressure and test cycle, and record it as a test tube sample after the test is completed; Step 6: Collect and analyze test data. The appearance and size changes of the test tube sample compared to the test tube section are collected in real time through a high-definition camera system. The displacement change data of the test tube sample compared to the test tube section are collected through a displacement sensor. The data is transmitted to the data acquisition and analysis system 14 for test data analysis.

[0016] The beneficial effects of this invention are: The cryogenic performance testing device and method for multi-layer flexible composite pipes provided by this invention not only fills the gap in existing technologies for comprehensive evaluation of the overall performance of multi-layer flexible composite pipes, but also provides a scientific and accurate performance evaluation method for the construction of flexible composite pipes in cold regions. By comprehensively evaluating the overall performance of pipelines at low temperatures, this invention can guide on-site construction and operations, improving construction quality and safety. Furthermore, the cryogenic performance testing device and method for multi-layer flexible composite pipes provided by this invention also have high application value and can be widely used in pipeline performance testing under other similar extreme environmental conditions. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of a multi-layer flexible composite tube ultra-low temperature performance testing device.

[0018] In the diagram, 1. Airflow circulation system, 2. Temperature control system, 3. Pressure simulation system, 4. Dynamic loading device, 5. Temperature sensor, 6. Pressure sensor, 7. Cryogenic test chamber, 8. Fixture, 9. Stress test tube section, 10. Initial test tube section, 11. Refrigeration unit, 12. Protective laboratory, 13. Control room, 14. Data acquisition and analysis system, 15. Emergency stop device, 16. Alarm system, 17. Control system, 18. Gas recovery device, 19. Thermal insulation layer, 20. Shell. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0020] A multi-layer flexible composite tube ultra-low temperature performance testing device includes a refrigeration device 11. The refrigeration device 11 is connected to a low-temperature test module via pipes. The outer wall of the low-temperature test module is covered by an insulation module. The low-temperature test module is connected to a control module via wires. The insulation module includes a thermal insulation layer 19, which covers the outer wall of the low-temperature test module. A shell 20 seals the thermal insulation layer 19. The thermal insulation layer 19 is made of silica aerogel, with a thickness of 20-30 mm, a density of 1-3 kg / m³, and a thermal conductivity range of 0.013-0.03 W / (m·K).

[0021] The low-temperature test module includes a low-temperature test chamber 7, which is connected to a refrigeration unit 11 via pipes. Several clamps 8 are fixed on the worktable inside the low-temperature test chamber 7, and each clamp 8 is connected to a displacement sensor. The test sample held by the clamps 8 is a test tube segment, which may be a stress test tube segment 9 or an initial test tube segment 10. A high-definition camera system is also installed inside the low-temperature test chamber 7, and is connected to the control module via wires. The low-temperature test chamber 7 is sequentially connected to an airflow circulation system 1, a temperature control system 2, a pressure simulation system 3, and a dynamic loading device 4. The temperature control system 2 is connected to a temperature sensor 5; the pressure simulation system 3 is connected to a pressure sensor 6; and the low-temperature test chamber 7 is also connected to a gas recovery device 18.

[0022] The control module is the control room 13, which is equipped with a control system 17. The control system 17 includes a data acquisition and analysis system 14, an emergency stop device 15, and an alarm system 16. The alarm system 16 is connected to a temperature control system 2 and a pressure simulation system 3. The emergency stop device 15 is connected to the alarm system 16. The data acquisition and analysis system 14 is connected to a high-definition camera system. A protective laboratory 12 is set between the shell 20 and the control room 13.

[0023] A method for testing the ultra-low temperature performance of multilayer flexible composite tubes includes the following steps: Step 1: Cut a pipe sample from the flexible composite pipe, pre-treat the pipe sample, and obtain the test pipe section; Take pipe samples from flexible composite pipe sections produced at least 24 hours ago. Design and process the end joints according to the inner diameter, outer diameter and nominal pressure rating requirements of the test pipe samples. Assemble them strictly according to the crimping process. The test pipe sample includes the pipe sample and the joints. The length of the flexible composite pipe in the middle of the joint is ≥ 5 times the diameter of the pipe sample. Step 2: Place the test tube section inside the low-temperature test chamber 7 and use clamps 8 to hold the test tube section; After conditioning the test tube section at (23±2)℃ for at least 24 hours, prepare for the test. Condition the tube section according to the test design temperature. Generally, pretreatment at the test temperature should be no less than 8 hours. Step 3: Set the test temperature, test pressure and test cycle of the low temperature test chamber 7 through the control system 17, and adjust the stress on the test tube section through the dynamic loading device 4; Step 4: Turn on the refrigeration device 11 to cool down the low-temperature test chamber 7, and turn on the airflow circulation system 1 to make the temperature distribution in the low-temperature test chamber 7 uniform. The test temperature can be set by reducing the lowest measured temperature at the application site of the flexible composite pipe by 15°C; the test pressure is 1.5 times the nominal pressure of the flexible composite pipe, and the test cycle is 168h~1000h. Step 5: Conduct ultra-low temperature performance tests on the test tube section according to the set test temperature, test pressure and test cycle, and record it as a test tube sample after the test is completed; Step 6: Collect and analyze test data. The appearance and size changes of the test tube sample compared to the test tube section are collected in real time through a high-definition camera system. The displacement change data of the test tube sample compared to the test tube section are collected through a displacement sensor. The data is transmitted to the data acquisition and analysis system 14 for test data analysis.

[0024] After the experiment, the experimenters need to wear protective clothing to enter the protective laboratory 12 to prevent frostbite. After taking out the test tube section, they need to collect the performance changes of the test tube section and compare it with the performance of the blank tube section to evaluate the safety and reliability of the multi-layer flexible composite pipe in low temperature environment.

[0025] Example 1 This embodiment provides a low-temperature performance testing device for multilayer flexible composite tubes, such as... Figure 1 As shown, the system includes a refrigeration device 11, which is connected to a low-temperature test module via pipes. The low-temperature test module is covered by an insulation module, and is connected to a control module via wires. The insulation module includes a thermal insulation layer 19, which covers the outer wall of the low-temperature test module and is sealed with a shell 20. The thermal insulation layer 19 is made of silica aerogel, with a thickness of 20-30 mm, a density of 1-3 kg / m³, and a thermal conductivity range of 0.013-0.03 W / (m·K). The low-temperature test module includes a low-temperature test chamber 7, which is connected to the refrigeration device 11 via pipes. Several clamps 8 are fixed on the worktable inside the low-temperature test chamber 7, and each clamp 8 is connected to a displacement sensor. The test sample held by the clamps 8 is a test tube segment, which may be a stress test tube segment 9 or an initial test tube segment 10. A high-definition camera system is also installed inside the low-temperature test chamber 7, and is connected to the control module via wires. The cryogenic test chamber 7 is sequentially connected to an airflow circulation system 1, a temperature control system 2, a pressure simulation system 3, and a dynamic loading device 4; the temperature control system 2 is connected to a temperature sensor 5; the pressure simulation system 3 is connected to a pressure sensor 6; the cryogenic test chamber 7 is also connected to a gas recovery device 18.

[0026] The refrigeration device 11 employs a two-stage refrigeration system, a cascade refrigeration system, or a liquid nitrogen refrigeration system. This device efficiently removes heat from the cryogenic test chamber 7 and discharges it to the external environment, thus lowering the temperature inside the chamber to a minimum of -70℃. It maintains system stability and reliability over a wide temperature range. A high-definition camera system is installed inside the chamber 7 to record images and video data during the test for subsequent analysis and evaluation. A thermal insulation layer 19, made of highly efficient insulating silica aerogel, is installed outside the chamber 7. This layer has a thickness of 20-30 mm, a density as low as 1-3 kg / m³, and a thermal conductivity range of 0.013-0.03 W / (m·K). The thermal insulation layer 19 ensures temperature stability within the chamber and accurately simulates ultra-low temperature environments. The shell 20 is a high-sealing device made of high-strength, corrosion-resistant materials such as stainless steel or aluminum alloy. High-performance seals are installed at key locations such as the inlet / outlet and interfaces of the shell 20 to enhance the sealing effect, ensuring that external environmental factors such as gas, liquid, and pressure will not interfere with the test process, thereby guaranteeing the accuracy and reliability of the test results. Several clamps 8 are fixed on the worktable of the cryogenic test chamber 7 for fixing and holding the test tube segment. The test tube segment is either the stress test tube segment 9 or the initial test tube segment 10. The clamps 8 are CNC controlled, featuring precise positioning to ensure they maintain a stable position during the test. Furthermore, displacement sensors mounted on the clamps 8 measure the displacement change of the test tube segment under stress or temperature changes, and can transmit this data to the control module via a data cable.

[0027] The cryogenic test chamber 7 is connected to an airflow circulation system 1. This system uses a fan to circulate the air within the chamber, ensuring thorough mixing of air in all areas and achieving a uniform temperature distribution. The temperature control system 2 monitors the chamber temperature using a temperature sensor 5 and controls the refrigeration system based on the difference between the set and actual temperatures. The pressure simulation system 3 consists of a main pump oil source module for simulating conventional steady-state pressure and a pulse booster module for short-term ultra-high pressure simulation and pulse impact. By controlling the oil pressure, the working state of the seals under different pressures can be simulated, and the pressure sensor 6 provides feedback on the pressurization pressure of the test pipe section. The dynamic loading device 4 applies dynamic loads to the specimen during the test to simulate the stress conditions in actual operation. This device typically includes a drive system, loading mechanism, and control system, and can adjust the magnitude, direction, and frequency of the loading force as needed. The gas recovery device 18 captures and treats the waste gas generated within the cryogenic test chamber 7, recovering useful gases and reducing harmful gas emissions. During the operation of the refrigeration unit, the refrigerant waste gas generated by the refrigeration unit 11 can also be recovered and treated by the gas recovery device 18 to prevent it from being directly discharged into the atmosphere and causing environmental pollution.

[0028] Example 2 Based on Example 1, this example provides a multilayer flexible composite tube cryogenic performance testing device, such as... Figure 1 As shown, the system includes a refrigeration device 11, which is connected to a low-temperature test module via pipes. The low-temperature test module is covered by an insulation module, and is connected to a control module via wires. The insulation module includes a thermal insulation layer 19, which covers the outer wall of the low-temperature test module and is sealed with a shell 20. The thermal insulation layer 19 is made of silica aerogel, with a thickness of 20-30 mm, a density of 1-3 kg / m³, and a thermal conductivity range of 0.013-0.03 W / (m·K). The low-temperature test module includes a low-temperature test chamber 7, which is connected to the refrigeration device 11 via pipes. Several clamps 8 are fixed on the worktable inside the low-temperature test chamber 7, and each clamp 8 is connected to a displacement sensor. The test sample held by the clamps 8 is a test tube segment, which may be a stress test tube segment 9 or an initial test tube segment 10. A high-definition camera system is also installed inside the low-temperature test chamber 7, and is connected to the control module via wires. The cryogenic test chamber 7 is sequentially connected to an airflow circulation system 1, a temperature control system 2, a pressure simulation system 3, and a dynamic loading device 4; the temperature control system 2 is connected to a temperature sensor 5; the pressure simulation system 3 is connected to a pressure sensor 6; the cryogenic test chamber 7 is also connected to a gas recovery device 18.

[0029] The control module is the control room 13, which is equipped with a control system 17. The control system 17 includes a data acquisition and analysis system 14, an emergency stop device 15, and an alarm system 16. The alarm system 16 is connected to a temperature control system 2 and a pressure simulation system 3. The emergency stop device 15 is connected to the alarm system 16. The data acquisition and analysis system 14 is connected to a high-definition camera system. A protective laboratory 12 is set between the shell 20 and the control room 13.

[0030] The control system 17 employs a numerical control system, integrating high-precision control, real-time monitoring and feedback, high-precision temperature and pressure control, automated data acquisition and processing, and a comprehensive safety protection mechanism. The data acquisition and analysis system 14 processes and analyzes the acquired data, generating test reports and performance evaluation results. It includes data processing software, data analysis algorithms, and report generation software for data cleaning, filtering, and conversion preprocessing, and for in-depth analysis of patterns and trends in the data. Finally, it automatically generates test reports and charts for easy viewing and understanding of the test results. An emergency stop device 15 and an alarm system 16 are installed on the control panel for emergency handling of system alarms. The protective laboratory 12 is a constant temperature and humidity laboratory. After the test tube sections are clamped, personnel must evacuate the laboratory before starting the experiment to avoid frostbite. The control room 13 is a separate room, convenient for personnel to monitor the test process and set up programs. After the test, personnel must wear protective clothing to enter the protective laboratory 12 to prevent frostbite. After removing the test tube samples, the performance changes of the test tube samples are collected and compared with the performance of blank samples to evaluate the safety and reliability of the multilayer flexible composite tube in low-temperature environments.

[0031] Example 3 The ultra-low temperature performance testing device and method for multi-layer flexible composite tubes using the method described in Example 2 include the following steps: Step 1: Cut a pipe sample from the flexible composite pipe, pre-treat the pipe section, and obtain the test pipe section; Take pipe samples from flexible composite pipe sections produced at least 24 hours ago. Design and process the end joints according to the inner diameter, outer diameter and nominal pressure rating requirements of the test pipe samples. Assemble them strictly according to the crimping process. The test pipe sample includes the pipe sample and the joints. The length of the flexible composite pipe in the middle of the joint is ≥ 5 times the diameter of the pipe sample. Step 2: Place the test tube section inside the low-temperature test chamber 7 and use clamps 8 to hold the test tube section; After conditioning the test tube section at (23±2)℃ for at least 24 hours, prepare for the test. Condition the tube section according to the test design temperature. Generally, pretreatment at the test temperature should be no less than 8 hours. Step 3: Set the test temperature, test pressure and test cycle of the low temperature test chamber 7 through the control system 17, and adjust the stress on the test tube section through the dynamic loading device 4; Step 4: Turn on the refrigeration device 11 to cool down the low-temperature test chamber 7, and turn on the airflow circulation system 1 to make the temperature distribution in the low-temperature test chamber 7 uniform. The test temperature can be set by reducing the lowest measured temperature at the application site of the flexible composite pipe by 15°C; the test pressure is 1.5 times the nominal pressure of the flexible composite pipe, and the test cycle is 500 hours. Step 5: Conduct ultra-low temperature performance tests on the test tube section according to the set test temperature, test pressure and test cycle, and record it as a test tube sample after the test is completed; Step 6: Collect and analyze test data. The appearance and size changes of the test tube sample compared to the test tube section are collected in real time through a high-definition camera system. The displacement change data of the test tube sample compared to the test tube section are collected through a displacement sensor. The data is transmitted to the data acquisition and analysis system 14 for test data analysis.

[0032] After the experiment, the experimenters need to wear protective clothing to enter the protective laboratory 12 to prevent frostbite. After taking out the test tube section, they need to collect the performance changes of the test tube section and compare it with the performance of the blank tube section to evaluate the safety and reliability of the multi-layer flexible composite pipe in low temperature environment. The burst strength test of the test tube sample should be completed within 10 minutes after the low temperature test is completed; The interlayer bonding strength of the flexible composite pipe was tested after the experiment. The bonding strength and microstructure between each layer were evaluated using equipment such as a peel tester and a microscope. The tensile properties of the flexible composite pipe lining material after the test were evaluated, such as tensile strength, elongation at break, and elastic modulus. The glass transition temperature (T) of the inner lining material of the flexible composite pipe after testing was tested. g ), embrittlement temperature, impact toughness, T g Embrittlement temperature is an important indicator for measuring the low-temperature toughness and service life of plastic materials, while impact toughness is a key factor determining the service life of plastic materials at low temperatures.

[0033] This multi-layer flexible composite pipe cryogenic performance testing device can perform simulated cryogenic tests on test pipe samples under the same temperature and pressure, and can also perform simulated cryogenic tests on test pipe samples under different pressures at the same temperature, with a temperature accuracy of ±0.1℃. The cryogenic performance testing system and method for multi-layer flexible composite pipes of this invention not only fills a gap in existing technology, but also provides a scientific and accurate performance evaluation method for the construction of flexible composite pipes in cold regions. By comprehensively evaluating the overall performance of pipelines at low temperatures, this invention can guide on-site construction and operations, improving construction quality and safety. Furthermore, the testing system and method of this invention have high application value and can be widely applied to pipeline performance testing under other similar extreme environmental conditions.

Claims

1. A device for testing the ultra-low temperature performance of a multi-layer flexible composite pipe, characterized in that, The application relates to a test device for testing the super-low-temperature performance of a flexible composite pipe, which comprises a refrigeration device (11) connected with a low-temperature test module through a pipeline, wherein the outer wall of the low-temperature test module is coated with a heat insulation module, and the low-temperature test module is connected with a control module through a wire.

2. The multi-layer flexible composite pipe ultra-low temperature performance testing apparatus of claim 1, wherein, The heat insulation module comprises a heat insulation layer (19) coated on the outer wall of the low-temperature test module, and the heat insulation layer (19) is sealed with a shell (20).

3. The multi-layer flexible composite tube ultra-low temperature performance testing device of claim 2, wherein, The material of the heat insulation layer (19) is silica aerogel.

4. The multi-layer flexible composite tube ultra-low temperature performance testing device of claim 2, wherein, The low-temperature test module comprises a low-temperature test cabin (7) connected with the refrigeration device (11) through a pipeline, a plurality of clamps (8) fixed on a workbench in the low-temperature test cabin (7), displacement sensors connected with the clamps (8) respectively, and a high-definition camera system arranged in the low-temperature test cabin (7) and connected with the control module through a wire.

5. The multi-layer flexible composite tube ultra-low temperature performance testing apparatus of claim 4, wherein, The low-temperature test cabin (7) is sequentially connected with an air flow circulation system (1), a temperature control system (2), a pressure simulation system (3) and a dynamic loading device (4); the temperature control system (2) is connected with a temperature sensor (5); the pressure simulation system (3) is connected with a pressure sensor (6); and the low-temperature test cabin (7) is further connected with a gas recovery device (18).

6. The multi-layer flexible composite tube ultra-low temperature performance testing device of claim 4, wherein, The test sample held by the clamps (8) is a test pipe section.

7. The multi-layer flexible composite tube ultra-low temperature performance testing device of claim 4, wherein, The control module is a control room (13) provided with a control system (17), a data acquisition and analysis system (14), an emergency shutdown device (15) and an alarm system (16); the alarm system (16) is connected with the temperature control system (2) and the pressure simulation system (3); and the emergency shutdown device (15) is connected with the alarm system (16).

8. The multi-layer flexible composite tube ultra-low temperature performance testing apparatus of claim 7, wherein, The data acquisition and analysis system (14) is connected with the high-definition camera system.

9. The multi-layer flexible composite tube ultra-low temperature performance testing apparatus of claim 8, wherein, A protection laboratory (12) is arranged between the shell (20) and the control room (13).

10. A method of testing the ultra-low temperature performance of a multi-layer flexible composite pipe, characterized by, The test device is used, and the steps are specifically as follows: Step 1: a pipe sample is cut from a flexible composite pipe, and the pipe sample is pretreated to obtain a test pipe section; Step 2: the test pipe section is placed in the low-temperature test cabin (7), and the test pipe section is clamped by the clamps (8); Step 3: the test temperature, the test pressure and the test period of the low-temperature test cabin (7) are set by the control system (17), and the stress of the test pipe section is adjusted by the dynamic loading device (4); Step 4: the refrigeration device (11) is started to cool the low-temperature test cabin (7), and the air flow circulation system (1) is started to make the temperature in the low-temperature test cabin (7) uniform; Step 5: the super-low-temperature performance test of the test pipe section is carried out according to the set test temperature, test pressure and test period, and the test pipe sample is recorded after the test is completed. Step 6: Collecting analysis test data, collecting the appearance change and size change of the test pipe sample compared with the test pipe segment in real time through the high-definition camera system, collecting the displacement change data of the test pipe sample compared with the test pipe segment through the displacement sensor, and transmitting the data to the data collection and analysis system (14) for test data analysis.

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