System and method for testing pressure characteristics of core drill pressure chamber

Abstract

The present invention relates to a pressure-maintaining characteristic test system and method for a pressure-maintaining cabin of a core drill, comprising a pressure supply unit, a pressure cabin, a data acquisition and analysis unit and a control unit, wherein the pressure supply unit is connected to the pressure cabin through a pipeline to adjust the pressure in the pressure cabin; the data acquisition and analysis unit comprises a strain sensor, and the pressure supply unit and the data acquisition and analysis unit are both connected to the control unit. The present invention can test the pressure-resistant characteristics of the pressure-maintaining cabin, verify the feasibility and scientificity of the design scheme, facilitate the improvement of the fidelity cabin in terms of structure and material, and provide experimental basis and data support for the research and development and design of a fidelity coring drill; the present invention can realize continuous pressure testing of the test cabin at 0-100MPa, long-term pressure maintenance, and online pressure monitoring and deformation testing under the pressure maintenance state, verify the barrel wall strength design, and can also be used to test the sealing performance and deformation amount of the lower sealing device (flap valve) of the pressure-maintaining cabin under different working conditions.

Description

Technical Field

[0001] The invention relates to the technical field of core drill test systems, and in particular to a system and method for testing the pressure-maintaining characteristics of a core drill pressure-maintaining cabin. Background Art

[0002] After the seabed drilling rig obtains samples in the deep sea, a fidelity chamber pressure control device is required to maintain the pressure and seal the samples in the in-situ environment.

[0003] The pressure-maintaining performance of the fidelity chamber needs to be continuously verified and improved through tests, so the test platform came into being. In order to test the deformation characteristics of the fidelity chamber under different working conditions, verify the feasibility and scientificity of the design scheme, and improve the fidelity chamber from the structural and material aspects, it is necessary to design an ultra-high pressure pressure-maintaining characteristic test platform to test the pressure-resistant characteristics of the pressure chamber, and provide test basis and data support for the research and development and design of the fidelity coring rig. Summary of the invention

[0004] The present invention aims to provide a pressure-maintaining characteristic test system and method for a core drill pressure-maintaining cabin, which can test the deformation characteristics of the pressure-maintaining cabin under different working conditions.

[0005] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0006] The core sampling device pressure chamber pressure maintaining characteristic test system comprises a pressure supply unit, a pressure chamber, a data acquisition and analysis unit and a control unit. The pressure supply unit is connected to the pressure chamber through a pipeline to adjust the pressure in the pressure chamber; the pressure supply unit and the data acquisition and analysis unit are both connected to the control unit.

[0007] Furthermore, the core drill pressure chamber pressure-maintaining characteristic test system also includes an explosion-proof box, and the pressure chamber is placed in the explosion-proof box.

[0008] Furthermore, the pressure supply unit includes a power supply system, a low-pressure pump and a high-pressure pump. The power supply system is connected to the high-pressure pump to provide driving force for the high-pressure pump. The medium output by the low-pressure pump is transmitted to the pressure chamber after passing through the high-pressure pump.

[0009] The data acquisition and analysis unit includes a strain sensor and a pressure sensor, and the outlet of the pressure supply unit is provided with a pressure sensor and / or the pressure chamber is provided with a pressure sensor.

[0010] Furthermore, a plurality of strain sensors are installed inside and outside the pressure chamber.

[0011] Furthermore, the pressure chamber includes a cylinder, an upper end sealing device for sealing the upper end of the cylinder, and a lower end sealing device for sealing the lower end of the cylinder, and the upper end sealing device is provided with a medium channel connected to the inside of the cylinder.

[0012] Furthermore, the core sampling device pressure chamber pressure maintaining characteristic test system also includes a flap valve, which is installed in the cylinder body. The flap valve includes a valve seat and a valve disc, and strain sensors are installed on the top and bottom surfaces of the valve disc.

[0013] Furthermore, the core sampling device pressure maintaining chamber pressure maintaining characteristic test system also includes a mounting ring and a spring. The cylinder body is provided with a step for supporting the mounting ring. One end of the mounting ring is supported on the step. One end of the spring is supported on the mounting ring. The other end of the spring is supported on the valve disc to provide initial sealing pressure to the valve disc.

[0014] The pressure resistance characteristics testing method of the core drill pressure chamber is to conduct a continuous pressure test of 0-140MPa on the pressure chamber by using the pressure characteristics testing system of the core drill pressure chamber, and the deformation of the pressure chamber is tested by a strain sensor to verify the strength design of the pressure chamber wall.

[0015] Furthermore, a flap valve is installed in the pressure chamber to test the sealing performance and deformation of the flap valve under different pressures.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The present invention can test the pressure resistance characteristics of the pressure-maintaining cabin, understand its deformation characteristics under different working conditions, verify the feasibility and scientificity of the design scheme, facilitate the improvement of the fidelity cabin in terms of structure and material, and provide experimental basis and data support for the research and development and design of fidelity coring drilling rigs;

[0018] 2. The present invention can realize continuous pressure testing of the test chamber at 0-100MPa, long-term pressure maintenance, and online pressure monitoring and deformation testing under pressure maintenance, and can verify the strength design of the cylinder wall;

[0019] 3. The present invention can also be used to test the sealing performance and deformation of the lower sealing device (flap valve) of the pressure-maintaining tank under different working conditions, verify the nominal pressure of flap valves with different structures and shapes, and test the comprehensive performance of thread seal, end face seal, initial sealing pressure and the influence of the inlet and outlet liquid systems on the seal. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the present invention;

[0021] Figure 2 It is a schematic diagram of the structure of the explosion-proof box;

[0022] Figure 3 is a schematic diagram of the pressure chamber in a horizontal position;

[0023] Figure 4 is a schematic diagram of the pressure chamber in a vertical position;

[0024] Figure 5 It is a schematic diagram of the structure of the pressure chamber;

[0025] Figure 6 It is a structural schematic diagram of a flap valve;

[0026] Figure 7 It is a schematic diagram of a vertically inverted pressure chamber when the flap valve is installed;

[0027] Figure 8 It is a schematic diagram of the software interface. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings.

[0029] like Figure 1 As shown, the pressure-maintaining characteristic test system of the corer pressure-maintaining chamber disclosed in this embodiment includes a pressure supply unit, a pressure chamber 2, a data acquisition and analysis unit and a control unit 1. The pressure supply unit is connected to the pressure chamber 2 through a pipeline to adjust the pressure in the pressure chamber 2; the data acquisition and analysis unit includes a strain sensor, a pressure sensor 14 and a temperature sensor 15. The pressure chamber 2 is equipped with a strain sensor. The pressure supply unit and the data acquisition and analysis unit are both connected to the control unit 1. The control unit 1 includes a computer host and a display terminal. The display terminal adopts a touch screen and can display test data in real time and control the power unit in real time.

[0030] The pressure supply unit includes a power supply system and an ultra-high pressure boosting system. The entire system can be computer controlled and can output and control 0-100 MPa pressure at will. In this embodiment, the ultra-high pressure boosting system is an ultra-high pressure gas-driven boosting system, which includes a low-pressure pump 12 and a high-pressure pump 13.

[0031] The power supply system is a gas pressure supply system, which is connected to the high-pressure pump 13 to provide driving force for the high-pressure pump 13. The medium output by the low-pressure pump 12 is delivered to the pressure cabin 2 after passing through the high-pressure pump 13. When high-pressure output is required, the medium output by the low-pressure pump 12 is pressurized by the high-pressure pump 13 and delivered to the pressure cabin 2.

[0032] The gas pressure supply system uses an oil-free silent air compressor, which can achieve a pressure output of 0.1-0.8Mpa and provide power for the ultra-high pressure gas drive booster system. One of them is provided for reference in this embodiment, model WP1100-3 / 140, motor power 3600W, speed 1400r / min.

[0033] The output pressure of the ultra-high pressure boosting system is proportional to the driving air pressure, and the gas consumption is small: 0.3-1m3 / min. At high pressure, the pump output flow is 0.3L / min, and the pressure test range is: 0-200Mpa. The ultra-high pressure pipeline adopts high-pressure steel pipe, and the pipeline seal adopts ball head or cone hard seal. A check valve is installed in the pipeline of the ultra-high pressure boosting system.

[0034] In the present invention, the test fluid system and the driving fluid system are separated and the test media are diversified.

[0035] The data acquisition and analysis unit is used to realize pressure monitoring and strain monitoring inside the pressure chamber 2. The data acquisition and analysis unit includes various measuring elements and a data acquisition and analysis system. The measuring elements include pressure sensors, strain sensors, etc.

[0036] The pressure monitoring includes two pressure monitoring components, one for monitoring the outlet pressure of the pump station and the other for monitoring the internal pressure of the pressure chamber 2. A pressure sensor 14 is installed at the outlet of the pressure supply unit, a pressure sensor is installed inside the pressure chamber 2, and a pressure gauge is also provided in the pressure relief pipeline.

[0037] The strain monitoring inside the pressure chamber 2 is measured by a strain sensor. The strain sensor uses a 1 / 4 bridge two-wire common compensation type to ensure that 6 strain gauges can be installed inside the pressure chamber 2 and 20 strain gauges can be installed outside the pressure chamber 2 to measure the deformation of the pressure chamber 2.

[0038] The data acquisition and analysis system adopts the fully intelligent DH3816N static strain test data acquisition and analysis system; a single unit has 36 measuring points and uses wired communication to complete the collection of strain gauge data and pressure chamber 2 internal pressure data.

[0039] The data acquisition and analysis system uses Ethernet communication, which enables the system to achieve sampling, transmission, storage and display at the same time. It uses the computer's massive storage hard disk to record all channel signals in real time and continuously for a long time. This system can cooperate with various bridge sensors to accurately test physical quantities such as force and pressure. It can set any measuring point as a compensation measuring point, or use the public compensation terminal for compensation; the sampling control and analysis software compiled by Vc++ under the Chinese Windows XP / Vista / 7 operating system has extremely strong real-time performance and good portability, expandability and upgradeability. It also has the function of automatic correction of wire resistance and self-checking of bridge circuit.

[0040] Automatic correction function of wire resistance: The control software can complete the wire resistance measurement and automatic correction with one click, avoiding the influence of cumbersome manual inspection operation and large subjective reading errors on the measurement results during the test, and can improve the test accuracy.

[0041] Bridge self-check function: combined with the control software, it can accurately judge the short circuit, open circuit and other faults of the bridge, and remind the engineering personnel of the channel status with an intuitive graphic window, which is convenient for on-site status inspection and troubleshooting;

[0042] When measuring stress and strain, the software inputs the bridge mode, strain gauge resistance, wire resistance, and strain gauge sensitivity coefficient, and the software automatically corrects the measurement results; the software inputs the elastic modulus and Poisson's ratio of the material of the test piece, and the software completes the calculation of stress and the principal stress and direction of strain rosettes such as two right angles, three 45° right angles, 60° equilateral triangles, umbrellas, and fans.

[0043] like Figure 2 As shown, the pressure-maintaining characteristic test system of the core sampling device pressure-maintaining chamber also includes an explosion-proof box 4, and the pressure chamber 2 is placed in the explosion-proof box 4. The explosion-proof box 4 has built-in lighting equipment and a camera, through which the internal scene can be observed in real time on the PC client. At the same time, a 1TB hard disk burner and a network switch are configured to save the image data during the experiment. The explosion-proof box 4 can meet the safety requirements in the event of leakage.

[0044] The explosion-proof box 4 is welded with 6mm thick steel plates, and cushioning materials are laid inside. There are switch doors on the left and right sides for loading and unloading workpieces. The explosion-proof box 4 is provided with a perspective window 41 and a pipeline inlet and outlet, and the perspective window 41 is made of 26mm thick bulletproof glass.

[0045] The explosion-proof box 4 is designed with a rotating mechanism 8, and the explosion-proof box 4 is designed according to the size of the rotating mechanism. The pressure chamber 2 is installed on the rotating mechanism 8, so that the pressure chamber 2 can be rotated as a whole and fixed at two positions of 90° and 180°, so that the pressure chamber 2 can start relevant testing work in the horizontal position and the vertical position. Figure 3 , 4 As shown, the rotating mechanism 8 includes a bracket 81, a workpiece fixing seat 83, a bearing seat 82 and a horizontal position limit plate 84. The pressure chamber 2 is fixed on the workpiece fixing seat 83. The workpiece fixing seat 83 is provided with two horizontal shafts 85, and the horizontal shafts 85 are perpendicular to the axis of the pressure chamber 2.

[0046] The two horizontal shafts 85 are supported on the bearing seat 82 through bearings. The bearing seat 82 is fixedly connected to the bracket 81. The horizontal position limit plate 84 is vertically placed and fixedly connected to the bracket 81. The horizontal position limit plate 84 has a limit notch matching the shape of the pressure chamber 2. The limit notch opens above the horizontal position limit plate 84. A horizontal pin 87 is installed on the horizontal position limit plate 84. The workpiece fixing seat 83 has a pin hole 88 adapted to the horizontal pin 87, and the pin hole 88 is perpendicular to the horizontal shaft 85.

[0047] like Figure 3As shown, when the pressure cabin 2 is placed horizontally, the pressure cabin 2 is located in the limiting notch of the horizontal limiting plate 84, and the limiting notch is blocked by the pressure strip 86, so that the pressure cabin 2 is fixed in the horizontal position, and the pressure strip 86 is screwed to the horizontal limiting plate 84. At this time, the pin hole 88 is parallel to the vertical plane.

[0048] When the pressure chamber 2 needs to be adjusted to a vertical position, the screws are loosened, the pressure strip 86 is removed, and the pressure chamber 2 is rotated to a vertical position. Figure 4 As shown, at this time, the pin hole 88 is parallel to the horizontal plane and is directly opposite to the horizontal pin 87 on the horizontal position limit plate 84, and then the horizontal pin 87 on the horizontal position limit plate 84 is inserted into the pin hole 88, thereby fixing the pressure chamber 2 in the vertical position. Of course, in addition to the hardware part, the system also includes monitoring software. The monitoring software can realize the integrated display of the three subsystems of the ultra-high pressure boosting system pressure data, strain gauge data and pressure data inside the pressure chamber 2, and real-time video monitoring data on the same software platform, and can record the pressure changes in the pressure chamber 2 in real time, such as Figure 8 As shown, the holding pressure and holding time can be set through the software interface. The system also provides system login authority management function.

[0049] like Figure 5 As shown, the pressure chamber 2 includes a cylinder 21, an upper end sealing device for sealing the upper end of the cylinder 21, and a lower end sealing device for sealing the lower end of the cylinder 21.

[0050] The upper end sealing device includes an upper end plug 22, a lower end plug 23 and a sealing ring 24. The upper end plug 22 and the lower end plug 23 are both threadedly connected to the cylinder 21. The upper end plug 22 and the lower end plug 23 are both installed with a sealing ring 24 and a retaining ring to form a seal between the inner wall of the cylinder 21. The sealing ring 24 is a hydrolysis-resistant polyurethane sealing ring that can withstand high temperature and high pressure.

[0051] The upper end plug 22 is reserved with a medium channel 25 connected to the inside of the cylinder 21, a pressure sensor interface and a watertight connector interface. A watertight connector is installed at the watertight connector interface for transmitting strain sensor data. The medium channel 25 is used as an injection port and is connected to an external hydraulic source. The watertight connector is used to transmit strain sensor data.

[0052] In order to test the pressure-maintaining performance of the pressure-maintaining cabin under different temperature conditions, a heater for heating the hydraulic medium is also provided in this embodiment. The heater can be arranged before the low-pressure pump. It is also possible to heat the pressure cabin 2 by arranging an annular steam heat pipe, a resistance wire, an eddy current heating system, or a water bath.

[0053] The test method of the pressure resistance characteristics of the corer pressure chamber is to connect the low-pressure pump 12 to the stainless steel liquid tank, use water as the liquid medium at low temperature, and use oil as the liquid medium at high temperature. The data acquisition and analysis unit is also used to realize temperature monitoring. Temperature monitoring mainly monitors the internal temperature of the pressure chamber 2. The temperature monitoring unit can select the MWT202 integrated temperature transmitter, which consists of three parts: temperature sensor, compensation circuit and conversion circuit. It has the advantages of stable performance, high sensitivity and strong reliability. It uses the characteristics that the resistance of the platinum resistor changes with temperature and presents a certain functional relationship to measure the temperature of the object being measured.

[0054] If a water bath or oil bath is used for heating, a temperature sensor can be installed in the water bath to monitor the temperature of the water bath or oil bath. The pressure chamber 2 is subjected to a continuous pressure test of 0-100MPa using the pressure chamber pressure holding characteristic test system of the core drill. After the pressure is held for a specified time, the system performs a safe pressure relief, and the specified pressure holding time is set according to the experimental needs. In this process, the deformation of the cylinder wall of the pressure chamber 2 is monitored by a strain gauge, and the strength design of the cylinder wall of the pressure chamber 2 is verified, so as to improve the test platform in terms of structure and material, and reduce the wall thickness of the cylinder 21 under absolute safety.

[0055] Of course, the sealing performance of the pressure chamber 2 can also be tested. There are two ways to test the sealing performance. Method 1: Add a fluorescent agent to the liquid medium entering the pressure chamber 2. After the test, the leakage path can be detected with a fluorescence meter. It can be used to test the sealing performance of thread seals, end face seals, and sealing rings. Method 2: Install multiple acoustic emission sensors and use an acoustic detector to perform valve leakage detection. Of course, these two methods can also be used at the same time.

[0056] The performance of the valve plate valve 5, the sealing ring and other components can be tested by using the pressure-maintaining characteristic test system of the corer pressure-maintaining chamber. The following description will be made by taking the test of the valve plate valve 5 as an example.

[0057] like Figure 6 , 7 As shown, the flap valve comprises a valve seat 51 and a valve flap 52, and a valve sealing ring 53 is arranged between the valve seat 51 and the valve flap 52. The flap valve is fixed to the cylinder 21 through a mounting ring 6 and a spring 7. During testing, the flap valve is placed at the bottom end of the cylinder 21.

[0058] like Figure 7As shown, when installing the flap valve, the pressure chamber 2 is vertically inverted, that is, the upper end plug 22 is located at the bottom, and then the lower end plug 23 is unscrewed, and the mounting ring 6 is placed in the pressure chamber 2. Since there is a step 211 inside the cylinder 21 for resisting the mounting ring 6, the mounting ring 6 stops when it falls on the step 211, and then the spring is placed in the cylinder 21, and then the flap valve in the closed state is placed in the cylinder 21. The lower end of the spring 7 presses against the mounting ring 6; the upper end of the spring 7 presses against the valve disc 52 to prevent the flap valve from falling further, and at the same time, the spring 7 is compressed to provide the initial sealing pressure to the valve disc 52, and then the lower end plug 23 is screwed on to press against the valve seat 52 to achieve the installation of the flap valve, and then the pressure chamber 2 can be turned upright. Strain sensors are installed on the top and bottom surfaces of the valve disc 52, and a sealing ring 24 is provided outside the valve seat 51 to achieve sealing with the cylinder 21.

[0059] Then change the output pressure of the pressure supply unit, monitor the sealing and deformation of the flap valve under different pressures and temperatures, and verify the nominal pressure of different flap valves.

[0060] The present invention can realize comprehensive performance testing of cylinder wall strength design verification, thread seal, end face seal, initial sealing pressure, and the influence of inlet and outlet liquid systems on sealing within 0-100MPa.

[0061] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, technicians familiar with the field may make various corresponding changes and modifications based on the present invention, but these corresponding changes and modifications should all fall within the scope of protection of the claims attached to the present invention.

Claims

1. The pressure-maintaining characteristics test system of the core drill pressure-maintaining chamber is characterized by: Comprising a pressure supply unit, a pressure chamber (2), a data acquisition and analysis unit and a control unit (1), wherein the pressure supply unit is connected to the pressure chamber (2) via a pipeline to adjust the pressure in the pressure chamber (2); the pressure supply unit and the data acquisition and analysis unit are both connected to the control unit (1); The pressure chamber (2) comprises a cylinder (21), an upper end sealing device for sealing the upper end of the cylinder (21), a lower end sealing device for sealing the lower end of the cylinder (21), a flap valve, a mounting ring (6) and a spring (7); the upper end sealing device is provided with a medium channel (25) communicating with the interior of the cylinder (21); The flap valve is installed in the cylinder (21), and comprises a valve seat (51) and a valve disc (52). The lower end plug (23) is threadedly connected to the cylinder (21), and the inner end of the lower end plug (23) abuts against the valve seat (51). The top surface and the bottom surface of the valve disc (52) are both installed with strain sensors. The cylinder (21) has a step (211) inside for abutting against the mounting ring (6), and one end of the mounting ring (6) abuts against the step (211). One end of the spring (7) abuts against the mounting ring (6), and the other end of the spring (7) abuts against the valve disc (52) to provide the valve disc (52) with an initial sealing pressure. It also includes an explosion-proof box (4), wherein the pressure chamber (2) is placed in the explosion-proof box (4); The pressure supply unit comprises a power supply system, a low-pressure pump (12) and a high-pressure pump (13); the power supply system is connected to the high-pressure pump (13) to provide driving force to the high-pressure pump (13); the medium output by the low-pressure pump (12) is transmitted to the pressure chamber (2) through the high-pressure pump (13).

2. The pressure-maintaining characteristics test system for the core drill pressure-maintaining chamber according to claim 1, characterized in that: The data acquisition and analysis unit also includes a strain sensor and a pressure sensor (14); the outlet of the pressure supply unit is provided with a pressure sensor (14) and / or the pressure chamber (2) is provided with a pressure sensor (14).

3. The pressure-maintaining characteristics test system for the core drill pressure-maintaining chamber according to claim 2, characterized in that: A plurality of strain sensors are installed inside and outside the pressure chamber (2).

4. A method for testing using the core drill pressure chamber pressure characteristics test system according to any one of claims 1 to 3, characterized in that: The pressure chamber (2) is subjected to a continuous pressure test of 0-100 MPa, and the deformation of the pressure chamber (2) is tested by a strain sensor to verify the strength design of the cylinder wall of the pressure chamber (2).

5. The method according to claim 4, characterized in that: A flap valve is installed in the pressure chamber (2) to test the sealing performance and deformation of the flap valve under different pressures.

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