An underwater cable hydrogen test device and test method

Abstract

The application relates to an underwater cable hydrogen test device and a test method. The test device comprises: a pressure-bearing cabin body for accommodating a measured cable section and being filled with a liquid medium; a sealing assembly arranged at the axial two ends of the pressure-bearing cabin body and used for forming a seal between the measured cable section and the pressure-bearing cabin body; a pressurizing mechanism in communication with the inside of the pressure-bearing cabin body and used for applying and maintaining a predetermined pressure to the liquid medium; a hydrogen detection mechanism at least partially located in the pressure-bearing cabin body and used for obtaining hydrogen content information in the liquid medium; and a fastening mechanism used for providing an axial pressing force to the sealing assembly to maintain the seal. The application can realize detection of hydrogen generated by the subsea cable or umbilical cable soaked in seawater under different environments; and the same set of devices can be adapted to cable sections with different diameters and lengths, thereby significantly reducing equipment investment.

Description

Technical Field

[0001] This invention relates to the field of cable testing technology, and in particular to an underwater cable hydrogen testing device and method. Background Technology

[0002] When laying submarine cables, the cable-laying vessel slowly descends to the seabed after passing through the arc of the launching bridge. The laid submarine cable forms a catenary shape on the seabed. When the galvanized steel sheath is wetted by seawater, the galvanized layer will preferentially oxidize to protect the steel wire and generate hydrogen gas.

[0003] To ensure the lifespan of submarine cables, it is necessary to test the amount of hydrogen produced by the cables immersed in seawater. However, due to current equipment limitations, it is not possible to accurately measure the amount of hydrogen.

[0004] Therefore, there is an urgent need for an underwater cable hydrogen testing device and method that can effectively detect the hydrogen content produced, which would be of guiding significance for submarine cable laying. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide an underwater cable hydrogen detection test device that can detect the amount of hydrogen produced by submarine cables or umbilical cables immersed in seawater under different environments; and the same device can be adapted to cable segments of different diameters and lengths, significantly reducing equipment investment. In a first aspect, to solve the above-mentioned technical problems, the present invention provides an underwater cable hydrogen measurement test device, comprising: A pressure chamber is used to contain the cable segment under test and fill it with liquid medium; the pressure chamber includes a tank, the tank is provided with flanges at both ends, the tank can be modularly spliced ​​along the axial direction to change the effective length, and the inner diameter of the tank can be replaced to adapt to cable segments of different diameters under test. A sealing assembly is provided at both axial ends of the pressure chamber to form a seal between the cable segment under test and the pressure chamber. A pressurizing mechanism, connected to the interior of the pressure chamber, is used to apply and maintain a predetermined pressure to the liquid medium; A hydrogen detection device, at least partially located within the pressure chamber, is used to obtain information on the hydrogen content in the liquid medium; A fastening mechanism is used to provide axial clamping force to the sealing assembly to maintain the seal.

[0006] In one embodiment of the present invention, the sealing assembly includes a sealing ring cover plate, a sealing ring, a sealing ring pressure plate and a sealing fixture arranged sequentially along the axial direction. The dimensions of the sealing ring cover plate and the sealing ring are interchangeable to adapt to cable segments of different diameters under test.

[0007] In one embodiment of the present invention, the fastening mechanism is a bolt assembly that passes axially through the sealing ring pressure plate, the sealing ring cover plate and the flanges at both ends of the tank and provides adjustable clamping force.

[0008] In one embodiment of the present invention, the pressurization mechanism includes a pressurization pump, a water pipe and a pressure sensor. The pressurization pump is connected to the interior of the pressure chamber through the water pipe, and the pressure sensor is connected to the pressure chamber through a water pressure signal line for real-time feedback of the pressure inside the pressure chamber.

[0009] In one embodiment of the present invention, an automatic control unit is also connected, which starts or stops the pressurization pump or adjusts the flow rate according to the feedback signal of the pressure sensor to maintain stable water pressure in the pressure chamber.

[0010] In one embodiment of the present invention, the water pipe is provided with a control valve, which is electrically connected to an automatic control unit and is used to cut off or reduce the output flow of the pressurization pump when the pressure reaches a set value, so as to maintain the stability of the water pressure in the pressure chamber.

[0011] In one embodiment of the present invention, the connection between the water pressure signal line and the pressure chamber is fixed with sealant.

[0012] In one embodiment of the present invention, the hydrogen detection mechanism includes a hydrogen sensor and a hydrogen signal line. One end of the hydrogen signal line passes through a sealing assembly and is connected to the hydrogen sensor, and a seal is provided between the hydrogen signal line and the sealing assembly.

[0013] Secondly, to solve the above-mentioned technical problems, the present invention provides an underwater cable hydrogen measurement test method, which is implemented using the apparatus described in the first aspect and includes the following steps: Based on the outer diameter and length of the cable segment being tested, select a pressure chamber with the corresponding inner diameter and total length, and replace the sealing components accordingly. The cable segment to be tested is passed through the pressure chamber, and the matching sealing components are installed at both ends to form a seal; The liquid medium is injected into the chamber and pressurized to a predetermined pressure through a pressurization mechanism; Maintain the predetermined pressure for at least a set time, during which hydrogen content information is obtained using a hydrogen detection device; The hydrogen permeability of the tested cable segment is evaluated based on the hydrogen content information.

[0014] In one embodiment of the present invention, the predetermined pressure is 1 MPa, 2 MPa or 3 MPa, corresponding to simulated working conditions in shallow sea, mid-sea and deep sea, respectively.

[0015] In one embodiment of the present invention, the set time is 72 h, and hydrogen content data is recorded every 12 h during the pressure holding period to plot a hydrogen concentration-time curve.

[0016] Compared with the prior art, the above-described technical solution of the present invention has the following advantages: (1) The underwater cable hydrogen testing device of the present invention continuously pressurizes the pressure chamber by operating the pressurizing mechanism to apply a certain pressure, and reads the hydrogen content generated by the test sample by the hydrogen detection mechanism, so that it can detect the amount of hydrogen generated by the submarine cable or umbilical cable immersed in seawater under different environments; since the pressure chamber can be axially modularly spliced ​​and the inner diameter can be replaced, the same device can be adapted to cable segments of different diameters and lengths, significantly reducing equipment investment.

[0017] (2) The underwater cable hydrogen measurement test method described in this invention achieves universal testing of a series of cable segments of all diameters and lengths by a single device through a five-step process of selecting a cabin, changing the sealing assembly, closed-loop pressure stabilization and continuous hydrogen measurement. The replacement process does not require processing new tooling and can be completed by a single person in a short time, significantly shortening the test cycle. Attached Figure Description

[0018] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein... Figure 1 This is a schematic diagram of the underwater cable hydrogen measurement test device in a preferred embodiment of the present invention; Figure 2 This is a schematic diagram of the pressure chamber structure in this invention; Explanation of reference numerals in the accompanying drawings: 1. Pressure chamber; 10. Support frame; 11. Tank body; 12. Flange; 2. Sealing assembly; 20. Sealing fixture; 21. Sealing ring pressure plate; 22. Sealing ring; 23. Sealing ring cover plate; 3. Pressurization mechanism; 31. Pressurization pump; 32. Water pipe; 33. Pressure sensor; 34. Water pressure signal line; 4. Hydrogen detection mechanism; 41. Hydrogen sensor; 42. Hydrogen signal line. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0020] Reference Figure 1-2 As shown, an underwater cable hydrogen measurement test device of the present invention includes: The pressure chamber 1 is used to accommodate the cable segment to be tested and fill it with liquid medium. The lower side of the pressure chamber 1 is fixed by a bracket 10. The pressure chamber 1 includes a tank 11. Flanges 12 are provided at both ends of the tank 11. The tank 11 can be modularly spliced ​​along the axial direction to change the effective length. The inner diameter of the tank 11 can be replaced to adapt to cable segments of different diameters. Sealing assembly 2 is disposed at both axial ends of the pressure chamber 1 and is used to form a seal between the cable segment under test and the pressure chamber 1. The pressurizing mechanism 3 is connected to the interior of the pressure chamber 1 and is used to apply and maintain a predetermined pressure to the liquid medium. Hydrogen detection unit 4, at least partially located inside the pressure chamber 1, is used to obtain information on the hydrogen content in the liquid medium; A fastening mechanism is provided to provide axial clamping force to the sealing assembly 2 to maintain the seal.

[0021] Preferably, the sealing assembly 2 includes a sealing ring cover plate 23, a sealing ring 22, a sealing ring pressure plate 21, and a sealing fixture 20 arranged sequentially along the axial direction. The dimensions of the sealing ring cover plate 21 and the sealing ring 22 are interchangeable to adapt to cable segments of different diameters under test. The sealing assembly 2 adopts an axially stacked structure, and the dimensions of the sealing ring cover plate 21 and the sealing ring 22 are serialized, allowing for quick replacement as the cable diameter changes. Replacement only requires disassembling and assembling bolts, without the need to process new fixtures. The operation time per person is reduced from several hours to minutes, while ensuring uniform pressure at the sealing interface, long-term pressure maintenance without leakage, and significantly improving test efficiency and data reliability.

[0022] Preferably, the fastening mechanism is a bolt assembly that passes axially through the sealing ring pressure plate 21, the sealing ring cover plate 23, and the flanges 12 at both ends of the tank body 11, providing adjustable clamping force. The fastening mechanism provides adjustable axial clamping force through evenly distributed bolt assemblies, eliminating the need to disassemble the entire tank when changing samples; this can be done quickly by a single person, significantly improving testing efficiency.

[0023] In this embodiment, the pressurization mechanism 3 includes a pressurization pump 31, a water pipe 32, and a pressure sensor 33. The pressurization pump 31 is connected to the interior of the pressure chamber 1 via the water pipe 32, and the pressure sensor 33 is connected to the pressure chamber 1 via a water pressure signal line 34 for real-time feedback of the pressure inside the pressure chamber 1. An automatic control unit is also included, which starts, stops, or adjusts the flow rate of the pressurization pump based on the feedback signal from the pressure sensor to maintain stable water pressure inside the pressure chamber 1.

[0024] The pressurization mechanism adopts a closed-loop circuit of pressurization pump 31-water pipe 32-pressure sensor 33. The pressure sensor 33 collects the pressure inside the pressure chamber 1 in real time via the water pressure signal line and feeds it back to the automatic control unit, so that the pressurization pump can adjust the output in real time and the pressure fluctuation can be stably controlled within ±0.05 MPa. This structure eliminates the traditional overflow valve bypass, reduces energy loss and heat accumulation, and avoids the impact of pressure overshoot on the sealing component 2, significantly extending the equipment life and improving the repeatability and accuracy of hydrogen permeation test.

[0025] Furthermore, a control valve is provided on the water pipe 32. The control valve is electrically connected to the automatic control unit and is used to cut off or reduce the output flow of the booster pump 31 when the pressure reaches a set value, so as to maintain stable water pressure in the pressure chamber 1. The design of the control valve allows for precise adjustment of the flow rate without stopping the booster pump 31, avoiding motor overheating and pressure pulses caused by frequent start-stop operations, extending the life of the booster pump 31 and further improving pressure stability.

[0026] Furthermore, the connection between the water pressure signal line 34 and the pressure chamber is fixed with sealant. After the sealant cures, a non-moving sealing surface is formed at the connection between the water pressure signal line 34 and the pressure chamber 1, resulting in a simple seal that requires no additional mechanical cover. The water pressure signal line refers to the signal cable that converts water pressure into an electrical signal.

[0027] Preferably, the hydrogen detection mechanism 4 includes a hydrogen sensor 41 and a hydrogen signal line 42. One end of the hydrogen signal line 41 passes through the sealing assembly 2 and is connected to the hydrogen sensor 41, and a seal is provided between the hydrogen signal line 42 and the sealing assembly 2. The hydrogen signal line 42 is an electrical signal cable used to lead the hydrogen concentration electrical signal to an external acquisition system.

[0028] This invention also provides a method for underwater cable hydrogen measurement, which is implemented using an underwater cable hydrogen measurement test device, and specifically includes the following steps: Based on the outer diameter and length of the cable segment being tested, select the pressure chamber 1 with the corresponding inner diameter and total length, and replace the sealing component 2 accordingly. The cable segment to be tested is passed through the pressure chamber 1, and the matching sealing components 2 are installed at both ends to form a seal; The liquid medium is injected into the chamber and pressurized to a predetermined pressure by the pressurization mechanism 3; Maintain the predetermined pressure for at least a set time, during which hydrogen content information is obtained using hydrogen detection device 4; The hydrogen permeability of the tested cable segment is evaluated based on the hydrogen content information.

[0029] The predetermined pressure is 1 MPa, 2 MPa or 3 MPa, corresponding to simulated working conditions in shallow sea, mid-sea and deep sea, respectively.

[0030] In this embodiment, the set time is 72 hours, and hydrogen content data is recorded every 12 hours during the pressure holding period to plot a hydrogen concentration-time curve.

[0031] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. An underwater cable hydrogen measurement test device, characterized in that, include: A pressure chamber is used to contain the cable segment under test and fill it with liquid medium; the pressure chamber includes a tank, the tank is provided with flanges at both ends, the tank can be modularly spliced ​​along the axial direction to change the effective length, and the inner diameter of the tank can be replaced to adapt to cable segments of different diameters under test. A sealing assembly is provided at both axial ends of the pressure chamber to form a seal between the cable segment under test and the pressure chamber. A pressurizing mechanism, connected to the interior of the pressure chamber, is used to apply and maintain a predetermined pressure to the liquid medium; A hydrogen detection device, at least partially located within the pressure chamber, is used to obtain information on the hydrogen content in the liquid medium; A fastening mechanism is used to provide axial clamping force to the sealing assembly to maintain the seal.

2. The apparatus according to claim 1, characterized in that, The sealing assembly includes a sealing ring cover plate, a sealing ring, a sealing ring pressure plate, and a sealing fixture arranged sequentially along the axial direction. The dimensions of the sealing ring cover plate and the sealing ring are interchangeable to adapt to cable segments of different diameters.

3. The apparatus according to claim 1 or 2, characterized in that, The fastening mechanism is a bolt assembly that passes axially through the sealing ring pressure plate, the sealing ring cover plate, and the flanges at both ends of the tank body, and provides adjustable clamping force.

4. The apparatus according to claim 1, characterized in that, The pressurization mechanism includes a pressurization pump, a water pipe, and a pressure sensor. The pressurization pump is connected to the interior of the pressure chamber through the water pipe, and the pressure sensor is connected to the pressure chamber through a water pressure signal line to provide real-time feedback on the pressure inside the pressure chamber.

5. The apparatus according to claim 4, characterized in that, It also includes an automatic control unit connection, which starts or stops the pressurization pump or adjusts the flow rate based on the feedback signal from the pressure sensor to maintain stable water pressure in the pressure chamber.

6. The apparatus according to claim 5, characterized in that, The water pipe is equipped with a control valve, which is electrically connected to the automatic control unit. The control valve is used to cut off or reduce the output flow of the pressurization pump when the pressure reaches the set value, so as to maintain the stability of the water pressure in the pressure chamber.

7. The apparatus according to claim 1, characterized in that, The connection between the water pressure signal line and the pressure chamber is secured with sealant.

8. The apparatus according to claim 1, characterized in that, The hydrogen detection mechanism includes a hydrogen sensor and a hydrogen signal line. One end of the hydrogen signal line passes through a sealing assembly and is connected to the hydrogen sensor, and a seal is provided between the hydrogen signal line and the sealing assembly.

9. A method for hydrogen measurement via underwater cable, characterized in that, Implemented using the apparatus according to any one of claims 1 to 6, and comprising the following steps:   Based on the outer diameter and length of the cable segment being tested, select a pressure chamber with the corresponding inner diameter and total length, and replace the sealing components accordingly. The cable segment to be tested is passed through the pressure chamber, and the matching sealing components are installed at both ends to form a seal;   The liquid medium is injected into the chamber and pressurized to a predetermined pressure through a pressurization mechanism; Maintain the predetermined pressure for at least a set time, during which hydrogen content information is obtained using a hydrogen detection device;   The hydrogen permeability of the tested cable segment is evaluated based on the hydrogen content information.

10. The method according to claim 9, characterized in that, The predetermined pressure is 1MPa, 2MPa or 3MPa, corresponding to simulated working conditions in shallow sea, mid-sea and deep sea, respectively.

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