Ocean cable extrusion testing device and testing method

Abstract

The invention discloses a marine cable extrusion testing device and method, and the device comprises a portal frame, supporting members, a pressing block, a first dynamic pressure unit, a second dynamic pressure unit, a first static pressure unit, and a second static pressure unit, a sample cable horizontally penetrates through the portal frame, the supporting members are disposed at two ends of the sample cable, and are used to horizontally support the sample cable, and the pressing block is used to press the sample cable. The first dynamic pressure unit, the second dynamic pressure unit, the first static pressure unit and the second static pressure unit are distributed in the portal frame in an annular array mode with the sample cable as the circle center, and the pressing blocks are arranged at the ends, facing the sample cable, of the first dynamic pressure unit, the second dynamic pressure unit, the first static pressure unit and the second static pressure unit respectively. The relationship between the extrusion force and the section shape of the marine cable can be determined by calculating the ovality of the sample cable under the specified pressure, and the influence of extrusion on the section of the sample cable is evaluated by measuring the ovality change of the sample cable before and after the extrusion experiment, so that the extrusion performance and the engineering application range of the sample cable are analyzed.

Description

Technical Field

[0001] The present invention relates to the technical field of marine cable extrusion testing, and particularly to a marine cable extrusion testing device and a testing method. Background Art

[0002] The compressive strength test of a cable is a crucial quality control step, aiming to ensure that the cable can withstand a certain pressure without insulation damage under normal working conditions.

[0003] The invention patent with the publication number CN116337644A discloses a cable processing voltage withstand test device and a test method with multiple stress parts, which includes a detection table and a voltage withstand measurement device installed on the detection table. The voltage withstand measurement device includes an environment simulation component for building a severe cold environment. The environment simulation component is used to hold the cable and enable the cable to perform ice hanging simulation within the environment simulation component. An offset component and a pressure component are arranged within the environment simulation component. The offset component is used to simulate the influence of wind force on the cable in the ice hanging state, and the pressure component is used to simulate the influence of additional pressure on the cable in the ice hanging state. By simulating the ice hanging state of the cable in the measurement chamber in the outdoor environment and using the wind force to impact the cable in the ice hanging state, the specific state of the cable when it is affected by wind force in the ice hanging state is simulated, and the voltage withstand performance of the cable when it is affected by wind force in the ice hanging state is tested.

[0004] Marine cables are laid on the seabed and do not get iced. Therefore, the above-mentioned testing device and testing method are not applicable to marine cables. In the field of marine cables, it is a very important part to determine the relationship between the extrusion force and the cable cross-sectional shape, evaluate the influence of extrusion on the cross-section of the sample cable, and analyze its extrusion performance and engineering application scope. However, the prior art lacks systematic research on the evaluation of cable extrusion performance, has an unclear understanding of the relationship between the extrusion force and the cable cross-sectional shape, and cannot accurately judge the performance changes of the cable under different extrusion conditions, resulting in difficulty in determining the best application scope of the cable in engineering applications, and thus unable to ensure that the cable can withstand the predetermined pressure without insulation damage under normal working conditions, and improvement is needed. Summary of the Invention

[0005] The main technical problem to be solved by the present invention is to provide a marine cable extrusion testing device and a testing method to perform extrusion testing on marine cables and ensure that the compressive capacity of the cables meets the usage requirements.

[0006] To solve the above technical problems, a technical solution adopted by the present invention is: to provide an extrusion test device for submarine cables, including: a gantry, a support member, a pressing block, a first dynamic pressure unit, a second dynamic pressure unit, a first static pressure unit, and a second static pressure unit. The sample cable horizontally penetrates the gantry, and the support members are arranged at both ends of the sample cable to provide horizontal support for the sample cable. The first dynamic pressure unit, the second dynamic pressure unit, the first static pressure unit, and the second static pressure unit are annularly arrayed around the sample cable in the gantry, and the pressing blocks are respectively arranged at one ends of the first dynamic pressure unit, the second dynamic pressure unit, the first static pressure unit, and the second static pressure unit facing the sample cable.

[0007] In a preferred embodiment of the present invention, the support member includes a supporting plate, a supporting rod, and a moving trolley. The supporting rod is vertically arranged on the moving trolley, and the supporting plate is horizontally arranged at the top of the supporting rod.

[0008] In a preferred embodiment of the present invention, the bottom of the moving trolley is provided with universal wheels with built-in brakes.

[0009] In a preferred embodiment of the present invention, the first dynamic pressure unit and the second dynamic pressure unit respectively include a jack and a pressure sensor, and the pressure sensor is arranged at the end of the jack.

[0010] In a preferred embodiment of the present invention, the first static pressure unit and the second static pressure unit respectively include a connecting rod.

[0011] In a preferred embodiment of the present invention, the pressing block is provided with an arc groove or a V-shaped groove corresponding to the outer wall of the sample cable.

[0012] In a preferred embodiment of the present invention, the included angle of the V-shaped groove is 120°.

[0013] In a preferred embodiment of the present invention, the first dynamic pressure unit is vertically arranged at the lower part of the gantry, the first static pressure unit is vertically arranged at the top of the gantry and directly above the first dynamic pressure unit, and the second dynamic pressure unit and the second static pressure unit are relatively horizontally arranged on both side walls of the gantry.

[0014] To solve the above technical problems, a technical solution adopted by the present invention is: to provide a method for testing the extrusion of submarine cables, including the following steps: S1. In the reset state of the first dynamic pressure unit and the second dynamic pressure unit, horizontally penetrate and place the sample cable in the gantry, and horizontally support both ends of the sample cable through the support members. Measure the maximum diameter and the minimum diameter of the sample cable at the place where it is about to be pressed, and calculate the ellipticity before extrusion; S2. Control the stroke of the first dynamic pressure unit. Make the pressing block at the top of the first dynamic pressure unit contact the bottom of the sample cable to apply a vertical preload, and adjust the position of the sample cable so that the sample cable passes through the central positions of the upper and lower pressing blocks. Control the stroke of the second dynamic pressure unit. Make the pressing block at the end of the second dynamic pressure unit contact the side of the sample cable to apply a horizontal preload, and adjust the position of the sample cable so that the sample cable just passes through the central positions of the four pressing blocks on the upper, lower, left, and right sides; S3. Control the first dynamic pressure unit and the second dynamic pressure unit to perform synchronous loading. Load the surface of the sample cable through the pressing blocks at the top of the first dynamic pressure unit and the end of the second dynamic pressure unit. Slowly apply the force, observe the compressed shape of the cross-section of the sample cable. After reaching the specified pressure, hold the pressure for 30 minutes. After the pressure holding is completed, unload the pressure, and use a vernier caliper to measure the maximum diameter and the minimum diameter of the compressed part of the sample cable, so as to calculate the ovality after extrusion; The calculation formula for the change in the ovality of the sample cable 5 is as follows:

[0015] where e is the ovality, D is the maximum outer diameter, and d is the minimum diameter; S4. After the sample cable 5 is unloaded from the pressure, let it stand for N hours, where N is not less than 0.5. Use a vernier caliper to measure the maximum diameter and the minimum diameter of the compressed part of the sample cable again, so as to calculate the ovality of the sample cable after standing for N hours after extrusion; S5. Disassemble the sample cable and measure the resistivity of the battery core in the sample cable and the on / off condition of the optical fiber.

[0016] In a preferred embodiment of the present invention, the specified pressure is 36.5 kN.

[0017] The beneficial effects of the present invention are as follows: An ocean cable extrusion test device and a test method proposed by the present invention can determine the relationship between the extrusion force and the cross-sectional shape of the ocean cable by calculating the ovality of the sample cable under the specified pressure. By measuring the change in the ovality of the sample cable before and after the extrusion experiment, the influence of extrusion on the cross-section of the sample cable is evaluated, so as to analyze its extrusion performance and engineering application scope, and ensure that the compressive capacity of the produced or selected ocean cable can meet the use requirements. Description of the Drawings

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to these drawings, where: Figure 1 is a schematic structural diagram of a preferred embodiment of an ocean cable extrusion test device of the present invention; Figure 2It is a schematic diagram of the operation process of the first dynamic pressure unit and the second dynamic pressure unit in a marine cable extrusion test method of the present invention. Detailed implementation mode

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0020] Please refer to Figures 1 to 2 , the embodiments of the present invention include: Such as Figure 1 The shown marine cable extrusion test device includes: a gantry 3, a support member, a pressing block 2, a first dynamic pressure unit 10, a second dynamic pressure unit 8, a first static pressure unit 11, and a second static pressure unit 4. The sample cable 5 horizontally penetrates through the gantry 3, and the support member is arranged at both ends of the sample cable 5 to horizontally support the sample cable 5. In this embodiment, the support member includes a supporting plate 1, a supporting rod 6, and a moving trolley 7. The supporting rod 6 is vertically arranged on the moving trolley 7, and the supporting plate 1 is horizontally arranged at the top of the supporting rod 6. The supporting plate 1 has an arc-shaped structure with an opening facing upward to support and self-center both ends of the sample cable 5.

[0021] The bottom of the moving trolley 7 is provided with a universal wheel with a built-in brake, which improves the flexibility of the support member, facilitates the position adjustment of the sample cable 5, and is braked after adjustment to ensure the stability of the support member and the sample cable 5 during the test.

[0022] The first dynamic pressure unit 10, the second dynamic pressure unit 8, the first static pressure unit 11, and the second static pressure unit 4 are annularly arrayed around the sample cable 5 in the gantry 3. In this embodiment, the first dynamic pressure unit 10 is vertically arranged at the lower part of the gantry 3, the first static pressure unit 11 is vertically arranged at the top of the gantry 3 and directly above the first dynamic pressure unit 10, and the second dynamic pressure unit 8 and the second static pressure unit 4 are relatively horizontally arranged on the two side walls of the gantry 3, so that the first dynamic pressure unit 10, the second dynamic pressure unit 8, the first static pressure unit 11, and the second static pressure unit 4 are distributed in a cross shape.

[0023] The pressing blocks 2 are respectively arranged at one ends of the first dynamic pressure unit 10, the second dynamic pressure unit 8, the first static pressure unit 11, and the second static pressure unit 4 facing the sample cable 5, which is conducive to the four pressing blocks 2 squeezing the sample cable 5 from the four directions of up, down, left, and right.

[0024] In this embodiment, the first dynamic pressure unit 10 and the second dynamic pressure unit 8 each include a jack and a pressure sensor 9. The pressure sensor 9 is arranged at the end of the jack. The pressure sensor 9 is connected to the controller of the jack, and the corresponding pressure value is displayed through the display on the controller, which is convenient for the actual control of the jack. The controller can use a PLC to perform manual or automatic control of the jack.

[0025] In addition, the first static pressure unit 11 and the second static pressure unit 4 each include a connecting rod. The structure is simple. The connecting rod is made of steel pipe with high supporting strength. One end of the connecting rod far from the sample cable 5 is fixed to the inner side of the gantry 3 by bolts, and the structure is stable.

[0026] To ensure stable contact between the pressing block 2 and the outer wall of the sample cable 5, an arc groove or V-shaped groove corresponding to the outer wall of the sample cable 5 is provided on the pressing block 2. In this embodiment, the included angle of the V-shaped groove is 120°. Through the contact between the two side walls in the V-shaped groove and the outer wall of the sample cable 5, self-centering is carried out, the stability during the extrusion process is high, and the adaptability to the outer diameter size of the sample cable 5 is good.

[0027] A marine cable extrusion test method includes the following steps: S1. In the reset state of the first dynamic pressure unit 10 and the second dynamic pressure unit 8, the sample cable 5 is horizontally penetrated and placed in the gantry 3. Both ends of the sample cable 5 are horizontally supported by support members. Measure the maximum diameter and the minimum diameter of the sample cable 5 at the place where it is about to be pressed, and calculate the ovality before extrusion; S2. Control the stroke of the first dynamic pressure unit 10. Through the pressing block at the top of the first dynamic pressure unit 10 contacting the bottom of the sample cable 5, apply a vertical preload, adjust the position of the sample cable 5 to make the sample cable 5 pass through the central position of the upper and lower pressing blocks. Control the stroke of the second dynamic pressure unit 8. Through the pressing block at the end of the second dynamic pressure unit 8 contacting the side of the sample cable 5, apply a horizontal preload, adjust the position of the sample cable 5 to make the sample cable 5 just pass through the central positions of the upper, lower, left and right four pressing blocks 2, and brake through the brakes of the universal wheels to ensure the position stability of the support members and the sample cable 5; S3. Control the first dynamic pressure unit 10 and the second dynamic pressure unit 8 to perform synchronous loading. Through the pressing blocks 2 at the top of the first dynamic pressure unit 10 and at the end of the second dynamic pressure unit 8, load the surface of the sample cable 5. Slowly apply the force, observe the compressed shape of the cross-section of the sample cable 5. After reaching the specified pressure of 36.5 kN, hold the pressure for 30 minutes. After the pressure holding is completed, unload the pressure, and use a vernier caliper to measure the maximum diameter and the minimum diameter of the sample cable 5 at the pressed place, so as to calculate the ovality after extrusion; The calculation formula for the change in the ovality of the sample cable 5 is as follows:

[0028] Wherein, e is the ovality, D is the maximum outer diameter, and d is the minimum diameter; S4. After unloading the pressure of the sample cable 5, let it stand for N hours, where N is not less than 0.5. Then, use a vernier caliper to measure the maximum diameter and the minimum diameter of the compressed part of the sample cable 5 again, so as to calculate the ovality of the sample cable 5 after standing for N hours after extrusion; The changes in ovality before, after extrusion testing, and after standing are shown in Table 1:

[0029] It can be seen that under the extrusion force of 36.5 kN, the sample cable 5 has undergone a certain degree of deformation. However, under this extrusion force condition, the deformation can be gradually restored, meeting the usage requirements; S5. Disassemble the sample cable 5 and measure the resistivity of the battery cells in the sample cable 5 and the on / off status of the optical fibers.

[0030] By measuring the resistivity of the battery cells and the on / off status of the optical fibers, the results shown in Table 2 are obtained:

[0031] It can be seen that under the extrusion force of 36.5 kN, the resistivity of the battery cells and the optical fibers are not damaged, and the compressive resistance meets the usage requirements. 36.5 kN is the maximum compressive resistance value of the sample cable. In the design of the sample cable, the extrusion force during the construction process is considered. To ensure that the sample cable can still work under compression, during the extrusion test, the extrusion load is selected as the maximum compressive resistance, that is, 36.5 kN.

[0032] In summary, an extrusion test device and test method for marine cables pointed out by the present invention can conduct extrusion tests on marine cables, improving the convenience of test operations. By measuring the changes in ovality before and after the extrusion experiment of the sample cable, the influence of extrusion on the cross-section of the sample cable is evaluated, so as to analyze the extrusion performance and engineering application scope of marine cables.

[0033] The above are only the embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. All equivalent structural or equivalent process transformations made using the content of the specification of the present invention, or directly or indirectly applied in other related technical fields, are equally included in the patent protection scope of the present invention.

Claims

1. An extrusion test device for marine cables, used to conduct extrusion tests on sample cables (5) of marine cables, characterized in that, Comprising: A gantry (3), a support member, a pressing block (2), a first dynamic pressure unit (10), a second dynamic pressure unit (8), a first static pressure unit (11) and a second static pressure unit (4). The sample cable (5) horizontally penetrates through the gantry (3). The support member is arranged at both ends of the sample cable (5) to horizontally support the sample cable (5). The first dynamic pressure unit (10), the second dynamic pressure unit (8), the first static pressure unit (11) and the second static pressure unit (4) are annularly arrayed around the sample cable (5) in the gantry (3). The pressing block (2) is respectively arranged at one end of the first dynamic pressure unit (10), the second dynamic pressure unit (8), the first static pressure unit (11) and the second static pressure unit (4) facing the sample cable (5).

2. The marine cable extrusion test device according to claim 1, characterized in that, The support member includes a supporting plate (1), a supporting rod (6) and a moving trolley (7). The supporting rod (6) is vertically arranged on the moving trolley (7), and the supporting plate (1) is horizontally arranged at the top of the supporting rod (6).

3. The marine cable extrusion test device according to claim 2, wherein, The bottom of the moving trolley (7) is provided with universal wheels with self-brakes.

4. The marine cable extrusion test device according to claim 1, wherein The first dynamic pressure unit (10) and the second dynamic pressure unit (8) respectively include a jack and a pressure sensor (9). The pressure sensor (9) is arranged at the end of the jack.

5. The marine cable extrusion test device according to claim 1, characterized in that, The first static pressure unit (11) and the second static pressure unit (4) respectively include a connecting rod.

6. The marine cable extrusion test device according to claim 1, characterized in that, The pressing block (2) is provided with an arc groove or a V-shaped groove corresponding to the outer wall of the sample cable (5).

7. The marine cable extrusion testing device according to claim 6, characterized in that, The included angle of the V-shaped groove is 120°.

8. The marine cable extrusion test device according to claim 1, characterized in that, The first dynamic pressure unit (10) is vertically arranged at the lower part of the gantry (3). The first static pressure unit (11) is vertically arranged at the top of the gantry (3) and directly above the first dynamic pressure unit (10). The second dynamic pressure unit (8) and the second static pressure unit (4) are relatively horizontally arranged on the two side walls of the gantry (3).

9. A method for extrusion testing of submarine cables, characterized in that, Using the marine cable extrusion test device according to any one of claims 1 to 8, and comprising the following steps: S1. Under the reset state of the first dynamic pressure unit (10) and the second dynamic pressure unit (8), horizontally place the sample cable (5) through the gantry (3). Both ends of the sample cable (5) are horizontally supported by the support member. Measure the maximum diameter and the minimum diameter of the sample cable (5) at the place where it is about to be pressed, and calculate the ovality before extrusion. S2. Control the stroke of the first dynamic pressure unit (10). Make the pressing block at the top of the first dynamic pressure unit (10) contact the bottom of the sample cable (5) to apply a vertical preload. Adjust the position of the sample cable (5) so that the sample cable (5) passes through the central positions of the upper and lower pressing blocks. Control the stroke of the second dynamic pressure unit (8). Make the pressing block at the end of the second dynamic pressure unit (8) contact the side of the sample cable (5) to apply a horizontal preload. Adjust the position of the sample cable (5) so that the sample cable (5) just passes through the central positions of the upper, lower, left and right four pressing blocks (2). S3. Control the first dynamic pressure unit (10) and the second dynamic pressure unit (8) to perform synchronous loading, and load the surface of the sample cable (5) through the pressure blocks (2) at the top of the first dynamic pressure unit (10) and the end of the second dynamic pressure unit (8). Slowly apply the force, observe the compressed shape of the cross-section of the sample cable (5), hold the pressure for 30 minutes after reaching the specified pressure. After the pressure holding is completed, unload the pressure, measure the maximum diameter and the minimum diameter of the compressed part of the sample cable (5), and thus calculate the ovality after extrusion; The calculation formula for the change in the ovality of the sample cable (5) is as follows: ； where e is the ovality, D is the maximum outer diameter, and d is the minimum diameter; S4. Let the sample cable (5) stand for N hours after unloading the pressure, and measure the maximum diameter and the minimum diameter of the compressed part of the sample cable (5) again, so as to calculate the ovality of the sample cable (5) after standing for N hours after extrusion; S5. Disassemble the sample cable (5) and measure the resistivity of the battery cells in the sample cable (5) and the on / off status of the optical fibers.

10. The marine cable extrusion test method according to claim 9, wherein The specified pressure is 36.5 kN, and the standing time of the sample cable (5) after unloading the pressure is not less than 0.5 hours.

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