A test method for active torsion limit of photoelectric composite umbilical

Abstract

The application discloses a kind of photoelectric composite umbilical cable active torsion limit test methods, comprising the following steps: take N section same length umbilical cable as sample, install to hydraulic horizontal tension testing machine one by one and carry out test, and the both ends of sample use load head to be fixed, one end is fixed, and the other end can rotate freely;Light power for measuring the change of fiber attenuation is injected in the one end of sample, and light monitoring device is connected in the other end of sample;Linear mark is made along the length direction in the one side of sample, and angle sensor is equipped in the rotating end of sample, load to actual working tension, then clockwise twist sample, stop rotation every certain angle and maintain tension, additional attenuation change of fiber in umbilical cable is observed in the process, until twist to specified additional attenuation value a, then anticlockwise rotation, rotate to original position and reset, additional attenuation change of fiber is observed, whether reversible is judged.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photoelectric composite umbilical testing, in particular to a test method for active torsion limit of photoelectric composite umbilical. BACKGROUND

[0002] With the accelerated development of the technology in the fields of marine scientific research, underwater detection and underwater mining, the demand for underwater equipment cables and the complexity of functions are also increasing, and the cable type used by the ROV and other underwater equipment at large depth (6.5km-11.0km) must adopt non-metallic armored technology. The mining car or ROV can continuously work in a harsh underwater environment and has become an important tool for developing the ocean. The working condition is very complex when mining in such a deep seabed, and when the mining car works on the seabed, the cable will be twisted due to the movement of the mining car itself and the seabed environment, thereby causing damage to the photoelectric unit inside the cable, and further causing problems such as the inability to control the mining car and the inability to supply power to the mining car. The most serious problem is that the cable breaks off, completely loses contact with the mining car, and causes the mining car to be lost, resulting in significant losses.

[0003] As a core component, the umbilical cable provides power for the mining car or ROV, transmits control signals from the water module and feedback signals from the underwater sensor, and the quality of the umbilical cable directly affects the stability of the mining car and ROV. With the in-depth application of the mining car and ROV in the development of offshore oil, the probability of umbilical cable failure is greatly increased due to the rotation of the umbilical cable under stress during the project operation, such as the adjustment of the heading of the mining car and ROV.

[0004] How to evaluate the torsion angle limit of the umbilical cable before it leaves the factory has attracted great attention, and it can also provide a valuable data for the mining car and ROV system, which is related to whether the umbilical cable can normally power and signal transmission at a certain limit angle during operation, and whether the umbilical cable is reversible after torsion. Since the umbilical cable is very long, it is also necessary to evaluate the transmission length of the upward torsion, etc. However, there is no good test method to verify or support these evaluation projects in the current industry. SUMMARY

[0005] The technical problem solved by the present application is to provide a test method for the active torsion limit of a photoelectric composite umbilical cable, to actively twist the photoelectric composite umbilical cable and test the torsion limit.

[0006] To solve the above technical problems, one technical solution adopted by the present application is to provide a test method for the active torsion limit of a photoelectric composite umbilical cable, comprising the following steps:

[0007] Step one: take N segments of umbilical cable as samples, install one of the samples to a hydraulic horizontal tensile testing machine, fix both ends of the sample with load heads, fix one end and rotate the other end freely, and ensure that the sample is not pulled off when the load is applied;

[0008] Step two: leave appropriate length at both ends of the sample, inject optical power to measure the change of optical fiber attenuation at one end of the sample, and connect an optical monitoring device to the other end of the sample to observe the optical fiber attenuation;

[0009] Step three: make a straight line mark along the length direction on one side of the sample to observe the angle change, and provide an angle sensor at the rotating end of the sample to monitor the change of the rotation angle, apply a uniform tension to the sample at a speed of 2-20 kN / min, load to the working tension of the actual working condition, then twist the sample clockwise, stop rotating every certain angle and maintain the tension, observe the additional attenuation change of the optical fiber in the umbilical cable in the process, until the additional attenuation value a is reached, record the corresponding rotation angle, then rotate counterclockwise, rotate to the original position for resetting, record the corresponding additional attenuation value b, observe the additional attenuation change of the optical fiber, and determine whether it is reversible;

[0010] Step four: the remaining samples are tested according to steps two and three in turn.

[0011] In a preferred embodiment of the present application, the optical monitoring device uses an optical power meter.

[0012] In a preferred embodiment of the present application, during step three, the corresponding additional attenuation value c is recorded every time the sample is twisted one turn.

[0013] In a preferred embodiment of the present application, the specified additional attenuation value a is 0.05 dB / km-0.1 dB / km.

[0014] In a preferred embodiment of the present application, during step three, when the specified additional attenuation value a is reached, observe whether the axial twisting of the sample is uniform, record the angle d twisted every 1 meter through the angle sensor, then actually measure the angle e twisted every 1 meter, compare the angle d and the angle e, and take the relatively smaller value as the single-meter twisting angle f of the single segment sample.

[0015] In a preferred embodiment of the present application, among the N segments of samples, take the minimum value of the single-meter twisting angle as the final result.

[0016] In a preferred embodiment of the present application, during step three, the sample is uniformly stretched at a speed of 2-20 kN / min, and the working tension of the actual working condition is 200 kN.

[0017] The beneficial effects of this invention are as follows: The method for testing the active torsional limit of an optoelectronic composite umbilical cable disclosed in this invention simulates actual working conditions by fixing one end of the umbilical cable and actively torsion the other end, thereby achieving the torsional limit test. The actual torsional angle and torsional transmission of the umbilical cable can be easily observed by using linear markings. Since the optical fiber is the most vulnerable unit in the umbilical cable, the determination of the torsional limit of the umbilical cable by additional attenuation monitoring of the optical fiber is more scientific. The test effect is verified by combining whether the umbilical cable can reversibly recover its original performance state after torsion. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein:

[0019] Fig. 1 This is a schematic diagram of a preferred embodiment of the test method for the active torsional limit of an optoelectronic composite umbilical cable according to the present invention;

[0020] Fig. 2 This is a schematic diagram of the steps of a preferred embodiment of the test method for the active torsional limit of an optoelectronic composite umbilical cable of the present invention;

[0021] Fig. 3 Attenuation data diagram of a preferred embodiment of the test method for the active torsional limit of an optoelectronic composite umbilical cable of the present invention. Implementation

[0022] 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, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please see Figs. 1-3 The embodiments of the present invention include:

[0024] like Fig. 2 The test method for the active torsional limit of the optoelectronic composite umbilical cable shown includes the following steps:

[0025] Step 1: Take three 60m long sections of the optoelectronic composite umbilical cable as samples, such as... Fig. 1 As shown, one of the specimens is installed on a hydraulic horizontal tensile testing machine. Both ends of the specimen are fixed with load-bearing heads. One end is fixed, while the other end can rotate freely, ensuring that the specimen is not pulled off when a load is applied.

[0026] Step 2: Leave appropriate lengths at both ends of the sample, inject optical power to measure the change in fiber attenuation into one end of the sample, and connect an optical monitoring device, such as an optical power meter, to the other end of the sample to observe the fiber attenuation.

[0027] Step 3: Mark a straight line along the length of one side of the sample to observe angle changes. An angle sensor is placed at the rotating end of the sample to monitor rotation angle changes. Apply a uniform tension to the sample at a speed of 10 kN / min, loading it to the actual working tensile force of 200 kN. Then, twist the sample clockwise, stopping rotation every 30 degrees while maintaining the tension. Observe the additional attenuation of the optical fiber in the umbilical cable during this process. Record the corresponding additional attenuation value 'c' for each twist, until the specified additional attenuation value 'a' is reached. Record the corresponding twist angle. If the recorded twist angle is 10 * 360°, i.e., the limit number of twists is 10, the attenuation situation is shown in [the original text]. Fig. 3 ;

[0028] The specified additional attenuation value 'a' is 0.05 dB / km to 0.1 dB / km. For multimode fiber, the additional attenuation value 'a' is 0.1 dB / km, and for single-mode fiber, the additional attenuation value 'a' is 0.05 dB / km. When the sample is twisted to the specified additional attenuation value 'a', observe whether the axial twist is uniform. Record the twist angle 'd' every 1 meter using an angle sensor, and then perform actual measurement to obtain the twist angle 'e' every 1 meter. Compare angle 'd' and angle 'e', ​​and take the relatively smaller value as the twist angle 'f' per meter of a single section of the sample.

[0029] Then rotate counterclockwise to the original position and reset. Record the corresponding additional attenuation value b, observe the change in the additional attenuation of the fiber, and determine whether it is reversible. If the change in additional attenuation is not significant, it is reversible within 10 turns.

[0030] Step 4: The remaining two test specimens are tested in sequence according to Step 2 and Step 3, and the minimum torsion angle per meter is taken as the final result.

[0031] In summary, the experimental method for the active torsional limit of the optoelectronic composite umbilical cable proposed in this invention simulates the actual working conditions of underwater operations in deep-sea mining. By actively applying torsion to the umbilical cable and restoring its original angle, the torsional limit test and reversibility verification are carried out. The process is scientific and has good operability.

[0032] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural or procedural transformations made based on the content of the present invention specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of the present invention.

Claims

1. A test method for the active torsional limit of an optoelectronic composite umbilical cable, characterized in that, Includes the following steps: Step 1: Take N segments of umbilical cable of the same length as samples. Install one of the samples on a hydraulic horizontal tensile testing machine. Fix both ends of the sample with a load-bearing head. Fix one end and allow the other end to rotate freely, ensuring that the sample is not pulled off when a load is applied. Step 2: Leave appropriate lengths at both ends of the sample, inject optical power to measure the fiber attenuation change into one end of the sample, and connect an optical monitoring device to the other end of the sample to observe the fiber attenuation. Step 3: Make a straight line mark along the length of one side of the sample to observe the angle change. An angle sensor is installed at the rotating end of the sample to monitor the rotation angle change. Apply tension to the sample at a uniform speed until the working tension under actual working conditions is reached. Then, twist the sample clockwise, stop rotating at certain angles and maintain the tension. Observe the additional attenuation change of the optical fiber in the umbilical cable during the process until it is twisted to the specified additional attenuation value 'a'. Record the corresponding twist angle. Then rotate counterclockwise to the original position and reset. Record the corresponding additional attenuation value 'b'. Observe the additional attenuation change of the optical fiber to determine whether it is reversible. When the specimen is twisted to the specified additional attenuation value a, observe whether the axial twist is uniform. Record the angle d of twist every 1 meter using an angle sensor, and then perform actual measurement to obtain the angle e of twist every 1 meter. Compare angle d and angle e, and take the relatively smaller value as the single-meter twist angle f of a single specimen segment. Step 4: The remaining samples are tested in sequence according to Step 2 and Step 3.

2. The test method for the active torsional limit of the optoelectronic composite umbilical cable according to claim 1, characterized in that, The optical monitoring device uses an optical power meter.

3. The test method for the active torsional limit of the optoelectronic composite umbilical cable according to claim 1, characterized in that, During step three, record the corresponding additional attenuation value c for each rotation.

4. The test method for the active torsional limit of the optoelectronic composite umbilical cable according to claim 1, characterized in that, The specified additional attenuation value 'a' is 0.05 dB / km to 0.1 dB / km.

5. The test method for the active torsional limit of the optoelectronic composite umbilical cable according to claim 1, characterized in that, In the N-segment specimen, the minimum torsion angle per meter is taken as the final result.

6. The test method for the active torsional limit of the optoelectronic composite umbilical cable according to claim 1, characterized in that, In step three, the sample is subjected to tension at a constant speed of 2~20kN / min, and the load is increased to the working tensile force of 200kN under actual working conditions.

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