CN111292884B - Submarine cable - Google Patents

Abstract

The invention belongs to the field of cables, and particularly relates to a submarine cable. It includes: the inner core pipe and the outer sheath are tightly coated outside the inner core pipe; the cross section of the outer sheath is oval, and the cross section of the inner core pipe is rectangular; the inner core pipe consists of an inner sheath, an I-shaped framework and a plurality of core wires; the upper end face and the lower end face of the I-shaped framework are arranged in parallel to the long axis of the oval outer sheath, and the upper end face and the lower end face of the I-shaped framework are abutted against the side wall of the inner sheath. The submarine cable has good pressure resistance, can reduce the compression deformation generated under the condition of huge water pressure, realizes good protection effect on the internal transmission line, has certain bending resistance and improves the protection effect on optical fibers or conductive wires.

Description

Submarine cable

Technical Field

The invention belongs to the field of cables, and particularly relates to a submarine cable.

Background

Submarine cables (submarine cables) are cables wrapped with insulating materials and laid on the sea floor for telecommunication transmission. In 1850 the first submarine cable in the world was laid between garley (france) and polyfluory (uk), and the first submarine cable in china was completed in 1888.

With the development of the times, the demand for submarine cables has changed gradually, and the current submarine cables not only meet the requirement of transmitting electric power, but also partially need to realize the function of transmitting optical signals, i.e. derivatives such as submarine optical cables and submarine optical cables, which are collectively called submarine cables, and are called submarine cables for short.

In order to meet the requirement of submarine transmission of optical signals, the optical fiber is more fragile than a conducting wire, so that the quality requirement of submarine cables is further improved.

Disclosure of Invention

The invention provides a submarine cable, aiming at solving the problems that the existing submarine cable has limited pressure resistance, is easy to damage and malfunction after long-term use or when being laid on an excessively deep seabed, and even cannot transmit photoelectric signals due to insufficient pressure resistance. The invention aims to: firstly, the pressure resistance of the submarine cable is improved; secondly, the submarine cable has certain bending resistance.

In order to achieve the purpose, the invention adopts the following technical scheme.

A submarine cable comprising:

the inner core pipe and the outer sheath are tightly coated outside the inner core pipe;

the cross section of the outer sheath is oval, and the cross section of the inner core pipe is rectangular;

the inner core pipe consists of an inner sheath, an I-shaped framework and a plurality of core wires;

the upper end face and the lower end face of the I-shaped framework are arranged in parallel to the long axis of the oval outer sheath, and the upper end face and the lower end face of the I-shaped framework are abutted against the side wall of the inner sheath.

Further, in the present invention,

the outer sheath is provided with an arch-shaped groove at each end of the inner core pipe along the long axis of the ellipse;

the arched groove is arched towards the outer side, and the bottom of the arched groove is tangent to the inner core pipe;

the arch-shaped groove is filled with functional filler, and the functional filler is water-saturated loose sandy soil or pressure gel.

Further, in the present invention,

the pressure gel is SAP gel which is saturated and adsorbed with silicon dioxide dispersion liquid;

the silicon dioxide dispersion liquid is prepared by ultrasonically mixing loose silicon dioxide, anhydrous ethanol with the volume of 1.65-1.7 times of that of the loose silicon dioxide and butanediol with the volume of 1.55-1.6 times of that of the loose silicon dioxide.

Further, in the present invention,

stainless steel braided wires are further arranged between the inner sheath and the outer sheath.

Further, in the present invention,

and a filling rope is arranged in a gap inside the inner sheath.

Further, in the present invention,

and coating or extruding water-blocking paint outside the outer sheath to form a water-blocking layer.

Further, in the present invention,

the core wire is formed by tightly wrapping a plurality of non-woven fabric wrapping belts outside the transmission wire;

the transmission line is an optical fiber or a conductive wire.

The invention has the beneficial effects that:

1) the submarine cable has good pressure resistance, can reduce the compression deformation generated under the condition of huge water pressure, and realizes good protection effect on the internal transmission line;

2) has certain bending resistance and improves the protection effect on optical fibers or conductive wires.

Drawings

FIG. 1 is a schematic structural view of the present invention;

fig. 2 is a schematic view of a testing process of the submarine cable according to the present invention.

In the figure: the test device comprises an outer sheath 1, an arch-shaped groove 101, an inner core pipe 2, an inner sheath 201, an I-shaped framework 202, a core wire 203, a 2031 transmission line, a 2032 non-woven fabric belting, a 3 water-blocking layer, 4 functional fillers, 5 stainless steel braided wires, 6 filling ropes, 7 test devices and 8 warm saline water.

Detailed Description

The invention is described in further detail below with reference to specific embodiments and the attached drawing figures. Those skilled in the art will be able to implement the invention based on these teachings. Moreover, the embodiments of the present invention described in the following description are generally only some embodiments of the present invention, and not all embodiments. Therefore, all other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative effort shall fall within the protection scope of the present invention.

Unless otherwise specified, the raw materials used in the examples of the present invention are all commercially available or available to those skilled in the art; unless otherwise specified, the methods used in the examples of the present invention are all those known to those skilled in the art.

Examples

A submarine cable as shown in fig. 1 and 2, comprising:

the section of the outer sheath 1 is oval, the section of the inner core pipe 2 is a rounded rectangle, the outer sheath 1 is tightly coated outside the inner core pipe 2, and when the inner core pipe 2 is the rounded rectangle, the oval long axis of the outer sheath 1 is parallel to the long edge of the rounded rectangle, in the embodiment, a rounded square is taken as an example;

the inner core tube 2 is composed of an inner sheath 201, an I-shaped framework 202 and a plurality of core wires 203, the core wires 203 are formed by tightly wrapping a plurality of non-woven fabric wrapping tapes 2032 outside the transmission line 2031, and the transmission line 2031 is an optical fiber or a conductive wire, plays a role in transmitting optical signals or electric power and is a main functional wire;

the upper end face and the lower end face of the I-shaped framework 202 are arranged in parallel to the long axis of the oval outer sheath 1, the upper end face and the lower end face of the I-shaped framework 202 abut against the side wall of the inner sheath 201 to realize abutting support on the inner sheath 201, the core wires 203 are provided with even numbers and are uniformly distributed on two sides of the I-shaped framework 202, and the filling ropes 6 are arranged in gaps inside the inner sheath 201;

the I-shaped framework 202 supports the inner sheath 201 and then forms good cooperation with the oval outer sheath 1, in the conventional circular submarine cable, external forces applied in all directions in its cross-section are almost equal, namely, the outer surface of the cable bears larger external pressure, so that the conventional submarine cable needs to be protected by arranging thicker metal armor outside the cable to protect the structures such as the inner core wire 203 and the like, the cable is prevented from generating serious distortion deformation, collapse or even direct fracture due to high pressure at the seabed, the circular cable has poorer anti-distortion capability from the structural aspect, and the stress in each direction is similar and larger, the irregular compression deformation is easy to generate to cause the collapse and damage of the internal structure, therefore, the performance of the cable is reduced, even the cable fails and is broken, the twisting strength of the cable with the oval structure is higher than that of a round cable, and a certain twisting resistance effect is improved;

in the technical scheme of the invention, firstly, the outer sheath 1 is under the action of strong pressure generated by high pressure at the sea bottom, the outer sheath 1 is in an oval shape, for convenience of description, the force applied to the outer sheath is simply divided into a longitudinal pressure F1 and a transverse pressure F2, and the pressure applied to the surface of the cable, namely all the positions on the surface of the outer sheath 1 is basically equal, so that simple calculation can be carried out, as shown in figure 1, the longitudinal pressure F1 applied to the outer sheath is obviously greater than the transverse pressure F2, under the condition that the longitudinal pressure and the transverse pressure have different magnitudes, the oval outer sheath 1 firstly deforms to a certain extent, the deformation trend of the oval outer sheath 1 is gradually flattened, namely the major axis of the oval outer sheath increases and the minor axis of the oval outer sheath shortens until the oval outer sheath is flat, and if the inner core tube 2 is a conventional round tube or an oval tube matched with the oval outer sheath 1, the inner core tube 2 can also deform to adapt to the deformation of the oval outer sheath 1, the core wire 203 in the inner core tube 2 is squeezed and even breaks, but the invention is specially selected to be the rectangular, especially the round-corner rectangular inner core tube 2, mainly because when the rectangle is stressed, firstly the straight side part of the rectangle is easy to deform, but the round-corner part is not easy to deform, therefore, the round-corner rectangular inner core tube 2 is arranged in the elliptic outer sheath 1, firstly the stability of the shape structure of the inner core tube 2 can be ensured, secondly, because the rectangular inner core tube 2 has unequal stress in the horizontal direction and the longitudinal direction, the stress difference is generated, as shown in figure 1, under the condition that the longitudinal pressure is larger than the transverse pressure, the round-corner rectangular inner core tube 2 generates the tendency of being crushed, so that the two horizontal sides generate the deformation force F3 pushed outwards, the deformation force F3 pushed outwards is offset with the transverse pressure F2 on the outer sheath 1 to a certain extent, the source of the deformation force F3 which is pushed outwards is the difference between the longitudinal pressure F1 and the transverse pressure F2, so that the longitudinal pressure F1 and the transverse pressure F2 which are applied to the cable can be offset to a certain extent through the structure, and the deformation force generated inside the cable structure can be offset from the external pressure through the condition of different pressures in all directions, so that the stability of the cable structure is ensured, the material requirement of the cable can be effectively reduced, and a good protection effect is generated on the core wire 203 inside the inner core tube 2;

because the longitudinal pressure F1 that the cable receives is greater than the transverse pressure F2 all the time, in order to further avoid the problem that the cable is damaged due to overlarge pressure difference, the I-shaped framework 202 is arranged to support the inner core tube 2 in the longitudinal direction, so that the structure of the cable can be prevented from being damaged, the longitudinal pressure that the cable receives can be further counteracted, and the structural integrity of the cable is ensured;

the outer sheath 1 is provided with an arch-shaped groove 101 at each end of the inner core tube 2 along the long axis of the ellipse, the arch-shaped grooves 101 are arched towards the outer side, and the bottoms of the arch-shaped grooves are tangent to the inner core tube 2;

the arch-shaped groove 101 is filled with functional filler 4, and the functional filler 4 is water-saturated loose sandy soil or pressure gel;

the pressure gel is SAP gel which is saturated and adsorbed with silicon dioxide dispersion liquid, the silicon dioxide dispersion liquid is prepared by ultrasonically mixing loose silicon dioxide, 1.65-1.7 times of volume of absolute ethyl alcohol and 1.55-1.6 times of volume of butanediol, and the silicon dioxide is silicon dioxide aerogel powder;

the silicon dioxide dispersion liquid has unique dilatancy, namely, the silicon dioxide dispersion liquid generates an effect similar to expansion under the action of internal shearing force generated by external pressure or directly receives the action of external shearing force, the viscosity is increased rapidly to generate hardening, and the silicon dioxide dispersion liquid can be used for absorbing the force acted on the silicon dioxide dispersion liquid by the outside to generate the effects of hardening and solidifying;

the loose sandy soil is similar to pressure gel formed by SAP gel which is saturated and adsorbed with silicon dioxide dispersion liquid, and has the effect of hardening when being subjected to external force action to a certain degree, so that the problem that the cable is deformed and damaged due to pressure difference in all directions of the outer sheath 1 can be further avoided, the density of the whole cable can be improved to a certain degree, and the stability of the cable laid on the seabed can be improved;

the stainless steel braided wire 5 is arranged between the inner sheath 201 and the outer sheath 1, the stainless steel braided wire 5 can further improve the structural stability and strength of the whole cable, a certain protection effect is generated on the inner sheath 201, fish biting damage of the submarine cable in the laying and using process can be reduced or even avoided, the damage rate of the submarine cable is reduced, and the service life of the submarine cable is prolonged;

and a water-blocking coating is coated or extruded outside the outer sheath 1 to form a water-blocking layer 3.

The pressure simulation test is carried out on the submarine cable, the submarine cable with the length of 1.5m and the two sealed ends is placed in a deep sea environment simulation hydrostatic test device 7(HSU-1301-J-20) for pressure test, the test is carried out according to a basic environment test method hydrostatic test HY 016.15-1992, the test schematic diagram is shown in fig. 2, the submarine cable is arranged in the test device 7, warm saline water 8 is injected, the same submarine cable is subjected to pressure test under the pressure condition of 1-10 MPa for 72h, and the test results are shown in the following table 1.

Table 1: and (5) simulating a test result by using pressure.

HSU-1301-J-20 pressure (MPa)	Submarine cable is relieved of pressure and taken out for observation and transmission test
		1.0	The outer wrapper is complete, the cross section appearance is kept as the original shape, and the transmission is normal
1.5	The outer wrapper is complete, the cross section appearance is kept as the original shape, and the transmission is normal
		2.5	The outer wrapper is complete, the cross section appearance is kept as the original shape, and the transmission is normal
5.0	The outer wrapper is complete, the cross section appearance is kept as the original shape, and the transmission is normal
		8.0	The outer wrapper is complete, the cross section appearance is kept as the original shape, and the transmission is normal
10.0	The outer wrapper is complete, the cross section appearance is kept as the original shape, and the transmission is normal

The test results show that the submarine cable can keep the structural and functional high integrity under the submarine high pressure condition, and the cross section of the cable can be restored to the original shape after the pressure is relieved, which indicates that the submarine cable is still in the recoverable elastic deformation range, and indicates that the integral pressure-bearing capacity is stronger.

A commercially available conventional round submarine cable (light guide cable) is selected as a comparative example, the diameter of the conventional round submarine cable is equal to the major axis of the submarine cable, the commercially available conventional round submarine cable and the submarine cable are sent to a certain research institute to be subjected to an ultra-high voltage test of 30-50 MPa, the ultra-high voltage test is carried out according to the steps, and the test results are shown in the following table 2.

Table 2: and (5) simulating a test result by ultrahigh pressure.

As can be seen from the results of the ultrahigh pressure simulation test, the submarine cable according to the present invention is significantly superior in the resistance to high pressure in the sea bottom and can withstand higher water pressure, compared to the conventional circular submarine cable on the market.

Claims (5)

1. A submarine cable, comprising:

the inner core pipe and the outer sheath are tightly coated outside the inner core pipe;

the cross section of the outer sheath is oval, and the cross section of the inner core pipe is rectangular;

the inner core pipe consists of an inner sheath, an I-shaped framework and a plurality of core wires;

the upper end surface and the lower end surface of the I-shaped framework are arranged in parallel to the long axis of the oval outer sheath, and the upper end surface and the lower end surface of the I-shaped framework are abutted against the side wall of the inner sheath;

the outer sheath is provided with an arch-shaped groove at each end of the inner core pipe along the long axis of the ellipse;

the arched groove is arched towards the outer side, and the bottom of the arched groove is tangent to the inner core pipe;

the arch-shaped groove is filled with functional filler, and the functional filler is water-saturated loose sandy soil or pressure gel;

the pressure gel is SAP gel which is saturated and adsorbed with silicon dioxide dispersion liquid;

the silicon dioxide dispersion liquid is prepared by ultrasonically mixing loose silicon dioxide, anhydrous ethanol with the volume of 1.65-1.7 times of that of the loose silicon dioxide and butanediol with the volume of 1.55-1.6 times of that of the loose silicon dioxide.

2. Submarine cable according to claim 1,

stainless steel braided wires are further arranged between the inner sheath and the outer sheath.

3. Submarine cable according to claim 1,

and a filling rope is arranged in a gap inside the inner sheath.

4. Submarine cable according to claim 1,

and coating or extruding water-blocking paint outside the outer sheath to form a water-blocking layer.

5. Submarine cable according to claim 1,

the core wire is formed by tightly wrapping a plurality of non-woven fabric wrapping belts outside the transmission wire;

the transmission line is an optical fiber or a conductive wire.

Images