High-strength lightning-stroke-resistant optical fiber composite overhead ground wire and preparation process thereof

Abstract

The invention discloses a high-strength lightning-stroke-resistant optical fiber composite overhead ground wire and a preparation process thereof. The preparation process comprises the following steps: carrying out looping and coloring pretreatment on a plurality of optical fibers; introducing the optical fiber and the fiber paste into extrusion molding equipment together, extruding to form a polymer protection tube wrapping the optical fiber, and performing vacuum shaping and graded cooling to obtain a central optical unit; melting an aluminum rod and coating the central optical unit with the aluminum rod to obtain an aluminum-coated optical unit; and stranding the six galvanized steel monofilaments and the four aluminum-clad steel wires around the aluminum-clad optical unit by using stranding equipment with a back-twisting function to obtain the high-strength lightning-stroke-resistant optical fiber composite overhead ground wire. According to the invention, the lightning stroke resistance and short-circuit current bearing capacity of the OPGW are remarkably improved, the long-acting corrosion resistance is realized, the ultrahigh mechanical strength and structural stability are ensured, the excellent communication transmission performance is ensured, the performance weakness of the traditional OPGW in a special environment is comprehensively broken through, and the strict use requirements of coastal and thunder areas are met.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of optical fiber composite overhead ground wires, in particular to a high-strength lightning-resistant optical fiber composite overhead ground wire and a preparation process. BACKGROUND

[0002] With the irreplaceable advantages of fast transmission speed, small signal loss, strong anti-electromagnetic interference ability and high information transmission security, optical fiber communication technology has become the preferred technical solution for constructing the backbone network of power grid information communication. As a special power cable that organically combines the functions of optical fiber communication and overhead ground wire lightning protection and mechanical load bearing, the optical fiber composite overhead ground wire (OPGW) can not only replace the traditional overhead ground wire to realize lightning protection for the power transmission line, but also can simultaneously complete the large-capacity data transmission within the power system and across the system, so it has been widely applied in high-voltage and ultra-high-voltage power transmission lines worldwide.

[0003] However, in the coastal areas and thunderstorm areas worldwide, the operating environment of OPGW faces severe challenges: on the one hand, the high-salt-mist and high-humidity environment in the coastal areas can cause strong corrosion to the metal structure of OPGW, resulting in the decrease of mechanical strength, the deterioration of electrical conductivity and the shortening of service life; on the other hand, the frequent lightning strikes in the thunderstorm areas can produce strong impact current, and if the lightning resistance of OPGW is insufficient, it may cause the interruption of optical fiber signal, affect communication transmission, or even cause the melting of the metal armor layer of OPGW, structural damage, and further cause the failure of the power transmission line, thereby posing a great threat to the safe and stable operation of the power system.

[0004] In the prior art, although there are some related researches on the performance optimization of OPGW, the existing solutions often only optimize the single performance or part of the performance of OPGW, and fail to form a collaborative improvement design for the multi-dimensional performances such as high strength, lightning resistance, corrosion resistance and large current capacity: for example, although the use of stainless steel coating can improve the corrosion resistance and optical fiber protection effect, the current carrying capacity of the overall cable body and the short-circuit current carrying capacity after lightning resistance are still insufficient; only relying on aluminum pipe coating and aluminum-clad steel wire armor, the long-term durability in the coastal high-corrosion environment is difficult to meet the requirements, and the structural stability under strong lightning impact still needs to be further improved.

[0005] Therefore, there is an urgent need for an OPGW preparation process and the corresponding product that can comprehensively solve the special environmental requirements in coastal and thunderstorm areas, realize the collaborative improvement of high strength, excellent lightning resistance, good corrosion resistance and large short-circuit current capacity, so as to meet the high performance requirements of OPGW for overhead communication in coastal and thunderstorm areas worldwide. SUMMARY

[0006] The application aims to provide a high-strength lightning-resistant optical fiber composite overhead ground wire and a preparation process, which are prepared by optimizing material selection, structure design and production process, and have high strength, excellent lightning-resistant performance, good corrosion resistance and large short-circuit current capacity, thereby meeting the high-performance requirements of overhead communication optical cables in coastal areas (high salt mist, high corrosion environment) and thunderstorm areas (high frequency lightning, strong impact current scene) worldwide, and solving the problems of insufficient operation stability and short service life of existing OPGW in special environments.

[0007] The above-mentioned purpose of the application is achieved by the following technical scheme:

[0008] A preparation process of a high-strength lightning-resistant optical fiber composite overhead ground wire, comprising the following steps:

[0009] (1) The multiple optical fibers are ringed and color-spectrum colored to obtain pretreated optical fibers;

[0010] (2) The pretreated optical fibers obtained in step (1) and the fiber paste are introduced into an extrusion device together, the wire tension is controlled, the high-molecular protective tube covering the optical fibers is extruded, and the center optical unit is obtained through vacuum setting and staged cooling;

[0011] (3) The aluminum rod is cleaned and extruded and melted, and is covered outside the center optical unit obtained in step (2), and the aluminum-covered optical unit is prepared through a dancing wheel and a traction device;

[0012] (4) The six galvanized steel filaments and the four aluminum-clad steel wires are twisted around the aluminum-covered optical unit prepared in step (3) by using a twisting device with a twist-off function to obtain the high-strength lightning-resistant optical fiber composite overhead ground wire.

[0013] The high-strength lightning-resistant OPGW provided by the application has multi-dimensional performance advantages. Firstly, in terms of structure protection and mechanical properties, the whole has high lateral pressure resistance and impact resistance, which can effectively resist the damage of external mechanical force to the cable structure. In terms of material function design, the OPGW not only has low conductivity, but also has high mechanical strength and excellent corrosion resistance, which can provide stable and reliable protection for the internal optical fibers and avoid damage of the optical fibers due to external environmental erosion or mechanical impact. At the same time, through the aluminum tube cladding structure design, the high conductivity of the aluminum tube is utilized to significantly improve the current carrying capacity of the OPGW. In addition, the whole cable is armored with aluminum-clad steel wires with high conductivity and high tensile strength. The armor layer not only bears the main force unit function of the whole cable, ensures the structural stability and mechanical bearing capacity of the OPGW in the overhead laying scene, but also effectively improves the lightning-resistant performance and short-circuit current melting resistance of the whole cable, and finally realizes the core effect of increasing the short-circuit current capacity of the whole cable.

[0014] Further, in step (1), the plurality of optical fibers are 24-core G652D optical fibers.

[0015] Further, in step (1), the ring marking is achieved by an ink jet printing device.

[0016] Further, in step (1), the color system of the color spectrum includes blue, orange, green, brown, gray, white, red, black, yellow, purple, pink, and cyan.

[0017] Further, in step (1), the color spectrum coloring uses a coloring mold, the inlet mold hole diameter of the coloring mold is 0.260-0.280 mm, and the outlet mold hole diameter is 0.250-0.260 mm; after coloring, the attenuation performance of the optical fiber meets: 1310 nm window ≤0.330 dB / km, and 1550 nm window ≤0.190 dB / km.

[0018] If the inlet mold hole diameter is less than 0.260 mm, it will cause excessive resistance of the optical fiber passing through the mold, easily causing damage to the optical fiber during stretching, affecting the transmission attenuation performance; if it is greater than 0.280 mm, it will cause uneven thickness of the colored layer, and local thin-thick deviation, reducing the protection effect. If the outlet mold hole diameter is less than 0.250 mm, it will excessively extrude the colored layer, causing the colored layer to crack after solidification; if it is greater than 0.260 mm, it will cause the colored layer not to be tightly attached to the optical fiber, and easily cause delamination in the subsequent extrusion process.

[0019] Further, in step (2), the wire laying tension is controlled by a weight counterbalance through a main motor wire laying device.

[0020] The main motor can realize synchronous matching of the wire laying speed and the extrusion speed, avoiding stretching or relaxation of the optical fiber due to speed difference; the weight counterbalance can accurately adjust the tension size (conventional control is 50-70 g), if the tension is too small, the optical fiber is easy to deviate during the extrusion process, causing uneven thickness of the polymer protection tube wall; if the tension is too large, it will cause permanent tensile deformation of the optical fiber, increase the transmission attenuation, and even break.

[0021] Further, in step (2), the fiber paste is heated to 110-130 ℃ and introduced into the extrusion equipment through an integrated introduction device together with the optical fiber.

[0022] The fiber paste, as a waterproof sealant of the central optical unit, can reduce the viscosity after heating, ensuring that it can uniformly fill the gap (0.2-0.3 mm) between the optical fiber and the polymer protection tube, forming a complete waterproof barrier.

[0023] Further, in step (2), the polymer protection tube is a polyether ether ketone (PEEK) tube.

[0024] PEEK material has the characteristics of high temperature resistance, acid and alkali corrosion resistance, mechanical strength, etc. Compared with traditional polyethylene (PE) or polypropylene (PP) material, it can prolong the service life in coastal high salt mist environment, and can resist mechanical impact (such as bird pecking, cable collision caused by wind load) during overhead laying.

[0025] Further, in step (2), the extrusion equipment is a single screw extruder, and the PEEK particles are dried at 140-160 ℃ for 3-4 hours before extrusion to reduce the water content to below 0.02%; the process parameters of the single screw extruder are set as follows: the maximum heating temperature of the barrel heater is 400±2 ℃, the working temperature of the barrel is 350-390 ℃, the screw bore temperature is 350±2 ℃, the flange temperature is 380±2 ℃, and the head temperature is 390±2 ℃; the extrusion mold specification is 6 / 7.5 mm, and the mold sleeve hole diameter is 11-13 mm.

[0026] Further, in step (2), the process parameters of the staged cooling are as follows: the cooling oil temperature is 130±20 ℃, and the hot water cooling temperature is 90±5 ℃.

[0027] Staged cooling can avoid the internal stress concentration of PEEK pipe due to excessive temperature difference, which leads to pipe cracking. If the cooling oil temperature is lower than 110 ℃, the PEEK pipe surface will be quickly cooled and solidified, and the internal heat cannot be released in time, forming a "hard outside and soft inside" structure, which is prone to deformation during subsequent cooling shrinkage; if it is higher than 150 ℃, the cooling speed is too slow, which will lead to poor PEEK pipe shaping effect and easy bending. If the hot water cooling temperature is lower than 85 ℃, the PEEK pipe will not be fully crystallized, and the mechanical strength will be insufficient; if it is higher than 95 ℃, the cooling time will be prolonged, and the production efficiency will be reduced.

[0028] Further, in step (2), the outer diameter of the high polymer protection pipe after cooling is 3.5±0.1 mm, and the excess length of the optical fiber in the pipe is 2.5-3.5‰. If the excess length is too small, the OPGW will be easily broken when stretched during overhead laying; if the excess length is too large, the optical fiber will be bent in the pipe, which will increase the transmission attenuation.

[0029] Further, in step (2), the outer diameter of the center optical unit is 3.5±0.1 mm.

[0030] The present application is designed according to the characteristics of PEEK material, and the process parameter system of the whole process of "140-160 DEG C drying + 350-390 DEG C extrusion + 110-150 DEG C oil cooling + 85-95 DEG C water cooling" is designed to solve the problem of bubble and internal stress cracking of PEEK material extrusion molding; at the same time, the excess length of optical fiber is accurately controlled to be 2.5-3.5 ‰, the tensile properties of OPGW and the transmission properties of optical fiber are balanced, and the problem of optical fiber fracture or attenuation increase caused by improper control of excess length in the prior art is avoided. In addition, the process of dancing wheel tension adjustment and traction speed matching in the aluminum layer coating process ensures the uniformity of the aluminum layer coating.

[0031] Further, in step (3), the outer diameter of the aluminum-coated optical unit is 7.2±0.2 mm. If the outer diameter is less than 7.0 mm, the thickness of the aluminum layer is insufficient, and the conductivity and protection performance are reduced; if it is greater than 7.4 mm, it will increase the weight of the whole cable, and at the same time, it will cause uneven gap between single filaments during subsequent outer layer stranding.

[0032] The introduction of the aluminum pipe not only provides a second mechanical protection for the central optical unit, but also improves the short-circuit current carrying capacity of the whole cable by taking advantage of the high conductivity of aluminum, laying a foundation for optimizing the lightning resistance performance.

[0033] A specific gap is required between the PEEK pipe and the aluminum pipe, which can avoid adhesion between the two during processing: on the one hand, it can prevent adhesion from causing PEEK pipe shaking, thereby avoiding increased transmission attenuation of optical fibers due to stress fluctuations; on the other hand, it can eliminate excessive stress on the optical fibers caused by adhesion, reducing the risk of broken fibers. At the same time, when the construction is strung, the reserved gap can provide space for the PEEK pipe, so that the optical fiber does not directly bear external force when the cable body is stretched or bent, further ensuring the integrity of the optical fiber and avoiding fiber breakage.

[0034] Further, in step (3), it also includes performance detection of the aluminum-coated optical unit, including the uniformity, continuity of the aluminum pipe and the attenuation performance of the internal optical fiber. Poor uniformity of the coating can cause the local aluminum layer to be too thin and be easily broken by lightning; poor continuity (such as broken belt and poor lap joint) can cause interruption of current transmission, and short-circuit current diversion cannot be achieved; internal optical fiber attenuation detection can timely find the damage to the optical fiber caused by improper tension control during the aluminum layer coating process, and avoid unqualified semi-finished products flowing into the subsequent process.

[0035] Further, in step (4), the galvanized steel wire is a G3A type galvanized steel wire, and the outer diameter of the galvanized steel wire is 3.0-3.2 mm; the outer diameter of the aluminum-coated steel wire is 3.0-3.2 mm.

[0036] Further, in step (4), the galvanized steel filaments and the aluminum-clad steel wires are arranged at intervals. The arrangement at intervals can complement the performance advantages of the two types of filaments, forming a three-dimensional protection system of “strength-conductivity-corrosion”, and compared with a single material twisted layer, can improve the lightning resistance performance and overall tensile force.

[0037] Further, in step (4), the twisting device is a cage twisting device, and the outer layer twisting pitch is 155-175 mm and the twisting rate is 1.85%-2.05% during twisting.

[0038] Further, in step (4), the outer diameter of the high-strength lightning-resistant optical fiber composite overhead ground wire is 13-14 mm.

[0039] The application also protects the high-strength lightning-resistant optical fiber composite overhead ground wire obtained by the above preparation process.

[0040] Further, the high-strength lightning-resistant optical fiber composite overhead ground wire comprises a central optical unit, an aluminum pipe and an outer layer twisted unit; the central optical unit is composed of 24-core G652D optical fibers, a polyether ether ketone pipe and a fiber paste; the aluminum pipe is wrapped outside the central optical unit; and the outer layer twisted unit is 6 galvanized steel filaments and 4 aluminum-clad steel wires twisted at intervals around the aluminum pipe.

[0041] The central optical unit is the core carrier of signal transmission, and the PEEK pipe and the fiber paste form a double protection, which can isolate the influence of water vapor and dust on the optical fiber, and ensure stable transmission performance without fluctuation in long-term operation; the aluminum pipe has the functions of electricity conduction, protection and structural support, and can shunt lightning current and short-circuit current, while isolating external water vapor and corrosive medium; and the 6 galvanized steel filaments and the 4 aluminum-clad steel wires twisted at intervals are the key guarantee for the mechanical strength and lightning resistance performance of the whole cable.

[0042] Further, the optical fiber attenuation performance of the high-strength lightning-resistant optical fiber composite overhead ground wire meets: ≤0.340 dB / km at a 1310 nm window, and ≤0.200 dB / km at a 1550 nm window, which can ensure the minimization of signal loss in long-distance communication.

[0043] Further, the electrical performance of the high-strength lightning-resistant optical fiber composite overhead ground wire meets: ≤0.617 Ω / km of direct current resistance, and low resistance can reduce current transmission loss and improve short-circuit current carrying capacity.

[0044] Further, the mechanical performance of the high-strength lightning-resistant optical fiber composite overhead ground wire meets: ≥98.87 kN of overall tensile force, which can resist mechanical external forces such as wind load and ice load during overhead laying, and avoid cable breakage.

[0045] Further, the lightning resistance performance of the high-strength lightning-resistant optical fiber composite overhead ground wire meets the test of at least 300 A current for 0.5 s and 150 C transferred charge (GB / T 7424.4-2003), and the residual tensile breaking force of the whole cable after lightning strike is not less than 0.75 times the rated tensile breaking force (RTS), which greatly reduces the risk of communication interruption caused by lightning in a lightning area, and ensures the continuous and stable operation of the power grid communication backbone network. Compared with the existing OPGW, the structure stability of the high-strength lightning-resistant OPGW provided by the application is more excellent after lightning strike, and the communication function can be quickly restored.

[0046] Advantages of the application:

[0047] 1. The application breaks through the limitation of the traditional OPGW center tube using PE / PP material and single material of the outer monofilament, selects PEEK material as the core material of the center tube, uses the characteristics of high temperature resistance, strong corrosion resistance and high mechanical strength to solve the problem of easy aging and corrosion of the center tube in the coastal high salt mist environment, and simultaneously uses the composite metal system of "aluminum pipe + galvanized single wire + aluminum clad steel wire" to realize the synergistic improvement of the conductivity, mechanical strength and corrosion resistance.

[0048] 2. The application constructs a four-layer protection structure of "optical fiber-PEEK tube-aluminum layer-galvanized single wire / aluminum clad steel wire", each layer of structure independently bears a specific function (such as PEEK tube corrosion resistance, aluminum layer conductivity, and outer monofilament tensile resistance), and forms an integrated system of "protection-conduction-bearing". The interval twisting design of the outer 6 galvanized single wires and the 4 aluminum clad steel wires optimizes the proportioning of the two kinds of monofilaments, greatly improves the current shunt capacity while ensuring the mechanical strength, and solves the performance contradiction that the existing OPGW cannot simultaneously have high strength and high conductivity.

[0049] 3. The application realizes long-acting corrosion resistance, guarantees ultra-high mechanical strength and structural stability, and ensures excellent communication transmission performance through the synergistic innovation of material selection, structure design and process optimization, and breaks through the performance short board of the traditional OPGW in special environment in all directions, and meets the harsh use requirements in coastal and lightning areas. BRIEF DESCRIPTION OF DRAWINGS

[0050] Figure 1 is a structural schematic diagram of the high-strength lightning-resistant optical fiber composite overhead ground wire of embodiment 1. DETAILED DESCRIPTION

[0051] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0052] The present application will be further described with reference to the drawings and specific examples in order to provide a better understanding of the present application and enable its practice by others skilled in the art. The examples are not intended to be limiting of the present application.

[0053] The experimental methods used in the following examples are conventional unless otherwise specified, and the materials, reagents, etc. used are commercially available unless otherwise specified. In the following examples, the imported high-temperature-resistant fiber paste is an Info-Gel hydrogen-absorbing fiber paste from Ireland. In the following examples, the A2-X aluminum rod is purchased from Jiangsu Hengtong Power Special Conductor Co., Ltd., the 3.1 mm galvanized steel wire is purchased from Zhejiang Guanming New Material Co., Ltd., and the 4.55 mm quenched steel wire is purchased from Huangshan Chuangxiang Technology Co., Ltd.

[0054] In the following examples, the 3.1 mm aluminum-clad steel wire is prepared by the following method: a high-strength quenched steel wire with an outer diameter of 4.55 mm is selected, and the surface is first treated by cleaning to remove the oxidation layer and impurities; then the steel wire is heated to 450°C, so that the surface appears reddish brown. At the same time, the surface of the A2-X 9.5 mm electrical round aluminum rod is cleaned, and after cleaning, it is melted under the action of the extrusion wheel, the molten aluminum liquid fills the mold cavity, and is uniformly coated on the surface of the pretreated steel wire, and finally an aluminum-clad steel rod with an outer diameter of 5.2 mm is prepared. Before drawing the aluminum-clad steel rod, the mold is matched according to the target single wire model LB20-3.1 mm; during the drawing process, the aluminum-clad steel rod with an outer diameter of 5.2 mm is drawn into a 3.1 mm aluminum-clad steel wire through the coordinated cooperation of the pressure die, the drawing die and the drawing powder. The tensile testing machine test shows that the strength of the aluminum-clad steel wire is 1420 MPa.

[0055] In the following examples, the performance of the metal wire / rod is tested, and the mechanical properties are tested by a conventional tensile testing machine, and the electrical properties are measured by a conventional resistance bridge device.

[0056] Example 1

[0057] A preparation process of a high-strength lightning-resistant optical fiber composite overhead ground wire includes the following steps:

[0058] (1) Fiber pretreatment: select 24-core G652D optical fiber, distinguish each optical fiber by ink jet equipment, color processing according to blue, orange, green, brown, gray, white, red, yellow, purple, pink, cyan; the color process adopts special coloring mold, the inlet mold hole diameter is 0.270 mm, the outlet mold hole diameter is 0.255 mm, and the coloring layer is ensured to be well cured through ultraviolet curing, and the pretreated optical fiber is obtained. After testing, the attenuation of the colored optical fiber is 0.300 dB / km at 1310 nm window, and the attenuation is 0.185 dB / km at 1550 nm window.

[0059] (2) PEEK tube extrusion molding: the pretreated optical fiber is installed on the optical fiber pay-off rack in order, the pay-off speed is controlled by the driving motor pay-off device, and the pay-off tension is stably controlled to 50 g by the weight counterweight method; select PEEK particles as raw materials, dry in a 150 ℃ oven for 3 hours, so that the water content of the material is reduced to below 0.02%, so as to avoid defects such as bubbles in the extrusion process; add the dried PEEK particles into the single screw extruder, set the extrusion parameters: the highest temperature of the barrel heater is 400 ℃, the working temperature of the barrel is 350 ℃, the screw bore temperature is 350 ℃, the flange temperature is 380 ℃, and the head temperature is 390 ℃, so as to ensure uniform temperature distribution; use an extrusion mold with a size of 6 / 7.5 mm (mold set hole diameter is 12 mm), and synchronously send the inlet high-temperature-resistant fiber paste heated to 120 ℃ and the optical fiber into the single screw extruder; the extruded PEEK tube is cooled by a vacuum shaping device, wherein the cooling oil temperature is controlled at 130 ℃, and the subsequent hot water cooling temperature is controlled at 90 ℃, so as to fully crystallize the PEEK tube through staged cooling; finally, a PEEK tube with an outer diameter of 3.6 mm is obtained, and the excess length of the optical fiber in the tube is 3‰, forming a center optical unit (PEEK optical unit) with an outer diameter of 3.6 mm.

[0060] (3) Aluminum layer coating processing: select A2-X aluminum rod, clean the surface to remove impurities, and then send it into the coating equipment. The aluminum rod is extruded and melted in the coating equipment. After the molten aluminum enters the mold cavity, it is uniformly and continuously coated on the surface of the PEEK optical unit. After adjusting the tension to 15 kg by the dancing wheel, and then stretching through the traction equipment, an aluminum-coated PEEK optical unit with an outer diameter of 7.2 mm is formed. Perform performance testing, including the uniformity and continuity of the aluminum tube and the attenuation performance of the internal optical fiber, the aluminum tube wall thickness eccentricity is less than 10%, the aluminum tube is produced continuously without seams, the attenuation at 1310 nm window is 0.310 dB / km, and the attenuation at 1550 nm window is 0.188 dB / km.

[0061] (4) Cabling process: adopt cage-twisting equipment with torque-releasing function, take the aluminum-coated PEEK light unit as the center, install the outer layer monofilament disc one by one on the equipment cradle, including 6 G3A-3.1 mm galvanized steel monofilaments and 4 3.1 mm aluminum-coated steel wires, the galvanized steel monofilaments and the aluminum-coated steel wires are arranged in intervals and uniformly distributed through the branch plate to preform, then are twisted around the aluminum-coated PEEK light unit, the outer layer twisting pitch is set to 165 mm, the twisting rate is 1.947%, after cabling, the high-strength lightning-resistant optical fiber composite overhead ground wire with an outer diameter of 13.4 mm is obtained, and a structural schematic diagram is shown in Figure 1

[0062] It is detected that the performance indicators of the high-strength lightning-resistant optical fiber composite overhead ground wire with an outer diameter of 13.4 mm obtained by the embodiment 1 are as follows:

[0063] The DC resistance is 0.6095 Ω / km;

[0064] The overall tensile strength is 113.06 kN;

[0065] The optical fiber attenuation is 0.340 dB / km in the 1310 nm window and 0.200 dB / km in the 1550 nm window;

[0066] The lightning resistance performance is that after the lightning test of 300 A current, 0.5 s duration and 150 C transferred charge, the residual tensile strength of the whole cable after lightning is 0.75 RTS.

[0067] After 1000 hours of salt tank spray test verification: the aluminum-coated steel wire only has a point corrosion of no more than one place, and the point corrosion does not expose the underlying steel layer in any way; the optical fiber unit is not damaged, the aluminum pipe maintains the original shape and does not deform, the galvanized steel monofilament coating is complete and does not fall off, which fully proves the excellent protection performance of the OPGW in the high-salt mist corrosion environment.

[0068] Obviously, the above embodiments of the present application are only examples for clearly illustrating the present application, and are not intended to limit the embodiments of the present application. Those skilled in the art should understand that on the basis of the above description, other different forms of changes or variations can also be made. Here, it is not necessary and impossible to enumerate all the embodiments. Any modification, equivalent replacement and improvement made within the spirit and principle of the present application shall be included in the protection scope of the claims of the present application.​

Claims

1. A manufacturing process for a high-strength, lightning-resistant optical fiber composite overhead ground wire, characterized in that, Includes the following steps: (1) Multiple optical fibers are ringed and colored to obtain pre-treated optical fibers; (2) The pretreated optical fiber and fiber paste obtained in step (1) are introduced into the extrusion equipment, the wire tension is controlled, and the polymer protective tube covering the optical fiber is extruded. After vacuum shaping and graded cooling, the central optical unit is obtained. (3) After cleaning the aluminum rod, it is extruded and melted, and then wrapped around the center light unit obtained in step (2). The aluminum-clad light unit is obtained by processing it with a dancing wheel and traction equipment. (4) Using a stranding device with untwisting function, six galvanized steel monofilaments and four aluminum-clad steel wires are stranded around the aluminum-clad optical unit obtained in step (3) to obtain the high-strength lightning-resistant fiber optic composite overhead ground wire.

2. The preparation process according to claim 1, characterized in that, In step (1), the ringing is distinguished by inkjet printing equipment; the coloring is done by coloring mold, the inlet mold aperture of the coloring mold is 0.260-0.280mm, and the outlet mold aperture is 0.250-0.260mm; the attenuation performance of the optical fiber after coloring meets the following requirements: 1310nm window ≤ 0.330dB / km, 1550nm window ≤ 0.190dB / km.

3. The preparation process according to claim 1, characterized in that, In step (2), the fiber paste is heated to 110-130°C and then introduced into the extrusion equipment along with the optical fiber through an integrated introductory device.

4. The preparation process according to claim 1, characterized in that, In step (2), the polymer protective tube is a polyetheretherketone (PEEK) tube; the extrusion equipment is a single-screw extruder, and the PEEK particles are dried at 140-160℃ for 3-4 hours before extrusion to reduce their moisture content to below 0.02%; the process parameters of the single-screw extruder are set as follows: the maximum heating temperature of the barrel heater is 400±2℃, the barrel working temperature is 350-390℃, the screw bore temperature is 350±2℃, the flange temperature is 380±2℃, and the die head temperature is 390±2℃.

5. The preparation process according to claim 1, characterized in that, In step (2), the process parameters for the staged cooling are: cooling oil temperature is 130±20℃, and hot water cooling temperature is 90±5℃.

6. The preparation process according to claim 1, characterized in that, In step (2), the outer diameter of the polymer protective tube after cooling is 3.5±0.1mm, and the excess length of the optical fiber inside the tube is 2.5-3.5‰.

7. The preparation process according to claim 1, characterized in that, In step (4), the stranding device is a cage stranding device, and the outer layer stranding pitch is 155-175mm, with a stranding rate of 1.85%-2.05%.

8. The preparation process according to claim 1, characterized in that, In step (3), the outer diameter of the aluminum-clad optical unit is 7.2±0.2mm; in step (4), the outer diameter of the high-strength lightning-resistant fiber optic composite overhead ground wire is 13-14mm.

9. A high-strength, lightning-resistant optical fiber composite overhead ground wire obtained by the preparation process described in any one of claims 1-8.

10. The high-strength lightning-resistant fiber optic composite overhead ground wire according to claim 9, characterized in that, The high-strength lightning-resistant fiber optic composite overhead ground wire includes a central optical unit, an aluminum tube, and an outer stranded unit. The central optical unit consists of 24-core G652D optical fibers, a polyetheretherketone tube, and fiber grease. The aluminum tube covers the central optical unit. The outer stranded unit consists of 6 galvanized steel monofilaments and 4 aluminum-clad steel wires stranded at intervals around the aluminum tube.

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