Durable high-voltage water-blocking cable and preparation method thereof

Abstract

The invention provides a durable high-voltage water-blocking cable and a preparation method, and relates to the technical field of cables. The waterproof cable comprises an inner layer which comprises an inner sheath, an insulating layer arranged outside a conductor, a filler arranged between the inner sheath and the insulating layer, a middle layer arranged outside the inner layer, an outer layer arranged outside the middle layer, the filler being granular, an air inlet pipe and an air outlet pipe arranged in the filler inside the inner sheath, and an outer layer arranged outside the outer layer, the middle layer comprises a water blocking sleeve, the water blocking sleeve comprises an inner sleeve and an outer sleeve which are in a coaxial state, a plurality of longitudinal partition strips and a plurality of transverse partition strips are arranged between the inner sleeve and the outer sleeve, the space between the inner sleeve and the outer sleeve is divided into a plurality of independent cavities, and the cavities are filled with water blocking materials. The preparation method comprises the following steps: preparing the inner layer, arranging the water-blocking sleeve outside the inner layer, injecting water-blocking oil between the water-blocking sleeve and the inner layer, and arranging the outer layer outside the water-blocking sleeve. According to the invention, whether water enters the cable can be detected, so that timely maintenance can be carried out.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, and in particular to a durable high-voltage water-blocking cable and a preparation method thereof. Background Art

[0002] A cable is made of one or more insulated conductors and an outer insulating protective layer. It is a wire that transmits electricity or information from one place to another.

[0003] In the prior art, it is difficult to detect in time when a water-blocking cable is damaged and water has entered the cable. The water ingress phenomenon is usually only discovered when the conductor is short-circuited or the cable is damaged, at which point damage to communications and electricity is inevitable. Summary of the invention

[0004] The purpose of the present invention is to develop a durable high-voltage water-blocking cable and a preparation method thereof, which can detect whether water has entered the cable so as to carry out repairs in time.

[0005] The present invention is achieved through the following technical solutions: A durable high-voltage water-blocking cable, comprising: The inner layer, where the conductor is located, includes: Inner sheath; Insulation layer, which is provided outside the conductor; Filling material, provided between the inner sheath and the insulating layer; The middle layer is arranged outside the inner layer; The outer layer is located outside the middle layer; Wherein, the filler is in granular form, an air inlet pipe and an air exhaust pipe are arranged in the filler inside the inner sheath, and the air inlet pipe and the air exhaust pipe are both provided with a plurality of pores with a diameter smaller than the particle diameter of the filler, the air inlet pipe and the air exhaust pipe extend out of the cable from the portion of the cable not buried in the water and are both provided with sealing plugs at the ends, and after removing the sealing plugs, the air inlet pipe and the air exhaust pipe can be connected to the air intake device and the air suction device respectively, and the ends of the air inlet pipe and the air exhaust pipe are also provided with sensors for detecting the moisture content in the gas; The middle layer comprises a water-blocking sleeve, which comprises an inner sleeve and an outer sleeve in a coaxial state, a plurality of longitudinal partitions and a plurality of transverse partitions are arranged between the inner sleeve and the outer sleeve, and the inner sleeve and the outer sleeve are divided into a plurality of independent cavities, and the cavities are filled with water-blocking material.

[0006] Optionally, the entire exhaust pipe is covered with multiple air holes, the number of the air inlet pipes is N, the 1 / N length area of ​​the air inlet pipe is covered with multiple air holes, and the pipe sections of the N air inlet pipes covered with air holes are staggered, and the arrangement areas of the air holes of the N air inlet pipes do not overlap in the axial direction of the cable.

[0007] Optionally, a plurality of support members are provided in the air intake pipe and the exhaust pipe, and the plurality of support members are arranged at equal intervals in the air intake pipe and the exhaust pipe.

[0008] Optionally, the support member includes a square support frame, the four corners of the support frame are respectively connected to the inner wall of the intake pipe or the exhaust pipe, the support frame is arranged perpendicular to the axial direction of the intake pipe and the exhaust pipe, and a cross-shaped support frame is arranged in the support frame, and the four ends of the support frame are respectively connected to the four corners of the support frame.

[0009] Optionally, the water-blocking material includes hydrophobic granules and water-absorbent powder, and the powder is a water-absorbent polymer.

[0010] Optionally, a sealing layer is provided between the inner sheath and the water-blocking sheath, and the sealing layer is silicone oil mixed with hydrophobic particles.

[0011] Optionally, a detection layer electrically connected to the TDR system is provided on the outside of the water-blocking sleeve, and the detection layer includes a substrate, carbon nanotubes and additives, the substrate is polyethylene, polyurethane or silicone rubber, the additive is a dispersant or a coupling agent, the carbon nanotubes form a conductive network through physical overlapping or tunneling effect, and the detection layer is coated with a layer of aluminum foil.

[0012] Optionally, the outer layer includes an outer sheath, the outer sheath is at the outermost part of the cable, an armor layer is provided inside the outer sheath, and an intermediate sheath is provided inside the armor layer.

[0013] Optionally, the outer sheath and the middle sheath are made of HDPE or polyurethane, the armor layer is a double layer of galvanized steel wire or steel belt spirally wound, and epoxy resin or hot melt adhesive is coated between the armor layer and the outer sheath and the middle sheath.

[0014] A method for preparing a durable high-voltage water-blocking cable comprises the following steps: S1. The conductor is covered with an insulating layer, and the conductor, air inlet pipe and exhaust pipe are inserted into the inner sheath and then filled with filler; S2. Place the water-blocking sleeve on the outside of the inner sheath; S3. Inject water-blocking oil between the water-blocking sleeve and the inner sheath; S4. An outer layer is provided outside the water blocking sleeve; Wherein, in the step S1, the filler is filled into the inner jacket in the form of vibration filling or air flow conveying, and then compacted by rolling or vacuuming; In the step S2, the inner sleeve, the longitudinal spacers and the transverse spacers of the water-blocking sleeve are integrally formed, and then fed into an injection barrel, in which the water-blocking sleeve is axially transported and rotated at a constant speed. Two expansion sections are provided in the injection barrel, and the water-blocking material is first injected into the outer side of the inner sleeve at one of the expansion sections, and the water-blocking material fills the multiple cavities formed by the longitudinal spacers and the transverse spacers on the outer surface of the inner sleeve, and the outer sleeve thermally connected to the longitudinal spacers and the transverse spacers is injected into the outer side of the longitudinal spacers and the transverse spacers at the other expansion section; In the step S4, the arrangement position of the exhaust pipe is marked on the outermost side of the outer layer by drawing a line.

[0015] The beneficial effects of the present invention are: The multi-layer waterproof structure is set up to improve the water resistance of the cable. The water-blocking jacket is divided into multiple independent cavities, and water-blocking materials are set in the cavities. When the cable is damaged and water enters, the powder in the water-blocking material absorbs water and expands to fill the gaps in the granular materials, so that water is blocked and difficult to continue to penetrate inward. The grid-like structure formed by the staggered longitudinal and transverse partitions in the water-blocking jacket can block the water flow when water enters locally, preventing the water flow from penetrating to other positions in the cable, thereby improving the cable's anti-permeability in the axial and circumferential directions; The first detection unit and the second detection unit can both detect whether water has entered the cable, thereby detecting whether the cable is damaged or leaking. The two sets of detection units operate independently, which cannot improve the accuracy of leakage detection, and when one of the detection units fails, the other detection unit can continue to detect leakage of the cable. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 This is the internal structure diagram of the cable; Figure 2 This is the structural diagram of the injection barrel.

[0018] Figure numerals: 1. inner sheath; 2. insulating layer; 3. water-blocking layer; 4. filling material; 5. sealing layer; 6. water-blocking sleeve; 7. water-blocking material; 8. intermediate sheath; 9. armor layer; 10. outer sheath; 11. air inlet pipe; 12. exhaust pipe; 13. detection layer; 14. support member; 100. injection barrel; 101. pipe inlet section; 102. first diameter expansion section; 103. first shaping section; 104. second diameter expansion section; 105. second shaping section; 106. injection tube; 107. extrusion tube. DETAILED DESCRIPTION

[0019] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation to the present invention.

[0021] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0022] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0023] like Figure 1 As shown, the present invention discloses a durable high-voltage water-blocking cable, comprising an inner layer, a middle layer and an outer layer, wherein the conductor is arranged in the inner layer, a first detection unit is arranged in the inner layer, and a second detection unit is arranged in the middle layer.

[0024] The inner layer includes an inner sheath 1, a sealing layer 5 is provided outside the inner sheath 1, an insulating layer 2 is provided outside the conductor, a conductor shielding layer is provided between the conductor and the insulating layer 2, an insulating shielding layer is provided outside the insulating layer 2, a water-blocking layer 3 is provided outside the insulating shielding layer, and a filler 4 is provided between the water-blocking layer 3 and the inner sheath 1. The sealing layer 5 is a water-blocking oil, which can be silicone oil mixed with hydrophobic particles. The filler 4 is a hydrophobic polymer particle, which can be one or more of polytetrafluoroethylene, polyethylene or polypropylene.

[0025] The middle layer includes a water-blocking sleeve 6 arranged outside the water-blocking oil, and the water-blocking sleeve 6 includes an inner sleeve and an outer sleeve in a coaxial state. A plurality of longitudinal partitions are arranged between the inner sleeve and the outer sleeve, and the longitudinal partitions are arranged parallel to the axial direction of the inner sleeve and the outer sleeve, and the plurality of longitudinal partitions are arranged at equal intervals in the circumferential direction of the inner sleeve and the outer sleeve. A plurality of transverse partitions are also arranged between the inner sleeve and the outer sleeve, and the transverse partitions are arranged in the circumferential direction of the inner sleeve and the outer sleeve, and the plurality of transverse partitions are arranged at equal intervals in the axial direction of the inner sleeve and the outer sleeve. The separation of the plurality of transverse partitions and the plurality of longitudinal partitions divides the inner sleeve and the outer sleeve into a plurality of mutually independent square cavities.

[0026] The cavity is filled with a water-blocking material 7, which includes hydrophobic granules and water-absorbent powder. The powder is a water-absorbent polymer. The granules and powder are mixed to fill the entire cavity.

[0027] The outer layer includes an outer sheath 10, which is at the outermost part of the cable, an armor layer 9 is provided inside the outer sheath 10, and an intermediate sheath 8 is provided inside the armor layer 9. The outer sheath 10 and the intermediate sheath 8 are made of HDPE (high-density polyethylene) or polyurethane, the armor layer 9 is a double-layer galvanized steel wire or steel belt spirally wound, and epoxy resin or hot melt adhesive is coated between the armor layer 9 and the outer sheath 10 and the intermediate sheath 8.

[0028] The first detection unit includes an exhaust pipe 12 and two air inlet pipes 11 disposed in the filler 4. The position of the exhaust pipe 12 is marked on the outer sheath 10 so that the exhaust pipe 12 is at the bottom when the cable is laid. The exhaust pipe 12 is fully covered with multiple air holes, and the half section of the two air inlet pipes 11 is fully covered with air holes. The sections of the two air inlet pipes 11 covered with air holes are staggered, and the arrangement areas of the air holes of the two air inlet pipes 11 do not overlap in the axial direction of the cable. In addition to this embodiment, the number of air inlet pipes 11 can also be 1 or more than 2. When the number of air inlet pipes 11 is N, the 1 / N section length of the air inlet pipe 11 is fully covered with air holes, and the sections of the N air inlet pipes 11 covered with multiple air holes are staggered, and the arrangement areas of the air holes of the N air inlet pipes 11 do not overlap in the axial direction of the cable. The longer the length of the cable buried underwater, the more air inlet pipes 11 are arranged.

[0029] The aperture of the pores is smaller than the particle size of the filler 4, so as to prevent the filler 4 from entering the air intake pipe 11 or the exhaust pipe 12. A plurality of support members 14 are provided in the air intake pipe 11 and the exhaust pipe 12, and the support members 14 prevent the air intake pipe 11 and the exhaust pipe 12 from being deformed by pressure. The plurality of support members 14 are arranged at equal intervals in the air intake pipe 11 and the exhaust pipe 12, and the support members 14 include a square support frame, and the four corners of the support frame are respectively connected to the inner wall of the air intake pipe 11 or the exhaust pipe 12, and the support frame is arranged perpendicular to the axial direction of the air intake pipe 11 and the exhaust pipe 12, and a cross-shaped support frame is provided in the support frame, and the four ends of the support frame are respectively connected to the four corners of the support frame. The air intake pipe 11 and the exhaust pipe 12 extend the cable from the part of the cable not buried in the water, and the ends of the air intake pipe 11 and the exhaust pipe 12 are provided with sealing plugs.

[0030] When testing, open the sealing plugs at the ends of the air intake pipe 11 and the exhaust pipe 12, connect the air intake pipe 11 to the air intake device, and connect the exhaust pipe 12 to the air suction device. Sensors for detecting the moisture content in the gas are also provided at the ends of the air intake pipe 11 and the exhaust pipe 12. The air intake device pumps the gas that has been tested for moisture content into the air intake pipe 11, and the gas finally enters the filler 4 in the inner sheath 1 through the air holes on the air intake pipe 11. The air suction device sucks the exhaust pipe 12, and the gas in the inner sheath 1 is sucked out by the exhaust pipe 12. The gas discharged from the exhaust pipe 12 is tested for moisture content, and the moisture content of the gas discharged from the exhaust pipe 12 is compared with the moisture content of the gas entering the air intake pipe 11. If the moisture content of the gas discharged from the exhaust pipe 12 is too high, or there is water in the gas discharged from the exhaust pipe 12, water has entered the inner sheath 1, the cable is leaking, and the water has penetrated into the inner layer. Since the filler 4 is in granular form, the airflow inputted from the air inlet pipe 11 can easily circulate in the filler 4 and be sucked into the exhaust pipe 12, and the water vapor or moisture that enters the inner sheath 1 and stays in the filler 4 is sucked out by the exhaust pipe 12 along with the airflow. After the test is completed, the air inlet device and the air suction device are disconnected, and then the sealing plugs are installed into the air inlet pipe 11 and the exhaust pipe 12.

[0031] The second detection unit includes a detection layer 13 disposed between the water-blocking sleeve 6 and the intermediate sheath 8. The detection layer 13 includes a substrate, carbon nanotubes and additives. The substrate is polyethylene, polyurethane, silicone rubber, etc. The additive is a dispersant or a coupling agent to improve the dispersion of the carbon nanotubes. The carbon nanotubes form a conductive network through physical overlap or tunneling effect. The detection layer 13 is electrically connected to the TDR system. The detection layer 13 is coated with a layer of aluminum foil as a shielding layer, which not only prevents external electromagnetic noise from interfering with the TDR signal, but also can block water and moisture.

[0032] When water enters the detection layer 13, the water causes a local short circuit in the detection layer 13. The TDR system locates the short circuit point by detecting the reflected signal, indirectly determines the water ingress position, and obtains the cable leakage point position in time.

[0033] The present invention also discloses a method for preparing a durable high-voltage water-blocking cable, comprising the following steps: S1. The conductor is coated with an insulating layer 2, the conductor, the air inlet pipe 11 and the exhaust pipe 12 are inserted into the inner sheath 1 and then the filler 4 is injected; S2. The water blocking sleeve 6 is disposed on the outside of the inner sheath 1; S3. Inject water-blocking oil between the water-blocking sleeve 6 and the inner sheath 1; S4. An outer layer is provided on the outside of the water blocking sleeve 6; In step S1, the filler 4 is filled into the inner jacket 1 in the form of vibration filling or air flow conveying, and then compacted by rolling or vacuuming to reduce the gaps between the fillers 4 and improve the filling density; In step S2, the inner sleeve, longitudinal spacers and transverse spacers of the water blocking sleeve 6 are integrally formed, and then sent into the injection barrel 100, in which the water blocking sleeve 6 is axially transported and rotated at a constant speed, and the injection barrel 100 is provided with two expansion sections, one of which is firstly injected with water blocking material 7 to the outside of the inner sleeve, so that the water blocking material 7 fills the multiple cavities formed by the longitudinal spacers and transverse spacers on the outer surface of the inner sleeve, and the other is injected with the outer sleeve thermally connected to the longitudinal spacers and transverse spacers at the other expansion section; In step S4 , before the outer layer is provided, the detection layer 13 is provided outside the water blocking sleeve 6 , and then the intermediate sheath 8 , the armor layer 9 and the outer sheath 10 are provided in sequence outside the detection layer 13 .

[0034] The structure of the injection barrel 100 is as follows Figure 2 As shown, the interior thereof sequentially includes an inlet pipe section 101, a first diameter expansion section 102, a first shaping section 103, a second diameter expansion section 104, and a second shaping section 105. The inner diameters of the inlet pipe section 101 and the first shaping section 103 are both adapted to the outer diameter of the crossbar, that is, the inner diameter of the outer sleeve, and the inner diameter of the second shaping section 105 is adapted to the outer diameter of the outer sleeve. An injection tube 106 is provided on the injection barrel 100 at the first diameter expansion section 102, and the injection tube 106 injects the water blocking material 7 into the first diameter expansion section 102, and the first shaping section 103 allows the water blocking material 7 to be pressed into the cavity. An extrusion tube 107 is provided on the injection barrel 100 at the second diameter expansion section 104. The material extruded by the extruder enters the second diameter expansion section 104 through the extrusion tube 107 to extrude the outer jacket. The second shaping section 105 controls the outer diameter of the outer jacket and cools it accordingly. A cooling water circulation pipeline is arranged in the injection barrel 100 outside the second shaping section 105 to cool the extruded outer jacket in the second shaping section 105.

[0035] The above embodiments are only preferred embodiments of the present invention and are not limitations of the technical solutions of the present invention. Any technical solution that can be implemented on the basis of the above embodiments without creative work should be deemed to fall within the scope of protection of the patent of the present invention.

Claims

1. A durable high-voltage water-blocking cable, characterized in that: include: The inner layer, where the conductor is located, includes: Inner sheath; Insulation layer, which is provided outside the conductor; Filling material, provided between the inner sheath and the insulating layer; The middle layer is arranged outside the inner layer; The outer layer is located outside the middle layer; Wherein, the filler is in granular form, an air inlet pipe and an air exhaust pipe are arranged in the filler inside the inner sheath, and the air inlet pipe and the air exhaust pipe are both provided with a plurality of pores with a diameter smaller than the particle diameter of the filler, the air inlet pipe and the air exhaust pipe extend out of the cable from the portion of the cable not buried in the water and are both provided with sealing plugs at the ends, and after removing the sealing plugs, the air inlet pipe and the air exhaust pipe can be connected to the air intake device and the air suction device respectively, and the ends of the air inlet pipe and the air exhaust pipe are also provided with sensors for detecting the moisture content in the gas; The middle layer comprises a water-blocking sleeve, which comprises an inner sleeve and an outer sleeve in a coaxial state, a plurality of longitudinal partitions and a plurality of transverse partitions are arranged between the inner sleeve and the outer sleeve, and the inner sleeve and the outer sleeve are divided into a plurality of independent cavities, and the cavities are filled with water-blocking material.

2. The durable high-voltage water-blocking cable according to claim 1, characterized in that: The exhaust pipe is covered with multiple air holes throughout the entire section, the number of the air intake pipes is N, the 1 / N section length area of ​​the air intake pipe is covered with multiple air holes, and the sections of the N air intake pipes covered with air holes are staggered, and the arrangement areas of the air holes of the N air intake pipes do not overlap in the axial direction of the cable.

3. The durable high-voltage water-blocking cable according to claim 1, characterized in that: A plurality of supporting members are arranged in the air intake pipe and the exhaust pipe, and the plurality of supporting members are arranged at equal intervals in the air intake pipe and the exhaust pipe.

4. The durable high-voltage water-blocking cable according to claim 3, characterized in that: The support member includes a square support frame, the four corners of which are respectively connected to the inner wall of the intake pipe or the exhaust pipe, the support frame is arranged perpendicular to the axial direction of the intake pipe and the exhaust pipe, and a cross-shaped support frame is arranged inside the support frame, and the four ends of the support frame are respectively connected to the four corners of the support frame.

5. The durable high-voltage water-blocking cable according to claim 1, characterized in that: The water-blocking material comprises hydrophobic granules and water-absorbent powder, and the powder is a water-absorbent polymer.

6. The durable high-voltage water-blocking cable according to claim 1, characterized in that: A sealing layer is provided between the inner sheath and the water blocking sheath, and the sealing layer is silicone oil mixed with hydrophobic particles.

7. The durable high-voltage water-blocking cable according to claim 1, characterized in that: A detection layer electrically connected to the TDR system is provided on the outside of the water-blocking sleeve. The detection layer includes a substrate, carbon nanotubes and additives. The substrate is polyethylene, polyurethane or silicone rubber. The additive is a dispersant or a coupling agent. The carbon nanotubes form a conductive network through physical overlapping or tunneling effect. The detection layer is coated with a layer of aluminum foil.

8. The durable high-voltage water-blocking cable according to claim 1, characterized in that: The outer layer comprises an outer sheath, which is located at the outermost part of the cable, an armor layer is arranged inside the outer sheath, and an intermediate sheath is arranged inside the armor layer.

9. The durable high-voltage water-blocking cable according to claim 8, characterized in that: The outer sheath and the middle sheath are made of HDPE or polyurethane, the armor layer is a double-layer galvanized steel wire or steel belt spirally wound, and epoxy resin or hot melt adhesive is coated between the armor layer and the outer sheath and the middle sheath.

10. The method for preparing a durable high-voltage water-blocking cable according to any one of claims 1 to 9, characterized in that: The steps include: S1. The conductor is covered with an insulating layer, and the conductor, air inlet pipe and exhaust pipe are inserted into the inner sheath and then filled with filler; S2. Place the water-blocking sleeve on the outside of the inner sheath; S3. Inject water-blocking oil between the water-blocking sleeve and the inner sheath; S4. An outer layer is provided outside the water blocking sleeve; Wherein, in the step S1, the filler is filled into the inner jacket in the form of vibration filling or air flow conveying, and then compacted by rolling or vacuuming; In the step S2, the inner sleeve, the longitudinal spacers and the transverse spacers of the water-blocking sleeve are integrally formed, and then fed into an injection barrel, in which the water-blocking sleeve is axially transported and rotated at a constant speed. Two expansion sections are provided in the injection barrel, and the water-blocking material is first injected into the outer side of the inner sleeve at one of the expansion sections, and the water-blocking material fills the multiple cavities formed by the longitudinal spacers and the transverse spacers on the outer surface of the inner sleeve, and the outer sleeve thermally connected to the longitudinal spacers and the transverse spacers is injected into the outer side of the longitudinal spacers and the transverse spacers at the other expansion section; In the step S4, the arrangement position of the exhaust pipe is marked on the outermost side of the outer layer by drawing a line.

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