Kilometer deep water equipment longitudinal watertight cable and its preparation method

Abstract

The application provides a longitudinal watertight cable for kilometer deep water equipment and a preparation method thereof, which comprises a longitudinal water-blocking conductor, a hydrophilic water-blocking rope and a longitudinal water-blocking cable core twisted together, and a first water-blocking tape layer, an inner sheath, a second water-blocking tape layer, a braided metal wire armor layer, a water-blocking shielding tape, a third water-blocking tape layer and an outer sheath designed layer by layer outside the cable core. The hydrophilic water-blocking rope is twisted together with the insulated wire core to form a cable, and the remaining gap in the middle of the cable core is filled with a hydrophobic sealant to form a longitudinal waterproof barrier. The application can realize the calculation of the watertight performance of the cable under the predetermined pressure, the water seepage length of the water absorption rate of the hydrophilic water-swelling polymer water-blocking filling, the force of the hydrophobic sealant, the active design of the longitudinal watertight performance of the cable, and the active design according to different depth use environments. Meanwhile, through the application of the hydrophobic and hydrophilic water-blocking material composite structure, the longitudinal watertight requirement of the cable for kilometer water depth equipment is realized.

Description

Technical Field

[0001] This invention relates to the field of watertight cable technology, and more specifically to a longitudinal watertight cable for kilometer-deep-water equipment and its design and manufacturing method. Background Technology

[0002] As deep-sea exploration and underwater vessels continue to expand into deeper waters, reaching depths exceeding 1,000 meters, higher requirements are placed on the water pressure resistance of the supporting longitudinal sealing cables, which must be able to withstand the longitudinal pressure at depths of 1,000 meters.

[0003] The highest longitudinal watertightness of existing cables is 10 MPa, corresponding to a theoretical water depth of approximately 1000 m. However, due to a design safety margin of approximately 1.2 to 1.5 times, existing cables can only be used in equipment at water depths of approximately 650 to 800 m, failing to meet the longitudinal water pressure requirements at depths of 1000 meters. Furthermore, existing longitudinal watertight cables rely on verification after research and production to determine their longitudinal watertightness. The manufacturing, inspection, and verification environments typically used are freshwater, neglecting reliability under seawater salinity conditions. This results in a lack of resistance to seawater corrosion and a risk of longitudinal watertightness failure under seawater pressure.

[0004] In addition, when existing watertight cables use hydrophobic or hydrophilic materials for watertight design, hydrophobic materials can easily cause small gaps in the cable to be unable to be filled, forming cavities and affecting the water-blocking effect. Hydrophilic materials can easily cause expansion that is insufficient to fill larger gaps in the cable, affecting the water-blocking effect. Summary of the Invention

[0005] The purpose of this invention is to provide a longitudinal watertight cable for kilometer-deep water equipment and a design and manufacturing method. By using suitable water-blocking materials and composite processes to form different cable components, the compatibility between materials and components is improved, and the failure risk of existing watertight cables is overcome.

[0006] According to a first aspect of the present invention, a longitudinal watertight cable for kilometer-deep-water equipment is provided, comprising:

[0007] The longitudinally water-blocking stranded conductor is formed by stranding multiple single wires together, and the stranded single wires are filled with hydrophobic sealant.

[0008] In the longitudinally water-blocking stranded conductor extruded with a conductor insulation layer, the stranded conductor and the conductor insulation layer form an insulated wire core;

[0009] A cable core with a circular cross-section is formed by twisting multiple insulated wire cores according to a predetermined pitch ratio. During the twisting process, a hydrophilic water-blocking rope made of water-absorbing and expanding yarn is filled between the insulated wire cores. The hydrophilic water-blocking rope is twisted together with the insulated wire cores to form a cable. The remaining gaps in the middle of the cable core are filled with hydrophobic sealant.

[0010] The water-blocking tape is wrapped around the outer surface of the cable core in a double-layer overlapping manner in both directions to form the first water-blocking tape layer.

[0011] An inner sheath is extruded onto the outer surface of the first water-blocking strip layer;

[0012] A second water-blocking strip is formed by wrapping a water-blocking strip around the outer surface of the inner sheath in a double-layered, opposite-side overlapping manner.

[0013] A braided metal wire armor layer filled with hydrophobic sealant is provided on the outer surface of the second water-blocking strip layer;

[0014] A water-blocking shielding tape is wrapped around the outer surface of the braided metal wire armor layer. The water-blocking shielding tape is penetrated and bonded by the injected hydrophobic sealant and forms an integral seal with the braided metal wire armor layer.

[0015] A third water-blocking layer is formed by wrapping the water-blocking strip around its outer surface in a double-layered, overlapping manner in both directions; and

[0016] An outer sheath is extruded onto the outer surface of the third water-blocking strip layer.

[0017] As an optional embodiment, the conductor insulation layer is double-extruded, consisting of a bottom layer insulation bonded to a hydrophobic sealant filled between the stranded conductors and individual wires, and a surface layer insulation on the surface of the bottom layer insulation.

[0018] As an optional embodiment, the hydrophilic water-blocking rope and the first water-blocking strip layer, the second water-blocking strip layer and the third water-blocking strip layer all use anionic polyacrylamide and polyethylene glycol and crosslinking agent as a water-blocking matrix.

[0019] As an optional embodiment, the hydrophilic water-blocking rope is composed of water-blocking yarn made of a water-blocking matrix and a microporous tape covering the water-blocking yarn. The inner water-blocking yarn expands when it comes into contact with water to achieve water blocking, and the outer microporous tape is used to prevent hydrophobic sealant from entering the interior of the water-blocking rope during cable production, and to reduce resistance when the water-blocking yarn expands outward when it comes into contact with water to ensure a seal.

[0020] As an optional embodiment, the braided metal wire armor layer is a braided copper wire armor layer. After armoring, adhesive is injected to fill the gaps between the armor wires with hydrophobic sealant, and then a water-blocking shielding tape is wrapped around it.

[0021] As an optional embodiment, the water-blocking shielding tape has a multi-layer composite structure, with an inner layer of copper or aluminum plating, a middle layer of polyester fiber film, and an outer layer coated with water-blocking powder, thus having both shielding and expansion-based water-blocking functions.

[0022] As an optional embodiment, the water-blocking shielding strip is combined with a stranded copper wire drain line to form an overall shield.

[0023] As an optional embodiment, the longitudinal watertight cable is configured such that the water penetration length, water absorption rate, and cable core design of the hydrophilic water-blocking rope are determined in the following manner:

[0024] During the stranding process, the water absorption and seepage length of the hydrophilic water-blocking rope (3) made of water-absorbing and expanding yarn stranded between the insulating wire cores satisfies:

[0025]

[0026] Where L is the water penetration length under pressure, in meters; ΔF is the longitudinal watertightness test pressure, in MPa; R0 is the inner radius of the seepage channel, in mm; R1 is the outer radius of the seepage channel, in mm; σ is the kinematic viscosity of water at 20℃, in MPa·S; ρ is the water absorption expansion rate of the filled hydrophilic water-blocking rope, in mm / s; k1 is the compressibility coefficient of the cable in the radial direction; and k2 is the stranding coefficient of the insulated core when stranded into a cable.

[0027] According to a second aspect of the present invention, a method for manufacturing a longitudinal watertight cable for kilometer-deep-water equipment is also provided, comprising the following steps:

[0028] (1) Conductor stranding and sealing glue injection

[0029] The stranded conductor is made of multiple tin-plated copper single wires stranded together, and hydrophobic sealant is filled between the stranded single wires. The stranding pitch ratio is controlled at (10~15) times to increase the longitudinal water resistance of the hydrophobic sealant.

[0030] (2) Extrusion insulation

[0031] A double-layer, multi-stage extrusion insulation material is used on the outer surface of the stranded conductor. The inner insulation layer is extruded through an extrusion die to fill the gaps around the outermost conductor. Simultaneously, the stranded conductor is preheated before insulation extrusion to maintain its temperature at (50±10)℃, thereby increasing the adhesion between the stranded conductor, the hydrophobic sealant filling the conductor, and the inner insulation layer. The outer insulation layer is extruded using the same material as the inner insulation layer to ensure a tight bond. After the stranded conductor is extruded with double insulation, it forms an insulated core.

[0032] (3) Stranded into cable

[0033] The insulated wire cores are twisted into a cable at a pitch ratio of (15±5). The insulated wire cores are filled with a composite sealing process. Several hydrophilic water-blocking ropes made of water-absorbing and expanding yarns are filled between the insulated wire cores. The hydrophilic water-blocking ropes are twisted together with the insulated wire cores to form a cable. The remaining gaps in the middle of the cable cores are filled with hydrophobic adhesive. The hydrophobic adhesive completely fills the gaps between the wire cores to form a longitudinal waterproof barrier.

[0034] (4) Wrap the first water-blocking strip layer

[0035] The first water-blocking tape layer is wrapped around the outer surface of the cable core in two overlapping layers in both directions, with an overlap rate of 40-50%.

[0036] (5) Inner sheath of the extrusion package

[0037] A water-blocking sheath material is extruded onto the outer surface of the first water-blocking strip layer to form an inner sheath.

[0038] (6) Wrap the second water-blocking layer

[0039] The water-blocking strip is wrapped around the outer surface of the inner sheath in a double-layer overlapping manner in both directions to form a second water-blocking strip layer with an overlap rate of 40-50%.

[0040] (7) Woven Armor

[0041] A braided metal wire armor layer for injecting hydrophobic sealant is prepared on the outer surface of the second water-blocking strip layer. The braided copper wire armor layer is wrapped around the outer surface of the second water-blocking strip layer. After armoring, the sealant is injected to fill the gaps between the armor wires with hydrophobic sealant.

[0042] (8) Water-blocking shielding tape

[0043] A water-blocking shielding tape is wrapped around the outer surface of the braided metal wire armor layer. The water-blocking shielding tape is penetrated and bonded by the injected hydrophobic sealant and forms an integral seal with the braided metal wire armor layer.

[0044] The water-blocking shielding tape has a multi-layer composite structure, with an inner layer of copper or aluminum plating, a middle layer of polyester fiber film, and an outer layer coated with water-blocking powder. It has both shielding and expansion water-blocking functions. The water-blocking shielding tape is combined with a stranded copper wire drain line to form an overall shield.

[0045] (8) Wrap the third water-blocking layer

[0046] A third water-blocking layer is formed by wrapping a water-blocking strip around the outer surface of the shielding strip in a double-layer overlapping manner in both directions.

[0047] (9) Extrusion outer sheath

[0048] An outer sheath is extruded onto the outer surface of the third water-blocking strip layer;

[0049] The hydrophilic water-blocking rope, as well as the first, second, and third water-blocking tape layers, all use anionic polyacrylamide and a mixed graft of polyethylene glycol and a crosslinking agent as the water-blocking matrix. Their water penetration length and water absorption rate satisfy the following requirements for the cable core:

[0050]

[0051] Where L is the water penetration length under pressure, in meters; ΔF is the longitudinal watertightness test pressure, in MPa; R0 is the inner radius of the seepage channel, in mm; R1 is the outer radius of the seepage channel, in mm; σ is the kinematic viscosity of water at 20℃, in MPa·S; ρ is the water absorption expansion rate of the filled hydrophilic water-blocking rope, in mm / s; k1 is the compressibility coefficient of the cable in the radial direction; and k2 is the stranding coefficient of the insulated core when stranded into a cable.

[0052] As an optional embodiment, the hydrophilic water-blocking rope is composed of water-blocking yarn made of a water-blocking matrix and a microporous tape covering the water-blocking yarn. The inner water-blocking yarn expands when it comes into contact with water to achieve water blocking, and the outer microporous tape is used to prevent hydrophobic sealant from entering the interior of the water-blocking rope during cable production, and to reduce resistance when the water-blocking yarn expands outward when it comes into contact with water to ensure a seal.

[0053] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below may be considered part of the inventive subject matter of this disclosure, provided that such concepts do not contradict each other. Furthermore, all combinations of the claimed subject matter are considered part of the inventive subject matter of this disclosure.

[0054] The foregoing and other aspects, embodiments, and features of the teachings of the present invention will be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the invention, such as features and / or beneficial effects of exemplary embodiments, will become apparent from the following description or may be learned through practice of specific embodiments according to the teachings of the present invention. Attached Figure Description

[0055] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the invention will now be described by way of example and with reference to the accompanying drawings, wherein:

[0056] Figure 1 This is a structural design drawing of a longitudinal watertight cable for a kilometer-deep-water equipment according to an embodiment of the present invention. Detailed Implementation

[0057] To better understand the technical content of the present invention, specific embodiments are described below in conjunction with the accompanying drawings.

[0058] Various aspects of the invention are described in this disclosure with reference to the accompanying drawings, which illustrate numerous illustrative embodiments. The embodiments of this disclosure are not necessarily intended to encompass all aspects of the invention. It should be understood that the various concepts and embodiments described above, as well as those described in more detail below, can be implemented in any of many ways, because the concepts and embodiments disclosed herein are not limited to any particular implementation. Furthermore, some aspects of the invention disclosed may be used alone or in any suitable combination with other aspects of the invention disclosed.

[0059] Combination Figure 1 As shown, the longitudinal watertight cable for kilometer-deep water equipment according to an embodiment of the present invention includes a longitudinal water-blocking cable core formed by stranding a longitudinal water-blocking conductor 1 and a conductor insulation layer 2 together with a hydrophilic water-blocking rope 3, and a first water-blocking tape layer 4-1, an inner sheath 5, a second water-blocking tape layer 4-2, a braided metal wire armor layer 6, a water-blocking shielding tape 7, a third water-blocking tape layer 4-3, and an outer sheath 8, which are designed layer by layer on the outer circumferential surface of the cable core.

[0060] In the process of twisting the longitudinal water-blocking cable core, a hydrophilic water-blocking rope 3 made of water-absorbing and expanding yarn is filled between the insulated wire cores. The hydrophilic water-blocking rope 3 is twisted together with the insulated wire core to form a cable. The remaining gap in the middle of the cable core is filled with hydrophobic sealant to form a longitudinal waterproof barrier.

[0061] Furthermore, each conductor is a longitudinally water-blocking stranded conductor 1, which is obtained by stranding multiple single wires together. During the stranding process, hydrophobic sealant is filled between the single wires to achieve a stable longitudinal water-blocking effect for each single wire.

[0062] In an embodiment of the present invention, the longitudinally water-blocking stranded conductor 1 is formed by stranding multiple single wires, such as tin-plated copper single wires, and the stranded single wires are filled with hydrophobic sealant.

[0063] Among them, the hydrophobic sealant is a hydrophobic adhesive material, which adopts an elastomer composite conductive water adhesive. It has excellent adhesion to copper conductors and temperature cycle stability. During heating / cooling temperature fluctuations, it will not shrink rapidly or expand significantly. While achieving stable water blocking, it will not affect the conductor resistance and current carrying capacity.

[0064] The conductor insulation layer 2, which is extruded over the longitudinally water-blocking stranded conductor 1, is double-extruded and consists of a bottom layer insulation bonded to the hydrophobic sealant filling between the stranded conductor 1 and the individual wires, and a surface layer insulation on the surface of the bottom layer insulation.

[0065] The inner insulation is extruded through an extrusion die to fill the gaps around the outermost conductor. Simultaneously, the stranded conductor is preheated before insulation extrusion to maintain its temperature at (50±10)℃, thereby increasing the adhesion between the stranded conductor, the hydrophobic sealant filling the conductor, and the inner insulation. The outer insulation is extruded using the same material as the inner insulation to ensure a tight bond between them.

[0066] After stranded conductor 1 is extruded with double-layer insulation, it forms an insulated wire core.

[0067] Based on this, multiple insulated wire cores are twisted together according to a predetermined pitch ratio to form a cable core with a circular cross-section. During the twisting process, a hydrophilic water-blocking rope 3 made of water-absorbing and expanding yarn is filled between the insulated wire cores. The hydrophilic water-blocking rope 3 is twisted together with the insulated wire cores to form a cable. The remaining gaps in the middle of the cable core are filled with hydrophobic sealant. The hydrophobic sealant always completely fills the gaps between the wire cores to form a longitudinal waterproof barrier.

[0068] In an embodiment of the present invention, the hydrophilic water-blocking rope 3 is composed of water-blocking yarn made of a water-blocking matrix and a microporous strip covering the water-blocking yarn. The inner water-blocking yarn expands when it comes into contact with water to achieve water blocking, and the outer microporous strip is used to prevent hydrophobic sealant from entering the interior of the water-blocking rope during cable production, and to reduce resistance when the water-blocking yarn expands outward when it comes into contact with water to ensure a seal.

[0069] Water-blocking tape is wrapped around the outer surface of the cable core in a double-layer overlapping manner in both directions to form the first water-blocking tape layer 4-1.

[0070] A water-resistant sheath material is used on the outer surface of the first water-blocking strip layer 4-1 to extrude the inner sheath 5.

[0071] Furthermore, a water-blocking strip is wrapped around the outer surface of the inner sheath 5 in a double-layer overlapping manner in both directions to form a second water-blocking strip layer 4-2.

[0072] Then, a braided metal wire armor layer 6, filled with hydrophobic sealant, is provided on the outer surface of the second water-blocking strip layer 4-2.

[0073] In an embodiment of the present invention, the braided metal wire armor layer 6 is a braided copper wire armor layer. After armoring, glue is injected to fill the gaps between the armor wires with hydrophobic sealant, and then the water-blocking shielding tape 7 is wrapped around it.

[0074] In an embodiment of the present invention, a water-blocking shielding tape 7 is wrapped around the outer surface of the braided metal wire armor layer. The water-blocking shielding tape is penetrated and bonded by the injected hydrophobic sealant and forms an integral seal with the braided metal wire armor layer.

[0075] Preferably, the water-blocking shielding tape 7 has a multi-layer composite structure, with an inner layer of copper or aluminum plating, a middle layer of polyester fiber film, and an outer layer coated with water-blocking powder, thus having both shielding and expansion-water-blocking functions.

[0076] To facilitate grounding and achieve shielding effect, the water-blocking shielding strip 7 is combined with a stranded copper wire drain line to form an overall shield.

[0077] Then, the water-blocking shielding strip 7 is wrapped around the outer surface of the water-blocking strip in a double-layer overlapping manner in both directions to form the third water-blocking strip layer 4-3.

[0078] Ideally, an outer sheath 8 should be extruded onto the outer surface of the third water-blocking layer 4-3 to form a protective layer for the entire cable structure.

[0079] The hydrophilic water-blocking rope 3, as well as the first water-blocking strip layer 4-1, the second water-blocking strip layer 4-2, and the third water-blocking strip layer 4-3, all use a mixed graft of anionic polyacrylamide and polyethylene glycol with a crosslinking agent as the water-blocking matrix. This water-blocking matrix is ​​a water-absorbing and swelling resin resistant to seawater salt ions, characterized by high water absorption, good water-blocking properties, heat stability, and good compatibility. Its expansion height and rate change upon contact with seawater are minimal. The water-blocking performance of the water-blocking rope and strip in laboratory seawater solutions as specified in DIN 50905-4 and ASTM D 1141 standards is as follows: expansion rate not less than 12 mm / min, and expansion height not less than 16 mm after immersion in seawater solution for 5 minutes.

[0080] In particular, the expansion rate, expansion height, and high temperature thermal stability of the hydrophilic water-blocking rope in deionized water meet the requirements of YD / T 1115.2-2001 "Water-blocking materials for communication cables and optical cables, Part 2: Water-blocking yarn", and the diameter of the water-blocking rope is 1.05 to 1.2 times the theoretically calculated diameter.

[0081] Based on the above structural design of the watertight cable of this invention, the longitudinal watertightness of the cable refers to its ability to prevent external water from seeping from one end of the cable along its length to the other end. There are two main types of water-blocking materials and processes used to achieve longitudinal watertightness in cables: hydrophilic filling and hydrophobic filling. Using either material alone has significant drawbacks and limitations in achieving watertightness, failing to meet the watertight requirements of deep-water equipment. For example, hydrophobic adhesives, due to their high viscosity and poor flowability, can easily leave small gaps in the cable unfilled, forming cavities and affecting water resistance. Conversely, hydrophilic water-swellable polymer materials, when filling larger gaps in the cable, tend to expand insufficiently to fill the gaps, also affecting water resistance. Therefore, this invention addresses the shortcomings of existing watertight cables by proposing the use of different water-blocking materials and composite processes between different cable components to achieve longitudinal water resistance under high water pressure.

[0082] This invention overcomes the shortcomings of the common practice of determining the longitudinal watertightness of cables by verification after production through improvements in the above-mentioned structural design and optimization of the composite process. After extensive testing and verification, this invention proposes a design for the longitudinal watertightness of cables based on calculations of the seepage length under predetermined pressure, taking into account structural parameters and the water absorption rate of the hydrophilic water-swellable polymer filler. The specific details are as follows:

[0083] During the stranding process, the water absorption and seepage length of the hydrophilic water-blocking rope 3, which is made of water-absorbing and expanding yarn stranded between the insulated wire cores, satisfies the following:

[0084]

[0085] Where L is the water penetration length under pressure, in meters; ΔF is the longitudinal watertightness test pressure, in MPa; R0 is the inner radius of the seepage channel, in mm; R1 is the outer radius of the seepage channel, in mm; σ is the kinematic viscosity of water at 20℃, in MPa·S; ρ is the water absorption expansion rate of the filled hydrophilic water-blocking rope, in mm / s; k1 is the compressibility coefficient of the cable in the radial direction; and k2 is the stranding coefficient of the insulated core when stranded into a cable.

[0086] Therefore, cables and their manufacturing processes that meet the permeability standards can be designed according to different usage environments and equipment requirements, and can meet the pressure resistance, seawater corrosion resistance and permeability resistance performance requirements of equipment in deep waters at depths of thousands of meters.

[0087] {Example 1}

[0088] The design of a longitudinal watertight cable for kilometer-deep-water equipment according to the foregoing embodiments of the present invention, as an example, includes the following cable manufacturing method:

[0089] (1) Conductor stranding and sealing glue injection

[0090] The stranded conductor 1 is made of multiple tin-plated copper single wires stranded together, and hydrophobic sealant is filled between the stranded single wires. The stranding pitch ratio is controlled at 10 to 15 times to increase the longitudinal water resistance of the hydrophobic sealant.

[0091] (2) Extrusion insulation

[0092] A double-layer, multi-stage extrusion insulation material is used on the outer surface of the stranded conductor 1. The inner insulation layer is extruded through an extrusion die to fill the gaps around the outermost conductor. Simultaneously, the stranded conductor 1 is preheated before insulation extrusion to maintain its temperature at 50±10℃, thereby increasing the adhesion between the stranded conductor, the hydrophobic sealant filling the conductor, and the inner insulation layer. The outer insulation layer is extruded using the same material as the inner insulation layer to ensure a tight bond. After the stranded conductor 1 is extruded with double insulation, it forms an insulated wire core.

[0093] (3) Stranded into cable

[0094] The insulated wire cores are twisted into a cable at a pitch ratio of 15±5. The insulated wire cores are filled with a composite sealing process. Several hydrophilic water-blocking ropes 3 made of water-absorbing and expanding yarn are filled between the insulated wire cores. The hydrophilic water-blocking ropes 3 are twisted together with the insulated wire cores to form a cable. The remaining gaps in the middle of the cable cores are filled with hydrophobic adhesive as a central sealant 9. The hydrophobic adhesive completely fills the gaps between the wire cores to form a longitudinal waterproof barrier.

[0095] (4) Wrap the first water-blocking strip layer

[0096] The first water-blocking tape layer 4-1 is wrapped around the outer surface of the cable core in two overlapping layers in both directions, with an overlap rate of 40-50%.

[0097] (5) Inner sheath of the extrusion package

[0098] The inner sheath 5 is extruded with water-blocking sheath material on the outer surface of the first water-blocking strip layer 4-1.

[0099] (6) Wrap the second water-blocking layer

[0100] The water-blocking strip is wrapped around the outer surface of the inner sheath 5 in a double-layer overlapping manner in both directions to form the second water-blocking strip layer 4-2, with an overlap rate of 40-50%.

[0101] (7) Woven Armor

[0102] A braided metal wire armor layer 6 for injecting hydrophobic sealant is prepared on the outer surface of the second water-blocking strip layer 4-2. The braided copper wire armor layer is wrapped around the outer surface of the second water-blocking strip layer 4-2. After armoring, the sealant is injected to fill the gaps in the armor wires with hydrophobic sealant.

[0103] (8) Water-blocking shielding tape

[0104] The water-blocking shielding tape 7 is wrapped around the outer surface of the braided metal wire armor layer. The water-blocking shielding tape is penetrated and bonded by the injected hydrophobic sealant and forms an integral seal with the braided metal wire armor layer.

[0105] The water-blocking shielding strip 7 has a multi-layer composite structure, with an inner layer of copper or aluminum plating, a middle layer of polyester fiber film, and an outer layer coated with water-blocking powder. It has both shielding and expansion water-blocking functions. The water-blocking shielding strip 7 is combined with a stranded copper wire drain line to form an overall shield.

[0106] (8) Wrap the third water-blocking layer

[0107] The water-blocking tape is wrapped around the outer surface of the shielding tape in a double-layer overlapping manner in both directions to form the third water-blocking tape layer 4-3.

[0108] (9) Extrusion outer sheath

[0109] An outer sheath 8 is extruded onto the outer surface of the third water-blocking layer 4-3;

[0110] The hydrophilic water-blocking rope 3, as well as the first water-blocking tape layer 4-1, the second water-blocking tape layer 4-2, and the third water-blocking tape layer 4-3, all use anionic polyacrylamide and a mixed graft of polyethylene glycol and a crosslinking agent as the water-blocking matrix. Their water penetration length and water absorption rate satisfy the following requirements for the cable core:

[0111]

[0112] Where L is the water penetration length under pressure, in meters; ΔF is the longitudinal watertightness test pressure, in MPa; R0 is the inner radius of the seepage channel, in mm; R1 is the outer radius of the seepage channel, in mm; σ is the kinematic viscosity of water at 20℃, in MPa·S; ρ is the water absorption expansion rate of the filled hydrophilic water-blocking rope, in mm / s; k1 is the compressibility coefficient of the cable in the radial direction; and k2 is the stranding coefficient of the insulated core when stranded into a cable.

[0113] In a preferred embodiment, the hydrophilic water-blocking rope 3 is composed of water-blocking yarn made of a water-blocking matrix and a microporous strip covering the water-blocking yarn. The inner water-blocking yarn expands when it comes into contact with water to achieve water blocking, and the outer microporous strip is used to prevent hydrophobic sealant from entering the interior of the water-blocking rope during cable production, and to reduce resistance when the water-blocking yarn expands outward when it comes into contact with water to ensure a seal.

[0114] {Example 2}

[0115] Below, we will describe the implementation process of the above embodiments of the present invention in more detail with a specific example.

[0116] Conductor stranding and sealing: The conductor is made of 7, 19 or 37 tinned copper single wires stranded together. The stranded single wires are filled with hydrophobic sealant. The stranding pitch ratio is controlled at (10 to 15) times to increase the longitudinal water resistance of the sealant.

[0117] The hydrophobic sealant is a hydrophobic material made from commercially available elastomeric composite water-based adhesive. It has excellent adhesion to copper conductors and resistance to temperature cycling. During heating / cooling temperature fluctuations, it will not shrink rapidly or expand significantly. While achieving stable water blocking, it will not affect the conductor resistance and current carrying capacity.

[0118] In this embodiment, the properties of the hydrophobic sealant are as follows:

[0119] Melt Flow Index (50±10)g / 10min@150℃ Processing temperature (180±10)℃ coefficient of thermal expansion ≤8％ High temperature thermal stability No dripping occurs at 150℃ for 24 hours. Low temperature stability Keeps soft at -45℃

[0120] The conductor sealing and injection is completed simultaneously during conductor stranding.

[0121] During the stranding process of the conductor wires, the conductor wires are stranded by a tube stranding machine. Before the single wires are formed into a conical shape and rotated into the stranding and merging mold by passing through the wire separator, a heated pressure plate unloading machine is used to heat and melt the hydrophobic sealant. The sealant is then pressed into the channel set on the top of the merging mold sleeve through a conveying hose, thus entering the mold sleeve's glue cavity and forming a glue pool. As the conductor continues to rotate forward into the glue cavity and merging mold, the molten hydrophobic sealant is pushed into the mold and continuously deposited on the single wire. The conductor continues to move forward through the sizing mold, causing the hydrophobic sealant to compactly fill the gaps between the stranded conductors.

[0122] During this process, closed-loop feedback can be provided to the pressure plate unloader and regulating valve through optical scanners and sensors to control the flow rate of hydrophobic sealant, so as to achieve full loading of the sealant cavity and ensure that the hydrophobic sealant always completely fills the conductor gap, forming a longitudinal waterproof barrier.

[0123] Extruded insulation: The conductor insulation layer is formed by double-layer extrusion of insulation material. The inner insulation layer of the conductor insulation has an extrusion thickness of (0.20±0.05) mm. It is extruded through an extrusion die to fill the gaps on the outermost conductor. At the same time, the conductor is preheated before insulation extrusion to keep the conductor temperature at (50±10)℃ to increase the adhesion between the stranded conductor, the hydrophobic sealant filling the conductor, and the insulation.

[0124] The outer insulation layer is extruded according to specific needs and can be made of the same commercial insulation material as the inner layer, including but not limited to polyvinyl chloride (PVC), polyethylene, etc., so that it is tightly bonded to the inner insulation layer.

[0125] Stranded cable: The insulated cores are stranded into a cable with a pitch ratio of (15±5). The cores are filled with a composite sealing process. Several hydrophilic water-blocking ropes 3 made of water-absorbing and expanding yarns resistant to seawater corrosion are set between the insulated cores. The expansion rate, expansion height and high temperature thermal stability of the water-blocking ropes in deionized water meet the requirements of YD / T 1115.2-2001 "Water-blocking materials for communication cables and optical cables, part 2: water-blocking yarn". The diameter of the water-blocking rope is 1.05 to 1.2 times the theoretically calculated diameter. The water-blocking ropes are stranded together with the insulated cores into a cable. The remaining gaps in the middle of the cable cores are filled with hydrophobic sealant.

[0126] The cabling process is carried out on a cage stranding machine. Its glue injection process is similar to that of conductor glue injection. It can provide closed-loop feedback to the pressure plate unloading machine and regulating valve through optical scanners and sensors to control the flow of hydrophobic sealant to achieve full loading of the glue cavity, so that the hydrophobic sealant always completely fills the gaps of the wire core, forming a longitudinal waterproof barrier.

[0127] Then, a double-layered, high-expansion, seawater-resistant, corrosion-resistant water-blocking tape with a thickness of 0.25mm to 0.3mm is wrapped around the outside of the cable core in both directions, with an overlap rate of 40% to 50%, forming the first water-blocking tape layer. The expansion rate, expansion height, and high-temperature thermal stability of the double-layered, seawater-resistant, corrosion-resistant water-blocking tape in deionized water should meet the requirements of JB / T 10259-2014 "Requirements for Water-Blocking Tape for Cables and Optical Cables".

[0128] It should be understood that, in the embodiments of the present invention, the water-blocking matrix of the seawater-resistant water-blocking rope and water-blocking tape is a mixed graft of anionic polyacrylamide and polyethylene glycol with a crosslinking agent. This is a water-absorbing and swelling resin resistant to seawater salt ions, characterized by high water absorption, good water blocking properties, heat stability, and good compatibility. The expansion height and rate change upon contact with seawater are minimal. The water-blocking performance of the water-blocking rope and water-blocking tape in laboratory seawater solutions as specified in DIN 50905-4 and ASTM D 1141 standards is as follows: expansion rate not less than 12 mm / min, and expansion height not less than 16 mm after immersion in seawater solution for 5 minutes.

[0129] The seawater corrosion resistant water-blocking rope consists of water-blocking yarn and a microporous tape covering the water-blocking yarn. The inner water-blocking yarn can expand and block water when it comes into contact with water, while the outer microporous tape can prevent hydrophobic sealant from entering the water-blocking rope during cable production. It also reduces resistance when the water-blocking yarn expands outward when it comes into contact with water, thus ensuring a seal.

[0130] Inner sheath: The inner sheath is extruded from the outer surface of the first water-blocking strip layer using water-blocking sheath material such as chlorosulfonated polyethylene, chloroprene rubber, high-density polyethylene, polyether polyurethane, or ethylene-vinyl acetate copolymer.

[0131] Armor and outer sheath: The inner sheath is wrapped with a water-resistant, high-expansion water-blocking tape or a melt-sealing water-blocking tape to form a second water-blocking tape layer. Then, copper wire armor is woven on its outer surface. After armoring, glue is injected to fill the gaps between the armor wires with hydrophobic sealant.

[0132] Then, an armored outer layer of water-blocking shielding tape (including drainage lines) is wrapped around it, followed by an overlapping and molten sealing water-blocking tape to form a third water-blocking layer. Finally, waterproof chlorosulfonated polyethylene, neoprene rubber, high-density polyethylene, polyether polyurethane, or ethylene-vinyl acetate copolymer is extruded to form an outer sheath.

[0133] The water-blocking shielding tape adopts a multi-layer composite structure, with an inner layer of copper or aluminum plating, a middle layer of polyester fiber film, and an outer layer coated with water-blocking powder, which has the dual functions of shielding and expansion water blocking.

[0134] To facilitate grounding and achieve a shielding effect, the water-blocking shielding strip is combined with a stranded copper wire drain line to form an overall shield.

[0135] Combining the longitudinal watertight cable and its manufacturing process proposed in the above embodiments, on the one hand, the watertight performance of the cable under predetermined pressure is calculated based on structural parameters, the water absorption rate of the hydrophilic water-swellable polymer filler, the seepage length, and the force of the hydrophobic sealant. This allows for proactive design of the cable's longitudinal watertight performance, meeting the standards and requirements for longitudinal sealing at depths of up to 1,000 meters, and enabling proactive design based on different depth environments. On the other hand, the application of a composite structure of hydrophobic and hydrophilic water-blocking materials achieves the longitudinal watertight requirements of equipment at depths of up to 1,000 meters. The preheating of the adhesive and the automatic flow control of the adhesive injection process ensure uniform and consistent sealing at each stage, guaranteeing watertightness in deep-sea environments. Furthermore, the use of seawater-resistant corrosion-resistant water-blocking tape ensures reliable longitudinal watertightness in seawater conditions. Simultaneously, the structural improvements and composite process design of the watertight cable of this invention reduce the bending radius of the longitudinal watertight cable to no more than 5 times the cable's outer diameter.

[0136] Comparison of key performance characteristics of the longitudinal watertight cable of the present invention with existing longitudinal watertight cables

[0137]

[0138] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A longitudinal watertight cable for kilometer-deep-water equipment, characterized in that, include: The longitudinally water-blocking stranded conductor (1) is formed by stranding multiple single wires together, and the stranded single wires are filled with hydrophobic sealant. The conductor insulation layer (2) is extruded onto the longitudinal water-blocking stranded conductor (1), and the stranded conductor (1) and the conductor insulation layer (2) form an insulated core; A cable core with a circular cross section is formed by twisting multiple insulated wire cores according to a predetermined pitch ratio. During the twisting process, a hydrophilic water-blocking rope (3) made of water-absorbing and expanding yarn is filled between the insulated wire cores. The hydrophilic water-blocking rope (3) is twisted together with the insulated wire cores to form a cable. The remaining gap in the middle of the cable core is filled with hydrophobic sealant as a central seal filler (9). The water-blocking tape is wrapped around the outer surface of the cable core in a double-layer overlapping manner in both directions to form the first water-blocking tape layer (4-1). An inner sheath (5) is extruded onto the outer surface of the first water-blocking strip layer (4-1). The water-blocking strip is wrapped around the outer surface of the inner sheath (5) in a double-layer overlapping manner in both directions to form the second water-blocking strip layer (4-2). A braided metal wire armor layer (6) filled with hydrophobic sealant is provided on the outer surface of the second water-blocking strip layer (4-2). A water-blocking shielding tape (7) is wrapped around the outer surface of the braided metal wire armor layer. The water-blocking shielding tape is penetrated and bonded by the injected hydrophobic sealant and forms an integral seal with the braided metal wire armor layer. The water-blocking shielding strip is wrapped around its outer surface in a double-layered, overlapping manner to form a third water-blocking strip layer (4-3); and An outer sheath (8) is extruded onto the outer surface of the third water-blocking strip layer (4-3); Among them, the hydrophilic water-blocking rope (3) and the first water-blocking strip layer (4-1), the second water-blocking strip layer (4-2), and the third water-blocking strip layer (4-3) all use anionic polyacrylamide and polyethylene glycol and crosslinking agent as a mixed graft as the water-blocking matrix. The hydrophilic water-blocking rope (3) is composed of water-blocking yarn made of water-blocking matrix and microporous tape covering the water-blocking yarn. The water-blocking yarn inside expands when it comes into contact with water to achieve water blocking. The microporous tape outside is used to prevent hydrophobic sealant from entering the interior of the water-blocking rope during cable production. It also reduces resistance when the water-blocking yarn expands outward when it comes into contact with water to ensure sealing.

2. The longitudinal watertight cable for kilometer-deep-water equipment according to claim 1, characterized in that, The conductor insulation layer (2) is double-extruded, consisting of a bottom layer insulation bonded to the stranded conductor (1) and the hydrophobic sealant filling between the single wires, and a surface layer insulation on the surface of the bottom layer insulation.

3. The longitudinal watertight cable for kilometer-deep-water equipment according to claim 1, characterized in that, The braided metal wire armor layer (6) is a braided copper wire armor layer. After armoring, glue is injected to fill the gaps in the armor wires with hydrophobic sealant, and then a water-blocking shielding tape (7) is wrapped around it.

4. The longitudinal watertight cable for kilometer-deep-water equipment according to claim 1, characterized in that, The water-blocking shielding tape (7) has a multi-layer composite structure, with an inner layer of copper or aluminum plating, a middle layer of polyester fiber film, and an outer layer coated with water-blocking powder, which has both shielding and expansion water-blocking functions.

5. The longitudinal watertight cable for kilometer-deep-water equipment according to claim 4, characterized in that, The water-blocking shielding strip (7) is combined with a stranded copper wire drain line to form an overall shield.

6. A longitudinal watertight cable for kilometer-deepwater equipment according to any one of claims 1-5, characterized in that, The longitudinal watertight cable is configured as follows: During the stranding process, the water absorption and seepage length of the hydrophilic water-blocking rope (3) made of water-absorbing and expanding yarn stranded between the insulating wire cores satisfies: ； Where L is the permeation length of water under pressure, in meters; This is the longitudinal watertightness test pressure, in MPa; It is the inner radius of the seepage channel, in mm; It is the outer radius of the seepage channel, in mm; It is the kinematic viscosity of water at 20°C, measured in MPa·s; is the water absorption and expansion rate of the filled hydrophilic water-blocking rope, in mm / s; k1 is the compressibility coefficient of the cable in the radial direction; k2 is the stranding coefficient of the insulated core when stranded into a cable.

7. A method for manufacturing a longitudinal watertight cable for kilometer-deep-water equipment according to any one of claims 1-6, characterized in that, Includes the following steps: (1) Conductor stranding and sealing glue injection The stranded conductor (1) is made of multiple tin-plated copper single wires stranded together. The stranded single wires are filled with hydrophobic sealant. The stranding pitch ratio is controlled at (10~15) times to increase the longitudinal water resistance of the hydrophobic sealant. (2) Extrusion insulation Double-layer extruded insulation material is used on the outer surface of the stranded conductor (1). The inner insulation is extruded through an extrusion die to fill the gaps around the outermost conductor. At the same time, the stranded conductor (1) is preheated before the insulation is extruded to keep the temperature of the stranded conductor (1) at (50±10)℃ to increase the adhesion between the stranded conductor, the hydrophobic sealant filling the conductor, and the inner insulation. The outer insulation is extruded with the same material as the inner insulation to make it tightly bonded to the inner insulation. After the stranded conductor (1) is extruded with double insulation, it forms an insulated core. (3) Stranded into cable The insulated wire cores are twisted into a cable with a pitch ratio of (15±5). The insulated wire cores are filled with a composite sealing process. Several hydrophilic water-blocking ropes (3) made of water-absorbing and expanding yarn are filled between the insulated wire cores. The hydrophilic water-blocking ropes (3) are twisted together with the insulated wire cores to form a cable. The remaining gaps in the middle of the cable cores are filled with hydrophobic adhesive. The hydrophobic adhesive completely fills the gaps between the wire cores to form a longitudinal waterproof barrier. (4) Wrap the first water-blocking strip layer The first water-blocking strip layer (4-1) is wrapped around the outer surface of the cable core in two overlapping layers in both directions, with an overlap rate of 40-50%. (5) Inner sheath of the extrusion package A water-blocking sheath material is extruded onto the outer surface of the first water-blocking strip layer (4-1) to form an inner sheath (5); (6) Wrap the second water-blocking strip layer The water-blocking strip is wrapped around the outer surface of the inner sheath (5) in a double-layer overlapping manner to form the second water-blocking strip layer (4-2), with an overlap rate of 40-50%. (7) Woven Armor A braided metal wire armor layer (6) for injecting hydrophobic sealant is prepared on the outer surface of the second water-blocking strip layer (4-2). The braided copper wire armor layer is wrapped around the outer surface of the second water-blocking strip layer (4-2). After armoring, the sealant is injected to fill the gaps in the armor wires with hydrophobic sealant. (8) Water-blocking shielding tape The water-blocking shielding tape (7) wrapped around the outer surface of the braided metal wire armor layer is penetrated and bonded by the injected hydrophobic sealant and forms an integral seal with the braided metal wire armor layer. Among them, the water-blocking shielding tape (7) is a multi-layer composite structure, with an inner layer of copper or aluminum plating, a middle layer of polyester fiber film, and an outer layer coated with water-blocking powder, which has both shielding and expansion water-blocking functions. The water-blocking shielding tape (7) is combined with a stranded copper wire drain line to form an overall shield. (9) Wrap the third water-blocking layer The water-blocking tape is wrapped around the outer surface of the shielding tape in a double-layer overlapping manner in both directions to form the third water-blocking tape layer (4-3). (10) Extrusion outer sheath An outer sheath (8) is extruded onto the outer surface of the third water-blocking strip layer (4-3); The hydrophilic water-blocking rope (3), the first water-blocking tape layer (4-1), the second water-blocking tape layer (4-2), and the third water-blocking tape layer (4-3) all use anionic polyacrylamide and polyethylene glycol and crosslinking agent as a mixed graft as the water-blocking matrix, and their water penetration length and water absorption rate meet the requirements of the cable core: ； Where L is the permeation length of water under pressure, in meters; This is the longitudinal watertightness test pressure, in MPa; It is the inner radius of the seepage channel, in mm; It is the outer radius of the seepage channel, in mm; It is the kinematic viscosity of water at 20°C, measured in MPa·s; is the water absorption and expansion rate of the filled hydrophilic water-blocking rope, in mm / s; k1 is the compressibility coefficient of the cable in the radial direction; k2 is the stranding coefficient of the insulated core when stranded into a cable.

8. The method for preparing a longitudinal watertight cable for kilometer-deep-water equipment according to claim 7, characterized in that, The hydrophilic water-blocking rope (3) is composed of water-blocking yarn made of water-blocking matrix and microporous tape covering the water-blocking yarn. The water-blocking yarn inside expands when it comes into contact with water to achieve water blocking. The microporous tape outside is used to prevent hydrophobic sealant from entering the interior of the water-blocking rope during cable production. It also reduces resistance when the water-blocking yarn expands outward when it comes into contact with water to ensure sealing.

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