Medium-voltage large-section comprehensive sheath power cable

Abstract

The utility model relates to the technical field of power cables, and discloses a medium-voltage large-section comprehensive sheath power cable, which comprises a polyethylene outer sheath, a steel tape armoring layer is arranged on the inner side of the polyethylene outer sheath, a polyethylene inner sheath is arranged on the inner side of the steel tape armoring layer, an aluminum composite tape is tightly arranged on the inner wall of the polyethylene inner sheath, and the aluminum composite tape is tightly arranged on the inner wall of the polyethylene inner sheath. The inner side of the aluminum composite tape is provided with a water-blocking tape wrapping layer, the inner side of the water-blocking tape wrapping layer is provided with a pp water-absorbing rope filler, the inner side of the pp water-absorbing rope filler is provided with a metal shield, and the inner side of the metal shield is provided with an insulation shielding layer. According to the medium-voltage large-cross-section comprehensive sheath power cable, in the working and using process of the medium-voltage large-cross-section comprehensive sheath power cable, the production technology and the manufacturing technology are easy to achieve, the cable is simple in structural design and high in reliability, the structure is compact and seamless through the multi-layer water-blocking design, the service life of the water-blocking cable is prolonged, and the service life of the cable is prolonged. And the water-blocking performance of the product is effectively improved.

Description

Technical Field

[0001] The utility model relates to the technical field of engineering construction, in particular to a medium-voltage large-section integrated sheath power cable. Background Art

[0002] Wires and cables have evolved from simple power transmission to multifunctionality, that is, some new features have been added according to different uses. For example: flame-retardant cables, fire-resistant cables, low-halogen and low-smoke cables, halogen-free and low-smoke cables, water-blocking cables, etc. The requirements for water-blocking of power cables have also developed in recent years. In the past, the requirements for water-blocking were mainly limited to submarine cables, ultra-high voltage cables and communication cables. With the deepening of research and understanding of insulation water absorption and water trees, people are increasingly aware of the importance of waterproof performance to medium and high voltage power cables, and more and more users have put forward waterproof requirements for cables.

[0003] After searching, the existing patent (publication number: CN205595108U) discloses a power cable, including an outer sheath, an insulating layer, an armor layer, a conductor shielding layer and a central conductor, the insulating layer, the armor layer, the conductor shielding layer and the central conductor are all located in the outer sheath, and wrap the central conductor layer by layer, the armor layer is a low-carbon steel armor layer, the surface of the armor layer is coated with a lubricant, the inner surface of the conductor shielding layer is bonded with a conductive cloth pad, the central conductor is a rare earth aluminum alloy conductor plate, a telescopic device is arranged on the central conductor, the central conductor is hingedly connected to the telescopic device, the central conductor is arranged in a zigzag shape, a gap is arranged between the central conductor and the conductor shielding layer, and a conductive rubber is arranged in the gap. The power cable has a novel design, a reasonable structure, and is convenient and practical.

[0004] However, the current domestic production of water-blocking cables has a structure of water-blocking conductor + insulation + conventional sheath design. The conventional water-blocking power cables produced do not consider complete water-blocking design during the production process. There are gaps between layers, and they do not meet the requirements of water-blocking cables in a strict sense. Due to the simple production process, the water-blocking effect is not very ideal.

[0005] Therefore, in order to solve the above problems, a medium voltage large-section composite sheath power cable is proposed. Utility Model Content

[0006] 1. Technical issues to be resolved

[0007] In view of the deficiencies in the prior art, the utility model provides a medium-voltage large-section integrated sheathed power cable, which solves the problem mentioned in the above background technology that the domestically produced water-blocking cables are mostly designed with a water-blocking conductor + insulation + conventional sheath. The conventional water-blocking power cables produced do not consider a complete water-blocking design during the production process, and there are gaps between the layers, which do not meet the requirements of water-blocking cables in a strict sense. Due to the relatively simple production process, the water-blocking effect is not very ideal.

[0008] (II) Technical solution

[0009] To achieve the above-mentioned purpose, the utility model provides the following technical solutions: a medium-voltage large-section composite sheath power cable, comprising a polyethylene outer sheath, a steel belt armor layer is arranged on the inner side of the polyethylene outer sheath, a polyethylene inner sheath is arranged on the inner side of the steel belt armor layer, an aluminum composite tape is tightly arranged on the inner wall of the polyethylene inner sheath, a water-blocking tape wrapping layer is arranged on the inner side of the aluminum composite tape, a PP water-absorbing rope filling is arranged on the inner side of the water-blocking tape wrapping layer, a metal shield is arranged on the inner side of the PP water-absorbing rope filling, an insulating shielding layer is arranged on the inner side of the metal shielding, a cross-linked polyethylene insulation is arranged on the inner side of the insulating shielding layer, a conductor shielding layer is arranged on the inner side of the cross-linked polyethylene insulation, and a profiled wire water-blocking conductor is arranged on the inner side of the conductor shielding layer.

[0010] As a preferred solution, the shaped wire water-blocking conductor adopts a single-layer longitudinal wrapping method, and the compression coefficient of the shaped wire water-blocking conductor is above 0.95.

[0011] As a preferred solution, the insulating shielding layer, the cross-linked polyethylene insulation layer and the conductor shielding layer are cross-linked three-layer co-extruded.

[0012] As a preferred solution, the material of the insulating shielding layer is a water-tree resistant cross-linked polyethylene material, the material of the cross-linked polyethylene insulation is a water-tree resistant cross-linked polyethylene material, and the material of the conductor shielding layer is a water-tree resistant cross-linked polyethylene material.

[0013] As a preferred solution, the metal shielding is a non-differentiated copper tape shielding.

[0014] As a preferred solution, when the PP water-absorbing rope is filled into a cable, a layer of water-blocking tape is added to the filling rope.

[0015] As a preferred solution, the polyethylene inner sheath is made of medium-density polyethylene material, and the aluminum composite tape is a double-film aluminum composite tape.

[0016] As a preferred solution, the water-blocking tape wrapping layer is a 0.8 mm thick galvanized steel tape.

[0017] As a preferred solution, the polyethylene inner sheath fits tightly with the aluminum composite belt, the front end of the aluminum composite belt is flat and gradually shrinks into a cylindrical shape along the forward direction of the aluminum belt, and the length of the aluminum composite belt is greater than 50 cm.

[0018] As a preferred solution, the polyethylene outer sheath is made of polyethylene material to enhance the waterproof effect, achieving multi-layer waterproof and complete waterproof effects.

[0019] The utility model provides a medium voltage large cross-section integrated sheath power cable. It has the following beneficial effects:

[0020] (1) The medium-voltage large-section integrated sheath power cable has an easy-to-implement production process and manufacturing technology during its operation. The cable structure is simple in design and has high reliability. The multi-layer water-blocking design makes the structure tight and seamless, thereby improving the service life of the water-blocking cable and effectively increasing the water-blocking performance of the product. The cable not only has longitudinal water-blocking but also multi-layer radial water-blocking capabilities. The insulating material is made of water-tree-resistant material. The structure is embodied in the water-blocking conductor, water-absorbing PP filling rope, water-blocking tape, longitudinal aluminum composite tape + polyethylene structure, and outer polyethylene. The gaps between the layers are tightly connected, thereby achieving maximum water-blocking in the radial direction. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the side view of the appearance structure of the utility model;

[0022] Figure 2 This is a schematic diagram of the structure of the insulation shielding layer and the cross-linked polyethylene insulation of the utility model cooperating with each other;

[0023] Figure 3 It is a schematic diagram of the planar structure of the utility model.

[0024] Among them: 1. Polyethylene outer sheath; 2. Steel belt armor layer; 3. Polyethylene inner sheath; 4. Aluminum composite tape; 5. Water-blocking tape wrapping layer; 6. PP absorbent rope filling; 7. Metal shielding; 8. Insulation shielding layer; 9. Cross-linked polyethylene insulation; 10. Conductor shielding layer; 11. Type water-blocking conductor. DETAILED DESCRIPTION

[0025] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0026] See also Figures 1 to 3The utility model provides a technical solution: a medium-voltage large-section integrated sheath power cable, comprising a polyethylene outer sheath 1, a steel belt armor layer 2 is arranged on the inner side of the polyethylene outer sheath 1, a polyethylene inner sheath 3 is arranged on the inner side of the steel belt armor layer 2, an aluminum composite tape 4 is tightly arranged on the inner wall of the polyethylene inner sheath 3, a water-blocking tape wrapping layer 5 is arranged on the inner side of the aluminum composite tape 4, a PP water-absorbing rope filling 6 is arranged on the inner side of the water-blocking tape wrapping layer 5, a metal shielding 7 is arranged on the inner side of the PP water-absorbing rope filling 6, an insulating shielding layer 8 is arranged on the inner side of the metal shielding 7, a cross-linked polyethylene insulation 9 is arranged on the inner side of the insulating shielding layer 8, a conductor shielding layer 10 is arranged on the inner side of the cross-linked polyethylene insulation 9, and a profiled wire water-blocking conductor 11 is arranged on the inner side of the conductor shielding layer 10.

[0027] Furthermore, the profiled wire water-blocking conductor 11 is wrapped in a single-layer longitudinal manner, and the compression coefficient of the profiled wire water-blocking conductor 11 is greater than 0.95.

[0028] Furthermore, the insulating shielding layer 8, the cross-linked polyethylene insulation 9 and the conductor shielding layer 10 are cross-linked three-layer co-extruded.

[0029] Furthermore, the material of the insulating shielding layer 8 is a water-tree resistant cross-linked polyethylene material, the material of the cross-linked polyethylene insulation 9 is a water-tree resistant cross-linked polyethylene material, and the material of the conductor shielding layer 10 is a water-tree resistant cross-linked polyethylene material.

[0030] Furthermore, the metal shielding 7 is a non-differentiated copper tape shielding.

[0031] Furthermore, when the PP water-absorbing rope is filled to 60%, a layer of water-blocking tape is added to the filling rope.

[0032] Furthermore, the polyethylene inner sheath 3 is made of medium-density polyethylene material, and the aluminum composite tape 4 is a double-film aluminum composite tape 4 .

[0033] Furthermore, the water-blocking tape wrapping layer 5 is a galvanized steel tape with a thickness of 0.8 mm.

[0034] Furthermore, the polyethylene inner sheath 3 is tightly fitted to the aluminum composite belt 4, the front end of the aluminum composite belt 4 is flat and gradually shrinks into a cylindrical shape along the forward direction of the aluminum belt, and the length of the aluminum composite belt 4 is greater than 50 cm.

[0035] Furthermore, the polyethylene outer sheath 1 is made of polyethylene material to enhance the waterproof effect, achieving multi-layer waterproof and complete waterproof effects.

[0036] The working principle of the utility model is: step one, manufacturing of the profiled wire water-blocking conductor 11: longitudinally wrapping a layer of single-sided insulating water-blocking tape on each layer of the conductor, and the production process control process adopts a single-layer longitudinal wrapping method; during the entire manufacturing process of the profiled wire conductor, through layered water-blocking filling, the profiled wire water-blocking conductor 11 itself has the characteristic of very small single-filament gap, and is proportioned through a trapezoidal mold design with a high deformation rate, and the compression coefficient is above 0.95, so that the theoretical and practical gaps between the conductors are minimized, and water leakage to the inside is completely prevented from occurring from the conductor gaps. A layer of single-sided water-blocking binding tape is wrapped between the outermost layer of the conductor and the conductor shielding. This binding tape is superior in toughness and water-blocking performance, and the production process control process adopts an overlapping wrapping method, and the overlap rate is at least 55%.

[0037] Step 2: The insulating shielding layer 8, the cross-linked polyethylene insulation 9, and the conductor shielding layer 10 are cross-linked in three layers and co-extruded, and the extrusion process temperature adopts a low-temperature extrusion process; the cross-linked three-layer co-extrusion mostly adopts water-tree-resistant cross-linked polyethylene material as the main insulating material, and the base material of the cross-linked polyethylene insulation 9 is a polyethylene mixture. The polyethylene itself has good water-blocking properties. The highest level of water-blocking control is carried out on the raw materials to increase the service life of the cable. From the production process, the production speed and production process temperature need to be formulated. In theory, the slower the production speed is, the better it is without burning the insulating shield. This will greatly improve the gas residue and control inside the insulating layer. The process temperature adopts a low-temperature extrusion process to effectively resist dripping and reduce gas generation.

[0038] Step 3: For the degassing process of the gas inside the insulation layer, the temperature control range is between 60 and 65°C, and the degassing time is controlled within 192 hours. Through the summary and analysis of the theoretical data of degassing of the insulating core, the gas degassing speed and degassing degree reach the highest level at the appropriate temperature. Too low or too high temperature is not conducive to the control of the gas inside the insulation. In addition, when degassing large-section cables, high temperature settings may cause compression and deformation to the insulation. The appropriate temperature control range is between 60 and 65°C. Strictly speaking, our degassing time is controlled within 192 hours, but in order to speed up the flow, the time can be 24 hours. Under this condition, there is generally no air gap in the cross-linked core in the entire cable, and it can flow to the next production process only after degassing is completed.

[0039] Step 4: Non-differentiated copper tape shielding.

[0040] Step 5: Cabling process: Use water-absorbent PP filling rope and add a layer of water-blocking tape.

[0041] Step 6: The polyethylene inner sheath 3 is made of medium-density polyethylene. Polyethylene itself has a good waterproof effect. Its water tightness is hundreds of times that of polyvinyl chloride. The thickness can meet international standards. When the cable is in water or humid environment for a long time, the radial water-blocking ability of polyethylene becomes insufficient. Now, an aluminum composite tape 4 is tightly longitudinally wrapped in front of the polyethylene inner sheath. The combination of the two is theoretically thousands of times more water-tight than single polyethylene. In the manufacturing process, if you want the aluminum composite tape 4 to fit tightly on the large-section three-core power cable, it is a crucial step in the comprehensive sheath. The key process is divided into two aspects. One is the longitudinal wrapping process, which requires tightness and roundness. The front end of the longitudinal wrapping Taichung aluminum tape preforming mold is flat and gradually shrinks into a cylindrical shape along the forward direction of the aluminum tape. The length is kept above 50cm as much as possible, because the angle can be as small as possible when the preforming mold gradually becomes cylindrical, so that the aluminum tape is not easy to deform. The flat front end must have a downward chamfer to prevent the aluminum tape from being scratched when the aluminum tape is fed into the line, causing the tape to break. The cylindrical end of the preforming mold is about 3-4mm larger than the actual cable core. After the preforming mold is a sizing mold to lock the aluminum tape into a tubular structure. The sizing mold is selected to be larger than the outer surface of the wire core. The diameter is preferably 1.5-2mm. A pressing plate is used between the preforming die and the sizing die to press on the overlap of the aluminum strip to make the surface of the aluminum strip as flat as possible. The second is the bonding process. The bonding is divided into two aspects. One is the bonding of the aluminum strip overlap and the other is the bonding of the aluminum strip and polyethylene. There are two ways to overlap the aluminum strip, one is burning and the other is hot melt adhesive. This patent uses hot melt adhesive. The advantages of choosing hot melt adhesive are fast curing, no pollution, low energy consumption, and high safety factor. The purchased aluminum composite tape 4 is a double-film aluminum composite tape, the thickness of the unilateral copolymer film is 0.055mm, and the heat sealing strength is above 20N / cm. The aluminum composite tape 4 is bonded to polyethylene by high-temperature and low-speed extrusion. The extrusion port temperature is 180-185°C. When the aluminum composite tape 4 encounters high-temperature polyethylene, the copolymer on the aluminum composite tape 4 will quickly fuse and bond with the polyethylene and fit tightly. The polyethylene at high temperature will shrink rapidly when encountering cooling water to strengthen the close fit with the aluminum composite tape 4.

[0042] Step 7. Wrap two layers of 0.8mm thick galvanized steel tape around the gap to strengthen the protection of the cable core.

[0043] Step 8: Use of polyethylene outer sheath 1: Continue to use medium-density polyethylene sheath to enhance the waterproof effect, achieving multi-layer waterproof and complete waterproof effect.

[0044] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A medium voltage large cross-section composite sheath power cable, comprising a polyethylene outer sheath (1), characterized in that: A steel belt armor layer (2) is arranged on the inner side of the polyethylene outer sheath (1), a polyethylene inner sheath (3) is arranged on the inner side of the steel belt armor layer (2), an aluminum composite tape (4) is tightly arranged on the inner wall of the polyethylene inner sheath (3), a water-blocking tape wrapping layer (5) is arranged on the inner side of the aluminum composite tape (4), a PP water-absorbing rope filling (6) is arranged on the inner side of the water-blocking tape wrapping layer (5), a metal shield (7) is arranged on the inner side of the PP water-absorbing rope filling (6), an insulating shielding layer (8) is arranged on the inner side of the metal shield (7), a cross-linked polyethylene insulation (9) is arranged on the inner side of the insulating shielding layer (8), a conductor shielding layer (10) is arranged on the inner side of the cross-linked polyethylene insulation (9), and a profiled wire water-blocking conductor (11) is arranged on the inner side of the conductor shielding layer (10).

2. A medium voltage large cross-section composite sheath power cable according to claim 1, characterized in that: The shaped wire water-blocking conductor (11) is formed by a single-layer longitudinal wrapping method, and the compression coefficient of the shaped wire water-blocking conductor (11) is greater than 0.

95.

3. A medium voltage large cross-section integrated sheath power cable according to claim 1, characterized in that: The insulating shielding layer (8), the cross-linked polyethylene insulation (9) and the conductor shielding layer (10) are cross-linked three-layer co-extruded.

4. A medium voltage large cross-section composite sheath power cable according to claim 1, characterized in that: The material of the insulating shielding layer (8) is a water-tree resistant cross-linked polyethylene material, the material of the cross-linked polyethylene insulation (9) is a water-tree resistant cross-linked polyethylene material, and the material of the conductor shielding layer (10) is a water-tree resistant cross-linked polyethylene material.

5. A medium voltage large cross-section integrated sheath power cable according to claim 1, characterized in that: The metal shield (7) is a non-differentiated copper tape shield.

6. A medium voltage large cross-section integrated sheath power cable according to claim 1, characterized in that: When the PP water-absorbing rope is filled (6) into a cable, a layer of water-blocking tape is added to the filling rope.

7. A medium voltage large cross-section composite sheath power cable according to claim 1, characterized in that: The polyethylene inner sheath (3) is made of medium-density polyethylene material, and the aluminum composite tape (4) is a double-film aluminum composite tape (4).

8. A medium voltage large cross-section composite sheath power cable according to claim 7, characterized in that: The water-blocking tape wrapping layer (5) is a 0.8 mm thick galvanized steel tape.

9. A medium voltage large cross-section integrated sheath power cable according to claim 1, characterized in that: The polyethylene inner sheath (3) is tightly fitted to the aluminum composite belt (4); the front end of the aluminum composite belt (4) is flat and gradually shrinks into a cylindrical shape along the forward direction of the aluminum belt; the length of the aluminum composite belt (4) is greater than 50 cm.

10. The medium voltage large cross-section composite sheath power cable according to claim 1, characterized in that: The polyethylene outer sheath (1) is made of polyethylene.

Images