CN211670030U - Anti-interference self-supporting medium-voltage non-armored single-core cable - Google Patents

Abstract

The utility model relates to a cable, to the problem that easy damage, during operation easily received the interference when the non-armor single core cable of middling pressure lays, provide an anti-interference self-supporting formula middling pressure non-armor single core cable, including the conductor, be equipped with steel strand wires in the middle of the conductor, the conductor outside by interior cladding in proper order outside to have conductor shielding layer, insulating layer, shielding structure and oversheath, shielding structure accompanies the multilayer metal integrated configuration of tinned copper wire woven mesh in the middle of the compound area of two-layer plastic-aluminum. The bearing structure steel stranded wires are arranged in the conductors, so that the damage of the cable caused by uneven stress in the process of lifting and drawing the cable is eliminated; the shielding structure is formed by combining a plurality of layers of metal structures, can resist electromagnetic interference, can also shield poor grounding and other power line conducted interference, reduces inductance, and can also be used as a grounding channel of short-circuit current.

Description

Anti-interference self-supporting medium-voltage non-armored single-core cable

Technical Field

The utility model relates to a cable especially relates to an anti-interference self-supporting middling pressure non-armor single core cable.

Background

In power engineering applications, cables are usually laid in direct burial, cable trenches, tunnels, cable shafts, and the like. The laying mode is more special in the laying process of the cable of the high-rise shaft, the cable is mainly pulled upwards to be lifted from bottom to top through traction force in the laying environment of the high-rise shaft, the stress is uneven in the cable lifting process, the stress is large at stress points and above, and the cable is damaged and the outer sheath and the appearance are deformed. Meanwhile, only one cable is possible in the shaft, and the cable is susceptible to external electromagnetic interference in a relatively closed environment. The conventional metal tape shielding wrapped around the insulating shielding layer also has difficulty in ensuring that the cable is not interfered by external electromagnetic interference.

In order to improve the mechanical stress damage resistance of the single-core cable, an armor layer is generally added to the cable. According to the requirements of the national standard GB/T12706, the armor is a metal belt wound in a clearance mode, such as a galvanized steel belt, a stainless steel belt, an aluminum belt and other metal belt materials. The standard requirement of the steel belt for the standard YB/T024 armored cable is that the strength of the steel belt is not less than 295 Mpa. However, the metal tape armored structure can generate induced voltage and eddy current loss in the alternating current power transmission process, and the accident of multi-point breakdown of the cable sheath is caused under the action of the induced voltage of the metal tape armored structure, so that the electrical risk of the cable is increased, and the current carrying capacity of the cable is influenced. In addition, in the cable dragging, laying and installing construction, if the environmental conditions are severe, the mechanical damage of the outer sheath of the cable is easily caused. Therefore, a non-metal armored cable is invented, for example, a non-metal armored single-core power cable disclosed in chinese patent ZL200920044080.5, the outermost layer of the cable is a sheath, a non-metal armored layer is arranged in the sheath, a wrapping layer is arranged in the non-metal armored layer, an insulating layer is arranged in the wrapping layer, and a conductor is arranged in the insulating layer. The non-metal armor layer is a composite armor layer formed by combining a foamed polyethylene buffer layer and a polyvinylidene fluoride (PVDF) layer. In the view of the armor structure, the material for resisting the damage of the mechanical external force mainly depends on the polyvinylidene fluoride (PVDF) layer, but the strength of the polyvinylidene fluoride (PVDF) layer is only about 40MPa, and is far from the strength required by the standard which is not less than 295 MPa. The cable construction does not have the basic requirements of armouring in the sense that the armouring itself is resistant to mechanical external damage. Accordingly, an ideal technical structure is needed to solve the above problems.

Disclosure of Invention

The utility model provides an anti-interference self-supporting medium-voltage non-armored single-core cable, which is provided with a bearing structure steel strand in the conductor to eliminate the cable damage caused by uneven stress in the process of lifting and drawing the cable; the shielding structure is formed by combining a plurality of layers of metal structures, can resist electromagnetic interference, can also shield poor grounding and other power line conducted interference, reduces inductance, and can also be used as a grounding channel of short-circuit current.

In order to achieve the above purpose, the utility model adopts the following technical scheme: the utility model provides an anti-interference self-supporting middling pressure non-armor single core cable, includes the conductor, is equipped with the steel strand wires in the middle of the conductor, and the conductor outside has conductor shielding layer, insulating layer, shielding structure and oversheath by interior cladding in proper order outside to, shielding structure presss from both sides the multilayer metal integrated configuration of tinned copper wire woven mesh in the middle of for two-layer aluminum-plastic composite belt.

The utility model is a non-armored single-core cable, which has no induced voltage, no eddy current loss and no influence on the current-carrying capacity of the cable in the alternating current transmission process, thereby greatly improving the power transmission capacity of the armored cable; meanwhile, even if the outer protection layer of the cable is damaged by partial mechanical external force, the nonmetal armor belt does not generate induced voltage, so that the danger of armor breakdown to multiple points on the ground due to reduction of insulation resistance caused by mechanical damage of the protection layer receiving part is avoided. The steel strand is arranged in the conductor to serve as a bearing structure, so that the cable damage caused by uneven stress in the lifting and pulling process of the cable can be eliminated, and the defect that the unarmored cable is easy to damage is overcome. The shielding structure is formed by combining a plurality of layers of metal structures, can resist electromagnetic interference, can also shield poor grounding and other power line conducted interference, reduces inductance, and can also be used as a grounding channel of short-circuit current.

Preferably, an inner sheath is arranged between the insulating layer and the shielding structure, and the inner sheath is made of halogen-free low-smoke flame-retardant polyolefin. The halogen-free low-smoke flame-retardant polyolefin sheath has flame retardance, does not generate halogen in the combustion process, and has the effect of environmental protection.

Preferably, a copper strip is arranged between the inner sheath and the insulating layer. The copper strip shield is used for grounding and conducting short-circuit current.

Preferably, a halogen-free low-smoke high-flame-retardant belt is arranged between the inner sheath and the copper belt. The halogen-free low-smoke high-flame-retardant belt plays a role in environmental protection and halogen-free flame retardance.

Preferably, the insulating layer is coated with an insulating shield layer.

Preferably, the conductor is made of an aluminum alloy.

Preferably, the material of the outer sheath is halogen-free low-smoke flame-retardant polyolefin. The polyolefin material has low density, usually 0.83-0.96 g/cm³In addition, the weight of the cable can be reduced, and therefore the transportation and laying cost of the cable is reduced. The polyolefin has good chemical corrosion resistance and resistance to corrosion of chemical substances such as acid, alkali, salt and the like, so the polyolefin can be used in chemical enterprises, sewage treatment enterprises, seasides and other occasions with corrosion sources, and the application occasions are wider. The polyolefin is wear-resistant and can well protect the cable. Polyolefins have good insulating properties against electricity, heat and sound. However, polyolefin is flammable and generates a large amount of black smoke and toxic gas during combustion, so that halogen-free low-smoke flame-retardant polyolefin is selected as the material of the outer sheath.

Therefore, the utility model discloses following beneficial effect has: (1) the cable is provided with the bearing structure steel stranded wires in the conductor, so that the damage of the cable caused by uneven stress in the process of lifting and drawing the cable is eliminated; (2) the shielding structure is formed by combining a plurality of layers of metal structures, can resist electromagnetic interference, can also shield poor grounding and other power line conducted interference, reduces inductance, and can also be used as a grounding channel of short-circuit current; (3) the inner sheath and the outer sheath adopt halogen-free low-smoke flame-retardant polyolefin, and have the advantages of wear resistance, light weight, flame retardance and environmental protection.

Drawings

Fig. 1 is a schematic structural diagram of the present invention.

In the figure: 1. the cable comprises a steel strand, 2, a conductor, 3, a conductor shielding layer, 4, an insulating layer, 5, an insulating shielding layer, 6, a copper strip, 7, a halogen-free low-smoke high-flame-retardant belt, 8, an inner sheath, 9, a shielding structure, 91, an aluminum-plastic composite belt, 92, a tinned copper wire woven mesh, 10 and an outer sheath.

Detailed Description

The present invention will be further described with reference to the accompanying drawings and the detailed description.

As shown in fig. 1, the anti-interference self-supporting medium-voltage unarmored single-core cable comprises a conductor 2, a conductor shielding layer 3, an insulating layer 4, an insulating shielding layer 5, a copper strip 6, a halogen-free low-smoke high-flame-retardant strip 7, an inner sheath 8, a shielding structure 9 and an outer sheath 10 which are sequentially coated from inside to outside.

The processing process comprises the following steps: the conductor 2 is an aluminum alloy conductor, the steel strand 1 is arranged in the center of the aluminum alloy conductor, and the steel strand 1 serves as a bearing structure to eliminate damage caused by uneven stress of the cable in the lifting and pulling process. The conductor 2 is extruded with a conductor shielding layer 3, an insulating layer 4 and an insulating shielding layer 5. And a layer of copper strip 6 and a layer of halogen-free low-smoke high-flame-retardant belt 7 are lapped outside the insulating shielding layer 5 in an overlapping way, wherein the copper strip 6 is a red copper strip. The rear part of the halogen-free low-smoke high-flame-retardant belt 7 is extruded with a layer of inner sheath 8 of halogen-free low-smoke flame-retardant polyolefin. The inner sheath 8 outside is equipped with shielding structure 9, and shielding structure 9 presss from both sides the multilayer metal integrated configuration who presss from both sides tinned copper wire woven mesh 92 in the middle of two-layer aluminum-plastic composite belt 91, can anti-electromagnetic interference, also can shield ground connection harmfully and other power cord conducted interference, reduces the inductance, can also regard as short-circuit current's ground connection passageway. The specific connection of the inner sheath 8 and the shielding structure 9 is: a layer of aluminum-plastic composite tape 91 is lapped and wound behind the inner sheath 8, a tinned copper wire mesh grid 92 is adopted behind the aluminum-plastic composite tape 91, and a layer of aluminum-plastic composite tape 91 is lapped and wound behind the tinned copper wire mesh grid 92. And finally, the outer sheath 10 of the halogen-free low-smoke flame-retardant polyolefin is extruded and coated behind the aluminum-plastic composite belt 91.

The components and materials of the utility model, which are not specifically described, are conventional commercially available components and materials. The center of the aluminum alloy conductor 2 is provided with a bearing structure steel strand, which ensures that the resistance of the aluminum alloy conductor meets or is superior to the national standard; meanwhile, the combined metal shielding structure 9 adopted by the metal structure behind the inner sheath 8 is difficult to select the type of a braiding machine with a large outer diameter before braiding due to high voltage level and thick insulation thickness, the braiding machine and the number of braided strands are reasonably selected according to the outer diameter of the cable, and the braiding density of the tinned copper wire is ensured to meet the corresponding national standard requirement.

The utility model can avoid the damage and deformation caused by uneven stress on the cable due to the traction force in the laying process of the high-rise shaft; meanwhile, the device can normally operate in a vertical shaft and is free from other electromagnetic interference.

Claims (7)

1. The utility model provides an anti-interference self-supporting middling pressure non-armor single core cable, includes conductor (2), its characterized in that is equipped with steel strand wires (1) in the middle of conductor (2), and the cladding has conductor shielding layer (3), insulating layer (4), shielding structure (9) and oversheath (10) outside conductor (2) outside from inside to outside in proper order, shielding structure (9) accompany the multilayer metal composite construction of tinned copper wire woven mesh (92) for two-layer aluminum-plastic composite tape (91) in the middle of.

2. The anti-interference self-supporting medium-voltage unarmored single core cable according to claim 1, characterized in that an inner sheath (8) is arranged between the insulating layer (4) and the shielding structure (9), the inner sheath (8) is made of halogen-free low-smoke flame retardant polyolefin.

3. A self-supporting medium voltage unarmored mono core cable of immunity to interference according to claim 2 characterized in that copper tape (6) is provided between the inner sheath (8) and the insulating layer (4).

4. An anti-interference self-supporting medium-voltage unarmored single core cable according to claim 3, characterized in that a halogen-free low-smoke high flame retardant tape (7) is arranged between the inner sheath (8) and the copper tape (6).

5. Anti-interference self-supporting medium voltage unarmored single core cable according to claim 1 characterized in that the outside of the insulating layer (4) is covered with an insulating shielding layer (5).

6. A tamper resistant self-supporting medium voltage unarmored single core cable according to claim 1 wherein the material of the conductor (2) is an aluminium alloy.

7. An anti-interference self-supporting medium voltage unarmored single core cable according to any one of claims 1 to 6 wherein the material of the outer sheath (10) is a halogen free low smoke flame retardant polyolefin.

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