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

An anti-interference self-supporting medium voltage unarmored single-core cable

technical field

The utility model relates to a cable, in particular to an anti-interference self-supporting medium-voltage non-armoured single-core cable.

Background technique

In power engineering applications, cables are usually laid in direct burial, cable trenches, tunnels and cable wells. In the laying process, the special laying method is the laying and installation of cables in high-rise shafts. When laying cables in the laying environment of high-rise shafts, the cables are mainly pulled up and raised by traction force from bottom to top, and the force is uneven during the lifting process of cables. , The force is large at the force point and above, which will cause damage to the cable and deformation of the outer sheath and appearance. At the same time, it is not possible to have only one cable in the shaft. In a relatively closed environment, the cable itself is susceptible to external electromagnetic interference. It is also difficult to ensure that the cable itself is not disturbed by external electromagnetic interference by wrapping the metal tape around the insulating shielding layer.

In order to improve the resistance to mechanical damage of the single-core cable, an armoring layer is generally added to the cable. According to the requirements of the national standard GB/T12706, the armor is a metal strip wrapped with a gap, such as some metal strips such as galvanized steel strips, stainless steel strips, and aluminum strips. The standard YB/T024 steel tape for armored cables requires that the strength of the steel tape is not less than 295Mpa. However, the structure of the metal tape armor will generate induced voltage and eddy current loss during the AC power transmission process. Under the action of the induced voltage of the metal tape armor, it will cause the accident of multi-point penetration of the cable sheath, which increases the electrical danger and influence of the cable. the current carrying capacity of the cable. In addition, in the construction of cable dragging and laying, if the environmental conditions are harsh, it is easy to cause mechanical damage to the outer sheath of the cable. To this end, someone invented a non-metal armored cable, 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, and the sheath is provided with The non-metallic armoring layer, the non-metallic armoring layer is provided with a wrapping layer, the wrapping layer is provided with an insulating layer, and the insulating layer is provided with a conductor. The non-metal armor layer is a composite armor layer composed of a foamed polyethylene buffer layer and a polyvinylidene fluoride (PVDF) layer. From the perspective of the armored structure, the material that resists mechanical external force damage mainly depends on the polyvinylidene fluoride (PVDF) layer, but the strength of the polyvinylidene fluoride (PVDF) layer is only about 40Mpa, which is far from the standard required strength of not less than 295Mpa. Far. Therefore, in the sense of the armor's resistance to mechanical external force damage itself, the cable structure does not yet have the basic requirements for armor. Accordingly, an ideal technical structure is required to solve the above problems.

SUMMARY OF THE INVENTION

The utility model provides an anti-interference self-supporting medium-voltage non-armoured single-core cable in order to overcome the problems that the medium-voltage non-armoured single-core cable is easy to be damaged during laying and easily interfered during operation. Steel stranded wire can eliminate the cable damage caused by uneven force in the process of lifting and pulling the cable; the shielding structure is composed of multi-layer metal structures, which can resist electromagnetic interference, and can also shield poor grounding and other power line conduction interference, reduce Small inductance can also be used as a ground path for short-circuit currents.

In order to achieve the above purpose, the present utility model adopts the following technical solutions: an anti-interference self-supporting medium-voltage non-armoured single-core cable, comprising a conductor, a steel strand is arranged in the middle of the conductor, and the outer side of the conductor is sequentially covered with A conductor shielding layer, an insulating layer, a shielding structure and an outer sheath, the shielding structure is a multi-layer metal composite structure in which two layers of aluminum-plastic composite tapes are sandwiched with a tinned copper wire braided net.

The utility model is a non-armoured single-core cable, which has no induced voltage, no eddy current loss and no influence on the current carrying capacity of the cable during the alternating current transmission process, thereby greatly improving the power transmission capacity of the armoured cable; If damaged by some mechanical external force, since the non-metal armored tape does not generate induced voltage, it will not cause the danger of armoring to the ground more breakdown due to the decrease of the insulation resistance caused by the mechanical damage of the sheath. Setting the steel strand in the conductor as the load-bearing structure can eliminate the cable damage caused by the uneven force of the cable in the process of ascending and pulling, and make up for the disadvantage of the unarmored cable being easily damaged. The shielding structure is composed of multi-layer metal structures, which can resist electromagnetic interference, shield poor grounding and other power line conduction interference, reduce inductance, and can also be used as a grounding channel for short-circuit current.

Preferably, an inner sheath is arranged between the insulating layer and the shielding structure, and the material of the inner sheath is halogen-free low-smoke flame retardant polyolefin. The halogen-free low-smoke flame-retardant polyolefin sheath is flame-retardant, and no halogen is produced during the combustion process, which plays a role in environmental protection.

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

Preferably, a halogen-free, low-smoke, and high flame-retardant tape is arranged between the inner sheath and the copper tape. Halogen-free, low-smoke, and high-flame retardant tapes play an environmentally friendly halogen-free flame retardant role.

Preferably, the outer side of the insulating layer is covered with an insulating shielding layer.

Preferably, the material of the conductor is aluminum alloy.

Preferably, the material of the outer sheath is halogen-free low-smoke flame-retardant polyolefin. The density of polyolefin material is small, usually between 0.83 and 0.96 g/cm ³ , which can reduce the weight of the cable, thereby reducing the transportation and laying costs of the cable. Polyolefin has good chemical corrosion resistance and is resistant to acid, alkali, salt and other chemical substances, so it can be used in chemical enterprises, sewage treatment enterprises, seaside and other occasions with corrosion sources, and the application occasions are more extensive. Polyolefin is abrasion resistant and protects cables well. Polyolefin has good insulating properties for electricity, heat and sound. However, polyolefin is flammable and produces a lot of black smoke and toxic gas when burning, so halogen-free low-smoke flame-retardant polyolefin is selected as the material of the outer sheath.

Therefore, the utility model has the following beneficial effects: (1) the cable is provided with a load-bearing structure steel strand in the conductor to eliminate the cable damage caused by uneven force in the process of lifting and pulling the cable; (2) the shielding structure is composed of multiple It is composed of layers of metal structure, which can resist electromagnetic interference, can also shield poor grounding and other power line conduction interference, reduce inductance, and can also be used as a grounding channel for short-circuit current; (3) The inner and outer sheaths are halogen-free and low-smoke flame retardant. Polyolefin, wear-resistant, lightweight, flame-retardant and environmentally friendly.

Description of drawings

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

In the picture: 1. Steel strand, 2. Conductor, 3. Conductor shielding layer, 4. Insulating layer, 5. Insulating shielding layer, 6. Copper tape, 7. Halogen-free low-smoke high flame-retardant tape, 8. Inner protection Cover, 9, shielding structure, 91, aluminum-plastic composite tape, 92, tinned copper wire braided mesh, 10, outer sheath.

Detailed ways

The present utility model will be further described below with reference to the accompanying drawings and specific embodiments.

As shown in Figure 1, an anti-interference self-supporting medium-voltage non-armoured single-core cable includes a conductor 2, a conductor shielding layer 3, an insulating layer 4, an insulating shielding layer 5, a copper Belt 6, halogen-free low-smoke high flame-retardant belt 7, inner sheath 8, shielding structure 9 and outer sheath 10.

The processing process is as follows: the conductor 2 adopts an aluminum alloy conductor, and the aluminum alloy conductor has a steel strand 1 in the center. The steel strand 1 serves as a load-bearing structure to eliminate the damage caused by the uneven force of the cable in the process of ascending and pulling. The conductor 2 is extruded with the conductor shielding layer 3 , the insulating layer 4 and the insulating shielding layer 5 . The insulating shielding layer 5 is overlapped and wrapped with a layer of copper tape 6 and a layer of halogen-free, low-smoke, high flame-retardant tape 7, and the copper tape 6 is specifically a red copper tape. The halogen-free, low-smoke, high-flame-retardant tape 7 is extruded and wrapped with an inner sheath 8 of halogen-free, low-smoke, and flame-retardant polyolefin. The outer side of the inner sheath 8 is provided with a shielding structure 9. The shielding structure 9 is a multi-layer metal composite structure in which two layers of aluminum-plastic composite tapes 91 are sandwiched with a tinned copper wire braided mesh 92, which can resist electromagnetic interference, and can also shield poor grounding and Other power lines conduct interference, reduce inductance, and also serve as a ground path for short-circuit currents. The specific connection between the inner sheath 8 and the shielding structure 9 is as follows: the inner sheath 8 is overlapped and wrapped with a layer of aluminum-plastic composite tape 91 . After 92, a layer of aluminum-plastic composite tape 91 is overlapped and wrapped. Finally, the outer sheath 10 of halogen-free low-smoke flame retardant polyolefin is extruded after the aluminum-plastic composite tape 91 .

The components and materials of the present invention are conventional commercially available components and materials that are not specifically described. There is a load-bearing structural steel strand in the center of the aluminum alloy conductor 2, and the resistance of the aluminum alloy conductor should meet the national standard or better than the national standard; at the same time, the metal structure behind the inner sheath 8 adopts the combined metal shielding structure 9, which is composed of high voltage level and insulation thickness. Thickness makes it difficult to select a braiding machine with a larger outer diameter before braiding. The braiding machine and the number of braiding strands should be reasonably selected according to the outer diameter of the cable, and the braiding density of the tinned copper wire should meet the corresponding national standard requirements.

The cable of the utility model will not be damaged and deformed due to the uneven force on the cable due to the traction force during the laying process of the high-rise shaft; meanwhile, the cable can run normally in the shaft without other electromagnetic interference.

Claims (7)

1. An anti-interference self-supporting medium-voltage non-armoured single-core cable, comprising a conductor (2), characterized in that a steel strand (1) is arranged in the middle of the conductor (2), and the outer side of the conductor (2) is from inside to The outside is covered with a conductor shielding layer (3), an insulating layer (4), a shielding structure (9) and an outer sheath (10) in sequence, and the shielding structure (9) is sandwiched between two layers of aluminum-plastic composite tapes (91). Multilayer metal composite structure with tinned copper wire braid (92). 2. An anti-interference self-supporting medium-voltage non-armoured single-core cable according to claim 1, characterized in that an inner sheath (8) is provided between the insulating layer (4) and the shielding structure (9). , the material of the inner sheath (8) is halogen-free low-smoke flame retardant polyolefin. 3. An anti-interference self-supporting medium-voltage non-armoured single-core cable according to claim 2, characterized in that a copper tape (6) is provided between the inner sheath (8) and the insulating layer (4). . 4. An anti-jamming 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). 5 . The anti-interference self-supporting medium voltage non-armoured single-core cable according to claim 1 , wherein the outer side of the insulating layer ( 4 ) is covered with an insulating shielding layer ( 5 ). 6 . 6 . The anti-interference self-supporting medium-voltage non-armoured single-core cable according to claim 1 , wherein the conductor ( 2 ) is made of aluminum alloy. 7 . 7. An anti-interference self-supporting medium voltage non-armoured single-core cable according to any one of claims 1-6, characterized in that the material of the outer sheath (10) is halogen-free, low-smoke, flame-retardant polymer. Olefins.

Images