CN212934207U - Medium-voltage single-core direct-current fireproof fire-resistant cable - Google Patents

Abstract

The utility model discloses a single core direct current fire prevention fire resisting cable of middling pressure, which comprises a conductor, the conductor is equipped with inner screen, insulating layer, outer screen, semiconduction buffering water-blocking tape, does not have steamed low cigarette high fire-retardant area, inner sheath, silicon rubber ceramization area, glass fiber area, separates oxygen layer and oversheath outward in proper order. According to the technical scheme, the inner sheath, the outer sheath and the oxygen isolation layer are made of halogen-free low-smoke flame-retardant polyolefin, and do not contain halogen, so that the environment-friendly effect is achieved; structurally guarantee the fire prevention fire resistance of cable through the fire-resistant material of multilayer fire prevention simultaneously, multilayer fire prevention fire-resistant structure has the effect of not delaying to fire and not dripping when the conflagration breaing out, forms hard ceramic armour body simultaneously, guarantees the fire-resistant effect of fire prevention of cable.

Description

Medium-voltage single-core direct-current fireproof fire-resistant cable

Technical Field

The utility model relates to a power transmission field especially relates to a single core direct current fire prevention fire resisting cable of middling pressure.

Background

In the direct current transmission, the voltage distribution along the direct current transmission line is stable, no capacitance current exists, and the power loss of a direct current line is about 2/3 of that of an alternating current line under the conditions that the sectional areas of the leads are the same and the useful power is transmitted. And no parallel reactance compensation is required. Due to the intrinsic characteristics of ac and dc, ac cables have dielectric losses in insulation and magnetic induction losses in the sheath in addition to the resistance losses of the core. Dc cables, however, have essentially only resistive losses of the core and the insulation also ages much more slowly, so that the annual operating costs are much lower than for corresponding ac cables.

However, the running process of the direct current cable also faces the risk of fire, water and fire are in no way, and countless people lose lives in the fire. And the sheath layer of the cable is mostly made of halogen-containing materials, so that once a fire disaster is spread, a large amount of dense smoke can be generated, and hydrogen halide gas with strong corrosivity and secondary disaster can be generated, so that the life of people is endangered, and equipment and the environment are harmed. Even if the halogen-free and low-halogen flame-retardant material is adopted, the time for the flame-retardant insulating material to be sintered into powder can only be delayed, if the flame-retardant insulating material is continuously burnt, the flame-retardant insulating material is gradually changed into powder to fall off, the protection effect is lost, and the cable is easily punctured to cause short circuit, so that the safe smoothness of communication and electric power under the condition of fire is difficult to ensure.

The existing fireproof structure mainly adopts the halogen-free low-smoke flame-retardant inner and outer sheaths which only can stop flame spreading, but the materials of the outer sheath can be completely burnt and pulverized in a fire disaster to completely lose the effect, so that the cable insulation is damaged and the cable short circuit is caused, the transmission of electric power cannot be ensured, the illumination is provided for the fire rescue, and huge loss which can not recover life and economy is caused.

Chinese patent document CN206058987U discloses a "direct current united-hop fireproof control cable for rail transit". The cable comprises a cable core unit protection layer, wherein a cable core unit is arranged in the cable core unit protection layer, and a plurality of cable cores are arranged in the cable core unit; filling materials are filled in the cable core unit protective layer and each cable core unit; each cable core comprises a cable core protective layer and a conductor positioned in the cable core protective layer; the cable core protection layer comprises a fire-resistant layer, an insulating layer and an isolating layer which are sequentially arranged from inside to outside; the cable core unit protective layer comprises a fire insulation layer, an inner protection layer, an armor layer and an outer protection layer which are sequentially arranged from inside to outside. The halogen-free low-smoke flame-retardant inner and outer sheaths adopted by the technical scheme can only play a role in stopping flame spread, but can completely lose the function when the material of the outer sheath is completely combusted and pulverized in a fire disaster.

Disclosure of Invention

The utility model mainly solves the technical problems that the prior fireproof cable contains halogen, generates polluting corrosive gas during burning, or adopts halogen-free low-smoke flame-retardant materials to be completely burnt or pulverized to lose effect, provides a medium-voltage single-core direct-current fireproof cable, adopts the materials of the inner sheath, the outer sheath and the oxygen isolation layer as the halogen-free low-smoke flame-retardant polyolefin materials, does not contain halogen, and plays a role in environmental protection; structurally guarantee the fire prevention fire resistance of cable through the fire-resistant material of multilayer fire prevention simultaneously, multilayer fire prevention fire-resistant structure has the effect of not delaying to fire and not dripping when the conflagration breaing out, forms hard ceramic armour body simultaneously, guarantees the fire-resistant effect of fire prevention of cable.

The above technical problem of the present invention can be solved by the following technical solutions: the utility model discloses a conductor, the conductor is equipped with inner shield, insulating layer, outer screen, semiconduction buffering water-blocking tape, the high fire-retardant area of steamed low cigarette, inner sheath, ceramic silicon rubber area, glass fiber area, separate oxygen layer and oversheath outward in proper order outward. The conductor adopts two types of compact round conductors which simultaneously meet the requirements of national standards GB/T12706.1-2008 and GB/T3956-2008.

Preferably, the semiconductive buffering water-blocking tape is wrapped with a copper tape for metal shielding.

Preferably, the silicon ceramic rubber belt, the glass fiber belt and the oxygen isolation layer are respectively provided with two layers and are sequentially covered according to the sequence of the silicon ceramic rubber belt, the glass fiber belt and the oxygen isolation layer.

Preferably, the oxygen-insulating layer is a ceramic halogen-free low-smoke flame-retardant fireproof polyolefin oxygen-insulating layer, and the thickness of the oxygen-insulating layer is more than or equal to 3.0 mm. The oxygen isolating layer is made of ceramic materials, has high flame retardance and no flame delay, and can be burnt into hard ceramic armor when a fire disaster occurs, the harder the ceramic armor is burnt for a longer time, and the fired hard ceramic armor has honeycomb-shaped pores which can play the roles of fire isolation and heat insulation.

Preferably, an armor is arranged between the oxygen isolation layer and the outer sheath, the armor is an alloy belt interlocking armor, and a gap exists between the alloy belt interlocking armor and the wire core. The alloy should guarantee during the chain armor of strip between its armor and the sinle silk too tightly of package, should have certain clearance, damage the sinle silk when preventing the cable bending, secondly have certain clearance can play certain fire prevention, thermal-insulated effect, and the armor should guarantee the smooth no burr in surface, the integrality of chain armor and guarantee not damage in production and separate the oxygen layer simultaneously.

Preferably, the wrapping mode of the ceramic silicon rubber belt is a mode of contacting a smooth surface and a non-smooth surface. When the ceramic silicon rubber belt is wrapped, the smooth surface and the non-smooth surface are in contact with each other, so that the phenomenon of slipping in the wrapping process is prevented, and the problem that the cover overlapping rate of the ceramic silicon rubber belt is insufficient and the outer diameter changes greatly is solved.

Preferably, the inner screen and the outer screen are made of ultra-smooth semi-conductive shielding materials.

Preferably, the inner sheath and the outer sheath are halogen-free low-smoke high-flame-retardant polyolefin sheaths. The air pollution caused by toxic gas can not occur in the actual production and the process of fire hazard occurrence, and the short sight line distance of people can not be caused.

Preferably, the insulating layer is made of cross-linked polyethylene insulating material. The crosslinked polyethylene insulating material is usually used for crosslinked cables of direct current 35kV and below, and the crosslinked polyethylene insulating material for the crosslinked cables of direct current 35kV and below is selected due to the essential characteristics of the direct current cables, so that the direct current cables have no insulating medium loss.

The utility model has the advantages that:

1. the inner sheath, the outer sheath and the oxygen isolation layer are made of halogen-free low-smoke flame-retardant polyolefin, and do not contain halogen, thereby playing a role in environmental protection.

2. Meanwhile, the ceramic silicon rubber belt selected from the lapped belt material is also a halogen-free material.

3. Structurally guarantee the fire prevention fire behavior of cable through the fire-resistant material of multilayer fire prevention, the interlocking armor of adoption also has the fire-resistant isolated high temperature's of fire prevention effect.

4. The multilayer fireproof and fire-resistant structure has the effects of no flame delay and no dripping when a fire disaster happens, and simultaneously forms a hard ceramic armor body to ensure the fireproof and fire-resistant effects of the cable.

Drawings

Fig. 1 is a cross-sectional view of the present invention.

In the figure, 1 conductor, 2 inner screens, 3 insulating layers, 4 outer screens, 5 semiconductive buffering water-blocking tapes, 6 copper tapes, 7 halogen-free low-smoke high-flame-retardant tapes, 8 inner jackets, 9 ceramic silicon rubber tapes, 10 glass fiber tapes, 11 oxygen insulating layers, 12 armors and 13 outer jackets are adopted.

Detailed Description

The technical solution of the present invention is further specifically described below by way of examples and with reference to the accompanying drawings.

Example (b): the medium-voltage single-core direct-current fireproof fire-resistant cable comprises a conductor 1, wherein an inner screen 2, an insulating layer 3, an outer screen 4, a semiconductive buffering water-blocking tape 5, a copper strip 6 for metal shielding, a halogen-free low-smoke high-flame-retardant tape 7, an inner sheath 8, a silicon rubber ceramic tape 9, a glass fiber tape 10, an oxygen-insulating layer 11, an armor 12 and an outer sheath 13 are sequentially arranged outside the conductor 1, as shown in fig. 1.

The conductor 1 adopts two types of compact round conductors which simultaneously meet the requirements of national standards GB/T12706.1-2008 and GB/T3956-2008. The inner screen 2 and the outer screen 4 are made of ultra-smooth semi-conductive shielding materials. The insulating layer 3 is made of cross-linked polyethylene insulating material. The crosslinked polyethylene insulating material is usually used for crosslinked cables of direct current 35kV and below, and the crosslinked polyethylene insulating material for the crosslinked cables of direct current 35kV and below is selected due to the essential characteristics of the direct current cables, so that the direct current cables have no insulating medium loss. The inner sheath 8 and the outer sheath 13 adopt halogen-free low-smoke high-flame-retardant polyolefin sheaths. The air pollution caused by toxic gas can not occur in the actual production and the process of fire hazard occurrence, and the short sight line distance of people can not be caused.

The armor 12 is an alloy belt interlocking armor, and a gap exists between the alloy belt interlocking armor and the wire core. The alloy should guarantee during the chain armor of strip between its armor and the sinle silk too tightly of package, should have certain clearance, damage the sinle silk when preventing the cable bending, secondly have certain clearance can play certain fire prevention, thermal-insulated effect, and the armor should guarantee the smooth no burr in surface, the integrality of chain armor and guarantee not damage in production and separate the oxygen layer simultaneously.

The silicon rubber ceramic belt 9, the glass fiber belt 10 and the oxygen isolation layer 11 are respectively provided with two layers and are sequentially covered according to the sequence of the silicon rubber ceramic belt 9, the glass fiber belt 10 and the oxygen isolation layer 11. The oxygen-isolating layer 11 is a ceramic halogen-free low-smoke flame-retardant fireproof polyolefin oxygen-isolating layer, and the thickness of the oxygen-isolating layer 11 is more than or equal to 3.0 mm. The oxygen isolating layer is made of ceramic materials, has high flame retardance and no flame delay, and can be burnt into hard ceramic armor when a fire disaster occurs, the harder the ceramic armor is burnt for a longer time, and the fired hard ceramic armor has honeycomb-shaped pores which can play the roles of fire isolation and heat insulation.

The wrapping mode of the ceramic silicon rubber belt 9 is a mode of contacting a smooth surface and a non-smooth surface. When the ceramic silicon rubber belt is wrapped, the smooth surface and the non-smooth surface are in contact with each other, so that the phenomenon of slipping in the wrapping process is prevented, and the problem that the cover overlapping rate of the ceramic silicon rubber belt is insufficient and the outer diameter changes greatly is solved.

The semi-conductive buffer water-blocking tape wrapped outside the outer screen is relatively thick, and is wrapped in an overlapping covering mode, so that the wrapped outer diameter is different, the outer diameter after cabling is larger, and consumption of subsequent processes is increased; therefore, when the semi-conductive buffer water-blocking tape is wrapped, the tension and the angle of the wrapping head need to be well controlled.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications, additions and substitutions for the specific embodiments described herein may be made by those skilled in the art without departing from the spirit of the invention or exceeding the scope of the invention as defined in the accompanying claims.

Although terms such as inner screen, oxygen barrier, halogen-free low-smoke high flame-retardant tape are used more often herein, the possibility of using other terms is not excluded. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed in a manner that is inconsistent with the spirit of the invention.

Claims (9)

1. The medium-voltage single-core direct-current fireproof fire-resistant cable is characterized by comprising a conductor (1), wherein an inner screen (2), an insulating layer (3), an outer screen (4), a semi-conductive buffering water-blocking tape (5), a halogen-free low-smoke high-flame-retardant tape (7), an inner sheath (8), a silicon rubber ceramic tape (9), a glass fiber tape (10), an oxygen-isolating layer (11) and an outer sheath (13) are sequentially arranged outside the conductor (1).

2. The medium voltage single core dc fireproof fire-resistant cable according to claim 1, wherein the semi-conductive buffer water-blocking tape (5) is wrapped with copper tape (6) for metal shielding.

3. The medium voltage single core direct current fireproof fire-resistant cable according to claim 1, wherein the silicon ceramic rubber tape (9), the glass fiber tape (10) and the oxygen barrier layer (11) are respectively provided with two layers, and the two layers are sequentially covered according to the sequence of the silicon ceramic rubber tape (9), the glass fiber tape (10) and the oxygen barrier layer (11).

4. The medium voltage single core direct current fireproof fire-resistant cable according to claim 1 or 3, wherein the oxygen isolation layer (11) is a ceramic halogen-free low-smoke flame-retardant fire-resistant polyolefin oxygen isolation layer, and the thickness of the oxygen isolation layer (11) is greater than or equal to 3.0 mm.

5. The medium voltage single core direct current fireproof fire-resistant cable according to claim 1, wherein an armor (12) is arranged between the oxygen barrier layer (11) and the outer sheath (13), the armor (12) is an alloy strip interlocking armor, and a gap exists between the alloy strip interlocking armor and the wire core.

6. A medium voltage single core dc fireproof cable according to claim 1 or 3, wherein the ceramic silicone rubber tape (9) is wrapped in a smooth and non-smooth contact manner.

7. The medium voltage single core direct current fireproof fire-resistant cable according to claim 1, wherein the inner screen (2) and the outer screen (4) are made of ultra-smooth semi-conductive shielding materials.

8. The medium voltage single core direct current fireproof fire-resistant cable according to claim 1, wherein the inner sheath (8) and the outer sheath (13) are halogen-free low smoke high flame retardant polyolefin sheaths.

9. A medium voltage single core dc fireproof cable according to claim 1, wherein the insulation layer (3) is a cross-linked polyethylene insulation.

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