CN114864159A

CN114864159A - Medium-voltage fire-resistant cable

Info

Publication number: CN114864159A
Application number: CN202210797701.7A
Authority: CN
Inventors: 苏运成; 盛俊凯; 李广波; 张晓欢
Original assignee: Jianye Cable Group Co ltd
Current assignee: Jianye Cable Group Co ltd
Priority date: 2022-07-08
Filing date: 2022-07-08
Publication date: 2022-08-05
Anticipated expiration: 2042-07-08
Also published as: CN114864159B

Abstract

The application provides a middling pressure fire resisting cable belongs to the cable field. Medium voltage fire resisting cable, including oversheath, a plurality of fire-resistant sinle silk, thermal deformation spare and tensile rope. The outer sheath is flat, made of a thermal hardening refractory material and embedded with an anti-breaking net surrounding along the side wall, and elastic inward-bending parts are arranged at the corners of the side wall; the plurality of refractory wire cores are arranged in the outer sheath and arranged along the long axis of the outer sheath; the thermal deformation piece is arranged along the inner wall of the inward bending part and is suitable for expanding the inward bending part after being heated; the tensile rope has an electrothermal effect, is arranged in the inward bending part, is in heat conduction connection with the thermal deformation part and is suitable for heating the thermal deformation part; the temperature required by the thermal deformation piece for propping the inward bent part is lower than the hardening temperature of the outer sheath, and the thermal deformation piece props the inward bent part of the outer sheath under the thermal deformation, so that the fire-resistant wire core can be conveniently replaced, the whole cable does not need to be replaced, and the cost is reduced; the breakage-proof net can prevent the outer sheath of the thermal deformation part from being broken and falling off, and the fire resistance is guaranteed.

Description

Medium-voltage fire-resistant cable

Technical Field

The application belongs to the technical field of cables, and more specifically relates to a medium-voltage fire-resistant cable.

Background

A conventional cable generally has a plurality of cores built therein to transmit various currents or signals. However, when a certain core of the cable is damaged, the whole cable needs to be replaced, so that other intact cores are discarded at the same time, and waste is caused. And the fire-resistant cable is higher in cost, and the maintenance cost of an enterprise is higher due to the fact that the whole cable is directly replaced.

Disclosure of Invention

In view of this, the embodiment of the present application provides a medium voltage fire-resistant cable to solve the technical problem that the whole cable needs to be replaced after a cable core is damaged in the prior art.

In order to achieve the above object, the present application adopts a technical solution that a medium voltage fire resistant cable is provided, including:

the outer sheath is flat, made of a thermal hardening refractory material and embedded with an anti-breaking net surrounding along the side wall, and elastic inward-bending parts are arranged at the corners of the side wall;

the plurality of refractory wire cores are arranged in the outer sheath and are arranged along the long axis of the outer sheath;

the thermal deformation piece is arranged along the inner wall of the inward bending part and is suitable for expanding the inward bending part after being heated; and

the tensile rope has an electrothermal effect, is arranged in the inward bending part, is in heat conduction connection with the thermal deformation part, and is suitable for heating the thermal deformation part;

the temperature required by the thermal deformation piece for expanding the inner bent part is less than the hardening temperature of the outer sheath.

In some embodiments, the shatter prevention mesh is a metal mesh, and the thermally deformable member is in heat-conducting contact with a portion of the shatter prevention mesh located at the inflected portion.

In certain embodiments, the thermal deformation comprises:

the passive layer is arranged along the inner wall of the inward bending part and is in heat conduction contact with the anti-breaking net; and

the active layer is stacked on one side of the passive layer, which is back to the inner wall of the inward bending part, and is in heat conduction connection with the tensile rope;

the passive layer and the active layer are fixed at corresponding ends, and the coefficient of thermal expansion of the active layer is greater than that of the passive layer.

In some embodiments, at least one of the two sets of corresponding ends of the active layer and the passive layer is fixed by a rivet having a maximum heat resistant temperature greater than a plastic temperature of the outer sheath and less than a hardening temperature of the outer sheath.

In certain embodiments, the outer sheath is a flattened rectangle comprising:

the two wide walls are oppositely arranged in parallel and separated, and a plurality of refractory wire cores are arranged in the middle; and

the two narrow walls are respectively connected between the corresponding end parts of the two wide walls, and the two wide walls are pulled to clamp the plurality of refractory wire cores in the middle;

the inward bending part is arranged at each joint of the wide wall and the narrow wall, and the shatter prevention net extends to the wide wall and the narrow wall from the inward bending part.

In some embodiments, the inner side of the wide wall is provided with a partition embedded between two adjacent refractory cores.

In certain embodiments, an open constriction of the inflected section traps the tensile strand within the inflected section.

In some embodiments, a thermal insulation layer is provided between the inner bend and the adjacent refractory core.

In certain embodiments, the outer sheath is made of ceramic silicone rubber or crust type polyolefin, and the outer layer of the fire-resistant core is made of ceramic silicone rubber.

In certain embodiments, the tensile strand is a steel cord.

The beneficial effect of the fire-resistant cable of middling pressure that this application embodiment provided lies in: compared with the prior art, the medium-voltage fire-resistant cable provided by the embodiment of the application adopts the tensile rope to heat the thermal deformation piece in an electrified manner, the original structure of the cable is fully utilized, the thermal deformation piece is subjected to thermal deformation to prop open the inward bending part of the outer sheath, so that the inner space of the outer sheath is enlarged, the side wall is separated from the wire core, and the drawing resistance of the wire core is reduced, so that the damaged fire-resistant wire core can be conveniently drawn out, a new fire-resistant wire core is inserted, the replacement of a single wire core can be realized, the replacement of the whole cable is not needed, and the cost is reduced; when a fire breaks out, the outer sheath is heated and hardened, the inner anti-breaking net can prevent the outer sheath which is hardened from being broken and falling off due to deformation of the thermal deformation piece, and the fire resistance is ensured.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.

Fig. 1 is a schematic structural diagram of a medium-voltage fire-resistant cable provided in an embodiment of the present application;

fig. 2 is an enlarged view of a point a in fig. 1.

Wherein, in the figures, the respective reference numerals:

1-an outer sheath; 11-wide wall; 12-narrow walls; 13-a partition; 14-shatter prevention net; 2-an inward bend; 21-a thermal insulation layer; 3-a refractory wire core; 4-a thermally deformable member; 41-a passive layer; 42-an active layer; 43-rivets; 5-tensile resistance rope.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects to be solved by the present application clearer, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or be indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or be indirectly connected to the other element.

It will be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and the like, as used herein, refer to an orientation or positional relationship indicated in the drawings that is solely for the purpose of facilitating the description and simplifying the description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be considered as limiting the present application.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "plurality" or "a plurality" means two or more unless specifically limited otherwise.

Referring to fig. 1 and 2 together, a medium voltage fire resistant cable according to an embodiment of the present application will now be described. A medium voltage fire resistant cable comprising:

the outer sheath 1 is flat, made of a thermal hardening refractory material, embedded with a shatter prevention net 14 surrounding along the side wall, and provided with an elastic inward-bending part 2 at the corner of the side wall;

the fire-resistant wire cores 3 are arranged in the outer sheath 1 and are arranged along the long axis of the outer sheath 1;

the thermal deformation piece 4 is arranged along the inner wall of the inward bending part 2 and is suitable for expanding the inward bending part 2 after being heated; and

the tensile rope 5 has an electrothermal effect, is arranged in the inward bending part 2, is in heat conduction connection with the thermal deformation piece 4, and is suitable for heating the thermal deformation piece 4;

the temperature required by the thermal deformation piece 4 to stretch the inward bending part 2 is less than the hardening temperature of the outer sheath 1.

Compared with the prior art, the medium-voltage fire-resistant cable provided by the embodiment of the application adopts the tensile rope 5 to heat the thermal deformation piece 4 by electrifying, the original structure of the cable is fully utilized, the thermal deformation piece 4 is deformed by heating to prop the inward bending part 2 of the outer sheath 1 open, so that the inner space of the outer sheath 1 is enlarged, the side wall is separated from the wire core, and the drawing resistance of the wire core is reduced, so that the damaged fire-resistant wire core 3 can be conveniently drawn out, a new fire-resistant wire core 3 is penetrated in, the replacement of a single wire core can be realized, the whole cable does not need to be replaced, and the cost is reduced; when a fire breaks out, the outer sheath 1 is heated and hardened, the inner anti-breaking net 14 can prevent the hardened outer sheath 1 from being broken and falling off due to deformation of the thermal deformation piece 4, and the fire resistance is guaranteed.

When the wire core is replaced, firstly detecting and determining the damaged wire core; then, connecting two ends of the tensile rope 5 with a power supply to enable the tensile rope 5 to generate heat, and transmitting heat generated by the tensile rope 5 to the thermal deformation piece 4 to enable the thermal deformation piece 4 to prop open the inward bending part 2; then, fixing a pulling wire (a fish wire or a thin steel wire or the like) which is thinner than the damaged wire core at one end of the damaged wire core, pulling the other end of the damaged wire core, and pulling out the damaged wire core and simultaneously threading the pulling wire; and finally, fixing a replacement wire core at one end of the traction rope, pulling the other end of the traction rope, drawing out the traction rope, penetrating the replacement wire core, cutting off a power supply of the tensile rope 5, and restoring the thermal deformation piece 4 and the inward bending part 2 to finish the replacement of the wire core. And a proper amount of talcum powder can be smeared on the surface of the replacement wire core, so that the friction force during penetration is reduced.

In this embodiment, the outer sheath 1 may be made of a thermosetting elastic refractory material used in a conventional fire-resistant cable, so that the outer sheath 1 can be thermally hardened at a high temperature. The corner of the lateral wall of oversheath 1 inwards bends and forms sunken inflexion 2 for when inflexion 2 is in pristine condition, the lateral wall of oversheath 1 just in time with each sinle silk laminating, and when inflexion 2 expandes, the inner space of oversheath 1 can increase, makes the lateral wall of oversheath 1 and each sinle silk appear separating, reduces the resistance of taking out of sinle silk. The fire-resistant structure of the fire-resistant wire core 3 plays a certain fire-resistant role. The shatter prevention net 14 may be embedded when the outer jacket 1 is molded, and may be an asbestos net or a metal net, etc., to increase the strength of the hardened outer jacket 1.

The plurality of refractory wire cores 3 are arranged along the long axis of the outer sheath 1, so that the refractory wire cores 3 are mainly wrapped by the outer sheath 1 to realize fixation, and the acting force between the adjacent refractory wire cores 3 is small; when the incurved portion 2 expandes, oversheath 1 and sinle silk separation back, the resistance of taking out of fire-resistant sinle silk 3 can reduce greatly, and can not receive the resistance of adjacent sinle silk.

The thermal deformation piece 4 is arranged close to the inner wall of the inward bending part 2 in the inward bending part 2, so that the deformation of the thermal deformation piece 4 can directly drive the inward bending part 2 to deform. The tensile strand 5 is arranged in close contact with the thermally deformable part 4, so that heat of the tensile strand 5 can be quickly transferred to the thermally deformable part 4. When the wire core is replaced, the temperature and the deformation of the thermal deformation piece 4 are controlled by controlling the current in the tensile rope 5. The temperature of the thermal deformation piece 4 reaching the required deformation is less than the hardening temperature of the outer sheath 1, so that when the thermal deformation piece 4 reaches the required deformation, the outer sheath 1 cannot be hardened and damaged due to overhigh temperature; when the external fire breaks out, the thermal deformation piece 4 begins to deform at a lower temperature, the outer sheath 1 is hardened after the thermal deformation piece is deformed to a certain degree, the acting force of the deformation of the thermal deformation piece 4 on the hardened outer sheath 1 can be reduced, and the hardened outer sheath 1 is prevented from being broken.

Referring to fig. 1 and 2, as a specific embodiment of the medium voltage fire-resistant cable provided by the present application, the shatter prevention mesh 14 is a metal mesh, and the thermal deformation element 4 is in thermal conductive contact with a portion of the shatter prevention mesh 14 located at the inward bending portion 2.

In this embodiment, when the cable is heated at any local portion, the metal anti-breaking mesh 14 can rapidly transfer heat to the thermal deformation member 4, so that the thermal deformation member 4 deforms before the whole outer sheath 1 is heated and hardened.

In a specific implementation, the metal mesh may be a woven mesh or a spiral mesh surrounding the cable.

Referring to fig. 2, as an embodiment of the medium voltage fire resistant cable provided by the present application, the thermal deformation member 4 includes:

a passive layer 41 disposed along an inner wall of the inflected section 2 and in heat-conductive contact with the shatter prevention mesh 14; and

the active layer 42 is stacked on one side, back to the inner wall of the inward bending part 2, of the passive layer 41 and is in heat conduction connection with the tensile rope 5;

the passive layer 41 and the active layer 42 are fixed at their respective ends, and the coefficient of thermal expansion of the active layer 42 is larger than that of the passive layer 41.

In this embodiment, two sides of the thermal deformation member 4 are respectively connected with the shatter prevention net 14 and the tensile string 5 in a heat conduction manner, so that heat of the shatter prevention net 14 and the tensile string 5 can be rapidly transferred to the thermal deformation member 4. Initially, the thermal deformation piece 4 is attached to the inner wall of the inner bending part 2 and is arc-shaped; when the thermally deformable member 4 is heated, the elongation of the active layer 42 is greater than that of the passive layer 41, so that the whole thermally deformable member 4 is gradually straightened, and the side wall of the inward bending portion 2 is gradually straightened.

In a specific implementation, metals with different thermal expansion coefficients can be used for the passive layer 41 and the active layer 42, and the metals have better thermal conductivity and are easier to deform by heat.

Referring to fig. 2, as a specific embodiment of the medium voltage fire-resistant cable provided by the present application, at least one of two sets of corresponding ends of the active layer 42 and the passive layer 41 is fixed by a rivet 43, and a maximum heat-resistant temperature of the rivet 43 is greater than a plastic temperature of the outer sheath 1 and less than a hardening temperature of the outer sheath 1.

After the fire is started, the thermal deformation piece 4 is thermally deformed at the beginning; after the temperature is gradually increased to the plastic temperature of the outer sheath 1, the elasticity of the inner bent part 2 disappears, and the original shape can not be recovered; then, the temperature is continuously increased, the rivet 43 is damaged by heat, and the thermal deformation piece 4 can not continuously push the inward bending part 2 to deform, so that the inward bending part 2 is approximately kept in the current shape; finally, the temperature continues to rise to the hardening temperature of the outer sheath 1, the outer sheath 1 is integrally hardened, and at the moment, the rivet 43 is damaged, so that the thermal deformation piece 4 can not generate acting force on the inward bending part 2 any more, and the hardened outer sheath 1 is prevented from being broken.

In a specific implementation, the rivet 43 may be made of a plastic material, and may be melted and broken after being heated, and the temperature at which the rivet 43 is melted and broken is used as the maximum heat-resistant temperature. The temperature at which the rivet 43 is melt broken is between the plastic temperature and the hardening temperature of the neck-in portion 2 by the selection of the particular plastic material.

Referring to fig. 1, as an embodiment of the medium voltage fire resistant cable provided by the present application, the outer sheath 1 is a flat rectangle, and includes:

the two wide walls 11 are oppositely and parallelly arranged in a separated mode, and a plurality of the refractory wire cores 3 are arranged in the middle; and

the two narrow walls 12 are respectively connected between the corresponding end parts of the two wide walls 11, and the two wide walls 11 are pulled to clamp the plurality of refractory wire cores 3 in the middle;

the inward bending part 2 is arranged at each joint of the wide wall 11 and the narrow wall 12, and the shatter prevention net 14 extends from the inward bending part 2 to the wide wall 11 and the narrow wall 12.

In this embodiment, each of the refractory cores 3 is mainly clamped and fixed by two wide walls 11. The interior curved part 2 is located the junction of broad wall 11 and narrow wall 12, and four angles of oversheath 1 all are equipped with interior curved part 2, and when interior curved part 2 was strutted, the distance increase between two broad walls 11 for each fire-resistant sinle silk 3 can be very easy taken out. The shatter prevention net 14 is distributed on each part of the whole outer sheath 1, so that after each part of the outer sheath 1 is heated, the shatter prevention net 14 can transfer heat to the thermal deformation piece 4 in the inward bending part 2.

Referring to fig. 1, as an embodiment of the medium voltage fire resistant cable provided by the present application, the inner side of the wide wall 11 is provided with a partition 13 embedded between two adjacent fire resistant cores 3.

In this embodiment, the partition 13 can fix the position of each of the refractory cores 3, and prevent the dislocation of each of the refractory cores 3. In the specific implementation, the inner side of the wide wall 11 of the sheath 1 is undulated, forming a partition 13.

Referring to fig. 1, as an embodiment of the medium voltage fire-resistant cable provided by the present application, the opening of the inward bending portion 2 is shrunk to limit the tensile cord 5 in the inward bending portion 2.

In this embodiment, the tensile strand 5 is prevented from escaping from the inturned portion 2. When the wire core is replaced, an electrode of a power supply can be inserted from the opening of the inward bending part 2 to be in contact with the tensile rope 5, so that the tensile rope 5 is locally electrified or wholly electrified.

Referring to fig. 1, as a specific embodiment of the medium voltage fire resistant cable provided by the present application, a heat insulation layer 21 is disposed between the inward bending portion 2 and the adjacent fire resistant core 3.

Change 3 tensile ropes 5 of fire-resistant sinle silk at every turn and all can generate heat, adjacent fire-resistant sinle silk 3 can be heated, so relapse, adjacent fire-resistant sinle silk 3 damages easily. In this embodiment, the heat insulating layer 21 is provided to prevent heat of the tensile cord 5 and the thermal deformation member 4 from being transferred to the refractory core 3, thereby reducing the influence on the adjacent refractory core 3. In a concrete implementation, the heat insulating layer 21 is attached to the outer side of the side wall of the inward bending portion 2.

Referring to fig. 1, as a specific embodiment of the medium voltage fire-resistant cable provided by the present application, an outer sheath 1 is made of ceramic silicone rubber or a crusting polyolefin, and an outer layer of the fire-resistant core 3 is made of ceramic silicone rubber.

In this embodiment, the outer sheath 1 and the refractory core 3 both have a certain refractory capacity, so as to further improve the overall refractory performance.

Referring to fig. 1, as a specific embodiment of the medium voltage fire-resistant cable provided by the present application, the tensile cord 5 is a steel cord.

In the embodiment, the steel wire rope is used as the tensile rope 5, so that the strength is ensured, and the steel wire rope can conduct electricity and generate heat; moreover, in case of fire, the steel wire rope can conduct heat more quickly, so that the thermal deformation member 4 is deformed.

The above description is only exemplary of the present application and should not be taken as limiting the present application, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. Medium voltage fire resistant cable, characterized in that comprises:

2. The medium voltage fire resistant cable according to claim 1, wherein the shatter prevention mesh is a metal mesh, and the thermally deformable member is in thermally conductive contact with a portion of the shatter prevention mesh located at the inflected section.

3. The medium voltage fire resistant cable according to claim 2, wherein the thermally deformable member comprises:

the active layer is stacked on one side, back to the inner wall of the inward bending part, of the passive layer and is in heat conduction connection with the tensile rope;

4. The medium voltage fire resistant cable according to claim 3, wherein at least one of the two sets of corresponding ends of the active layer and the passive layer is fixed by rivets having a maximum heat resistance temperature greater than the plasticity temperature of the outer sheath and less than the hardening temperature of the outer sheath.

5. The medium voltage fire resistant cable according to claim 1, wherein said outer jacket is a flattened rectangle comprising:

6. The medium voltage fire resistant cable according to claim 5, wherein the inner side of the wide wall is provided with a partition embedded between two adjacent fire resistant cores.

7. The medium voltage fire resistant cable of claim 1, wherein the open constriction of the inturned portion traps the tensile strand within the inturned portion.

8. The medium voltage fire resistant cable according to claim 1, wherein a thermal insulation layer is provided between the inturned portion and the adjacent fire resistant core.

9. The medium voltage fire resistant cable according to claim 1, wherein the outer sheath is made of a ceramic silicone rubber or a encrusted polyolefin and the outer layer of the fire resistant core is a ceramic silicone rubber.

10. The medium voltage fire resistant cable of claim 1, wherein the tensile strand is a steel cord.