CN116189986B

CN116189986B - Cold-resistant cable

Info

Publication number: CN116189986B
Application number: CN202310452660.2A
Authority: CN
Inventors: 白雪松; 白摩西; 贾志敏; 白月明; 白岩峰; 吴力金; 蔡进健
Original assignee: Jintai Cable Co ltd
Current assignee: Jintai Cable Co ltd
Priority date: 2023-04-25
Filing date: 2023-04-25
Publication date: 2023-07-04
Anticipated expiration: 2043-04-25
Also published as: CN116189986A

Abstract

The invention provides a cold-resistant cable, relates to the technical field of cables, and aims to solve the technical problem that a cable shell can be frozen and cracked when the ambient temperature is reduced; the cold-resistant cable comprises a cable core, a heat conducting layer coated on the outer side of the cable core, a heat insulating layer coated on the outer side of the heat conducting layer and a heating assembly arranged in the heat insulating layer; the heating assembly comprises an electric heating wire, a first contact piece and a temperature changing piece; the heating wire is used for being electrically connected with the positive electrode or the negative electrode of the first power supply, the temperature change piece is correspondingly electrically connected with the negative electrode or the positive electrode of the first power supply, the first contact piece is electrically connected with the heating wire, and the temperature change piece can deform along with the change of the external temperature so as to be electrically connected with or disconnected from the first contact piece. The cold-resistant cable disclosed by the invention can start the heating component to heat when the environmental temperature is reduced, and the heat conduction layer and the electric heating component jointly provide heat for the heat preservation layer, so that the cable has better cold resistance.

Description

Cold-resistant cable

Technical Field

The invention relates to the technical field of cables, in particular to a cold-resistant cable.

Background

The cable is an electric energy or signal transmission device, and a common cable comprises a wire for energizing, wherein the wire is externally wrapped with a shell, and the shell has certain insulating capability.

With the development of China society, the national infrastructure is more and more perfect, and the laying of foundation equipment such as cables is more and more wide, and with the laying range of the cables being larger and larger, the environments of areas through which the cables are required to pass are different. The transmission condition of the cable is affected by the external temperature, so that for cold cable laying, an antifreezing cable is generally adopted.

The existing antifreezing cable, such as the one provided by Chinese patent with application number 201710630400.4, discloses a cold-resistant medium voltage power cable, wherein a cold-resistant polyurethane wrapping layer and a cold-resistant polyvinyl chloride sheath layer are arranged outside an outer shielding layer, and cold-resistant materials are adopted, so that various cold-resistant performances are effectively improved.

Aiming at the related technology, the applicant considers that the anti-freezing cable is dependent on the cold-resistant material layer on the surface layer, the cold-resistant material layer can be frozen and cracked along with the continuous reduction of the environmental temperature, the anti-freezing performance is lost, the protection means is single, the anti-freezing cable is difficult to continue to use once accidents occur, and the service life is low.

Disclosure of Invention

Therefore, the invention provides the cold-resistant cable which can be used normally when the ambient temperature is continuously reduced.

The technical scheme of the invention is as follows:

the cold-resistant cable comprises a cable core, a heat conducting layer coated on the outer side of the cable core, a heat insulating layer coated on the outer side of the heat conducting layer, and a heating assembly arranged on the heat insulating layer;

the heating assembly comprises an electric heating wire, a first contact piece and a temperature changing piece; the heating wire is used for being electrically connected with the positive electrode or the negative electrode of the first power supply, the temperature change piece is correspondingly electrically connected with the negative electrode or the positive electrode of the first power supply, the first contact piece is electrically connected with the heating wire, and the temperature change piece can deform along with the change of the external temperature so as to be electrically connected with or disconnected from the first contact piece.

Through adopting above-mentioned technical scheme, first power is external power source, is connected heating element and first power, under the higher circumstances of ambient temperature, first contact piece and temperature change piece mutually separate. When the cable works, current passes through the cable core, the cable core can generate heat, the heat is transmitted to the heat insulation layer outwards through the heat conduction layer, the heat insulation layer is heated while the cable core is cooled, the heat insulation layer is more cold-resistant, and the cold-resistant effect of the cable is improved.

The setting of heat conduction layer and heat preservation has utilized the cable core self to generate heat and has resisted external low temperature, but cable core self generates heat and is limited, and when external environment temperature continued to reduce, the heat that the cable core produced is insufficient to resist the decline of temperature, and the temperature of heat preservation reduces the temperature change temperature to the temperature change piece this moment, and the temperature change piece takes place deformation, is connected with first contact to the temperature change piece for the heating wire is circular telegram, generates heat, heats the heat preservation, continues to resist external environment temperature's decline.

This application is through the comprehensive utilization to cable core self heat and heating element, and when external environment temperature degree of reduction was less, the reduction of ambient temperature can be resisted to cable self heat, and heating element is in idle state this moment, and along with ambient temperature's continuation reduces heating element and carries out work, has both improved the cold-resistant performance of cable, has reduced the waste of electric quantity again.

Further, the heat insulation device further comprises a first electromagnet arranged in the heat insulation layer, the first contact piece is arranged in the heat insulation layer in a sliding mode, and the first electromagnet can apply acting force to the first contact piece to enable the first contact piece to slide to be in contact with the temperature change piece.

The temperature of deformation required by the occurrence of the temperature change piece is fixed, namely when the fixed temperature is reached, the heating wire is electrified, but after the heating wire is electrified and generates heat, the temperature of the heat preservation layer can be increased, the temperature change piece can recover deformation, and the heating wire is powered off, so that frequent on-off of the heating wire can be caused. Through adopting above-mentioned technical scheme, when temperature change piece and first contact switch-on, first electromagnetic work adsorbs first contact, and the heating wire circular telegram heats, and heat preservation temperature increases gradually, along with the rising of heat preservation temperature, and temperature change piece resumes deformation gradually, along with the deformation of temperature change piece, first electromagnet adsorbs and drives first contact and remove to the direction that is close to temperature change piece for temperature change piece remains to be connected with first contact, thereby guarantees the heating time of heating wire, solves the problem that the heating wire frequently switches on and off.

Further, the device also comprises a second power supply; the second power supply is in power supply connection with the first electromagnet, a switch unit is arranged between the second power supply and the first electromagnet, the switch unit comprises a second contact piece and a third contact piece, and when the second contact piece is in contact with the third contact piece, the second power supply supplies power for the first electromagnet.

By adopting the technical scheme, when the temperature change piece is not connected with the first contact piece, the second contact piece is not connected with the third contact piece, at the moment, the circuit where the heating wire is positioned and the circuit where the first electromagnet is positioned are in a disconnection state, and the heating wire and the first electromagnet do not work; when the temperature change piece is communicated with the first contact piece, the second contact piece is communicated with the third contact piece, the first electromagnet is started to adsorb the first contact piece, and the communicated state of the temperature change piece and the first contact piece is ensured; after the set heating time is reached, the second contact piece is separated from the third contact piece, the adsorption force of the first electromagnet to the first contact piece is disappeared, the first contact piece is separated from the temperature change piece, and the heating wire stops heating.

Further, the electric heating wire heating device further comprises a second electromagnet, the second electromagnet and a second power supply are connected in series in a circuit connected with the electric heating wire in parallel, a fourth contact piece is further arranged in the circuit, and the temperature change piece can be connected with one of the first contact piece and the fourth contact piece in a conductive mode; when the temperature change piece is connected with the fourth contact piece, the second electromagnet can drive the second contact piece and the third contact piece to be separated, and the first power supply charges the second power supply.

By adopting the technical scheme, the second power supply is a charging power supply, such as a capacitor, when the ambient temperature is high, the temperature change piece is communicated with the fourth contact piece, at the moment, the first power supply is communicated with the second power supply, the first power supply charges the second power supply, the charging speed of the capacitor is high, and the charging can be automatically stopped after the capacitor is fully charged; when the second power supply is charged, the first power supply supplies power to the second electromagnet, the second electromagnet attracts the first contact piece, so that the second contact piece is separated from the third contact piece, and the first electromagnet is in a power-off state. When the ambient temperature is reduced, the temperature-changing piece deforms, the temperature-changing piece is separated from the fourth contact piece and is connected with the first contact piece, the heating wire starts to heat, at the moment, the second electromagnet is powered off and loses acting force on the second contact piece, the second contact piece is connected with the third contact piece, so that the first electromagnet is connected with the second power supply, and the first electromagnet adsorbs the first contact piece; as the heating wire heats, the temperature of the heat preservation layer rises, the temperature change piece deforms, and the first electromagnet adsorbs the first contact piece, so that the connection state of the temperature change piece and the first contact piece is ensured; and along with the heating, the electric quantity of the second power supply is consumed, the first electromagnet is powered off, the adsorption of the first contact piece is lost, and then the first contact piece is separated from the temperature change piece, and the heating is finished.

Further, the second contact piece is an elastic metal piece, one end of the second contact piece is fixedly connected to the heat insulation layer, the free end of the second contact piece is electrically connected with the third contact piece, and when the second electromagnet adsorbs the free end of the second contact piece, the second contact piece is separated from the third contact piece.

Further, the heating wires are uniformly arranged in a plurality of along the circumferential direction of the heat preservation layer.

Through adopting above-mentioned technical scheme, evenly set up multiunit heating wire can make the heat preservation be heated evenly, avoided local being heated and accelerated the ageing of part of heat preservation.

Preferably, an insulating layer is arranged outside the insulating heat conducting layer, a plurality of heat conducting blocks are fixedly connected to the circumferential surface of the heat conducting layer, and the other ends of the heat conducting blocks penetrate through the insulating layer and are fixedly connected to the heat insulating layer.

Through adopting above-mentioned technical scheme, the insulating layer can isolate the electric current of cable core and outwards transmit, and the heat that produces when the cable core circular telegram is transmitted for the heat conduction layer earlier, and the rethread heat conduction piece transmits for the heat preservation, guarantees that the heat that the cable core produced can transmit to the heat preservation.

Preferably, the heat conducting blocks and the heating wires are arranged in a staggered mode.

When the temperature continuously reduces, the heat conducting blocks and the heating wires jointly provide heat for the heat preservation layer, and by adopting the technical scheme, the heat conducting blocks and the heating wires are arranged in a staggered mode, which is equivalent to providing more heat transfer points for the heating layer.

The working principle and the beneficial effects of the invention are as follows:

according to the cold-resistant cable provided by the invention, the heat conducting layer is matched with the heating component, so that when the reduction degree of the external environment temperature is small, the heat of the cable can resist the reduction of the environment temperature, and the heating component is in an idle state, so that the electric waste is reduced; as the environmental temperature continues to be reduced, the temperature change piece in the heating component deforms, the heating component works, and the heat conduction layer and the heating wire supply heat for the heat preservation layer together so as to resist the reduction of the environmental temperature; the temperature change piece deforms along with the temperature change of the heating layer, and whether the heating assembly works or not is controlled, so that the cold resistance of the cable is improved, and the waste of electric quantity is reduced.

Drawings

The invention will be described in further detail with reference to the drawings and the detailed description.

FIG. 1 is a schematic cross-sectional view of an embodiment of the present application taken perpendicular to the cable axis;

FIG. 2 is a cross-sectional view showing a heating assembly;

FIG. 3 is a schematic diagram showing the connection relationship of components in a thermal insulation layer;

FIG. 4 is an enlarged view of a portion of FIG. 3 at A;

fig. 5 is an equivalent circuit diagram of an embodiment of the present application.

In the figure: 1. a cable core; 2. a heat conducting layer; 21. a heat conduction block; 3. an insulating layer; 4. a heat preservation layer; 5. A thermal insulation layer; 6. An outer protective layer; 7. a heating assembly; 71. heating wires; 72. a first contact; 721. a first connector; 722. a first elastic sheet; 723. a first magnet; 73. a temperature change member; 731. a first metal sheet; 7311. a second electrical contact; 732. a second metal sheet; 7321. a first electrical contact; 7322. a first electromagnet; 8. a second power supply; 81. a second contact; 82. a third contact; 83. a second electromagnet; 84. a fourth contact; 841. a second connector; 8411. a second elastic sheet; 842. and a second magnet.

Description of the embodiments

The technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by one of ordinary skill in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1 and 2, the embodiment provides a cold-resistant cable, which comprises a cable core 1, wherein a heat conducting layer 2, an insulating layer 3, a heat insulating layer 4, a heat insulating layer 5 and an outer protective layer 6 are sequentially coated outside the cable core 1 from inside to outside, and a heating assembly 7 is arranged in the heat insulating layer 4. Heat is transferred to the heat insulation layer 4 through the matching of the heat conduction layer 2 and the heating component 7, and cold resistance of the cable is improved.

Referring to fig. 1, a plurality of heat conducting blocks 21 are fixedly connected to the outer periphery of the heat conducting layer 2 along the circumferential direction, one end, away from the heat conducting layer 2, of the heat conducting blocks 21 is fixedly connected to the heat insulating layer 4, and the heat conducting layer 2 and the heat conducting blocks 21 are made of heat conducting insulating materials, such as heat conducting silica gel materials. When the cable works, the cable core 1 can generate heat, the heat generated by the cable core 1 is transferred to the heat conducting layer 2, the heat of the heat conducting layer 2 is transferred to the heat insulating layer 4 through the heat conducting block 21, the heat insulating layer 4 is heated while the cable core 1 is cooled, and the cold-resistant effect of the cable is improved.

Referring to fig. 2-5, the heating assembly 7 includes an electric heating wire 71, a first contact member 72, and a temperature change member 73, where the electric heating wire 71 is fixedly disposed in the heat insulation layer 4, the electric heating wire 71 is uniformly disposed with a plurality of electric heating wires 71 along the circumferential direction of the heat insulation layer 4, the electric heating wire 71 is staggered with the heat conducting block 21, the electric heating wire 71 is connected with the positive pole or the negative pole of the first power supply through a wire, the first power supply is an external power supply, the temperature change member 73 is connected with the negative pole or the positive pole of the first power supply through a wire, the temperature change member 73 is fixedly connected with a first electric contact member 7321, the first electric contact member 7321 is electrically connected with the electric heating wire 71, the temperature change member 73 can deform along with the change of the external temperature, so that the first electric contact member 7321 is electrically connected with or electrically disconnected from the first contact member 72, and when the first electric contact member 7321 contacts with the first contact member 72, the first power supply, the electric heating wire 71, the first electric contact member 7321 and the first contact member 72 together form a complete electric heating wire circuit, so that the first power supply is supplied to the first power supply 71. When the external ambient temperature is high, the first electrical contact 7321 and the first contact 72 are in a separated state; the heating of the cable core 1 is limited, when the external environment temperature continues to decrease, the heat generated by the cable core 1 is insufficient to resist the decrease of the temperature, at this time, the temperature changing piece 73 is deformed, the first electric contact piece 7321 is connected with the first contact piece 72, the electric circuit where the heating wire 71 is located is conducted, the heating wire 71 heats the heat insulation layer 4, and the continuous decrease of the external environment temperature is resisted.

Referring to fig. 3 and 4, the temperature-changing member 73 is a bimetal, and includes a first metal sheet 731 and a second metal sheet 732 that are attached to each other, the first metal sheet 731 is fixedly connected to the second metal sheet 732, the thermal expansion coefficient of the first metal sheet 731 is greater than that of the second metal sheet 732, the first electrical contact 7321 is disposed on a side of the second metal sheet 732 away from the first metal sheet 731, when the temperature decreases to a predetermined value, the temperature-changing member 73 is deformed, the first electrical contact 7321 on the second metal sheet 732 is connected to the first contact 72, the electric circuit where the heating wire 71 is located is connected, and the heating wire 71 generates heat.

Referring to fig. 3 and 5, a first connecting member 721 is connected to the first contact member 72, the first connecting member 721 is electrically connected to the heating wire 71, the first connecting member 721 is fixedly connected to the heat insulation layer 4, the first contact member 72 is slidably connected to the first connecting member 721, the sliding direction of the first contact member 72 is parallel to the deformation direction of the temperature change member 73, and a first elastic sheet 722 is fixedly connected between the first contact member 72 and the first connecting member 721; the heat preservation layer 4 is also internally provided with a first electromagnet 7322, the first electromagnet 7322 is fixedly connected with one end of a temperature change part 73, and a first magnet 723 which is in adsorption fit with the first electromagnet 7322 is fixedly connected with a first contact part 72. After the temperature change piece 73 is communicated with the first contact piece 72, the first electromagnet 7322 adsorbs the first contact piece 72 through the first magnet 723, the temperature of the heat insulation layer 4 is increased along with the heating of the heating wire 71, the temperature change piece 73 gradually recovers to deform, the first electric contact piece 7321 gradually moves away from the first contact piece 72, at this time, the first contact piece 72 moves towards the direction close to the first electric contact piece 7321 under the adsorption action of the first electromagnet 7322, the communication between the first electric contact piece 7321 and the first contact piece 72 is ensured, the circuit of the heating wire 71 is prevented from being disconnected after the temperature is increased, and the repeated on-off of the circuit of the heating wire 71 is avoided.

Referring to fig. 2 and 4, a second power supply 8, a second contact 81 and a third contact 82 are further disposed in the heat insulation layer 4; the third contact member 82 is electrically connected with the first electromagnet 7322, the second contact member 81 is electrically connected with the second power supply 8, the second contact member 81 is an elastic metal sheet, one end of the second contact member 81 is fixedly connected with the heat insulation layer 4, the other end of the second contact member 81 is electrically connected with the third contact member 82, namely, an acting force is applied to the second contact member 81, so that the connection and disconnection of the second contact member 81 and the third contact member 82 can be realized, when the second contact member 81 and the third contact member 82 are connected, the second power supply 8, the second contact member 81, the third contact member 82 and the first electromagnet 7322 form a circuit, the second power supply 8 supplies power to the first electromagnet 7322, and the heating time of the heating wire 71 is adjusted by controlling whether the first electromagnet 7322 is electrified or not.

Referring to fig. 3 to 5, a second electromagnet 83 and a fourth contact element 84 are further disposed in the heat insulation layer 4, the second power source 8 is a capacitor, the second electromagnet 83 and the second power source 8 are connected in series in a circuit parallel to the heating wire 71, the fourth contact element 84 is electrically connected with the second power source 8 in the circuit, the fourth contact element 84 and the first contact element 72 are symmetrically disposed with respect to the temperature change element 73, a second electric contact element 7311 is disposed on one side of the first metal sheet 731 away from the second metal sheet 732, the second electric contact element 7311 can be electrically connected with the fourth contact element 84, that is, the temperature change element 73 can be electrically connected with one of the first contact element 72 and the fourth contact element 84; the second electromagnet 83 is fixedly connected to the heat insulation layer 4, and the second electromagnet 83 is in adsorption fit with the second contact piece 81. When the second electric contact 7311 is electrically connected to the fourth contact 84, the first power source, the second electric contact 7311, the fourth contact 84, the second electromagnet 83, and the second power source 8 form a complete circuit, in which the first power source charges the second power source 8, the second electromagnet 83 is energized to attract the second contact 81 so that the second contact 81 is separated from the third contact 82, and the first electromagnet 7322 is in a power-off state; when the first electric contact 7321 is electrically connected to the first contact 72, the circuit formed by the first power source, the second electric contact 7311, the fourth contact 84, the second electromagnet 83, and the second power source 8 is disconnected, the second power source 8 stops charging, the second electromagnet 83 is powered off, the second contact 81 is electrically connected to the third contact 82, and the second power source 8 supplies power to the first electromagnet 7322; the circuit formed by the first power source, the heating wire 71, the first electrical contact 7321, and the first contact 72 is turned on, and the heating wire 71 heats up until the electric quantity of the second power source 8 is exhausted.

Referring to fig. 3, a second connecting member 841 is slidably connected to the fourth contact member 84, the fourth contact member 84 is electrically connected to the second connecting member 841, the second connecting member 841 is electrically connected to the second power source 8, the second connecting member 841 is fixedly connected to the insulating layer 4, a second magnet 842 that repels the first electromagnet 7322 is fixedly connected to the fourth contact member 84, and a second elastic sheet 8411 is fixedly connected between the fourth contact member 84 and the second connecting member 841. As the temperature of the heat insulation layer 4 increases with the heating of the heating wire, the temperature-changing piece 73 returns to deformation, as the temperature-changing piece 73 deforms, the first electric contact piece 7321 is far away from the first contact piece 72, the second electric contact piece 7311 approaches to the fourth contact piece 84, at this time, the first electromagnet 7322 attracts the first contact piece 72 through the first magnet 723, the electric connection between the first electric contact piece 7321 and the first contact piece 72 is kept, and at the same time, the first electromagnet 7322 repels the fourth contact piece 84 through the second magnet 842, so as to ensure the separation state of the second electric contact piece 7311 and the fourth contact piece 84.

The implementation principle of the embodiment is as follows: when the external environment temperature is higher, the second electric contact 7311 on the temperature-changing element 73 is electrically connected with the fourth contact 84, at this time, the circuit composed of the first power supply, the second power supply 8 and the second electromagnet 83 is turned on, the first power supply charges the second power supply 8 and supplies power to the second electromagnet 83, the second electromagnet 83 adsorbs the second contact 81, so that the second contact 81 is separated from the third contact 82, and the first electromagnet 7322 is in a non-energized state.

When the ambient temperature starts to decrease, the heat generated by the cable core 1 is transmitted to the heat insulation layer 4 through the heat conduction layer 2 and the heat conduction block 21, and the heat insulation layer 4 is heated to resist the decrease of the ambient temperature while the cable core 1 is cooled; as the ambient temperature continuously decreases, the heat generated by the cable core 1 is insufficient to resist the decrease of the temperature, the temperature of the insulation layer 4 decreases, the temperature change member 73 deforms, so that the second electric contact 7311 is separated from the fourth contact 84, the first electric contact 7321 is electrically connected with the first contact 72, and at this time, the circuit composed of the first power supply, the second power supply 8 and the second electromagnet 83 is disconnected; the circuit composed of the first power supply and the heating wire 71 is turned on, the heating wire 71 starts to heat, meanwhile, the second electromagnet 83 is powered off, the second contact piece 81 is electrically connected with the third contact piece 82 under the elastic action, the circuit composed of the second power supply 8 and the first electromagnet 7322 is also turned on, and the first electromagnet 7322 magnetically attracts the first magnet 723 and repels the second magnet 842. As the heating wire 71 heats, the temperature-varying element 73 returns to its deformed state, the first electrical contact 7321 is far away from the first contact 72, the second electrical contact 7311 is close to the fourth contact 84, at this time, the first electromagnet 7322 attracts the first contact 72 through the first magnet 723, so as to keep the electrical connection between the first electrical contact 7321 and the first contact 72, and at the same time, the first electromagnet 7322 repels the fourth contact 84 through the second magnet 842, so as to ensure the separation state between the second electrical contact 7311 and the fourth contact 84. The heating process of the heating wire 71 continues until the electric quantity in the second power supply 8 is exhausted, after the electric quantity of the second power supply 8 is exhausted, the magnetism of the first electromagnet 7322 disappears, the adsorption of the first magnet 723 and the repulsive action of the second magnet 842 are lost, under the action of the first elastic piece 722 and the second elastic piece 8411, the first contact piece 72 and the fourth contact piece 84 are reset, the second electric contact piece 7311 and the fourth contact piece 84 are electrically connected, and then the charging process of the second power supply 8 is entered again, and the above steps are repeated.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.

Claims

1. The cold-resistant cable comprises a cable core (1) and is characterized by further comprising a heat conducting layer (2) coated on the outer side of the cable core (1), a heat insulating layer (4) coated on the outer side of the heat conducting layer (2), and a heating component (7) arranged in the heat insulating layer (4);

the heating assembly (7) comprises an electric heating wire (71), a first contact piece (72) and a temperature change piece (73); the heating wire (71) is electrically connected with the positive electrode or the negative electrode of the first power supply, the temperature changing piece (73) is correspondingly electrically connected with the negative electrode or the positive electrode of the first power supply, the first contact piece (72) is electrically connected with the heating wire (71), and the temperature changing piece (73) can deform along with the change of the external temperature so as to be electrically connected with or disconnected from the first contact piece (72);

the heat insulation device further comprises a first electromagnet (7322) arranged in the heat insulation layer (4), wherein the first contact piece (72) is slidably arranged in the heat insulation layer (4), and the first electromagnet (7322) can apply acting force to the first contact piece (72) so that the first contact piece (72) slides to be in contact with the temperature change piece (73);

also comprises a second power supply (8); the second power supply (8) is in power supply connection with the first electromagnet (7322), a switch unit is arranged between the second power supply (8) and the first electromagnet (7322), the switch unit comprises a second contact piece (81) and a third contact piece (82), and when the second contact piece (81) is in contact with the third contact piece (82), the second power supply (8) supplies power for the first electromagnet (7322);

the electric heating wire heating device further comprises a second electromagnet (83), the second electromagnet (83) and a second power supply (8) are connected in series in a circuit connected with the electric heating wire (71) in parallel, a fourth contact piece (84) is further arranged in the circuit, and the temperature change piece (73) can be connected with one of the first contact piece (72) and the fourth contact piece (84) in a conductive mode; when the temperature changing piece (73) is connected with the fourth contact piece (84), the second electromagnet (83) can drive the second contact piece (81) and the third contact piece (82) to be separated, and the first power supply charges the second power supply (8).

2. A cold-resistant cable according to claim 1, characterized in that: the second contact piece (81) is an elastic metal sheet, one end of the second contact piece (81) is fixedly connected to the heat insulation layer (4), the free end of the second contact piece is electrically connected with the third contact piece (82), and when the second electromagnet (83) adsorbs the free end of the second contact piece (81), the second contact piece (81) is separated from the third contact piece (82).

3. A cold-resistant cable according to claim 1, characterized in that: the electric heating wires (71) are uniformly arranged along the circumferential direction of the heat preservation layer (4).

4. A cold-resistant cable according to claim 3, characterized in that: an insulating layer (3) is arranged outside the heat conducting layer (2), a plurality of heat conducting blocks (21) are fixedly connected to the circumferential surface of the heat conducting layer (2), and the other ends of the heat conducting blocks (21) penetrate through the insulating layer (3) and are fixedly connected to the heat insulating layer (4).

5. The cold-resistant cable according to claim 4, wherein: the heat conducting blocks (21) and the heating wires (71) are arranged in a staggered mode.