A cross-linked polyethylene insulated power cable capable of reducing cracking of insulation layer

Abstract

The present invention discloses a cross-linked polyethylene insulated power cable capable of reducing cracking of the insulation layer, belonging to the technical field of cables, comprising an insulation layer body constituting the cable body and a wire core wrapped by the insulation layer body, and the cable also comprises a cooling mechanism, wherein both ends of the air pipe extend through the insulation layer body to the outside of the cable, and the middle section of the air pipe is parallel to the axis of the wire core. The cross-linked polyethylene insulated power cable capable of reducing cracking of the insulation layer redesigns the air pipe at the cable wire core and the related structures on the outside of the insulation skin, and can reduce the deformation cracking of the insulation layer by changing the temperature difference between the inside and outside of the cable while ensuring that the basic functions of the original cable are not affected, thereby effectively increasing the service life of the entire cable, and can use the same solution to achieve the effects of accelerating the cooling of the wire core and preventing insects and birds outdoors, which is more energy-saving and environmentally friendly.

Description

Technical Field

[0001] The present invention relates to the technical field of cables, in particular to a cross-linked polyethylene insulated power cable, in particular to a cross-linked polyethylene insulated power cable capable of reducing cracking of an insulation layer. Background Art

[0002] Power cable is a short-distance / long-span power transmission facility that realizes short-distance / long-span power transmission through the conductivity of its internal core. Among them, cross-linked polyethylene insulated power cable refers to the insulation material wrapped on the outside of the core of the power cable, wherein the insulation layer actually includes the outer sheath of the cable and the magnetic insulation material between the core and the outer sheath. For example, the cross-linked polyethylene insulated power cable with announcement number CN113393961B in the prior art includes a cable body, and the cable body includes an insect repellent layer, an inner layer, an insulating layer, a waterproof filling layer and a core, and the insect repellent layer is arranged outside the inner layer. The insect repellent layer is provided with a plurality of insect repellent cavities, the inner layer is provided with a plurality of heating cavities, and the heating cavities correspond to the insect repellent cavities one by one, the bottom of the heating cavity is provided with a heat conducting plate, and the outer wall of the top of the heat conducting plate is provided with an air bag, a T-shaped column 1 is slidably connected to the connection between the heating cavity and the insect repellent cavity, a sliding cavity 1 is provided on the inner wall of the top of the insect repellent cavity, and sliding cavities 2 are provided on both sides of sliding cavity 1, the inner walls of the two sliding cavities 1 are slidably connected with blocking plates, and the outer walls of the two blocking plates are provided with a plurality of through holes 2, and through holes 1 are provided on both sides of the sliding cavity 1 with the same number as through holes 2, and through holes 1 and through holes 2 are the same size. The invention can repel small animals such as insects and ants to prevent them from damaging the cable body, thereby protecting the cable body;

[0003] Another example is a flame-retardant cross-linked polyethylene insulated power cable with a publication number of CN116230297B; it comprises a cable core, a cross-linked polyethylene tube is arranged between the plurality of cable cores, an insulating cloth is arranged on the outside of the plurality of cable cores, a filler is arranged between the insulating cloth, the cross-linked polyethylene tube and the cable core, and a heat-conducting component is arranged in the filler; the power cable provided by the invention does not generate acidic gas under fire conditions, can work for a long time at an ambient temperature of 125°C, and has excellent insulation resistance. By setting up the heat-conducting component, an excellent heat dissipation effect for the cable core is achieved. In addition, by filling the storage tank with inert gas, the air can be flame-retarded in the event of a fire to achieve a flame-retardant effect. The power cable provided has a wide range of application prospects, especially for occasions with high fire protection requirements such as environmental protection and fire fighting;

[0004] Although the cables in the prior art have relatively complete improvements in overall structural strength and overall heat dissipation of the cables, the internal temperature of power cables, especially high-power / ultra-high-power cables, is extremely high when in use (compared to the ambient temperature). Therefore, when running for a long time or being in an environment with a large temperature difference for a long time, the insulating material may crack due to the temperature difference between the inside and outside at the same time or due to thermal expansion and contraction over a long period of time in different time periods, thereby reducing safety performance. Summary of the invention

[0005] The object of the present invention is to provide a cross-linked polyethylene insulated power cable capable of reducing cracking of the insulation layer, so as to solve the problem that the cables in the prior art proposed in the above background technology have relatively complete improvements in overall structural strength and overall heat dissipation of the cables, but the internal temperature of the power cables, especially high-power / ultra-high-power cables, is extremely high when in use (compared with the ambient temperature). Therefore, when the power cables are in operation for a long time or are in an environment with a large temperature difference for a long time, the insulation material may crack due to the temperature difference between the inside and outside at the same time or the thermal expansion and contraction in different time periods for a long time, thereby reducing the safety performance.

[0006] To achieve the above-mentioned object, the present invention provides the following technical solutions: A cross-linked polyethylene insulated power cable capable of reducing cracking of an insulation layer, comprising an insulation layer body constituting a cable body and a wire core wrapped by the insulation layer body, the cable further comprising a cooling mechanism, wherein the cooling mechanism reduces the temperature difference between the inside and outside of the cable by removing heat around the wire core, thereby reducing cracking of the insulation layer of the cable;

[0007] As a further feature, the cooling mechanism includes an air pipe distributed around the outside of the wire core, wherein both ends of the air pipe extend through the insulating layer to the outside of the cable, and the middle section of the air pipe is distributed parallel to the axis of the wire core.

[0008] As a further feature, air holes are provided on the surface of the air pipe, wherein the air flow in the air pipe takes out nearby heat via the air holes, and the air holes are distributed toward the wire core.

[0009] As a further feature, a pulling mechanism is also provided on the surface of the insulating layer body, wherein the pulling mechanism reduces cracking and deformation of the insulating layer body by actively providing pulling or inner pulling force.

[0010] As a further feature, the pulling mechanism comprises a screw rod and a transverse cylinder threadedly connected to the inner end thereof, wherein the inner end of the transverse cylinder is fixed on a fixing ring, and the outer end of the screw rod in the same group is rotatably mounted on another fixing ring.

[0011] As a further feature, the fixing ring is installed on the outer surface of the insulating layer body by means of bolts and an anti-slip layer arranged on the inner wall of the ring, wherein the fixing ring is deformably arranged along the axis direction of the wire core.

[0012] As a further feature, the pulling mechanism includes a metal piece surrounding and embedded in the surface of the insulating layer, wherein the metal piece is made of a two-way memory alloy material.

[0013] As a further feature, the metal part is in a tubular structure, and its one-way input end is connected to the one-way output end of the air pipe through a connecting mechanism. The connecting mechanism is used to connect the two, and reduce the temperature difference between the inside and outside of the cable by conducting the temperature near the wire core to the surface of the insulation layer.

[0014] As a further feature, the connecting mechanism is composed of a bent pipe, two ends of which are respectively connected to the output end of the air pipe and the input end of the metal piece.

[0015] As a further feature, the connecting mechanism comprises a hollow ring fixed on the cable, the inner space of the hollow ring is connected with the air pipe and the metal part, and a valve plate is slidably installed at the side opening of the hollow ring, and the valve plate is connected to a driving device for driving the movement.

[0016] As a further feature, a shaft rod overlapping with its axis is rotatably installed in the metal part, and the shaft rod is divided into two parts, a rigid part and a flexible part. A turbine located in a hollow ring is installed at the end of the rigid part, while a metal sheet is fixed on the surface of the flexible part.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: the cross-linked polyethylene insulated power cable that can reduce the cracking of the insulation layer redesigns the air pipe at the cable core and the related structures on the outside of the insulation skin, and can reduce the deformation and cracking of the insulation layer by changing the temperature difference between the inside and outside of the cable while ensuring that the basic functions of the original cable are not affected, thereby effectively increasing the service life of the entire cable, and can use the same solution to achieve the effects of accelerating the cooling of the core and preventing insects and birds outdoors, which is more energy-saving and environmentally friendly, as shown in the following content:

[0018] 1. The structural design of the screw and the cross-bar can adjust the distance between the two fixing rings by simply rotating the screw through an external mechanism, thereby achieving the pulling control of the insulation layer on the cable surface. Therefore, the screw can be adjusted according to the external temperature, effectively reducing the cracking of the cable insulation layer, which is more suitable for old cables with better load-bearing capacity;

[0019] 2. The structural design of the metal parts can utilize its own deformation characteristics due to temperature changes to achieve the effect of automatically pulling the cable surface when the external temperature changes, thus eliminating the need for manual or electric drive operation and being more energy-saving and environmentally friendly;

[0020] Furthermore, the connection between the metal part and the air pipe enables the metal part to realize the function of the pulling mechanism and effectively reduce the temperature difference between the inside and outside of the cable through the conduction of airflow and temperature conduction, thereby avoiding deformation and cracking of the insulation layer caused by the operation of the cable itself;

[0021] Furthermore, the structural design of the shaft and the turbine enables the airflow to flow through the metal parts while generating a driving effect and driving the shaft and the metal sheet to rotate. Therefore, the swinging collision between the metal materials can be used to generate noise of a specific frequency, thereby achieving the effect of repelling insects and birds. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic diagram of the overall structure of Embodiment 1 of the present invention;

[0023] Figure 2 For the present invention Figure 1 A schematic diagram of the structure of the pulling mechanism;

[0024] Figure 3 This is a schematic diagram of the trachea distribution structure of the present invention;

[0025] Figure 4 This is a schematic diagram of the overall structure of Embodiment 2 of the present invention;

[0026] Figure 5 This is a schematic diagram of the structure of the connecting mechanism in the second embodiment of the present invention;

[0027] Figure 6 This is a schematic diagram of the overall structure of Embodiment 3 of the present invention;

[0028] Figure 7 It is a schematic diagram of the internal structure of the metal part of the present invention;

[0029] Figure 8 For the present invention Figure 7 Enlarged structural diagram at A in the middle.

[0030] In the figure: 1. Insulating layer; 2. Wire core; 3. Air pipe; 4. Fixing ring; 5. Screw; 6. Cross cylinder; 7. Air hole; 8. Metal part; 9. Hollow ring; 10. Valve plate; 11. Metal sheet; 12. Shaft; 13. Turbine. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] See also Figure 1-Figure 8 , the present invention provides the following technical solutions:

[0033] Embodiment 1: In this embodiment, in order to solve the problems existing in the prior art, a solution is disclosed. The solution is mainly embodied in that the heat near the cable core 2 is taken out to reduce the temperature difference between the inside and outside of the cable, and to avoid excessive deformation of the cable insulation layer to reduce cracking. The solution is mainly shown in the following content, and the specific solution can be referred to Figure 1 and Figure 3 , including an insulating layer body 1 constituting a cable body and a wire core 2 wrapped by the insulating layer body 1, the cable also includes a cooling mechanism, wherein the cooling mechanism reduces the temperature difference between the inside and outside of the cable by removing heat around the wire core 2, thereby reducing the cracking of the cable insulating layer body 1; wherein the cooling mechanism includes an air pipe 3 distributed around the outside of the wire core 2, wherein both ends of the air pipe 3 pass through the insulating layer body 1 and extend to the outside of the cable, and the middle section of the air pipe 3 is parallel to the axis of the wire core 2, and air holes 7 are opened on the surface of the air pipe 3, wherein the air flow flowing in the air pipe 3 takes out the nearby heat through the air holes 7, and the air holes 7 are distributed toward the wire core 2, during processing In this stage, the air pipe 3 only needs to be fixed integrally with the insulating layer material covering the outside of the wire core 2 to form a cable as a whole, or space is reserved in the segmented cable, and after completion, the air pipe 3 is inserted into the reserved space by guiding it with a metal wire. No matter which of the above-mentioned existing processing methods is used, it is only necessary to reserve the end of the air pipe 3 outside the cable. In this way, when the cable is running at high power, the air pipe 3 can be connected to equipment such as an air pump or a fan, so that the external airflow can be discharged after passing through the air pipe 3. During the flow of the airflow, the heat around the wire core 2 will be accelerated to be discharged through the air pipe 3, thereby achieving the above-mentioned effect.

[0034] This embodiment discloses a solution different from the above embodiment, and its essential purpose is also to reduce cracking, and the means adopted is to reduce the cracking of the insulation layer by means of external force limiting. For details, please refer to Figure 1 and Figure 2The surface of the insulating layer body 1 is also provided with a pulling mechanism, wherein the pulling mechanism reduces the cracking deformation of the insulating layer body 1 by actively providing a pulling or inner pulling force, and the pulling mechanism includes a screw 5 and a horizontal cylinder 6 threadedly connected to the inner end thereof, wherein the inner end of the horizontal cylinder 6 is fixed on a fixing ring 4, and the outer end of the same group of screws 5 is rotatably mounted on another fixing ring 4, and the fixing ring 4 is mounted on the outer surface of the insulating layer body 1 by bolts and an anti-slip layer arranged on the inner wall of the ring, wherein the fixing ring 4 is deformable along the axial direction of the wire core 2, and in a special section of the cable In the invention, an additional fixing ring 4 structure can be sleeved on the outer skin of the cable, that is, the outer surface of the insulating layer body 1, wherein two fixing rings 4 form a group, and each group of fixing rings 4 is connected by a screw 5 and a cross cylinder 6. Therefore, during use, the screw 5 can be rotated manually or electrically by the staff. Therefore, under the action of the threaded transmission, the cross cylinder 6 will correspondingly shorten or open the distance between the two fixing rings 4, thereby realizing the anti-cracking function of the cable insulation layer. The advantage of this solution is that it is suitable for old cables and has a better use effect. The disadvantage is that it requires manual or electrically controlled adjustment.

[0035] Embodiment 2: Although the pulling mechanism in the above embodiment has a good anti-cracking effect on old cables, the overall load on the cables is increased, and the manual / electrical control operation in high-altitude sections or special sections is inconvenient. Therefore, in order to solve this problem, the following solution different from the above embodiment is also disclosed in this embodiment, which can be referred to Figure 4 The pulling mechanism includes a metal piece 8 surrounding and embedded in the surface of the insulating layer body 1, wherein the metal piece 8 is a two-way memory alloy material, and the metal piece 8 is a tubular structure, and its one-way input end is connected to the one-way output end of the air pipe 3 through a connecting mechanism, and the connecting mechanism is used to connect the two, and the temperature near the core 2 is transmitted to the surface of the insulating layer body 1 to reduce the temperature difference between the inside and outside of the cable. When the ambient temperature or the surface temperature of the cable significantly increases or decreases, in order to counteract the thermal expansion and contraction characteristics of the insulating material itself, the metal piece 8 made of the memory alloy will form different states of deformation under high temperature and low temperature conditions, which can be specifically reflected as a curling tendency deformation under high temperature conditions, and The stretching tendency deformation under low temperature / normal temperature state can counteract the thermal expansion and contraction tendency of the insulating material to a certain extent, further reducing cracking. In order to further enhance the cooling effect of the cable itself, the present embodiment also discloses that the airflow and flow inside the air pipe 3 are transported to the metal part 8. The metal part 8 itself is also a hollow tube structure. Therefore, while it has the function of deformation caused by temperature change, it can conduct the heat of the wire core 2 absorbed in the air pipe 3 to the cable skin through the metal part 8 by heat conduction. Therefore, while the heat dissipation performance of the cable core 2 is improved, the temperature difference between the inside and outside of the cable can be reduced at the same time, further reducing cracking. The connecting mechanism is composed of a bent pipe, and the two ends of the bent pipe are respectively connected to the output end of the air pipe 3 and the input end of the metal part 8.

[0036] Embodiment 3: In this embodiment, in order to make the cable as a whole better for outdoor or special environment use, the following scheme is also disclosed. Figure 6-Figure 8 The connecting mechanism includes a hollow ring 9 fixed on the cable, the inner space of the hollow ring 9 is connected with the air pipe 3 and the metal part 8, and a valve plate 10 is slidably installed at the side opening of the hollow ring 9, and the valve plate 10 is connected to the driving device for driving the movement. A shaft 12 overlapping with its axis is rotatably installed in the metal part 8, and the shaft 12 is divided into a rigid part and a flexible part. A turbine 13 located in the hollow ring 9 is installed at the end of the rigid part, and a metal sheet 11 is fixed on the surface of the flexible part. The valve plate 10 moves back and forth in the hollow ring 9 under the drive of the driving device. During the reciprocating movement, the airflow in the air pipe 3 will be sucked into the hollow ring 9 and pressed into the metal part 8, and in this process, after the airflow hits the turbine 13, the shaft 12 will rotate accordingly, and drive the flexible part of the shaft 12 and the metal sheet 11 to rotate synchronously. The metal sheet 11 swings and hits the inside of the metal part 8, so a sound of a corresponding frequency is generated, achieving the effect of driving away birds and beasts, and when used outdoors, the internal heat is conducted to the metal part 8, which will also produce a heating effect on the outside of the cable to avoid residual snow, thereby further reducing the temperature difference between the inside and outside.

[0037] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A cross-linked polyethylene insulated power cable capable of reducing cracking of an insulation layer, comprising an insulation layer body (1) constituting a cable body and a wire core (2) wrapped by the insulation layer body (1), characterized in that: The cable also includes a cooling mechanism, wherein the cooling mechanism reduces the temperature difference between the inside and outside of the cable by removing heat from the surrounding of the wire core (2), thereby reducing cracking of the cable insulation layer (1); The cooling mechanism comprises an air pipe (3) which is distributed around the outside of the wire core (2), wherein both ends of the air pipe (3) pass through the insulating layer (1) and extend to the outside of the cable, and the middle section of the air pipe (3) is parallel to the axis of the wire core (2); The surface of the insulating layer body (1) is also provided with a pulling mechanism, wherein the pulling mechanism reduces cracking and deformation of the insulating layer body (1) by actively providing pulling or inner pulling force; The pulling mechanism comprises a metal piece (8) surrounding and embedded in the surface of the insulating layer (1), wherein the metal piece (8) is made of a two-way memory alloy material; The metal part (8) is in a tubular structure, and its one-way input end is connected to the one-way output end of the air pipe (3) through a connecting mechanism. The connecting mechanism is used to connect the two, and conduct the temperature near the wire core (2) to the surface of the insulating layer (1), thereby reducing the temperature difference between the inside and outside of the cable.

2. A cross-linked polyethylene insulated power cable capable of reducing cracking of the insulation layer according to claim 1, characterized in that: The surface of the air pipe (3) is provided with air holes (7), wherein the air flow in the air pipe (3) takes away nearby heat via the air holes (7), and the air holes (7) are distributed toward the wire core (2).

3. A cross-linked polyethylene insulated power cable capable of reducing cracking of the insulation layer according to claim 2, characterized in that: The connecting mechanism is composed of a bent pipe, the two ends of which are respectively connected to the output end of the air pipe (3) and the input end of the metal piece (8).

4. A cross-linked polyethylene insulated power cable capable of reducing cracking of the insulation layer according to claim 3, characterized in that: The connecting mechanism comprises a hollow ring (9) fixed on the cable, the internal space of the hollow ring (9) being connected to the air pipe (3) and the metal part (8), and a valve plate (10) being slidably mounted at the side opening of the hollow ring (9), the valve plate (10) being connected to a driving device for driving the movement.

5. A cross-linked polyethylene insulated power cable capable of reducing cracking of the insulation layer according to claim 4, characterized in that: A shaft (12) overlapping with the axis of the metal part (8) is rotatably mounted in the metal part. The shaft (12) is divided into two parts: a rigid part and a flexible part. A turbine (13) located in a hollow ring (9) is mounted at the end of the rigid part, while a metal sheet (11) is fixed on the surface of the flexible part.

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