A fire prevention method for a high-voltage cable joint

Abstract

The present invention relates to a fireproofing method for a high-voltage cable intermediate joint, comprising a fireproofing joint, wherein the fireproofing joint comprises at least two independent cables, cable A and cable B, a connecting pipe, a transition intermediate joint, a copper conductor, a shielding layer, a protective sleeve, and a semi-conductive layer; the fireproofing method for a high-voltage cable intermediate joint provided by the present invention strengthens the overall strength of the cable intermediate joint through the fireproofing joint design, and can isolate external heat by arranging a cable fireproof sealing filler in the protective sleeve, thereby preventing the cable from being invaded by high temperature and causing high-temperature deformation and spontaneous combustion of the intermediate joint part; the connecting pipe with a conical design cooperates with the transition intermediate joint to connect the copper conductor, thereby making the electric field of the cable joint part uniform, reducing the current resistance, and further effectively reducing the temperature effect of the cable intermediate joint part.

Description

Technical Field

[0001] The invention relates to the technical field of cable protection, and in particular to a fire prevention method for a high-voltage cable intermediate joint. Background Art

[0002] Cable terminals and intermediate joints are important components in power transmission and transformation cable lines. Their function is to disperse the electric field at the outer shielding cut-off point of the cable terminal, protect the cable from breakdown, and also have the functions of internal and external insulation and waterproofing. More than 60% of accidents in cable lines are caused by accessories, so the quality of joint accessories plays a very important role in the safety and reliability of the entire power transmission and transformation.

[0003] During the power transmission process of the cable line, the cable line itself will have a certain current resistance. In the transmission link, the electrical energy will be converted into heat energy due to the resistance factor, causing the cable to generate a certain amount of heat. At the same time, there are a large number of cable joints in the cable line. At the cable joint position, the current resistance will increase due to the insulation strength of the cable head, the tightness of the installation, the degree of contact and other issues, causing the cable temperature to rise abnormally; this will cause the cable joint to be more easily damaged than other parts of the cable, thereby triggering various cable accidents. For this reason, a fire prevention method for the intermediate joint of a high-voltage cable is proposed, which is used for the connection and installation of the intermediate joint of the cable. Summary of the invention

[0004] To this end, the present invention provides a fire prevention method for a high-voltage cable intermediate joint to overcome the problems in the prior art.

[0005] The present invention provides a fire prevention method for a high-voltage cable intermediate joint, comprising: the fire prevention joint comprises at least two independent cables, cable A and cable B, a pipe, a transition intermediate joint, a copper conductor, a shielding layer, a protective sleeve, and a semi-conductive layer; wherein the pipe comprises two cores for respectively connecting the cable A and the cable B, one end of each pipe is respectively equipped with the transition intermediate joint, one end of each transition intermediate joint is respectively connected to the left and right ends of the copper conductor, the surface of the pipe is wrapped with a semi-conductive layer, the shielding layer is sleeved on the outer periphery of each transition intermediate joint and the copper conductor, and the preparation method is as follows:

[0006] S1: Pre-clean cables A and B, strip the cables to their insulation layers, and polish them smooth with insulating sandpaper, leaving some of the cores of cables A and B exposed;

[0007] S2: crimp the exposed front ends of the cores of cable A and cable B into corresponding connecting pipes, which are of conical design;

[0008] S3: Apply a layer of silicone grease evenly on the insulation layer, semi-conductive layer and the inside of the transition intermediate joint of the cable;

[0009] S4: Install the intermediate joints for transition at one end of each connecting pipe respectively;

[0010] S5: Select a section of copper conductor with the same conductor specification as that of cable A and cable B, and crimp it to the two ends of the cables (cable A and cable B) through two intermediate joints for transition respectively to achieve conductor connection;

[0011] S6: Wrap semiconductive tape around the outer surfaces of the intermediate joints for transition and the connecting pipes to form the semiconductive layers of cable A and cable B;

[0012] S7: Wrap a shielding net around the semiconductive layer in S6 to form the shielding layer;

[0013] S8: After the preparation of S1 - S7, sleeved a protective sleeve outside the fireproof joint, and inject filler into the protective sleeve for sealing.

[0014] Furthermore, cable A and cable B are of the same material, and from outside to inside, they are composed of an outer sheath, a copper shielding tape, a semiconductive layer, an insulating layer, and a core in sequence.

[0015] Furthermore, the semiconductive tape in step S6 is a semiconductive water-resistant tape, and the shielding net in step S7 is a copper shielding tape.

[0016] Furthermore, the filler in the protective sleeve is a cable fireproof sealing filler.

[0017] Furthermore, the intermediate joint for transition is an aluminum - copper integrated terminal transition intermediate joint.

[0018] A method for fireproofing of a high - voltage cable intermediate joint provided by the present invention strengthens the overall strength of the cable intermediate joint through the design of the fireproof joint. By setting a cable fireproof sealing filler in the protective sleeve, it can isolate external heat, avoid the occurrence of high - temperature deformation and spontaneous combustion phenomena in the intermediate joint part of the cable due to high - temperature invasion. By using the connecting pipe with a tapered design to cooperate with the intermediate joint for transition to connect the copper conductor, it can evenly distribute the electric field at the cable joint part, reduce the current resistance, and further effectively reduce the temperature of the cable intermediate joint part. Description of the Drawings

[0019] Figure 1 It is a schematic diagram of the overall structure of the fireproof joint in a method for fireproofing of a high - voltage cable intermediate joint according to the present invention;

[0020] Figure 2 It is a schematic diagram of the disassembled structure of the fireproof joint in a method for fireproofing of a high - voltage cable intermediate joint according to the present invention;

[0021] Figure 3 It is a schematic diagram of the internal cross - sectional structure of the fireproof joint in a method for fireproofing of a high - voltage cable intermediate joint according to the present invention.

[0022] In the figure: cable A, cable B, connecting pipe 3, intermediate joint 4 for transition, copper conductor 5, shielding layer 6, protective sleeve 7, semiconductive layer 8, core 9, filler 10. Specific embodiments

[0023] In order to make the objectives and advantages of the present invention more clear and understandable, the present invention will be further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0024] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principles of the present invention and do not limit the protection scope of the present invention.

[0025] It should be noted that in the description of the present invention, the terms indicating directions or positional relationships such as "upper", "lower", "left", "right", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings. This is only for convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention.

[0026] In addition, it should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", and "coupling" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] The technical solutions provided by the embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0028] According to Figures 1 to 3A fire prevention method for a high-voltage cable intermediate joint, including a fire prevention joint. The fire prevention joint includes at least two independent cables, cable A and cable B, a connecting pipe 3, an intermediate joint 4 for transition, a copper conductor 5, a shielding layer 6, a protective sleeve 7, and a semi-conductive layer 8. Among them, there are two connecting pipes 3, which are used to connect the cores 9 of the cable A and the cable B respectively. One end of each connecting pipe 3 is respectively equipped with the intermediate joint 4 for transition. One end of each intermediate joint 4 for transition is respectively connected to the left and right ends of the copper conductor 5. The surface of the connecting pipe is wrapped with a semi-conductive layer 8. The shielding layer 6 is sleeved around the periphery of each intermediate joint 4 for transition and the copper conductor 5. The preparation method is as follows: S1: Pre-clean the cables A and B, strip the cables until their insulation layers are reached, and polish them smoothly with insulating sandpaper, so that part of the cores 9 of the cables A and B are exposed; S2: Press the front ends of the exposed cores 9 of the cables A and B into the corresponding connecting pipes 3 respectively. The connecting pipe 3 is designed in a conical shape; S3: Uniformly apply a layer of silicone grease inside the insulation layer, semi-conductive layer of the cable and the intermediate joint 4 for transition; S4: Install the intermediate joint 4 for transition at one end of each connecting pipe 3 respectively; S5: Select a section of copper conductor 5 with the same conductor specification as the cables A and B, and press it together with the two ends of the cables (cables A and B) through two intermediate joints 4 for transition respectively to achieve conductor connection; S6: Wrap a semi-conductive tape around the outer surfaces of the intermediate joint 4 for transition and the connecting pipe 3 to form the semi-conductive layer 8 of the cables A and B; S7: Wrap a shielding net around the semi-conductive layer 8 in S6 to form the shielding layer 6; S8: After the preparation of S1-S7 is completed, sleeve the protective sleeve 7 outside the fire prevention joint, and inject a filler 10 into the protective sleeve for sealing.

[0029] Example 1

[0030] According to Figures 1 to 3 A fire prevention method for a high-voltage cable intermediate joint includes the following steps:

[0031] S1: Pre-clean the cables A and B, strip the cables until their insulation layers are reached, and polish them smoothly with insulating sandpaper, so that part of the cores 9 of the cables A and B are exposed. The lengths of the cores 9 of the cables A and B are the same, both being 5-15 cm, and the chamfer of each insulation layer is 1×45° (not in the shape of a pencil tip);

[0032] S2: The length of the connecting pipe 3 is the same as that of the core 9; and press the front ends of the exposed cores 9 of the cables A and B into the corresponding connecting pipes 3 respectively. One side of the connecting pipe 3 is designed in the shape of a (conical) pencil tip;

[0033] S3: Uniformly apply a layer of silicone grease inside the insulation layer, semi-conductive layer of the cable and the intermediate joint 4 for transition. The thickness of the silicone grease is 5 mm - 1 cm;

[0034] S4: The intermediate joint 4 for transition is an aluminum-copper integrated terminal transition intermediate joint. The intermediate joint 4 for transition (aluminum end) is respectively installed at one end of each connecting pipe 3.

[0035] S5: Select a section of copper conductor 5 with the same conductor specification as that of cable A and cable B. The copper conductor 5 is a 1400 mm2 copper conductor 5 with a length of 20 - 30 cm. And it is respectively crimped to the two ends of the cables (cable A and cable B) through two intermediate joints 4 for transition (copper end) to realize conductor connection.

[0036] S6: Wrap semi-conductive tape around the outer surface of the intermediate joint 4 for transition and the connecting pipe 3 to realize the semi-conductive layer 8 of cable A and cable B. At both ends of the intermediate joint 4 for transition, wind the semi-conductive tape into a winding body not smaller than the diameter of the end of the intermediate joint 4 for transition, and then wind a layer of semi-conductive tape in an overlapping form of 1 / 3 to the other end of the joint to overlap with the semi-conductive layer of the cable.

[0037] S7: Wrap a shielding net around the semi-conductive layer 8 in S6 to realize the shielding layer 6.

[0038] S8: After the preparation of S1 - S7 is completed, set the protective sleeve 7 outside the fireproof joint and inject the filler 10 into the protective sleeve for sealing.

[0039] So far, the technical solution of the present invention has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

[0040] The above are only the preferred embodiments of the present invention and are not used to limit the present invention; for those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A fire prevention method for a high-voltage cable intermediate joint, including a fire prevention joint, characterized in that, The fireproof joint comprises at least two independent cables, cable A and cable B, a pipe, a transition intermediate joint, a copper conductor, a shielding layer, a protective sleeve, and a semi-conductive layer; wherein the pipe comprises two cores for respectively connecting the cable A and the cable B, one end of each pipe is respectively installed with the transition intermediate joint, one end of each transition intermediate joint is respectively connected to the left and right ends of the copper conductor, the surface of the pipe is wrapped with a semi-conductive layer, and the shielding layer is sleeved on the outer periphery of each transition intermediate joint and the copper conductor, and the preparation method is as follows: S1: Pre-clean cables A and B, strip the cables to their insulation layers, and polish them smooth with insulating sandpaper, leaving some of the cores of cables A and B exposed; S2: crimp the exposed front ends of the cores of cable A and cable B into corresponding connecting pipes, which are of conical design; S3: Apply a layer of silicone grease evenly on the insulation layer, semi-conductive layer and the inside of the transition intermediate joint of the cable; S4: Install the intermediate joint for transition at one end of each pipe; S5: Select a copper conductor with the same specifications as those of cable A and cable B, and crimp it to the cables at both ends through two transition intermediate joints to achieve conductor connection; S6: Wrap a semi-conductive tape around the outer surface of the transition intermediate joint and the connecting pipe to achieve a semi-conductive layer for cable A and cable B; S7: A shielding mesh is wrapped around the semi-conductive layer of S6 to realize a shielding layer; S8: After the preparations of S1-S7 are completed, the protective sleeve is placed on the outside of the fireproof joint, and a filler is injected into the protective sleeve for sealing; The cable A and the cable B are made of the same material, and are composed of an outer sheath, a copper shielding tape, a semi-conductive layer, an insulating layer, and a core from the outside to the inside.

2. The method for preventing fire of a high-voltage cable intermediate joint according to claim 1, wherein, The semi-conductive tape in step S6 is a semi-conductive water-resistant tape, and the shielding mesh in step S7 is a copper shielding tape.

3. A method for preventing fire of a high-voltage cable joint in the middle according to claim 1, characterized in that, The filler in the protective sleeve is a cable fireproof sealing filler.

4. A method for preventing fire of a high-voltage cable joint according to claim 1, characterized in that, The transition intermediate joint is an aluminum-copper integrated terminal transition intermediate joint.

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