CN-122000118-A - Composite cross-linked polyethylene insulated cable integrating signal and power transmission

CN122000118ACN 122000118 ACN122000118 ACN 122000118ACN-122000118-A

Abstract

The invention relates to the technical field of cables and discloses a composite crosslinked polyethylene insulated cable integrating signal and power transmission, which comprises a composite wire core, an inner semi-conductive shielding layer, a composite crosslinked polyethylene insulated layer and an outer semi-conductive shielding layer which are sequentially coated from inside to outside, wherein the composite crosslinked polyethylene insulated layer is prepared by extruding and crosslinking raw materials comprising, by weight, 90-95 parts of low-density polyethylene particles, 5.42-11.6 parts of a solid premix and 0.7-2.0 parts of a liquid co-solution, wherein the solid premix contains N, N' -m-phenylene bismaleimide and tetrabutyl titanate, and the liquid co-solution contains tetramethyl tetravinyl cyclotetrasiloxane and dicumyl peroxide. According to the invention, by constructing a coordination network to anchor byproducts, space charges and micropores of an insulating layer are eliminated, the withstand voltage is improved, the signal attenuation is reduced, and the long-term stability of the integrated transmission of the composite cable power and signals is ensured.

Inventors

GUO YAQIONG
GENG LICHUAN
ZHAO MEILING
GENG SONGSONG
MA YUANLING
LI XIJIAO
Li Xicha
Bo Jinyang
Feng Honghong
WANG SHANSHAN
ZHAO BINGYAN
ZHAO JIANGXIN
YAN CONGCONG

Assignees

友惠线缆有限公司

Dates

Publication Date: 20260508
Application Date: 20260318

Claims (10)

1. The composite crosslinked polyethylene insulated cable integrating signal and power transmission is characterized by comprising a composite wire core, an inner semiconductive shielding layer, a composite crosslinked polyethylene insulating layer and an outer semiconductive shielding layer which are sequentially coated from inside to outside; the composite crosslinked polyethylene insulating layer is prepared by extruding and crosslinking raw materials comprising, by weight, 90-95 parts of low-density polyethylene particles, 5.42-11.6 parts of solid premix and 0.7-2.0 parts of liquid co-solvent; Wherein the solid premix contains N, N' -m-phenylene bismaleimide and tetrabutyl titanate, and the liquid co-solution contains tetramethyl tetravinyl cyclotetrasiloxane and dicumyl peroxide.
2. The composite cross-linked polyethylene insulated cable for integrating signal and power transmission according to claim 1, wherein the composite cross-linked polyethylene insulated layer is made of raw materials comprising 92 parts by weight of low-density polyethylene particles, 8.86 parts by weight of solid premix and 1.2 parts by weight of liquid co-solvent.
3. The composite cross-linked polyethylene insulated cable integrating signal and power transmission according to claim 1, wherein the solid premix is composed of 5-10 parts by weight of low-density polyethylene powder, 0.1-0.5 part by weight of 4,4 '-thiobis (6-tert-butyl m-cresol), 0.3-1.0 part by weight of N, N' -m-phenylene bismaleimide and 0.02-0.10 part by weight of tetrabutyl titanate.
4. The composite cross-linked polyethylene insulated cable for integrating signal and power transmission according to claim 1, wherein the liquid co-solvent comprises, by weight, 0.2-0.8 parts of tetramethyl tetravinyl cyclotetrasiloxane and 0.5-1.2 parts of dicumyl peroxide.
5. A method for preparing a composite cross-linked polyethylene insulated cable for integrated signal and power transmission, which is used for preparing the composite cross-linked polyethylene insulated cable for integrated signal and power transmission according to any one of claims 1-4, and is characterized by comprising the following steps: Step 1, uniformly mixing low-density polyethylene particles and a solid premix by a mixer to obtain an insulating base material to be processed; Step 2, adding the insulating base material to be processed into a main feeding port of a double-screw extruder, and controlling the temperature of a first-stage screw temperature zone to perform melt plasticization to obtain a plasticization melt containing a coordination network; step 3, injecting the liquid co-solvent into a second stage screw section of the extruder at constant pressure by using a liquid metering pump, and controlling the temperature of the section to mix to obtain a composite melt containing a pseudo-complexing structure; step 4, introducing the composite melt into a three-layer coextrusion machine head, controlling the temperature of the machine head, and synchronously coating the composite melt, the inner semiconductive shielding material melt and the outer semiconductive shielding material melt serving as insulating layer materials on the outer layer of the composite wire core so that the composite melt is positioned between the inner semiconductive shielding material melt and the outer semiconductive shielding material melt to obtain a cable blank to be crosslinked; Step 5, the cable blank to be crosslinked is sent into a continuous vulcanizing tube for step heating crosslinking, and the composite crosslinked polyethylene insulated cable with in-situ grafting and crosslinking completed is obtained; and 6, carrying out gradient cooling on the composite crosslinked polyethylene insulated cable to room temperature through a water cooling section, and then carrying out winding.
6. The method for preparing a composite cross-linked polyethylene insulated cable for integrated signal and power transmission according to claim 5, wherein in step 1, the solid premix is prepared in advance by: Mixing low-density polyethylene powder with 4,4' -thiobis (6-tertiary butyl m-cresol) at 20-30 ℃ in a dry environment with relative humidity lower than 20% to obtain basic mixed powder; Subsequently, adding N, N' -m-phenylene bismaleimide and tetrabutyl titanate into the basic mixed powder material, and continuously mixing at 20-30 ℃ to obtain a powdery solid premix.
7. The method for preparing a composite cross-linked polyethylene insulated cable for integrated signal and power transmission according to claim 5, wherein in step 3, the liquid co-solvent is prepared in advance by: adding tetramethyl tetravinyl cyclotetrasiloxane into a closed material mixing tank subjected to dry nitrogen replacement treatment, and heating to 42-55 ℃ to obtain a preheated crosslinking modifier; Adding dicumyl peroxide into the crosslinking modifier, and continuously stirring until the dicumyl peroxide is completely dissolved to obtain a transparent homogeneous liquid co-solvent.
8. The method for preparing the composite cross-linked polyethylene insulated cable integrating signal and power transmission according to claim 5, wherein in the step 2, the temperature of a first-stage screw temperature zone of the twin-screw extruder is controlled to be 90-110 ℃, in the step 3, the temperature of a second-stage screw section of the twin-screw extruder is controlled to be 110-125 ℃, and in the step 4, the temperature of the three-layer co-extruder head is controlled to be 125-135 ℃.
9. The method for producing a composite cross-linked polyethylene insulated cable for integrated signal and power transmission according to claim 5, wherein in step 5, when the cable blank to be cross-linked is fed into a continuous vulcanization pipe, the pressure of the continuous vulcanization pipe is controlled to be 1.0-1.5MPa.
10. The method for preparing the composite cross-linked polyethylene insulated cable integrating signal and power transmission according to claim 5, wherein in step 5, the specific temperature control of the step heating cross-linking is that the temperature of the pre-cross-linking area is set to 165-175 ℃, the temperature of the main cross-linking area is set to 185-195 ℃ and the temperature of the deep cross-linking area is set to 205-215 ℃.

Description

Composite cross-linked polyethylene insulated cable integrating signal and power transmission Technical Field The invention relates to the technical field of cables, in particular to a composite crosslinked polyethylene insulated cable integrating signal and power transmission. Background Insulated cables are the infrastructure in the electrical network that takes on energy transport. The crosslinked polyethylene is a main current insulating layer matrix material because of stable dielectric and mechanical properties. With the development of smart power grids, signal interaction and power transmission are combined in a single cable to form a composite crosslinked polyethylene structure integrating signal and power transmission, and the composite crosslinked polyethylene structure has become the development requirement of multi-functionalization of modern cables. The conventional insulating layer manufacturing generally adopts a peroxide crosslinking technology, and the technology comprises the steps of mixing a polyethylene resin main material with a crosslinking agent, coating the outer side of a wire core through coextrusion by an extruder, and then sending the wire core into a vulcanization pipeline to heat to trigger macromolecular chain crosslinking, so as to construct a polymer network with pressure resistance and heat resistance, so as to adapt to the running working condition of a power grid. The existing crosslinking system and the manufacturing process have the defects in practical application. The peroxide crosslinking agent can release polar small molecule byproducts during high-temperature pyrolysis, the byproducts have free migration tendency in an insulating matrix, space charge accumulation and local electric field distortion can be caused under an operation electric field, and aging breakdown of the insulating material is accelerated. Meanwhile, the conventional process is to put the whole component materials into an extruder at one time, and the cross-linking agent is easily decomposed in early stage when heated and sheared at the front section of the machine barrel, so that the material is locally burnt. In addition, the low-boiling-point byproducts which are not effectively restrained are gasified in the high-temperature crosslinking section, so that micropore defects are left in the thick-wall insulating layer, the integral compressive strength is weakened, physical scattering and medium attenuation can be caused to high-frequency signals transmitted in the composite cable, and the dual requirements of high-voltage insulation and low-loss signal transmission are difficult to be met. Therefore, the invention provides a composite crosslinked polyethylene insulated cable integrating signal and power transmission, which solves the defects in the prior art. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a composite cross-linked polyethylene insulated cable integrating signal and power transmission, which solves the technical problems of space charge accumulation induced by cross-linked polar byproduct migration and signal transmission loss caused by micropore defects in a thick-wall insulating layer. In order to solve the problems, the invention provides the following technical scheme: in a first aspect, the invention provides a composite crosslinked polyethylene insulated cable for integrating signal and power transmission, which adopts the following technical scheme: The composite crosslinked polyethylene insulated cable for integrating signal and power transmission comprises a composite wire core, an inner semi-conductive shielding layer, a composite crosslinked polyethylene insulating layer and an outer semi-conductive shielding layer which are sequentially coated from inside to outside, wherein the composite crosslinked polyethylene insulating layer is prepared by extruding and crosslinking raw materials comprising, by weight, 90-95 parts of low-density polyethylene particles, 5.42-11.6 parts of solid premix and 0.7-2.0 parts of liquid co-solvent, wherein the solid premix contains N, N' -m-phenylene bismaleimide and tetrabutyl titanate, and the liquid co-solvent contains tetramethyl tetravinyl cyclotetrasiloxane and dicumyl peroxide. By adopting the technical scheme, the coordination component and the siloxane component are processed and compounded in solid and liquid forms respectively, so that the microstructure of the insulating layer after internal crosslinking and curing is changed, and the effects of inhibiting space charge accumulation and improving the electrical stability of the crosslinked polyethylene insulating layer are achieved. The specific action process of the system capable of inhibiting charge accumulation is mainly represented by sequential reaction of multiple components in extrusion and crosslinking environments. Tetrabutyl titanate contained in the solid premix has a titanium atom with an empty orbit, and when the material i